I II III IV V VI VII VIII IX X XI XII - wsu.bs.chde4c1330-0f5c-46aa-9414-99082fbbcd32/teil2.pdf · 2. specific know-how in project related tasks, 3. their ... the DHM project and

I II III IV V VI VII VIII IX X XI XIInichtfühlbar

kaumbemerkbar

schwach deutlich stark leichteGebäude-Schäden

Gebäude-Schäden

schwereGebäude-Schäden

zerstörend sehrzerstörend

verwüstend vollständigverwüstend

2 3 4 5 6 >6

0

5

10

15

20

25

1Magnituden

Intensitäten

Energie1x 32x 1'000x 32'000x 1'000'000x 32'000'000x

grösstes Ereignisin Soultz: M 2.9

z.B. Risseim Verputz

grösstes Ereignisin Basel ML 3.4

Gegenüberstellung von EMS98 Intensitätsskala und Lokalmagnituden. Das Beben ML 3.4 vom 8. 12. 2006liegt auf der Intensitätsskala bei IV.

Geothermal Explorers Ltd

Micro-Seismic Event Response Procedure

SEDSwiss Seismological ServiceMarkus Häring

Mr. Kindhauser(IWB)

Mission ControlPratteln

Event ML < 2.3PGV < 0.5 mm/s

Event ML ≥ 2.3PGV 0.5 - ≤ 2.0 mm/s

Event ML ≤ 2.9PGV > 2.0 – 5.0 mm/s

Event ML > 2.9PGV > 5 mm/s

• Regular operation• Continuing Pumping

• Call and inform drillingsupervisor

• Continuing pumping• Do not increase flow rate

· Call DSV· Maintain well headpressure at belowStimulation Pressure byPump at Slow Pump RateorStop PumpsorBleed off to stimulationpressure

Status reportML>=2.0

• Call and inform drillingsupervisor

• Stop pumping• Bleed off to minimumwellhead pressure

ML & PGV

Explanations

Media Police

ML Local magnitude (SED)PGV Peak ground velocity (SED)

Stimulation Pressure (StP)Surface pressure of first induced event occurs

Slow Pump Rate (SPR)StP and SPR defined in 48h look ahead


Anlage

2

Communication Response Procedures

PL: Project ManagementPE: Project DevelopmentGF: Managing Director


Anlage

3

Projektorganisation DEEP HEAT MINING

Präsident H. Schwendener (IWB)Vizepräs. U. Steiner (EBL)

P.A. Ceschi (AET)T. Fisch (AUE BS)B. Hürlimann (ewz)A. Isenburg (AUE BL)E. Schumacher (IWB)Ch. Stutz (GEL)H. Wach (GVM)N. Zepf (Axpo)M. Steiger (ED)

Sekretär J. Fricker (BEC)

VR Geopower Basel AG

Geschäftsführer D. Moll (IWB)

Projekt-entwickler

Dr. M. Häring (GEL)

Projekt-leiter

K. Johnstone (GEL)

ControllingS. Rapetti (EBP)

Oeffentlichkeits-arbeit

R. Kindhauser (IWB)

Finanzen +Rechnungswesen

P. Schafroth (EBL)

Wissenschaftl./techn. Qualitätssicherung

P. Burri

Wissenschaftlicher Beirat

Business-manager

J. Fricker (BEC)

Rg. -FührungA. Metil le

AdministrationD. Furler

Operation Eng.Ch. Häring

P. Wille

Drilling Superv isors

Drilling Eng.J. Beswick

Well Eng.B. Worall

Reservoir Eng.F. Ladner

GeophysikDr. U. Schanz

Dr. T. Spillmann

GeologieCh. Häring

P. Wille

Projektleitungsteam

Geothermal Explorers

Anlage 4


Anlage 5


Proposal for a SCIENTIFIC AND TECHNICAL ADVISORY BOARD to the DEEP HEAT MINING project in Basel

Author: Markus O. Häring, Geothermal Explorers Ltd

Date: 23. December 2004

To: Federal office of energy, Section Renewables, Mr. Markus Geissmann

Copy: All board members and management of Geopower Basel AG

Purpose The development of a geothermal cogeneration plant is a technically complex project comprising a number of scientific challenges. It is in the nature of a new technology that references and experience from equal projects are scarce or lacking all together. In order to optimise the development process and to ensure a high standard of quality in all procedures Geopower Basel AG endeavours to set up a scientific and technical advisory board consisting of accredited experts in their field.

Goals Selected external experts with acknowledged references in their field of competence are invited to review concepts and processes and express their views and recommendations. The aim is to achieve the highest level of quality in technical and scientific procedures and operations to optimise the chances of success and minimise the risk of failure, damage and harm to the project, society and the environment.

Scope of work The scope of work of the scientific / technical advisory board is to review concepts and processes in the project plan and express their approval or alternative views and make recommendations to support the project developer (PE) and project manager (PM) in their tasks.

Authority The advisory board – as individuals or in a group – issue recommendations on request of the management (GF, PL, PE) on a consulting base. The advisory board informs the board of directors biannually with a report of its assessment of the applied scientific/technical standards and progress of the project.

Members of the advisory board must not get involved in the project planning and they may not accept contracted planning tasks. In case of a conflict of interest with a contractual situation in the project the member would have to resign from the advisory board.

Confidentiality The advisory board members have access to all relevant data. All data must be treated as confidential and may not be made available to third parties nor be used as a base for any publication. Exceptions can be made under approval of the technical management (PL, PE) in writing.

Anlage 5


Organisation

Members / Qualifications Members of the advisory board are selected based on 1. their references and experience in similar projects and operations, 2. specific know-how in project related tasks, 3. their scientific track record, and 4. their independence to this project and/or competitive projects.

Appointment A committee consisting of 1. a member of the funding agency, eg Federal Office of Energy (BFE) (request pending) 2. the president of the board of directors GPB 3. the managing director of GPB 4. the project manager of GPB 5. the project developer of GPB

prepares a list of acknowledged experts for all relevant tasks. The list is subject to continuous review and update.

The funding agency has to approve the candidates of the advisory board. The candidates are then contacted by the committee and asked for their interest to participate.

The number of appointed advisors should not exceed 6 at any time of the project.

A preliminary list of potential members are listed in the attachment.

Remuneration Remuneration according to federal regulation for expert consultancy fees.

Duration of advisory board The extension of an individual appointment will be reviewed by the committee every two years. An extension of the advisory board as a whole for the development phase remains to be reviewed in due time.

Information Flow / Reporting The project management team will present an actual state of the project and an outlook for the next activities and operations to the advisory board in biannual meetings. The advisors will subsequently forward their individual reports of their assessment, comments and recommendations to the board of directors, the managment team and the funding agency.

The advisors can also be called individually or as a group for a review on request by members of the appointment committee. The calls should be coordinated by the managing director of

Budget An average commitment of 10 days estimated per advisor per annum results in annual consultancy fees of max. CHF 115'000.- including expenses. Not included are the costs of the project management team.

Anlage 5


Funding In order to warrant an independent opinion of the advisory board, funding should be provided by a neutral yet interested agency. An agency which has a high interested in the success of the DHM project and is also responsible to provide optimal general conditions for the development of sustainable energy systems is the Federal Bureau of Energy (BFE)

We therefore propose, that the BFE is carrying the costs of the advisory board to an upper limit of CHF 120'000.- per annum for the duration of the exploration phase of 2 years.

Preliminary list of experts

Name Field of Expertise Current Function Current Employment

Ladislaus Rybach Geothermal heat production, heat flow Prof. em. ETHZ Retired, Partner of Geowatt

Robert Hopkirk Geothermal Systems, System Engineering Independent Engineer Polydynamics Engineering

Bob Worall Drilling Technology Drilling Advisor SHELL IEP

Nic Shaw Review Geologist Review Geologist SHELL IEP

John Garnish EGS Research History Scienitfic / Technical advisor Soultz Group

Retired, independent, former EU commission Renewables

Steve Oates Seismic risk assessment Geophysicist, Seismic risk evaluations

SHELL IEP

Rudolf Minder Energy systems, energy conversion Independent Engineer Minder Energy Consulting

François Vuataz Geochemistry Senior Lecturer University of Neuchatel

Dieter Mayer-Rosa Seismology Prof. em. ETHZ Retired Geophysicist

Jörg Baumgärtner Drilling Operations Project Manager EGS Soultz-sous-Forêts

Bestec GmbH

Keith Evans Rock Mechanics Senior Scientist ETHZ, Department of Earth Sciences

Roy Baria Geophysics, Microseismicity, Well logging Project Manager EGS Soultz-sous-Forêts

EEIG

Adrian Pfiffner Structural Geology Prof. Structural Geology and Tectonics

University of Bern

Peter Huggenberger

Hydrogeology State Geologist Kt. BS Canton BS, University of Basel

GEOTHERMAL EXPLORERS LTD Anlage 6

08. Sept. 2005 Geothermal Explorers Ltd min_advbrd_010905.doc

MINUTES ON ADVISORY BOARD MEETING Date: 01. September 2005, 9:00-16:00 Venue: Geothermal Explorers Ltd, Schlossstrasse 3, CH-4133 Pratteln Participants: Baria, Roy Baumgärtner, Jörg Blattner, Michel Bommer, Julian Burri, Peter Garnish, John Geissmann, Markus Gorhan, Harald L. Häring, Markus Häring, Christian Hopkirk, Bop Huggenberger, Peter

Ladner, Florian Moll, Daniel Oates, Steve Rybach, Ladsi Schanz, Ulrich Schwendener, Heinrich Worrall, Bob

Introduction to the meeting Dr. Häring and Dr. Schwendener cordially welcome all meeting participants and express their view regarding the objectives of the advisory board and the tasks of the advisors. As a summary the following meeting purposes were expressed: - presentation of the whole project concept to the expert group - the expert group is encouraged to uncover fundamental errors in the project

conception and to review the approaches - risk minimization, result maximization - no monolog is intended but rather an open discussion - the experts are asked to summarize their comments, proposals and project

evaluations as written statements after this meeting. Introduction of advisors Dr. Häring first introduces the Geopower Basel representatives and the Geothermal Explorers team to the experts. Then the experts introduce themselves, summarizing their specialization and professional experiences in Geothermal energy. Introduction to the project During this meeting section Dr. Häring gives an overview of the general project concept, the organisaton of Geopower and the advisory board organisation. Then a discussion starts on the following issues:



Idea of advisory board meeting - Time critical aspects need to be listed. The advisory board should focus on and

judge the time critical aspects of the project time schedule. Thorough comments should be issued in written form (Huggenberger)

- Not all aspects shall be addressed, only the most important ones (Häring) - Small workshops on specific topics are proposed for more thorough discussions

(Bommer) - The number of workshops shall be increased (Worral) - The rules and the scheme of the advisory board is still under development. The

involvement of advisory board members in specific topics is different, but it is important and valuable to centre all experts for exchange of their Know How (Rybach).

Project time schedule - To carry out a full stimulation program in one month is not possible

(Baumgärtner) - 6 months is not a large time frame for a detailed design of drilling and stimulation

operations (Worrall) - A more detailed project chart is necessary including milestones. Then a better

evaluation of the time schedule by the experts can be done (Burri) - The time schedule is very narrow. Avoid to provoke wrong expectations with

project partners (Garnish) - The success of Geodynamics’ commercial project - which has a rather short

operational time frame - is accentuated. All partners of Geopower Basel are aware of their risk. They are informed that realizing this project is unlike building a house (Häring)

- Any contingency included in time schedule (Burri) ? → Some contingency is contained. Due to the significant increase of the oil price it is currently difficult to get a rig. Therefore, because of economic reasons, a back to back drilling operation is necessary (Häring)

Proposals - In order to address a wide range of possible drilling problems it is recommended

to setup various possible geological and operational scenarios. This provides GEL with the “reactive potential” necessary to immediately cope with specific upcoming problems. This saves time and expenses. Furthermore, if the planning is very detailed the investor confidence gets raised (Worrall).

