NEW DRILLING FLUID TECHNOLOGY 钻井液体系新进展 Chapter 10 Principles of Drilling Fluids 钻井液工艺原理 Prof. Dr. Xiuhua Zheng E-mail: [email protected]@cugb.edu.cn

NEW DRILLING FLUID TECHNOLOGY

钻井液体系新进展

Chapter 10

Principles of Drilling Fluids钻井液工艺原理

Prof. Dr. Xiuhua Zheng E-mail: [email protected] Dept. School of Engineering and Technology, China University of Geosciences(Beijing)

中国地质大学 ( 北京 ) 工程技术学院勘查教研室

mailto:[email protected]

钻井液 Drilling Fluids2010中国地质大学 ( 北京 ) page 2

China University of Geosciences (Beijing)§10

New Drilling Fluid Technology

Test for §9

1. Silica-Oxygen tetrahedron

2. octahedral sheet

3. 2:1-Type unit layer

4. hydrogen bonding

5. c-spacing

6. Isomorphous substitutions

7. Adsorption of a cation

8. exchangeable cations

9. Montmorillonite

10. Kaolinite

1. 硅氧四面体2. 八面体晶片方钻杆3. 单元晶层4. 氢键5. 晶层间距6. 晶格取代7. 吸附阳离子8. 可交换阳离子9. 蒙脱石10. 高岭石




Glossary of §10 1. Silicate-based

2. Mixed Metal Hydroxide

3. Polyol

4. Micro-bubble

5. Formate

6. Non-invasive

7. Polymeric Amine

8. Cloud point" （浊点）

1. 硅酸盐 2. 正电胶3. 聚合醇4. 微泡5. 甲酸盐钻井液6. 无侵害钻井液7. 聚胺钻井液




Contents

1 Silicate-based Drilling Fluid （硅酸盐钻井液）2 Mixed Metal Hydroxide Drilling fluid （正电胶钻井

液）

3 Polyol Technology System （聚合醇钻井液）4 Micro-bubble Drilling Fluid （微泡钻井液）

5 Formate Drilling Fluid （甲酸盐钻井液） 6 Non-invasive Drilling Fluid （无侵害钻井液）7 Polymeric Amine Drill Fluid （聚胺钻井液）




1.Silicate-based Drilling Fluid

silicate-based drilling fluids using sodium and potassium silicate （硅酸钠或硅酸钾） is a lower cost and effective drilling fluid with very good shale inhibitive capacity,

reduced formation damage and environmental safety. silicate-based drilling fluids offers the flexibility and

versatility to design a mud system for almost any drilling environment and provides.

Introduction




• Molar of silicate is the weight ratio of SiO2:Na2O ( 重量比） , being the key parameter that determines the properties of drilling fluid.

• liquid silicates with higher ratios will contain proportionately greater levels of condensed, complex species with higher molecular weights. the low and mid ratio liquids will contain significant levels of low molecular weight chains and cyclics as well as free mono-silicate.

Characteristics




In-gauge holes are achieved through a unique combination of versatile chemical reactions; most

notably gelation( 胶凝 ) and/or precipitation （沉淀） on shale surfaces.

These reactions also lead to the sealing of micro-fracture, cracks and rubble giving a silicate drilling

fluid a decided advantage over any oil mud, significantly reducing potential mud losses and

costs.silicate drilling fluids provide a thin, tough, ultra low

permeable filter cake reducing drilling problems such as differential sticking or torque & drag, while

providing improved cementing.

Mechanism




A. Superior Well Bore Stability

B. Excellent Shale Inhibitive Capacity

C. Excellent ROPD. Runnability

E. SafetyF. Cost

G. Environment

Advantages




2.Mixed Metal Hydroxide Drilling Fluid (MMH)

正电胶钻井液

Mixed metal layered hydroxide compounds are inorganic materials which are made up of

discreet layers, consisting of two or

more metal ions surrounded by

hydroxide ions.

Characteristics




When added to pre-hydrated bentonite, the positively charged MMH

particles interact with the negatively charged clays forming a strong complex that behaves

like an elastic solid when at rest.

Characteristics




the sheets are electron deficient and a

crystallographic positive charge is

generated, The surface interacts with these

anions through an ion exchange mechanism, similar to that of anion exchange resin or clay

mineral.

Mechanism




A. MMH has unusual rheology: excellent hole-cleaning properties

B. MMH has great gel strength at rest, the structure is easily broken.

C. MMH also provides chemical shale inhibition. D. MMH is a special fluid sensitive to many

traditional mud additives and some drilling contaminants.

Advantages




A. horizontal and short-radius wells

B. unconsolidated or depleted sandstone

C. high-temperature, unstable shale

D. wells with severe lost circulation

Application




3.Polymerized-Alcohols Drilling Fluids聚合醇钻井液

A. Polyol is the generic name for a wide class of chemicals including glycerol( 丙三醇 ),

polyglycerol( 聚丙三醇 ), glycols （乙二醇） and propylene glycol （丙二醇 ).