- The importance of the initial stimulation program is emphasized. The stimulation operation is an irreversible process, which is especially critical for the first well. In order to define appropriate stimulation parameters a detailed investigation of the stress conditions by a hydraulic pre-stimulation test is essential (Baria).

Introduction to the exploration program During this meeting part Dr. Häring presents the exploration steps, the project milestones and the seismic monitoring conception. Discussion summary Geothermal well Basel 1 - While drilling the vertical well Basel 1 it is not recommended to steer the drilling

direction. Instead, unless the direction goes completely wrong, it is suggested to



accept the influence of the natural stress field upon the borehole trajectory (Worrall).

- In discussing the possibility, that the borehole trajectory may come close to a fault zone, it is stated, that the risk of borehole breakouts, which could cause a complete failure of the drilling operation, is significantly increased (Worrall).

- Drilling target: achievement of 5000 m TVD or 200 °C rock temperature (Garnish) ? → The intention is to reach a rock temperature of 200 °C (Häring). → Is there enough casing available to drill two subsequent wells (Burri) ?

- The observed borehole breakouts in well Otterbach 2 are an indication for critical and differential formation stresses, which could evoke severe problems with drilling well Basel 1 (Baumgärtner).

- Max. flow rates in Basel 1 (Baria) ? → ~ 50 l/s (Häring) - Separation between wells (Baria) ? → ~ 500 m (Häring) - Lead time of uncommon casing sizes (Burri) ? → approximately 9 months

(Häring) - There is a consensus in not to take sidewall cores during drilling borehole

Basel 1 (Garnish et al.) Micro-Seismic Monitoring - From a pure geometrical point of view a reviewing of the monitoring station

network is recommended, based on the following issues (Baria): → an additional monitoring station in the NW network section is recommended → a 45° angle of incident wavefield is usually recommended. This would improve the vertical localization accuracy of the DHM monitoring network → an inadequate network geometry could perhaps produce misleading results

It is suggested to review the report by Proseis on the modelling of the monitoring station network (Baria).

- Discussing the modelling of wave attenuation, the significance of wave scattering as an additional wave attenuation effect is empasized (Baria).

- What is the micro-seismic network resolution like (Huggenberger, Oates) ? → In order to achieve a S/N-ratio of approximately 1 for an expected minimum detectable ground velocity of about 10-8 to 10-9 m/s, the required depths of the individual monitoring wells were modelled accordingly by Proseis. Background noise measurements at the surface of individual monitoring sites were taken into account. Furthermore the modelling was relied on spectral wave attenuation curves and a 3D velocity model. These parameters were derived from a VSP measurement in well Otterbach 2 (Schanz).

- Frequency bandwidth of geophone sensors (Baria) ? → Flat amplitude response in the frequency range of 4.5 to 500 Hz (Schanz)

- A frequency bandwidth up to 1000 Hz is preferable (Baria) → Supplementary answer of the author, based on the network modelling report by Proseis: The modelled dominant frequencies for the deepest monitoring station in well Otterbach 2 only range up to about 200 Hz. Above 200 Hz anelastic wave attenuation increasingly becomes effective.

- The resonance of the seismograph housing could have a significant impact on the recorded signal. Therefore: what is the resonance frequency of the seismograph casing like (Baria) ?

- Which source parameters will be studied (Oates) ? → Seismic moment et al. (Schanz).

- Is the shear displacement of the micro-seismic events - used for the network modelling - comparable with the events observed at the Soultz project (Rybach) ?



Supplementary answer of the author, based on the network modelling report by Proseis: the two hypothetical events had a seismic moment of 2 x 109 Nm respectively 2 x 1010 Nm. The minimum observed detection threshold during the summer 2000 hydraulic stimulation at the Soultz project corresponds to a seismic moment in the order of 5 x 108 Nm. Seismic moments > 1010 Nm occur at probabilities of approximately 40% in the Soultz case. Thus the DHM seismic model sources are comparable with observed events at the Soultz project.

Seismic hazard - In order to separate natural and induced seismicity, the development and

application of diagnostic methods is essential. The setup of a catalogue is suggested, that defines different levels of prohibitive courses of action, based on specific risks related to induced seismicity. A detailed information of the citizens of Basel on seismic hazard, involved with stimulation operations, is emphasized. This should be done already at an early project stage, prior to stimulation operations, in order to avoid a enforced project interruption by external authorities (Baria).

- Injected volumes are a critical parameter conducting a hydraulic stimulation. In this context it is of great importance to determine in detail the formation stress conditions after drilling well Basel 1 (Baria).

- Prior to drilling the Gotthard tunnel people living nearby were also informed on potential seismic hazard.

- Two aspects are of great importance: 1. communication with citizen. Inform the public of Basel, that some of the events are likely to be felt. 2. suitable technical equipment to separate hydraulically induced events from natural seismicity.

- The corner frequency of the induced micro-seismic events at the Soultz project often was in the range of 90-100 Hz, which is unlikely to cause damage to buildings and structures (Baria).

- There is little concern that induced seismicity will be noticed during day time but it probably will be felt during night time.

- A prototype strategy to control seismic hazard has been developed for the EGS project in El Salvador. There, a key part of the working organization was to communicate with the public (Worrall).

- It is important to have surface accelerometer at exposed buildings (Bommer). - To give presentations at schools is an efficient way of informing the public.

Positive experiences at Cornwall and El Salvador were asssessed (Bommer, Baria).

- The Swiss Earthquake Department (SED) should be involved into this project issue. There is an ongoing microzonation study to investigate the effects of ground movements at different frequencies on buildings and constructions at the Basel city area (Huggenberger).

- An attempt should be made to link measured accelerations at surface stations with intensity: Calibrate surface accelerometers to the ground motion occurring at buildings and to the damage effect, which is linked to this ground motion for specific building constructions (Bommer).

Introduction to the drilling program During the afternoon session B. Richardson gives an outline on the status of the drilling program. The presentation is subdivided into the scope of work, casing and drilling. Subsequently M. Häring summarizes the status of on the logging and stimulation program design.



Discussion summary Scope of work - 2 or 3 shifts during drilling operations (Rybach) ? → arbitrary (Richardson) - High borehole wall rugosity was encountered at high ROP values during drilling

of well Otterbach 2. Possibilities to avoid this ? Influence on geophysical logging (Huggenberger) ? → Geology largely affects the wall rugosity. There is no definit way to influence this feature by drilling parameters. Ovalization will occur in granite, which has a more severe impact (Worrall).

- Which kind of drilling contract has been selected (Baumgärtner) ? → Drilling contract is based on daily rates (Richardson).

- Who will manage the drilling operation (Baumgärtner) ? → GEL together with a drilling contractor (Richardson).

Drilling operation - To reduce wear problems, the application of roller reamers is recommended

(Baumgärtner). - Extensive breakouts falling behind the neck of the bit may cause the drill string to

get stuck (Baumgärtner). - Vibration is a severe cause for drill string failure in granite (Richardson). - A shock tool might be helpful but has been experienced to have a high risk to get

lost in hole. - In order to suppress drill string vibrations, the following aspects need to be taken

into consideration (Worrall): 1. the BHA design is of great importance 2. a damping system at the top drive is recommended to

compensate the vibration caused by the motor torque 3. The removal of fine grained granite particles in the mud is essential, which also results in a reduction of tool wearing - A significant pressure build up occurs if cold mud infiltrates into hot fractures and

gets heated up. To solve that problem it is recommended to use a rotating head at the BOP (Worrall).

- At the Soultz project, drilling the crystalline section just using water and some lubricator was experienced to work well (Baumgärtner)

- An efficient cooling system to cool down the mud is significant importance (Baumgärtner).

- Directional drilling: to place the kick-off point in the crystalline section has been tested in the Soultz project. Significant temperature problems with the MWD tools have been encountered, depending on the ambient temperature level (Baumgärtner).

- It is recommended to start the kick-off at the highest possible level. Subsequent to the kick-off it should be tried to keep the drill direction stable at an inclination of around 20° by the drill string itself. To kick-off the borehole trajectory in the crystalline should be avoided (Worrall).

- The successful application of PDC bits to drill granite is questionable (general expert consensus).

- Since the Basel 1 well diameter differs from the geothermal wells at the Soultz and Geodynamics project, special bit types to drill well Basel 1 are suggested (Worrall).

- Perhaps a fluid hammer offered by a swedish company (name ?) could be an option to drill the second well (Worrall).



Casing - Zero wellhead movement: at least slight movements will take place due to strong

active thermal stresses (Baumgärtner). - Wellhead movement of up to 1 m is normal due to thermal casing expansion

(Worrall). - In order to avoid a temperature change related casing damage during a shut in

phase, ENEL opens a small needle valve at the well head to continuously release steam, which maintains stabile the temperature level (Worrall).

- Connectors: minimize temperature changes in the well in order to increase lifetime of casing and threads. Shoulder connectors are superior to buttress connectors (Worrall) → those will be used (Richardson)

- It is proposed to continue this technical discussion in more detail in a small specialist group (Burri).

- Cementation: Cementing philosophy at Soultz was developed in three stages (Baumgärtner): 1. avoid class G cement � problems with high-T and

contamination 2. use salt saturated slurry to avoid contamination problems 3. use a blended cement

The application of high-T gasified cement lead to positive results at the Geodynamics project. The advantage of foam cement is that it doesn’t shrink during pumping (Worrall).

- Mud: experience with suitable polymers and other additives will be discussed directly with Mr. Richardson (Worrall).

- In comparison to other projects the DHM project so far is in good shape in terms

of drilling concept, contract, rig and instruments. Everything hitherto is rather good in time (Worrall).

Logging program - How will stress field measurements be carried out (Rybach) ? → Borehole

breakouts, UBI-Log et al. (Häring) Stimulation program - Packers for frac operations: these are dangerous to use. No decisions have been

made so far since the frac program is still under way (Häring). Meeting summary - The projects’ boundary conditions were presented - The seismic hazard issue is still to be discussed - It is a great challenge of the project to match all things in the given time frame

(Häring) The experts are asked to state what they were missing in the project presentation: - Comparison with Soultz project. Casing specification already fixed (Gorhan) ?

→ yes (Häring) - Casing for two wells available including contingency (Burri) ? → a contingency of

10% is foreseen (Richardson) - Compilation of different drilling scenarios is again emphasized (Worrall) - Casing inspection is an important issue. It is recommended to double check the

casing: immediately after the production and prior to the casing installation (Baumgärtner)



- Wear and tear of drilling tools in granite (Garnish) - Application of casing packers sensible ? Casing packers are used for anchoring

of the casing. The packer is considered to prevent casing corrosion (Baumgärtner)

- Closing round: During the closing round the advisory board experts are asked to give a short comment on this meeting. - Burri: It is evident that there is room for small meetings in order to discuss

specific topics in more detail. Additional work needs to be done on the Micro-seismic network and the stimulation program. Furthermore it is essential to evaluate, how realistic the project time schedule and planning is.

- Huggenberger: Who takes the responsibility for the subgroups ? Who organizes these small meetings ?

- Worrall: A detailed bargraph for the time schedule is essential. The contingency for the time schedule should be included. It is important to address the public relation approaches.

- Gorhan: A close cooperation with the Soultz project is suggested. - Hopkirk: An intensive peer review of the micro-seismic network design is strongly

advised. - Oates: The important points of the micro-seismic monitoring system were

addressed. In order to review the monitoring design he would like to look in detail on the study carried out by Proseis.