B. The water solubility of glycol decreases as temperature increases. The temperature at which glycol and water separate is known as the "cloud

point" （浊点） C. Polyol drilling fluid has the capability of excellent

borehole stability, upgraded lubrication on the mud itself and the borehole wall, reduced formation

damage and lowered dilution rate.

Characteristics




· the entire solution temperature has risen above the cloud point, two distinct

phases become visible. When the solution cools, the glycol and water recombine

to form a clear, single phase. The glycol drops out of

solution and attaches to the “hot” shale. This protective

layer prevents the shale from interacting with the water,

minimizing swelling.

Mechanism




The high performances of the glycol system are:

A. superior lubricity

B. improved fluid hydraulics

C. ease-of-conversion

D. excellent borehole stability

E. enhanced shale inhibition.

Advantages




4. Micro-bubble (Aphron) Drilling Fluid

可循环微泡沫钻井液

The Structure of a gas

aphron at the molecular

level:

The aphron is composed

of a gas core and a

more complex soapy

shell, which has an

inner as well as an outer

surface with a sheath of

viscous water between

them.

Features

Structure of a gas aphron




· Energized Micro-Environment of Aphron

Structure and Bubble Flow

An aphron, which has a diameter of 96 microns at

the 0.1 MPa surface pressures, is compressed into a smaller one with 16 micron diameter at 21.89

MPa.

Features




Bridging Mechanism in a Loss Zone

pressure resists intrusion of hydrophobic micro-bubbles into capillary

restrictions in the formation.

Features




Aphron drilling fluid possesses unique

viscosity structure and viscosity size, forms a

temporary blocking zone that deters or delays the

drilling fluid to enter reservoir, and enjoys

better leakage-proof and reservoir-protection.

Mechanism




5. Formate Drilling Fluid 甲酸盐钻井液

A. Formate is safe for the environment and crew.

B. Recycling cuts fluid costs by reclaiming formate and using them in multiple wells.

C. No weighting agent means no sag, and no sag means the elimination of a whole pile of problems, from additional hours circulating and conditioning

muds to serious well control incidents.

Characteristics




D. Naturally weighted. Formate brine drilling fluids are naturally

weighted, monovalent fluids with a maximum density of

2.30g/cm3 (19.10 ppg) for cesium formate, 1.57 g/cm3 (13.05

ppg) for potassium formate and 1.30 g/cm3 (10.85 ppg) for

sodium formate.

characteristics




E. An adequate amount of viscosifier, FL control agent, lubricant and defoamer are concurrently

used in the fluid for obtaining a system with satisfactory properties.

F. This system is characterized by its excellent stabilizing capacity and evidently reduced

formation damage. High cost and enormous quantity of formate required limit the application

range of this system.

characteristics




A. No weighting materials means no sag, improved ECD (Equivalent Circulating Densities) and better

overall circulation rates

B. High compatibility with reservoir fluids and minerals maximizes reservoir protection and

improves well productivity

C. Extremely versatile fluids used in all phases of drilling and completion eliminate the costs of fluid

change

D. Optimized hydraulic flow maximizes power transmission, facilitates hole cleaning and

increases ROP (Rate of Penetration)

Advantages




E. Alkaline properties give outstanding corrosion protection

F. Stabilizes shale and enhances borehole stability

G. Improves well control and allows faster tripping

H. Excellent compatibility with elaptomers and polymers

I. Facilitates faster and more accurate logging – even with extended reach drilling

J. Best environmental and safety profile of all drilling and completion fluids

Advantages




6. Non-invasive Drilling Fluid

（无侵害钻井液）Conventional drilling is conducted with an over-balanced pressure on the reservoir formation, which causes the drilling fluid to invade and damage the rock. In order to

overcome the problem of formation while drilling, a method was developed to drill with a bottom-hole pressure below the

pore pressure, called Under-balanced Drilling-UBD. The development and recent increase in UBD activity is due to

the understanding that there will be no formation damage if a reservoir is drilled under-balanced. UBD is, most probably, still the best way to achieve no-damage drillingSM. However, the big problem associated with UBD is how to guarantee that no overbalance periods will happen while drilling or

completing the well. Also, there are many situations in which technically it is not possible to have an under-balanced

pressure kept at all times. Just a small period of overbalance may cause damaging filtrate invasion.

Introduction




The NIFSM is a new class of drilling fluid, with ultra-low solids content, less than 10 ppb.

The characteristics of this fluid are its capacity to build up a sealing membrane of certain strength into certain thickness of the formations around the borehole by addition of special polymer type

additives into a water base or oil base drilling fluid.

characteristics




A. Totally friendly to the environment

B. Effective sealing of hetergenneous permeable formation with the same fluid composition

C. Allows increase of the leak-off pressure

D. Widens a narrow mud weight window

E. Seals permeable formation and micro-crack in shale

F. Can drill the overburden and the reservoir with the same fluid, including completion

G. Reduced transport and storage costs

H. Reduction of differential stuck pipe risk

I. Reduction of fluid losses, virtually eliminating them

J. Reduction of well-bore instability problems

K. Reduction formation damage

Advantages




– DWC2000, a viscosifier; (max dosage 30 kg/m3)– FLC2000, a dynamic fluid loss reducer (routine

dosage 6~12 kg/m3); – KFA2000(dosage range 20~300 kg/m3), a lubricant

The three additives are of one-sack type and can be used individually or in combination and the formulation must be determined by pilot tests.