- Garnish: The importance of the stimulation program is emphasized, “gentle stimulation”.

- Baumgärtner: Granite has a significant wear on drilling tools. Therefore thorough considerations need to be done in order to select the appropriate drilling equipment. A detailed design for the complete hydraulic program, including stimulation, pre- and post-stimulation testing is essential.

- Roy: Create a detailed bar chart on the project time schedule. Compile a list of actions, what individual people have to do.

- Rybach: Written statements of the individual advisory board experts should be made accessible to the others in order to achieve an equal level of information for everyone.

- Bommer: In order to cope with the seismic hazard the surface recording issue needs to be developed. It is proposed to organize the subsequent meetings with plenty of notice.

Miscellaneous / Next meeting The next advisory board meeting will focus on the design of the hydraulic testing program and the logging program as well (Häring). The next advisory board meeting will take place on February 16th 2006. Adjournment of meeting Dr. Häring expresses his thanks to the advisory committee and bid farewell to the participants. U. Schanz, Geothermal Explorers Ltd 08.Sept. 2005


page 1 of 4

MINUTES ON: Workshop on Stimulation Concept in Basel 1 and Basel 2. Date: 24. März 2006, 09:00-17:00 Venue: Geothermal Explorers Ltd, Schlossstrasse 3, CH-4133

Pratteln Participants: Keith Evans ETHZ Bob Hopkirk Polydynamics Engineering Thomas Mégel Geowatt John Beswick Edeco Markus Häring GEL

Bob Worall GEL Florentin Ladner GEL Uli Schanz (part time) GEL

Kris Johnstone (part time) GEL Rudolf Minder (part time) BFE Peter Burri (part time) Geopower Basel

Reinhard Jung (absent) GGA Introduction to the meeting Markus Häring cordially welcomes all meeting participants and presents the objectives of the workshop:

- a review of our initial stimulation concept by a group of external scientific advisors,

- a draft of a revised stimulation concept based on sound deliberation and consensual conclusions at the end of the workshop.

Markus Häring then introduces all the meeting participants and their specialization and professional experiences in geothermal energy. First Part: Presentation of the project, drilling program and stimulation options This round gives all participants the possibility to achieve the same state of knowledge of the project for further discussions. Markus Häring: Presentation of the projects objectives, constraints, overall

project plan, well objectives and stimulation objectives for Basel 1 and Basel 2.

Bob Worall: Setting of the scene, drilling rig, drilling program for 9 7/8”

hole through the granite, pumping capacity and options for stimulation without the rig.

Markus Häring: Presentation of the Monitoring System and Seismic Safety

Management System during stimulation. Florentin Ladner: Presentation of the Stimulation options


page 2 of 4

- Pre-Stimulation Tests - Massive / Medium High Rate Stimulation - “Tortoise Stimulation” - Flow Controlled Stimulation - Pressure Controlled Stimulation - Post-Stimulation Tests. Second part: Discussion (from 13:30 - 16:00) Chair: Bob Worall Undisturbed rock temperature before stimulation starts Due to the directly beginning of stimulation after reaching TD of Basel 1, there will be no realistic possibility to get an undisturbed temperature measurement at bottom hole. It takes too much time temperature to be re-equilibrated. Therefore modelling should help to estimate the undisturbed rock temperature. Fracture In- and Outflows If the well in the granite section will be drilled under-balanced with cold Rhine water, the back flow to the well should be recognized as warm kicks on a temperature log immediately after reaching TD. Formation Water Sample Producing the well and taking a water sample take a lot of time (2-3 weeks without using the rig) and therefore it would be too expensive. Taking a wireline formation sample has the disadvantage that the sample would be contaminated and not representative enough for the formation. Further it would imply complicated operations (PVT-analysis) to take such a sample. Two possible alternatives should be discussed with a geochemistry expert (F.-D. Vuataz):

1) Is it possible to derive chemical fluid properties from in- and outflow measurements (low salinity of Rhein water)?

2) What can be derived from fluid inclusions and micro fluids in a granite core sample?

Pre-Stimulation Tests The injection rates for the formation evaluation can not pre-planed exactly. For the tests a PT-sensor (either a PT-tool or a PT-sensor into the drill pipe) has to be installed for reliable hydraulic interpretation of the pressure data. Stimulated Rock Volume Two different opinions exist concerning the extent of the stimulated rock volume. Keith Evans proposes an extent of the stimulation to 500 m to be enough for the first step. He argues that there is more benefit for the project to stimulate a “smaller” area to demonstrate that the used technology is appropriate and successful than trying to stimulate a “big” area and then realizing that it doesn’t work. Further he mentions that a smaller volume of stimulated rock has less risk of hitting a fault which will activate seismic events. Markus Häring argues that the investors are not interested in a small reservoir even working, because the operation time will be too short and thus there is no return of


page 3 of 4

investment. The objective must be to achieve an extent of up to 1 km of stimulated rock. Main-Stimulation An overall accepted option is to start stimulating with a dense fluid to help the damage front to initiate as deep as possible and/or migrate downwards. Bob Hopkirk then proposes to pump as hard as possible to do as much damage as quickly and as far away as possible. Pressure and flow rate should be varied to maintain propagation of the damage front. The use of a viscous gel is discussed to concentrate the damage front on the major flow paths and avoid “random” micro-seismic events. For the stimulation to connect the second well to the system Dual Focussed Stimulation should be considered as a further option. Further the use of chemical treatments to reduce pressure losses between wells and host rock and the use of selective blocking of flow paths (using cement or viscous gels) which threaten to become short circuits should be considered. Keith Evans points out that there seems to be an empirical linear relationship between flow rate and injectivity. The higher the applied flow rate, the higher the resulting injectivity. He proposes to pump at high pressure. He does not see at the moment any benefit for a stimulation using different cycles where the pressure will be varied. Thomas Mégel suggests verifying the effect of a Pressure-Controlled Stimulation or Flow-Controlled Stimulation using coupled hydro-mechanical models. This allows to distinguish which desirable effect could be achieved by Pressure-Controlled or Flow-Controlled Stimulation. Further the stimulation strategy should more rely more on what will be found at the bottom hole. Is there only one joint or are there more. The “Tortoise Stimulation” is considered as not appropriate for our purposes (John Beswick, Bob Hopkirk and Keith Evans). If there are any effects they would be rather negative (higher seismic risk) than positive. Third part: Wrap up (from 16:00 – 17:00) At this phase Peter Burri is joining the meeting and Bob Worall summarizes what the meeting participants have worked out. Summary of the workshop The aim of the workshop was to develop a draft of a revised stimulation concept. The general strategy consisting of Pre-Stimulation tests, Main-Stimulation and Post-Stimulation tests was accepted by the participants. Concerning the options for the Main-Stimulation, some of the participants recommend rather a High Rate Stimulation for Basel-1 and afterwards a Dual Focussed Stimulation to connect Basel-2 to Basel-1, but a clear common consensus and a draft of a revised stimulation concept was not achieved by the participants. Further work has to be done: Pre-Stimulation and Post-Stimulation tests:

- The definitive program will be presented after the discussion with Dr. Reinhard Jung. He will join us end of April for a meeting.


page 4 of 4

- A definitive decision has to be made concerning the collaboration with an external service company supporting GEL during the whole hydraulic operations. One possible option is to collaborate with Solexperts AG giving us technical and engineering support. Other options may appear after the discussion with Dr. Reinhard Jung.

Main-Stimulation

- The stimulation options presented by GEL will be discussed with Dr. Reinhard Jung.

- For further investigations concerning the Main-Stimulation, one thing should be kept in mind: Pumping as hard as possible and keeping the operations as simple as possible.



MINUTES ON: Workshop on Seismic Event of Dec 8 and Way Ahead. Date: 18. Dec. 2006, 09:00-17:30 Venue: Geothermal Explorers Ltd (GEL), Schlossstrasse 3, CH-

4133 Pratteln Participants: Prof. Julian Bommer Imperial College

Dr. Reinhard Jung GGA Dr. Keith Evans ETH Zürich Dr. Nicolas Deichmann SED Dr. Ulrike Kastrup SED Dr. François Vuataz CREGE Dr. Thomas Mégel Geowatt Dr. Peter Huggenberger Univ. Basel Dr. Bob Hopkirk Polydynamics Engineering Dr. Rudolf Minder Programme Leader

Geothermics, BFE Dr. Ben Dyer Semore Seismic Prof. Hiroshi Asanuma Tohoku Univ., Sendai (J) Daniel Moll Geopower Basel (13:45–17:30) Dr. Peter Burri Geopower Basel

Dr. Markus Häring GEL Bob Worall GEL

Florentin Ladner GEL Dr. Uli Schanz GEL

Thomas Spillmann GEL Introduction to the meeting Markus Häring welcomes the participants and presents the objectives of the workshop and the tasks of the experts. He outlines the meeting schedule as announced in the invitation. Workshop goals:

1. Show what happened 2. Present the stimulation plan and operations 3. Find improvements for the next phase

Expert tasks: 1. Review the stimulation plan and operation 2. Respond to the questionnaire 3. Present suggestions for way ahead

The experts report is due December 19, 18:00, no final conclusion is expected within this short time frame.



Presentation of the Seismic Safety Management System, monitoring concept, stimulation programme, pre-stimulation test, stimulation test and micro-seismicity The presentations should give all participants the possibility to achieve the same state of knowledge of past operations for further discussions. Introduction, Seismic Safety Management System (Markus Häring) Markus Häring outlined the Deep Heat Mining (DHM) concept in Basel. He explains GEL’s response procedures and communication in case of seismic events that exceed thresholds of ML, PGV, or public reaction. Response was guided by the local magnitudes and peak ground velocities (PGVs) provided by the Swiss Seismological Service (SED) and was accepted by the local authorities. The public was informed by a media release about the official SED alarming system and the specific web page. P. Huggenberger informs about two minutes on the development of the alarming procedures. Monitoring concept (Ulrich Schanz) Ulrich Schanz presents the microseismic monitoring concept, the network geometry and its resolution (~100 m). A two-layer velocity model was used to locate micro-seismic events. N. Deichmann explains that SED has access to GEL’s monitoring data. Stimulation programme and results (Florentin Ladner) Florentin Ladner outlines the development of the stimulation programme and presents results from the pre-stimulation test. The test comprised two shut-ins and low flow injections from 3.14 – 9.94 l/min. Pressure reached a maximum of 73.8 bar. The pressure was not built up to a new steady state, in order to avoid any fracturing of the borehole already during the pre-stimulation. The intention of the pre-stimulation test was to test the formation strength at the borehole. Main stimulation started December 2 and ended with the bleed-of on December 8, 2006. During this time, a total volume 11‘566 m3 water was injected. The widely perceived M 3.4 earthquake that occurred on December 8, 16:48 (UTC) forced a bleed off of the well, which was actually decided immediately before the event. F. Ladner explains the sequence of events during main stimulation. Injection rates were ramping up to a maximum of 3750 l/min, the maximum pressure reached 296 bars. Microseismic results (Ulrich Schanz) Ulrich Schanz showed data examples and the locations of 18 micro-seismic events recorded prior to the hydraulic stimulation. During the main stimulation, 2559 micro-seismic events were manually picked and located. The corresponding hypocenter cloud is displayed in different views and perspectives. The hypocenter cloud forms a steeply dipping planar feature of ~200 m x 600 m horizontal and ~700 m vertical extent. The cloud strikes in a NNW-SSE direction. The main zone of activity near the borehole bottom is observed in a direction SSE form the borehole. N. Deichmann shows a preliminary faultplane solution for the M 3.4 event: it corresponds to a normal-fault/strike-slip mechanism with NE-SW trending T-axis (azimuth/plunge = 52/02) and strike/dip of the nodal planes 355/60 and 108/56. The first motion polarities seem to be compatible with a shear failure (double couple); a possible non-double-couple or volumetric component can however not be excluded and must be investigated by a full-waveform inversion for the complete



moment tensor. The point of nucleation of this event locates near the bottom of the hypocenter cloud. Presentation of the questionnaire List of questions (Markus Häring) Markus Häring re-groups the questionnaire proposed in the invitation and asks the plenum if questionnaire needs amendments. The ensuing discussions focus on:

what measures can be taken assuming that such events will occur again? how can we assess the current seismic risk and potential changes in

seismic risk from stimulation? the quality and state of the geothermal reservoir now probability of occurrence and size of future earthquakes size of damaging and perceived earthquakes earthquake mechanisms: induced, triggered and natural events, is it flow

rate, volume pumped or pressure that dominates earthquake initiation? communication of earthquakes to the public in terms of future activities.

After discussion, the questionnaire was regrouped in three topics: Group I: hydraulic stimulation

1. Were the flow rate and/or the injection pressure too high? 2. Were there alternatives? 3. Can the reservoir qualities be assessed with the present data set?

Group II: seismicity 4. Can the probability of a damaging earthquake be predicted? 5. What is the threshold of a damaging earthquake? 6. Why was the M 3.4 event perceived that strongly?

Group III: way ahead 7. What measures can be taken assuming similar events would occur again? 8. What are the consequences to this project applying such measures? 9. What are your future recommendations for further action? 10. How can we communicate the benefit and risk of our technology?

Discussion of questionnaire (from 13:45 – 16:30) The second part of the workshop was used to discuss and answer the reformulated questionnaire. Contributions that consider characterization of the Basel 1 reservoir are summarised next. Answers to the questionnaire are given in the following sections. Characterisation of the reservoir Jacking pressure reached at 235 bar well head pressure. Breakouts observed at 2.6 km depth show that σHmax ≥ σV, a result that is different form observations in Soultz. The seismic data is of good quality, the hypocenter cloud well outlines the fractured volume. Need for in-depth investigation of existing data, e.g. relative location or collapsing methods to enhance and visualise structures in the micro-seismic cloud, interpret the hydraulic data to derive rock mechanic conclusions. Need for cleaning and additional



televiewer log in Basel 1. Need for additional shut-in to characterize Basel 1. We don’t know if the hydraulic system is now tight or open against formation. Too low fracturing, the reservoir has not yet developed a useful size and the required permeability. Further stimulation will be required. Group I: GEL operations GEL has deviated from the original stimulation plan to keep the injection pressure low, in order to avoid a single vertical shear fracture along the entire open borehole section. This may have produced an unfavourable situation where the fracturing would propagate upwards along the cased borehole instead of progressing into the far field. This decision was taken based on the results of the pre-stimulation tests. The pressure in the annulus remained however low, so that the pressure could be raised. The question was raised and discussed if high pressures increase the probability to trigger larger earthquakes. Pressure is required, but the total volume injected can increase the triggering likelihood. GEL applied very conservative threshold in their response procedures well below the damaging threshold. The thresholds of the traffic light system are far lower than those applied in the Berlin project in El Salvador, although the quality of constructions in El Salvador is of a lower standard than in Basel. M 4.4 and PGV 100 mm/s were proposed as the lower limit for damaging earthquakes. The restrictions in the drilling permit require limits of 0.4 and 0.3 mm/s Vrms during day and night time, respectively. Geopower must communicate the safety/risk of operations not only in advance as they did, but in a far more persistent and conspicuous campaign that it is noticed by the public. Group II: seismicity According to T. Mégel it is the pressure distribution at depth that defines the triggering of a seismic event. The volume pumped defines the affected rock volume and therefore may be a measure of likelihood that larger events are triggered. There is however no consensus among the experts about this hypothesis. We can’t prohibit/control the occurrence of larger seismic events. The likelihood to trigger larger seismic events declines however the same way as the likelihood for natural seismic events. It is the large seismic events that dominate the release of seismic energy and slip within a given subsurface volume. K. Evans shows an impressive graph with cumulative seismic moments from Soultz and Basel stimulations. It is concluded that the seismic risk is controlled by large events, but cannot be quantified. The smaller induced events can be treated in a statistical manner. Rupture mechanisms and effects of the M 3.4 event are discussed in detail. The existing hypocenter location is the initiation point of a larger rupture surface. More knowledge on size, geometry and properties of this surface is required. The acquired seismic data will be used to improve existing microzonation and shake maps. In the order of 1000 reports from the public were received by the SED, which is fully consistent with the expectations for such an event. Very little damage was reported. The perceptions translate to a macroseismic intensity of I = IV with a few reports equivalent to I = V. People were probably frightened by the loud bang which occurred with the ground shaking. This effect may have biased the perception of the event as being much stronger. In the proximity of the hypocenter the vertical movement was likely to be strong. People perceive a vertical acceleration stronger than a horizontal one.



Group III: way ahead B. Worrall and R. Jung propose a low flow stimulation programme for future stimulations in Basel 1 (tickle the well). T. Mégel proposes short high pressure pulses as a mean for fracturing with reduced seismic consequences. Further stimulation will be required to develop a geothermal reservoir for circulation and production. There was no consensus about a stimulation programme that would avoid larger seismic events that can be felt, but efforts must concentrate on the development of low-seismicity programmes. Considerably lower event rates are expected for the production cycle where the water balance at depth is kept constant. However, thermal fracturing may produce seismic events. This will require fundamental scientific research. The now existing data base will provide an important data set to this research. The fracturing procedure underlies a number of operational constraints like operating costs and pumping capacity and pressure limits. There is consensus that communication to the public must be improved: The risk of enhanced geothermal systems has to be put in relation to well known risks, e.g. living near nuclear power plants. Explain the audible noise of small earthquakes. It is frightening to people, but not damaging. Improvements on the stimulation programme must be communicated. Wrap up (from 16:50 – 17:30)

1. After seven days of stimulation the reservoir has not yet developed to our needs

2. Reasons for adjustments to the initial stimulation plan were explained and agreed upon.

3. The M 3.4 event may have happened under all injection plans with reasonably high flow rates and pressures

4. GEL has reacted appropriate according to an approved procedure. 5. Within the short time available for discussion, no consensus on the many

options for the further stimulation programme was obtained. The focus in future will concentrate on stimulation methods with chances for a reduced seismic risk. Such methods need further investigations and cannot be adopted one to one from similar projects.

6. The size and frequency of future seismicity cannot be predicted quantitatively. 7. Natural stress conditions mainly define the sizes of potential earthquakes.

Pratteln, December 20, 2006 Thomas Spillmann (GEL)

Anlage 9


Final Stimulation Programfor Basel-1 based on all data

Reservoir Characterisation and Stimulation Workflow

Addenda for changein stimulation

External ExpertsOperations

Revised byExperts

Pre-Drilling Drafts:1) Pre-Stimulation Characterization Program

2) Stimulation Program3) Post-Stimulation Program

Drilling Basel-1 Mud LoggingData

Wireline LoggingABI-log

Data

Pre-Stimulation well testData

(PTS + surface)

Final Pre-StimulationCharacterization Program

Post-Stimulation well testData

(PTS + surface)

Stimulation Data(PTS + surface)

Shut-in Data(PTS + surface)

Input and Revi-sion by Experts

Consult Experts

Pre-Drilling Phase

Post-Processing of hydraulic data

Geothermal Explorers LTD

Rig down BOPRig up Xmas tree

Drill Basel-1 to TD

Consult Experts

Time

+

+

=

Consult Experts

Final Post-Stimulation Program

Pre-Stimulation Tests forreservoir characterization

Main-Stimulation of Basel-1

Shut-in and Bleed offof Basel-1

Post-Stimulation well testwhile nippling up BOP on

24.5" casing

SpudBasel-2

Run casingClean out casing

and

SkidRig

Run ABI-log

Anlage 10



MINUTES ON: Meeting with Reinhard Jung (hydraulic Stimulation) Date: 26. April 2006, 14:00-20:00 Venue: Geothermal Explorers Ltd, Schlossstrasse 3, CH-4133

Pratteln Participants: Reinhard Jung GGA Markus Häring GEL

Ulrich Schanz GEL Florentin Ladner GEL Bob Worall GEL

General comments on the hydraulic stimulation R. JUNG agrees to our general strategy of carrying out the hydraulic operations: Pre-Stimulation including a Slug-Injection test and low rate Injection test, Main-Stimulation, Post-Stimulation including High Rate Injection Test. For the Main-Stimulation, R. JUNG suggests to increase the flow rate slowly to the maximum flow rate of 100 l/s (stepped constant rate injection) rather than ramping up as fast and as high as possible. Otherwise there is a risk to create an axial tension fracture along the well. Such a tension fracture would impede the evolution of the fracture network into the far field of the reservoir. Regarding the objectives of the exploration phase for Basel 1, R. JUNG mentions that it would be difficult to achieve the required injectivity (100 l/s at a well head pressure of ≤ 5 MPa), if the maximum pump capacity for Basel 1 is 100 l/s (with short exceptions 115 l/s). More pumping capacity during the stimulation is required to prove this. As a worst case scenario in the case that the reservoir could not be stimulated due to missing pump capacity, R. JUNG proposes to be prepared using more pumps than the 3 rig pumps for the stimulation job. Corresponding to BOB WORALL this option is critical. There is a restricted electrical power supply on the rig site (3.2 MW). We can not have as much pumps as we want. Higher pump capacities can be achieved for Basel-2. Corresponding to R. JUNG another option could be the sequential stimulation through perforated casing. R. JUNG strongly recommends using GPS-Time stamped data. In- and Outflow measurements while drilling R. JUNG agrees to accurate in- and outflow measurements while drilling for determination of active flow structures. Further he points out that observation of the pressure recovery in the well during drilling interruptions could give a first estimation of the reservoir transmissivity. For this it would be necessary to have a pressure sensor in the well. Pre-Stimulation Corresponding to R. JUNG a Slug-Injection test estimates the transmissivity of the near well and gives instructions to design the following low rate injection test (flow rates).



The objective of the low rate injection test is to estimate the undisturbed injectivity and to get an idea of the flow regime (laminar or turbulent). A pump capacity of about 1.3 l/s (Solexperts pump) should be sufficient for this. It will not be necessary to have every time a shut-in phase after each step except the last one. Main-Stimulation R. JUNG proposes to ramp up slowly: Starting with very low flow rates and ramping up to the maximal flow rate (flow rate controlled stimulation). R. JUNG suggests 20 bar steps. The highest step (100 l/s) should be hold at least 2 days. R. JUNG recommends using filtered Rhine water while injecting to avoid clogging open fractures. The use of heavy salt brine at the beginning of the Main-Stimulation is recommended but may not be overestimated. An important thing for the assessment of the stimulated reservoir is the observation of the pressure decline during the shut-in phase after turn off the rig pumps. This pressure decline characterizes the stimulated reservoir. Post-Stimulation Corresponding to R. JUNG high rate injection test for determining the injectivity of the stimulated reservoir should be carried out. Such tests require pump rates up to 20 l/s. Thus the Solexperts pump covers a range from 0 to 1.3 l/s, and the rig pump covers a range from 8 l/s to 100 l/s, there is a gap from 1.3 to 8 l/s that could be covered by a pump from HPS (recommended by R. JUNG). Hardware The PTS-tool should be placed at the casing shoe and should resist high and turbulent flow rates. Corresponding to BOB WORALL Scientific Drilling Company (SDC) has the experience running logging and steering tools under such conditions. Corresponding to R.JUNG during the well tests it is essential to have a reliable tool measuring pressure and temperature. Software R. JUNG uses the oilfield software package from Kappa (Saphir) for well test analysis. Collaboration R. JUNG is interested to collaborate with GEL. He and eventually Thorsten Tischner (BGR) could contribute as consultants for the hydraulic data processing and interpretation. Next steps:

- Checking the water quality of the Rhine (especially the grain distribution). - Turbidity meter at the inflow of the suction pumps to observe turbidity of Rhine

water and to be able to interrupt injection if necessary. - Using the shale shakers to filter the Rhine water (60–80 µm). - Checking HPS pumps from R. Jung. - Working out a detailed stimulation program.