Formulation




When added to a water-based fluid, some of the

polymers in the blend dissolve to provide fluid loss control similar to

many conventional additives. However, other species only

partially solvate because of their oil-

loving characteristics; these polymers

organize into deformable aggregates

or micelles.

Mechanism




these micelles have the ability to form rapidly a low permeability seal over pore throats and

micro-fracture, thereby greatly limiting fluid

invasion.

Mechanism




In some respects, the micelles act like the

water droplets in invert emulsion oil mud; these

water droplets are known to concentrate in

the filter cake where they make a major contribution to the

invasion control seen with oil mud.

Mechanism




By functioning as a very low permeability barrier, the

additive has the ability to protect weak formations

against pressure transmission and fracturing.

This effective increase in fracture gradient widens the safe drilling window and has great potential for improving

drilling performance, not only in micro-fractured formations but also in

depleted zones, unconsolidated sands, etc.

Mechanism




Particle size analysis suggests that the micelles range from a few microns to close to 1000 microns in

diameter (the d50 is around 60 microns, the d10 is 9 microns and the d90 340 microns).

Mechanism




A. Particles are calcium carbonate and salt, an acidification job

or dissolution with water would eventually remove the damage

created.

B. Bridging approach requires the particles to penetrate into the

rock, and find a suitable pore size, according to the particle

size distribution.

C. Maintenance of the NIFSM is extremely easy. Addition of the

fluid loss controller additive, FLC2000, is enough to maintain

the sealing effectively. And the amount required is dictated by

a test conducted against a sand bed. If the sealing is not

effective, addition of more FLC2000, is needed.

Comparison with traditional drilling fluids




A. Reservoir inter-bedded with shale

B. Reservoir with different pressure exposed in the same open hole section

C. Severe well-bore instability problems due to mechanical causes ( high tectonic stresses, for

example)

D. Narrow mud weight window

Application




7. Polymeric Amine Drill Fluid ( 聚胺钻井液 )

A high performance water-based mud (HPWMB-also

called amine base drilling fluid) containing clay and

shale stabilizers, a ROP enhancer, and sealing

agents was developed to drill the well and is taken

as the substitution for oil base mud. The high

performance drilling fluids use a new cationic

polymer—ether/glycol polyamine as shale

inhibitor 。 This amine salt has a high inhibitive and

bit balling prevention capacity, and is

environmentally friendly.

Introduction




Ammonium Chloride → Ammonium Salt mud Systems → Organic Cationic Materials → Quaternary

Cationic Polymers → (PHPA-Partially Hydrolyzed Polyacrylamide) → Quaternary Alkyl-Amine

→Quaternary Hydroxyl Amines) → Amphoteric Poly-amine Acids →Alkyl-Diamines→ Polyamine Glycols

→ Ether/Glycol Polyamines.

Evolution of nitrogen-based shale inhibitor




HPWBM drilling fluid system significantly

reduces clay dispersion, hydration,

and accretion outperforming

previously developed inhibitive WBM systems

and reaching into the performance territory of

OBM.

characterictis




HPWBM drilling fluid system significantly

reduces clay dispersion, hydration,

and accretion outperforming

previously developed inhibitive WBM systems

and reaching into the performance territory of

OBM.

characterictis




The CHS functions in mechanism similar to potassium chloiride in

suppressing clay hydration, without

being constrained by the performance and environmental issues associated with KCl.

mechanism




The data presented demonstrate how the CHS effectively reduces the hydration and dispersion of

reconstituted shale wafers in laboratory tests.

mechanism




A. shale stability through reduced or reversed pressure transmission effects

B. suppression of reactive swelling clays

C. improved cuttings encapsulation and solid removal efficiency

D. minimizing differential sticking tendencies

E. maximizing rate of penetration(ROP)

F. minimizing torque and drag

G. environmental compliance

advantage




A. Extension of amine and oligomer performance to higher temperatures

B. Economically tailor oligomer to optimum and consistent molecular weight and configuration for

improved filtration control and membrane development.

C. Source less expensive amines which meet performance expectations.

D. Investigate of a broad range of organic and inorganic osmotic drivers which complement

membrane development.

Future development




Discussion

• Why and how are the new drilling fluids developed, and their applications.

Documents

NEW DRILLING FLUID TECHNOLOGY 钻井液体系新进展 Chapter 10 Principles of Drilling Fluids 钻井液工艺原理 Prof. Dr. Xiuhua Zheng E-mail: [email protected]@cugb.edu.cn