Anlage 12


Gutenberg-Richter Diagramm für natürliche Seismizität in Basel

Gutenberg-Richter Plot für die Region Basel über eine Zeitspanne von 5'300 v. Chr. bis 2002 n. Chr. (Giardini et al. 2004).

Magnitude

Anlage 13


Mikrozonierungskarte von Basel

GEL Oberflächenstation IWB- Laborgebäude, Neuhausstrasse 31 Kleinhüningen

Anlage 14

Mohr-Coulomb-Bruchkriterien

τ

σn τ0

σ1 σ3 σ3*

Bruch stabil

τ0

σ1 σ3

Bruch stabil

σ1*

τ0

σ1 σ3 σ3*

Bruch stabil

σ1*

p p

τ

τ

rdruckPorenwassepnungNormalspan

KohäsionungScherspannp

n

n

.........

...tan)(

0

0

σττ

ασττ −+=

Mohr-Coulomb Kriterium:

σn

σn

Mohrsche Spannungskreise für 3 Situationen, die zu induzierter Seismizität führen. Oben links: Erniedrigung von σ3. Oben rechts: Erhöhung von σ2. Unten links: Reduzierung der Hauptspannungen durch Porenwasserdruck.

Die konzeptuell leicht formulierbare Unterscheidung zwischen induzierter und getriggerter Seismizität ist in der Praxis kaum trennbar, da die Signale aller dieser Ereignisse gleicher Art sind. Distanz zur Injektionsstrecke und Magnitude sind zu unscharfe Kriterien um eine klare Zuordnung in eine der beiden Kategorien vornehmen zu können.“

…“In jedem Fall ist die Ursache eines Bebens eine Spannungsumlagerung im Untergrund hervorgerufen durch Veränderungen der Hauptspannungen (σ1 > σ2> σ3). Die Grenzbedingung, bei der es zum Bruchversagen im Untergrund kommt, kann über das Mohr-Coulomb Bruchkriterium definiert werden (Anlage 14). Das Mohr-Coulomb Bruchkriterium beschreibt eine Gerade im Mohrschen Spannungskreis, die den stabilen Bereich vom instabilen Bereich (Bruchbildung) trennt. Solange der Mohrsche Kreis diese Gerade nicht tangiert oder schneidet, herrschen stabile Verhältnisse. Tangiert oder schneidet der Mohrsche Kreis die Gerade, kommt es zum Bruchversagen. Zum Bruchversagen kommt es 1) wenn die kleinste Hauptspannung σ3 zusätzlich erniedrigt wird (Bsp. Tagebau beim Abbau von Gestein, wo die minimale Hauptspannung σ3 vertikal ist); 2) wenn die grösste Hauptspannung σ3 zusätzlich erhöht wird (Bsp. Wasserstauanlage in einem Gebiet, wo die maximale Hauptspannung σ1 vertikal orientiert ist); 3) wenn sowohl σ1 und σ3 durch den Geothermal Explorers Ltd

Anlage 14

Porenwasserdruck um den gleichen Betrag reduziert werden (Bsp. Hydraulische Stimulation im Rahmen von HDR-Projekten). Im Fall von Wasserstauanlagen sind sowohl die Erhöhung von σ3 als auch die gleichzeitige Reduzierung der Hauptspannungen durch den Porenwasserdruck für induzierte oder getriggerte Seismizität verantwortlich ist.


Anlage 15


Richtwerte der Schweizer Norm SN 640 312 a für Erschütterungseinwirkungen auf Bauwerke

Anlage16


Verteilung der maximalen Bodengeschwindigkeiten im SED-Netz von Basel

beim ML 3.4 Beben vom 08.12.2006

Station Kanal Typ pgv [cm/s] Datum Zeit (UTC)

OTTER HGE pgv 0.651000 2006-12-08 17:48:40

OTTER HGN pgv 0.930000 2006-12-08 17:48:40

SBAF HGE Pgv 0.406000 2006-12-08 17:48:40

SBAF HGN pgv 0.374000 2006-12-08 17:48:40

SBAP HGE pgv 0.543000 2006-12-08 17:48:40

SBAP HGN pgv 0.139000 2006-12-08 17:48:40

SBIS HGE pgv 0.620000 2006-12-08 17:48:40

SBIS HGN pgv 0.226000 2006-12-08 17:48:40

SMZW HGE pgv 0.311000 2006-12-08 17:48:40

SMZW HGN pgv 0.256000 2006-12-08 17:48:40

SRHB HGE pgv 0.171000 2006-12-08 17:48:40

SRHB HGN pgv 0.319000 2006-12-08 17:48:40

Anlage 17

Von: Florentin Ladner [mailto:[email protected]] Gesendet: Dienstag, 6. Dezember 2005 16:52 An: '[email protected]' Betreff: 1. Bereichtsentwurf:Massnahmen und Kontrolle induzierter Seismizität Guten Tag Herr Huggenberger Anbei erhalten Sie einen ersten Entwurf des oben genannten Berichtes als Grundlage für die Diskussion vom nächsten Donnerstag beim Schweizerischen Erdbebendienst. Attached befinden sich der Bericht, Beilage 1 (= Massnahmen.gig) und Beilage 2 (=Stufe 1 – 5.gif). Mit freundlichen Grüssen Florentin Ladner Geothermal Explorers LTDFlorentin Ladner Geologe, dipl. natw. ETH Schlossstrasse 3 CH-4133 Pratteln Tel +41 61 821 60 40 Fax +41 61 821 60 44


GEOTHERMAL EXPLORERS LTD

Protokoll:

Meeting über Massnahmen zur Überwachung und Kontrolleinduzierter Seismizität und Erschütterungen

Datum: 08.12.2005

Ort: ETH Zürich (NO-Gebäude)

Anwesende: Prof. Dr. D. Giardini (Schweizerischer Erdbebendienst)Dr. D. Fäh (Schweizerischer Erdbebendienst)Dr. N. Deichmann (Schweizerischer Erdbebendienst)PD Dr. P. Huggenberger (Universität Basel)Dr. M. Häring (Geothermal Explorers LTD)Dr. U. Schanz (Geothermal Explorers LTD)F. Ladner (Geothermal Explorers LTD), Protokollführer

Einführung in das Meeting

Der Grund für das Meeting ist die Präsentation des von den Geothermal Explorers LTDerarbeiteten Berichtes über Massnahmen zur Überwachung und Kontrolle in duzierterSeismizität und Erschütterungen. Nach einer kurzen Einführung in das Deep Heat MiningProjekt (DHM) in Basel erläutert M. Häring die Bauauflagen des Amtes für Umwelt undEnergie des Kantons Basel-Stadt (AUE), die mit dem DHM-Projekt verknüpft sind. Kernpunktdieser Auflagen sind Massnahmen zur Überwachung und Kontrolle der induziertenSeismizität. Das erarbeitete Massnahmen- und Kontrollkonzept stellt ein erster Entwurf darund dient als Diskussionsgrundlage. Zu Beginn der Präsentation wurden die wichtigstenAbbildungen aus dem Bericht an die Anwesenden abgegeben.

Messkonzeptes zur Erfassung der induzierten Seismizität

M. Häring erklärt den geographischen Aufbau des Monitoring Systems. Das MonitoringSystem umfasst 4 Bohrungen bis ins Dach des Malms, die Otterbachbohrung 2, abgeteuftbis ins Kristallin und die Riehen 2 Bohrung, die den Oberen Muschelkalk erreicht. DerStandort der Monitoring Stationen wurde aufgrund eines Geschwindigkeitsmodells, dasdurch die ProSeis AG mittels einer VSP-Messung in Otterbach 2 erstellt wurde, gewählt.Zusätzlich zu diesen Stationen kommen Episensoren und Strong Motion Stationen desSchweizerischen Erdbebendienstes (SED) dazu.

Diskussion:N. Deichmann: Obwohl eine Dämpfung der Geschwindigkeiten durch die tertiären Schichtenzu erwarten sei, wären die Standorte und die vorgeschlagenen Bohrtiefen gut gewählt.Besonders das Vertiefen der Bohrung Schützenmatte bis ins Dach des Malms sei einesinnvolle Erweiterung.P. Huggenberger stellt die Frage, wie es mit der theoretischen und praktischen Funktionalitätdes Monitoring Systems stehe. Vor Beginn des eigentlichen Fracturing Prozesses müssenachgewiesen werden, dass das Monitoringsystem zur Überwachung der Seismologiefunktioniere und die Auswertungen in der erforderlichen Genauigkeit gewährleistet sind (inkl.Qualitätssicherung). U. Schanz: Das verwendete Geschwindigkeitsmodell werde am Endeder Tiefbohrung Basel 1 geprüft, indem mit einer Schlagschere seismische Wellen erzeugt

Anlage 18



würden, die zur Kalibrierung der Geschwindigkeiten dienen. Theoretisch sei dieFunktionalität des Monitoringsystem überprüft worden, indem simuliert wurde, mit welcherGenauigkeit mikroseismische Ereignisse lokalisiert werden könnten, wenn beispielsweise einMessgerät ausfallen sollte. Die Ergebnisse seien zufriedenstellend gewesen. Die praktischeFunktionalität würde gewährleistet, indem für die Monitoring Stationen Haltingen, St. Johann,Schützenmatte und Riehen 2 sowohl ein Ersatzseismometer als auch ein Ersatzrecorder zurVerfügung stehe. Teilweise könnten auch die Messkabel ersetzt werden.

Technische Angaben zu den Sensoren

U. Schanz informiert über die technischen Angaben der Sensoren: Hersteller,Frequenzbereich, Sampling Rate, ADSL-Datenübertragung, Auflösung des Messnetzwerkes.Die schwachen Ereignisse würden über die 3-Komponenten Geschwindigkeits-Sensorenregistriert; die starken Ereignisse würden über die Beschleunigungs- Sensoren (MEMS )registriert.

Diskussion:N. Deichmann und D. Fäh würden den vorgesehenen Lennartz 1 Hz Geschwindigkeits-aufnehmer zur Messung von Bodengeschwindigkeiten an der Oberfläche nicht verwenden.Da die Oberflächensensoren in erster Linie, die an der Oberfläche wahrgenom menenErschütterungen quantifizieren sollen und nicht zur Lokalisierung von induzierten Mikrobebenbeitragen sollen, wären die 1 Hz Seismometer ungeeignet und die Empfindlichkeit zu hoch,bzw. die Sättigungsgrenze zu tief. Bei der in Basel vorhandenen natürlichen Bodenunruhewäre die hohe Empfindlichkeit der Lennartz-Sensoren nicht sinnvoll. Ein KinemetricsEpisensor würde diese Bodenunruhe bereits auflösen und hätte eine Bandbreite von 0 -100Hz und eine Sättigung erst bei viel höheren Beschleunigungen. Bei genügend starkenSignalen würden sich die gemessenen Beschleunigungen problemlos in Geschwindigkeitenumrechnen lassen.Angesprochen auf die Praxistauglichkeit der Sensoren meint U. Schanz, dass die Sensorenbereits in Amerika in der Praxis eingesetzt würden.

Datenfluss

Der vorgesehene Datenfluss wird von M. Häring erklärt. Er schlägt vor, dass derSchweizerische Erdbebendienst (SED) direkten Zugriff auf die Rohdaten und auf dieEreignis-Datenbank hat und damit die Funktion einer externen Kontrollinstanz einnehmenkönnte.

P. Huggenberger bekräftigt den Vorschlag, dass der SED die Position einer externenKontrollinstanz für das Deep Heat Mining Projekt in Basel einnehmen solle. Er führt weiteraus, dass beispielsweise deutsche Behörden Bedenken wegen der induzierten Seismizitätangemeldet hätten und, dass als einzige externe Kontrollinstanz für das Projekt der SED inFrage käme, weil nur damit eine glaubwürdige Information und Kommunikation gegenüberBehörden im In- und Ausland möglich wäre. Weiter seien die Geologischen Daten vollständigund dokumentiert dem GPI (Baugrundarchiv des K antons BS) abzuliefern (Kant.Gewässerschutzverordnung, §5 Abs. 4). P. Huggenberger ist der Ansicht, dass dies auch dierelevanten Daten der seismischen Auswertungen betreffen würde.

Diskussion:N. Deichmann sagt, dass der SED bereits erste Abklärungen vorgenommen hätte, um eineSchnittstellt für den Datenfluss zwischen den Geothermal Explorers LTD und dem SEDeinzurichten (Peter Zweifel vom SED). Das Ziel müsse sein, dass die Daten in beinaheEchtzeit in den Datenfluss des SED eingespeist werden könnten. Weiter schlägt N.Deichmann vor, dass sich der SED auf wichtige Ereignisse beschränken solle. Nicht jedesEreignis müsse durch den SED kommentiert werden. Für natürliche Beben existiere bereitsein Informationssystem: ab Magnitude 2.5 Alarm an die nationale Alarmzentrale; ab

Anlage 18



Magnitude 3 Alarm an die nationale Alarmzentrale und Meldung an die Behörden und an dieÖffentlichkeit.

Kontrollsystem

M. Häring stellt das Ampel-System, den Massnahmenkatalog und das entsprechendeKommunikationskonzept vor, das zur Überwachung und Kontrolle der induzierten Seismizitätdient.

Diskussion:P. Huggenberger gibt zu bedenken, dass seismische Ereignisse nicht unmittelbar mit demBeginn eines Fracturing Prozesses einsetzen. Das Beispiel von San Salvador zeige, dassseismische Aktivitäten erst mit einer zeitlichen Verzögerung erfolgen können. Es wäre alsodurchaus denkbar, dass eine Entwicklung der Bodengeschwindigkeiten bei Ereignissen vongelb (2 cm/s) nach gelb 3.5 cm/s oder > rot 3.5 cm/s (rot) erst nach dem Fracturing Prozesserfolgt. Damit stellt sich die Frage, wie weit sich ein solches Diagramm für die Beurteilungvon seismischen Events eignet und ob allenfalls noch zusätzliche Kriterien erforderlichwären. M. Häring entgegnet, dass Massnahmen nur dann eingeleitet werden könnten, wenntatsächlich Ereignisse stattgefunden hätten.

D. Fäh meint, dass die als Grenzwerte vorgeschlagenen Bodengeschwindigkeiten nichtunumstritten seien. Besonders wichtig sei in diesem Zusammenhang der geologischeAufbau des Untergrundes. Eine neue Mikrozonierungskarte für die Stadt Basel würde imSommer 2006 erscheinen. Diese würde sich von der alten Mikrozonierungskarte (1997) starkunterscheiden.

D. Giardini betont in diesem Zusammenhang, dass es wichtig sei, die Behörden bereits vordem Beginn der hydraulischen Stimulation zu informieren. Für D. Giardini sind die gewähltenGrenzwerte für die B odengeschwindigkeiten grundsätzlich vernünftig. Während derhydraulischen Stimulation würde sich zeigen, ob die gewählten Grenzwerte sinnvoll seienoder ob sie den Umständen entsprechend angepasst werden müssten.Ein viel ernsthafteres Problem stellt für ihn die klare Abgrenzung zwischen natürlichen undinduzierten oder „triggered“ Ereignissen dar. Das Problem bestehe darin den Beweis zuführen, dass ein natürliches seismisches Ereignis, das in der Region passiert und Schädenverursacht, nicht im Zusammenhang mit der hydraulischen Stimulation steht. Weiter stellt D.Giardini fest, dass das vorgestellte Kontrollsystem nur die Explorationsphase berücksichtige,nicht aber die Betriebsphase. Es müssten aber zwei Kontrollkonzepte vorhanden sein, einesfür die Explorationsphase und eines für die Betriebsphase.

M. Häring erklärt, dass für das DHM-Projekt eine zweistufige UVP vorgesehen sei: eine fürdie Exploration und eine zweite für die Betriebsphase. Das vorgestell te Konzept decke alsonur die Explorationsphase ab.

P. Huggenberger wendet ein, dass Studien über das Langzeitverhalten vonGeothermieanlagen nicht existieren. Dies betrifft nicht nur die Seismologie, sondern auch dieGesteins-Wasserwechselwirkung. Grundsätz lich stehe man vor dem Problem, dass eineneue Technologie (Energieerzeugung; Strom und Wärme) entwickelt werden solle, in die ausenergiepolitischen Gründen (Minderung des CO2-Ausstosses) sehr viele Erwartungengesetzt würde. Gleichzeitig würde diese Technologie jedoch auch gewisse Risiken bergen,die im schlimmsten Fall zu einem Projektabbruch führen könne. Es sei gerade das Ziel vonPilotprojekten, wie das DHM-Projekt in Basel, Erkenntnisse zu gewinnen, um die Prozesseund das Verhalten von Geothermieanlagen zu verstehen.P. Huggenberger sieht die berechtigten Anmerkungen von D. Giradini, was seismologischenRisiken für die Betriebsphase einer solchen Alnlage betrifft. Diese Aspekte wurden bis jetztjedoch nur ganz am Rande thematisiert. Eigentlich müssten diese Fragen konkretisiert und

Anlage 18



allenfalls auch mit Einbezug verschiedener Bundesstellen (auch in Bezug Finanzierung)angegangen werden.

D. Giardini gibt zu Bedenken, dass der räumliche und zeitliche Einflussbereich derhydraulischen Stimulation nicht klar definiert sei. Es sei deshalb nicht auszuschliessen, dassdie hydraulische Stimulation natürliche Beben in einer entfernten Bruchstruktur auslösenkönne. Damit dieses Problem eingegrenzt werden könne, müssten beispielsweise bekannteBruchstrukturen in der Region mit zusätzlichen Seismometern überwachet werden. Weiterseien gekoppelte hydromechanische und felsmechanische Modelle erforderlich, damit diePorenwasserdruckänderungen zeitlich und räumlich aufgelöst werden könnten. Er könnesich vorstelle n, dass mit Hilfe von Forschungs projekten (z.B . in der Form eines KTI-Projektes) diese Probleme untersucht werden könnten.Dem SED müssten die Kontrollkonzepte für die Explorations- und die Betriebsphasevorliegen, damit der SED die Rolle einer externen Kontrollinstanz wahrnehmen könne. Prof.Giardini betont nochmals die Problematik der Beweisführung und Verantwortbarkeit beieinem seismischen Ereignis, das Schäden in der Region verursacht.

N. Deichmann weist nochmals darauf hin, dass der Nachweis ob es sich um ein induziertes,triggered oder natürliches Ereignis handle, eines der Hauptprobleme sei.

Ende des Meetings: Zusammenfassung durch M. Häring

Grundsätzlich sei der Austausch von Daten und die Kontrolle durch den SED vorstellbar.Damit der Datenaustausch tatsächlich umgesetzt werden könne, seien aber noch technischeDetails zu klären. Der SED sei durch den Austausch nicht haftbar zu machen, sondern erstelle eine Kontrollinstanz dar, die die Ereignisse beurteilen würde.Die Geothermal Explorers werden ein Kontrollkonzept für die Betriebsphase des DHM-Projektes in Basel ausarbeiten und dem SED präsentieren. Weiter werden Modelleerarbeitet, um die induzierten Porenwasserdruck- und Spannungsänderungen im Nah- undFernbereich der Injektionsbohrung zu erfassen. Diese Modelle werden vorerst theoretischerNatur sein, weil bis jetzt keine Daten vorhanden sind. Mit Beginn der hydraulischenStimulation werden dann erste Daten zur Verfügung stehen, mit denen die Modelle kalibriertund nach Bedarf erweitert werden können.

F. Ladner, Geothermal Explorers LTD

19. Dezember 2005

Anlage 18


Anlage 19

Von: Markus O. Häring [mailto:[email protected]] Gesendet: Dienstag, 14. März 2006 11:58 An: Martin L ü chinger; Hans-Peter Rudin; Peter Huggenberger Cc: Florentin Ladner; Daniel Moll Betreff: DEEP HEAT MINING: Erschütterungen Sehr geehrte Herren Bezugnehmend auf den Bau-entscheid Nr. BBG 9’006’823 betreffend Projekt DEEP HEAT MINING schicken wir Ihnen die beiliegende Studie über die zu erwartenden Erschütterungsemissionen und -immissionen mit einem darauf abgestimmten Überwachungskonzept. Induzierte Seismizität in Zusammenhang mit der hydraulischen Stimulation können unter Umständen Erschütterungsimmissionen zur Folge haben. Zur Messung induzierter Seismizität liegt gemäss Auflage 18 bereits ein Konzept vor, das mit den Herren Huggenberger und Giardini (SED) am 8. 12. 05 besprochen wurde. Ergänzend zu diesem Konzept haben wir vom Ingenieurbüro Rutishauser in Zürich eine Studie betreffend allfälliger Immissionen induzierter Seismizität und wie diese zu messen seien, erstellen lassen (siehe Beilage). Die Studie schlägt ein Überwachungskonzept vor, das die Auflagen 61 – 67 betreffend Erschütterungen weitestgehend erfüllt und in Teilen auch darüber hinausgeht. Entsprechende Aufträge für die Erschütterungs- (und Lärm-)überwachung wurden bereits erteilt. Einzig betreffend Messung des Körperschalls (Auflage 66) kommt die Studie zum Schluss, dass solche erst durchgeführt werden sollten, falls diesbezügliche Reklamationen von den Anwohnern erhoben würden. Wir bitten Sie zu prüfen, ob diese Auflage entsprechend modifiziert werden könnte. Im weiteren wären wir Ihnen für eine Stellungsnahme zum vorgeschlagenen Messkonzept dankbar. Mit freundlichen Grüssen, Markus O. Häring Dr. Markus O. Häring Geothermal Explorers Ltd Schlossstrasse 3 CH-4133 Pratteln Tel +41 61 821 60 40 Fax +41 61 821 60 44 www.geothermal.ch

Please consider your environmental responsibility before printing this e-mail



Sitzungsprotokoll Datum: 04.04.2006, 16:15 Ort: Geologisches Institut der Universität Basel,

Bernoullistrasse 32, 4056 Basel Teilnehmer: Peter Huggenberger, Kantonsgeologe Basel-Stadt Martin Lüchinger, AUE Markus Häring, GEL Florentin Ladner, GEL Peter Huggenberger eröffnet die Sitzung und definiert die Traktandenliste:

1. Datentransfer 2. Induzierte Seismizität

Datentransfer Markus Häring informiert zuerst über den aktuellen Stand des Projektes und über die fertig gestellten Horchbohrungen, die seit 50 Tagen im Einsatz sind und seismische Ereignisse registrieren. Der Datenfluss wird folgendermassen abgewickelt: Alle Daten werden kontinuierlich in einer Rohdatenbank abgespeichert. Aus diesen Daten werden anschliessend diejenigen herausgepickt, die seismischen Ereignisse enthalten (im Moment noch manuell, während der Stimulation geschieht dies automatisch und manuell) und in einer Ereignisdatenbank abgespeichert. Dem Baugrundarchiv Basel-Stadt steht der Zugang zur Rohdatenbank und Ereignisdatenbank offen. Die Daten werden im SEGY-Format abgespeichert. Auch geologischen Daten (Bohr-Cuttings) werden dem Baugrundarchiv zur Verfügung gestellt. Peter Huggenberger nimmt mit GEL Kontakt auf, wie im konkreten Fall der Datenaustausch organisiert wird. Induzierte Seismizität Peter Huggenberger stellt zu Beginn die Frage nach der Auflösung bei der Lokalisation von induzierten Ereignissen. Markus Häring antwortet, dass die Auflösung von der Ablesegenauigkeit des Einsatzes der seismischen Wellen und dem Geschwindigkeitsmodell abhängt. Das Geschwindigkeitsmodell wird überprüft, indem mit einer Schlagschere in der Bohrung (Basis der Sedimente und in der Endtiefe) seismische Wellen angeregt werden, die von den Horchbohrungen registriert werden und zur Kalibrierung des Geschwindigkeitsmodells dienen. Markus Häring stellt das „Seismic Safty Management System“ vor und geht auf den Unterschied der Erschütterungsmessungen ein, die von den Ingenieurbüros Jauslin + Stebler und Rutishauser ausgeführt werden. Jauslin + Stebler führen sowohl Lärm- und Erschütterungsmessungen gemäss den Auflagen des AUE durch und rapportieren regelmässig dem AUE. Das Ingenieurbüro Rutishauser führt Geothermal Explorers Ltd


unabhängig davon ebenfalls Erschütterungsmessungen auf dem IWB-Gelände durch, die direkt in den Datenfluss von GEL eingespeisst werden und als eine der Grundlagen für das „Seismic Safty Management System“ dienen. Peter Huggenberger schlägt den Schweizerischen Erdbebendienst (SED) als unabhängige Kontrollinstanz für die Beurteilung der induzierten Seismizität vor. Eine solche Kontrollinstanz erhöht die Glaubwürdigkeit der seismischen Überwachung gegenüber den Behörden im benachbarten Deutschland und Frankreich. Zu diesem Zweck entwirft Peter Huggenberger bis Ende April 2006 zusammen mit dem AUE (Martin Lüchinger) einen Brief, der dem VR der Geopower AG zugestellt werden wird, in dem dieses Begehren ausführlich erklärt wird. Bezüglich des Berichtes „Massnahmen zur Überwachung und Kontrolle induzierter Seismizität und Erschütterungen“ wird Peter Huggenberger bis im Mai 2006 Stellung nehmen, damit der Bericht dem AUE (Martin Lüchinger) zugestellt werden kann. In der Zwischenzeit soll der Bericht auch vom SED beurteilt werden. Florentin Ladner, 06.04.2006


Inst itute of Geophys icsETH Höngge rberg (HPP)CH-8093 Zürich, Switzerland

Prof . Dr . Domenico GiardiniChair of Seismology and GeodynamicsDirector, Swiss Seismological ServiceTel.: + 41 44 633 26 10 / 2605 (secr).Fax: + 41 44 633 10 [email protected]

Herrn Markus HäringGeothermal Explorers LTD4133 Pratteln

Zürich, May 7, 2006

RE: Stellungnahme des SEDs zum projekt „Massnahmen zur Überwachungund Kontrolle induzierter Seismizität und Erschütterungen,Projekt Deep Heat Mining Basel“

Dear Mr. Häring,

Following our meeting on December 8, we received on April 5 the above mentioned projectdescription. I have discussed the report with N. Deichmann and oth ers at SED.

I found the report very well structured and interesting. The report correctly identifies the differencebetween induced seismicity (micro-events directly produced by the injection), triggered events(earthquakes whose occurrence is triggered by the injection activities) and natural seismicity (whichwould have taken place in any case during the injection period). The report is quite accurate indescribing the possible risk associated to the induced seismicity, under the assumption that theinduced seismicity will resemble that observed in Soultz-sous-Forets. The report is less accurate inthe description of natural and triggered seismic risk, in the statistical analysis and on the possibilitythat the injection and subsequent activities might trigger natural seismicity. Finally, the reportproposes a coherent traffic-light plan for the alert of the population based on instrumental measuresof surface shaking thresholds.

My comments concentrate on four aspects.

Seismic risk

The risk analysis presented in Chapter 4 is somewhat unclear.

a. In presenting the risk associated with the induced seismicity (4.1), the report mixes datafrom the injections at Soultz-sous-Forets with the natural seismicity of the last 30 years froma wide area around Basel, and draws irrelevant and sometimes erroneous conclusions on theproperties of the GB distribution and of the expected Mmax.

b. The possibility of significant triggered seismicity (4.2) is only commented upon, and littleevidence is presented. The conclusion that the more plausible possibility is that the hazardwill remain the same is not justified.

We agree that the risk associated with the induced seismicity is small, under the assumption thatthe seismicity will not exceed the bounds observed in France. We also point out that thepotential for the occurrence of a triggered larger earthquake is real and is not limited by the

Anlage 22


2

regional activity of the past 30 years. Taking into account the observed historical intensities, wehave no method to deterministically limit the possible intensity of a triggered event.

Estimation of earthquake size and surface shaking

The project is installing borehole instruments at depths of few hundred meters to few kilometers, torecord the induced seismicity as well as possible triggered events. The following comments need tobe made:

a. Borehole instruments will allow to precisely locate induced and natural earthquakes withvery small magnitudes. It is however not possible to estimate magnitudes for such events, ascalibrations for near-source waveform amplitudes from deep borehole recordings are notexisting, and will need to be calibrated for this specific experiment. It will be possible tocalibrate a magnitude scale only after the injection period. The relative size of the events canalways be estimated, and an absolute calibration in terms of seismic moment can beattempted (i.e. using the plateau of the displacement Fourier spectrum); but procedures forobtaining automatically such calibrations from band-passed data are not available and needto be urgently calibrated. As a side comment, the change in slope observed in Figure 7 for theSoultz-sans-Forets events could well be due to the difficulty to estimate a linear magnitudescale, rather than to a true physical properties of these events.

b. The report states clearly that the alert procedures will be based on surface measures of PGVand PGA (Page 36). It is very difficult to produce estimates of surface shaking on loose soilsfrom borehole measurements taken on deep, more compact rock; amplitude differences of10-20 are easily observed in similar conditions (cfr. the recent instrumental data fromJapan). The report proposes to use a single SM surface station of the SED to estimate thePGV, taking into account the qualitative microzonation produced by the SED and thegeography of the boreholes. We find that relying on a single-point measurement would betoo hazardous, and that a much more complete quantitative estimation of the shaking forsignificant events should be produced, combining surface measurements from as manypoints as possible with scenario modelling, in order to produce reliable alerts (as done, forexample, in the S.Francisco Bay area).

Alert procedures and role of the SED

The Aktionsplan proposed in Chapter 7 is based on five levels, depending on thresholds ofmagnitude, recorded surface PGV and public felt shaking. We note that:

a. the alerts are based on magnitude and recorded PGV, with the difficulties explained above;the report is not discussing the activities which will have to be conducted by SED in order toguarantee data access from the Basel are, to produce and test the required calibrations, andto produce the real-time mapping of shaking in Basel during the injections and in thefollowing transition period.

b. irrespectively of the procedures installed by Kanton Basel Stadt, the SED has the nationalresponsibility and duty for alerting in case of all events with M 3 and for any smaller eventfelt by the population; this responsibility is important also for the Basel experiment, due tothe significant possibility of triggered earthquakes which could be felt also in other cantonsand other countries. Both the SED automatic alerts and the alert verified by a seismologuewill be issued in any case during the Basel injections. The alert levels and procedures to beset up in Basel need to be integrated with those done by the SED, to avoid confusion,duplication of efforts and contrasting alerts.

Procedures for transitory period after injections and for long-term operations

The report concentrates on the injection period and defers the definition of long-term operationalmonitoring to a later phase. This approach however leaves entirely uncovered the period startingwith the end of the injections and leading to the operation phase; this period may last months to

Anlage 22


3

years. During this period, the underground state-of-stress will undergo significant re-adjustmentfollowing the injections, with the related possibility of triggered events. The plan has to becompleted with the procedures for data collection/analysis and alert in the transition period.

In conclusion, the report presents an important first step toward the definition of a viable andrealistic plan for the Project Deep Heat Mining Basel. I suggest that we set up a second meeting todiscuss future concrete steps toward the final definition of the plan.

With my best regards,

Domenico Giardini

cc: Drs. N. Deichmann, D. Faeh, S.Wiemer, SEDDr. P. Huggenberger, Kantongeologue, Basel Stadt

Anlage 22


GEOTHERMAL EXPLORERS LTD Anlage 23 Protokoll:

Stellungsnahme des SEDs zum Projekt „Massnahmen zur Überwachung und Kontrolle induzierter Seismizität und Erschütterung, Projekt Deep Heat Mining Basel“ Datum: 06.06.2006 / 10 Uhr Ort: ETH Zürich (HAD-Gebäude) Anwesende: Prof. Giardini (Schweizerischer Erdbebendienst) D. Fäh (Schweizerischer Erdbebendienst) N. Deichmann (Schweizerischer Erdbebendienst) P. Huggenberger (Universität Basel) H. Schwendener (Geopower AG Basel) M. Häring (Geothermal Explorers LTD) U. Schanz (Geothermal Explorers LTD) F. Ladner (Geothermal Explorers LTD) Traktanden:

1) Stellungsnahme des SEDs zum Bericht „Massnahmen zur Überwachung und Kontrolle induzierter Seismiziät und Erschütterungen“ vom 07.05.2006.

2) Definition der Zusammenarbeit zwischen SED und GEL 3) Nächste Schritte

Traktandum 1 Folgende Kommentare wurden zum oben genannten Bericht vom SED gemacht:

- Die im Kapitel 4 aus dem Gutenberg Richter Plot gezogenen Schlüsse für die Risikoeinschätzung der Region Basel können so nicht gemacht werden. Der im Bericht gezeigte Graph berücksichtigt nur Daten über einen Zeitraum von 30 Jahren (elektronisches Datenarchiv des SED auf dem Internet), historische Daten sind nicht berücksichtigt und deshalb ist der Plot nicht repräsentativ.

- Die Abschätzung einer maximal erreichbaren Magnitude natürlicher Beben aufgrund des Gutenberg-Richter Plots ist fragwürdig und sollte deshalb im Bericht nicht quantifiziert werden.

- Die beiden Begriffe „induziertes Beben“ und „getriggertes Beben“ müssen im Bericht klar voneinander getrennt werden. Wie ein seismisches Ereignis im konkreten Fall als induziertes oder getriggertes Beben definiert werden kann, bleibt schwierig zu beurteilen. Gemäss Prof. Giardini könnten die Entfernung eines seismischen Ereignisses zum Reservoir und eine Abweichung auf dem Gutenberg-Richter Plot für induzierte Seismizität als Unterscheidungskriterien dienen.

- Prof. Giardini führt weiter aus, dass eine Risikoeinschätzung von getriggerten Beben nicht möglich sei. Es gebe keine schlüssige Beurteilung bezüglich der Erhöhung oder Erniedrigung der getriggerten Erdbebengefährdung. Das einzige Mittel zur Beurteilung der Gefährdung bleibt die sorgfältige



Beobachtung der seismischen Aktivität der Region Basel mittels der Monitoringbohrungen und den Sensoren des SEDs.

- M. Häring meint, dass ausgehend von der natürlichen Erdbebengefährdung in der Region Basel, die Gefährdung eines getriggerten Bebens nicht grösser sein könne als die eines natürlichen Bebens. Das bedeute, dass die generelle Erdbebengefährdung in der Region Basel durch die hydraulische Stimulation nicht signifikant erhöht werden könne. Diese Aussage wäre wichtig für das Projekt und müsse in dieser Form im Bericht stehen.

- Der SED und P. Huggenberger schlagen vor im Bericht mehr Wert auf die Beschreibung der Phänomene als auf deren Beurteilung zu legen. Der Bericht sollte auch eine Zusammenstellung von Fallbeispielen weltweit im Zusammenhang mit induzierter Seismizität enthalten.

- Im Kapitel 5 muss erwähnt werden, dass der Betrieb des Monitoringsystems nicht nur während der Stimulation sondern sowohl vorgängig betrieben als auch auch nachher aufrechterhalten wird, um langfristig die seismische Aktivität in der Region überwachen zu können. Das Konzept der Überwachung der Seismizität muss dahin erweitert werden, dass es nicht nur die Überwachung der Stimulationsphasen beinhaltet, sondern auch jenes des Zirkulationstests.

- Die Bestimmung der Magnitude der seismischen Ereignisse wird vom SED vorgenommen und von GEL übernommenDamit wird ein klarer Kommmunikationsprozess unterstützt. Die Kommunikationsrollen und –verantwortungen müssen für verschiedene Ereignisklassen (z.B. Magnituden 2, 5, 2,5 < M < 4, etc.) noch defniert werden (siehe Traktandum 2). Die Bestimmung der Magnitude muss mit den Erdbebendiensten der benachbarten Ländern (Deutschland und Frankreich) abgestimmt werden.

Traktandum 2 Der SED wird bis nächste Woche (Woche 24) einen Vorschlag ausarbeiten, der die genaue Zusammenarbeit zwischen SED und GEL definiert. Die darin enthaltenen Kernpunkte sind, wie der konkrete Austausch von Daten abgewickelt werden kann, was für Aufgaben der SED übernimmt, wie die Aufgaben gelöste werden und welche finanziellen Konsequenzen die Zusammenarbeit für den SED mit sich bringt. Weiter schlägt der SED einen Ablauf vor, wie die Kommunikation gegenüber Nationalen Alarm Zentral (NAZ), Behörden, Presse und Bevölkerung aufeinander abgestimmt wird. Traktandum 3 Basierend auf diesem Vorschlag wird die Geopower AG einen offiziellen Auftrag dem SED erteilen, in dem der SED als Kontrollinstanz bestätigt wird. GEL wird den Bericht gemäss der Stellungsnahme von SED und P. Huggenberger bis Ende Monat Juni überarbeiten und den zuständigen Behörden übergeben. Florentin Ladner 08.06.2006


Basel magnitudes

Anlage24


Flow rates and well head pressure during Pre-Stimulation test in BS-1

1. Shut in 2. Shut in

13.9 bar13.1 bar 14.8 bar

32.9 bar

6.09 l/min

52.2 bar3.14 l/min

9.94 l/min

73.8 bar

26.2 bar

Anlage 25


Anlage 26


Anlage

27


BS-1: Setup of Surface Equipment for Main-Stimulation-Test


The microseismic monitoring network

ALLSCHWIL

607000 609000 613000 617000

274000

272000

270000

264000

619000

262000

PRATTELN

Riehen1247m

Muschelkalk

Haltingen543mMalm

St. Johann325mMalm

Schützenmatte553mMalm

OT-1535mMalm

CentralAcquisition-Server

Surface Station

rough estimationof flexure zones

Borehole Basel 1

Monitoring stations

Anlage 28

1100

0

1000

0

1200

0

East [m]1150

0

4000

4500

5000

North [m]

Dep

th[m

]

Basel-1

Small eventMedium eventLarge event

NML 3.4 (8.12.2006, 17:48:36)


Perspective view of the well Basel-1 andthe microseismic cloud

Anlage 29

700 m

Nor

thin

g[m

]

Northing [m]

Dep

th[m

]

Easting [m]

Events per cell

Basel 1

Open holeBasel 1

Basel 1

10000 10500 11000

Vertical sectionPlan view

N


Cumulative event density in 25m x 25m cells

a) b)

Anlage

30

Nor

thin

g[m

]

11000

10500

10000

Nor

thin

g[m

]

11000

10500

10000

Nor

thin

g[m

]

11000

10500

10000

Easting [m]11500 12000

Easting [m]11500 12000

Easting [m]11500 12000

Easting [m]11500 12000

20

10

0

Eve

nts

perc

ell

20

10

0

Eve

nts

perc

ell

20

10

0

Eve

nts

perc

ell

3700-3800 m depth 3800-3900 m depth 3900-4000 m depth 4000-4100 m depth




Event density in depth sections, 50m x 50m cellsAnlage

31

Anlage 32


Beziehung modifizierte Mercalli Intensität (Instrumental Intensity) mit Peak Ground Acceleration (PGA) und Peak Ground Velocity (PGV) gemäss USGS

Instrumental Intensity

Acceleration (%g)

Velocity(cm/s) Perceived Shaking Potential Damage

< 0.17 < 0.1 Not Felt None

0.17 - 1.4 0.1 - 1.1 Weak None

1.4 - 3.9 1.1 - 3.4 Light None

3.9 - 9.2 3.4 - 8.1 Moderate Very light

9.2 - 18 8.1 - 16 Strong Light

18 - 34 16 - 31 Very Strong Moderate

34 - 65 31 - 60 Severe Moderate to Heavy

65 - 124 60 - 116 Violent Heavy

> 124 > 116 Extreme Very Heavy

Anlage 33

Kompressionswellen-Signal x-Komponente y-Komponente z-Komponente

Amplitudenspektrum x-Komponente y-Komponente z-Komponente

Amplitudenspektrum des ML 2.7 Ereignisses vom 08.12.2006 03:06 Uhr UTC. Die Signale wurden am Aussenmesspunkt (Erdoberfläche) der Oberflächenstation beim IWB Laborgebäude in der Neuhausstrasse 31 (Kleinhüningen) aufgezeichnet. Die dominante Signalfrequenz für die Kompressionswelle liegt zwischen 10 Hz und 50 Hz. Ein Amplituden-Submaximum befindet sich zwischen 50 Hz und 70 Hz.


Anlage 34

Geothermal Explorers Ltd,

Medienmitteilung der Geopwer-Basel AG vom 21. Dezember 2006, 13:40

Pilotprojekt Geothermiekraftwerk Basel: Verwaltungsrat beschliesst Änderung im Projektablauf

Der Verwaltungsrat der Geopower Basel AG, der Trägerin des Geothermie-Pilotprojekts in Basel, hat an seiner Sitzung vom 20. Dezember 2006 eine Änderung im Ablau f des Erdwärmenutzungsprojekts „Deep Heat Mining Basel“ beschlossen. In einer zusätzlichen Phase sollen nun die vorliegenden Daten analy-siert und das Konzept für das weitere Vorgehen überarbeitet werden. Damit dies ohne Zeit- und Kosten-druck statt finden kann, hat der Verwaltungsrat beschlossen, den Bohrturm und das Bohrteam sofort freizugeben.

Nachdem für die Stimulationsphase - au fgrund des Erdstosses vom 8. Dezember - ein Stopp verfügt wurde, stellte sich für die Geopower Basel AG auch die Frage, ob es zielführend ist, die zweite Bohrung zu starten, solange nicht klar ist, mit welchen zusätzlichen Rahmenbedingungen und Auflagen das Projekt fortgesetzt wird.

Nach gründlicher Evaluation der Sachlage hat der Verwaltungsrat der Geopower Basel AG an seiner gest-rigen Sitzung entschieden, den Projektablauf zu ändern und eine zusätzliche Phase für die Analyse und die Überarbeitung des Konzepts zu initiieren. Die vorliegenden Daten aus der ersten Stimulationsphase, welche die Aufzeichnung von über 12'000 kleinsten und kleinen Erschütterungen umfasst, er fordern eine detaillierte Analyse. Während dieser Zeit würde aufgrund der bisherigen Planung der Bohrturm ungenutzt bereitstehen und Kosten verursachen. Um diese Kosten zu vermeiden, hat der Verwaltungsrat an seiner gestrigen Sitzung beschlossen, den Bohrturm und die Bohrmannschaft so fort freizugeben. Dabei ist er davon ausgegangen, dass es auch unter günstigsten Bedingungen nicht möglich sein wird, alle entschei-denden Fragen zu beantworten und die Arbeiten am Erdwärmeprojekt bis Ende Januar 2007 wieder aufzu-nehmen.

Die Geopower Basel AG stellt indessen nicht nur Kostenüberlegungen an. Die Mitglieder des Verwaltungs-rats sind trotz den Schwierigkeiten, die mit dem Erdstoss vom 8. Dezember 2006 auftraten, nach wie vor vom grossen Energieversorgungspotenzial der Geothermie überzeugt. Deshalb erachtet es der Verwal-tungsrat als wichtig, jetzt das umfangreiche Datenmaterial mit grosser Sorg falt, detailliert und ohne Zeit-druck auszuwerten, um damit zu neuen Erkenntnissen und Klarheit zu gelangen, wie das Reservoir in der Tiefe zur Zeit aussieht und wie es weiter entwickelt werden könnte. Das ist unbedingt nötig, nachdem die im Rahmen des Projekts erfolgte Einpressung von Wasser in den Untergrund zu einem in Basel und Umgebung stark wahrnehmbaren Erdstoss mit der Magnitude 3,4 auf der Richterskala sowie zu Ängsten in der Bevölkerung und zu Sachschäden geführt hatte.

Diese neuen Erkenntnisse werden auf verschiedenen Vorarbeiten beruhen, so namentlich auf einem umfangreichen Bericht, den die Geopower Basel AG bis zum 5. Januar 2007 zuhanden der Behörden ausarbeitet.

Ebenso fliessen Erkenntnisse ein, welche der unabhängige internationale wissenschaftliche Beirat am 18. Dezember 2006 mit Blick auf das Ereignis vom 8. Dezember 2006 und den Fragestellungen der Behörden und der Geopower Basel AG diskutiert hat.

Die Geopower Basel AG hält fest, dass es ihr derzeit in Absprache mit den Behörden möglich wäre, die ursprünglich vorgesehene zweite Tiefbohrung in Kleinhüningen zu starten. Der von den Behörden verfüg-te Stopp betrif f t ausschliesslich Aktivitäten, durch welche Erschütterungen ausgelöst werden können, insbesondere das Einpressen von Wasser in die Tiefe zum Öf fnen der bestehenden unterirdischen Risse und Klüfte. Die Geopower Basel AG sieht aber von einem Start der zweiten Bohrung im Januar 2007ab, da sie eine Bohrung nur dann als sinnvoll erachtet, wenn auch die anschliessenden weiteren Schritte definiert und möglich sind.

Der Verwaltungsrat stellte an seiner Sitzung vom 20. Dezember 2006 zudem fest, dass die Projektkosten bis und mit der neue Phase gedeckt sind. Die noch notwendige Kapitalaufstockung kann mit Mitteln er-folgen, welche bei den Aktionären bereits bewilligt sind.

21. Dezember 2006

Für weitere In formationen stehen Ihnen seitens Geopower Basel AG heute Donnerstag, 21. Dezember 2006 zwischen 14.00 und 15.00 Uhr Dr. Heinrich Schwendener, Verwaltungsratspräsident und Daniel Moll, Geschäfts führer über die Nummer +41 (0) 61 275 51 30 zur Verfügung.

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Documents

I II III IV V VI VII VIII IX X XI XII - wsu.bs.chde4c1330-0f5c-46aa-9414-99082fbbcd32/teil2.pdf · 2. specific know-how in project related tasks, 3. their ... the DHM project and