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Komplesi
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Kuliah 1bKuliah-1bKomplesi & Kerja Ulang Sumurp j g
(2 SKS)
Definisi & Konsep Dasar Komplesi & Kerja ulang Sumur
D I A d H li MMDosen : Ir. Andry Halim, MMUniversitas Trisakti - Jakarta
2012
Objective/Sasaran Konsep Dasar Komplesi Konsep Dasar Komplesi Konsep Kerja Ulangp j g
Konsep Dasar Komplesi
Well Completion atau penyelesaian sumur adalah Pekerjaan setelah pemboran, logging dan
pemasangan casing dan flanged sudah dilakukan. Komplesi dapat dilakukan dengan rig yang samaKomplesi dapat dilakukan dengan rig yang sama
atau diganti dengan snubbing unit atau unit lain yang lebih murah.
Konsep Dasar KomplesiKonsep Dasar Komplesi
Fundamentals: Why Discuss Inflow?
Completions is more than installing the equipment
It is also Designing the equipment for the life-of-the-well
Stimulating the formation to optimize well inflow
Designing the upper completion for optimum outflow
Fi di th i ht b l b t ll d ti it i t ll ti t Finding the right balance between well productivity, installation cost, operating cost and risk to optimize the well profitability.
The integration point for Reservoir, Drilling & Production
Completion Types
Open-Hole (Barefoot or Sand Control)
Single Cased-Hole Completion (perforated)
Multiple Cased-Hole Completion
Commingled Cased-Hole
Completion TypesCompletion Types
Horizontal
Dual Cased-Hole
Multi-Laterals
Commingled Monobores
Others
- Multiple tubingless
- Multi-lateralsMulti laterals
- Expandable Screens
Fundamentals: Design Process Design the ell from the reser oir o t Design the well from the reservoir out
- Well flow-rate capability- Completion sized to deliver capability
- Well drilled to contain the completion
Design for the life of the ell (e g artificial lift in late life?)- Design for the life-of-the well (e.g., artificial lift in late life?)
- Optimize completion based on NPV
Completion design is a process Completion design is a process- Plan the well (Peer Assists & Risk Assessments)
Execute the job (Action Reviews)- Execute the job (Action Reviews)
- Evaluate the results
- Document the lessons-learned (Retrospect)Document the lessons learned (Retrospect)
- Re-use the lessons to improve your next design
The Unocal Completions ProcessThe Unocal Completions Process
Determine Completion Options (Rates & NPVs)
-Identify-Validate
-Approve
(Rates & NPVs)
PLAN
-Approve
EXECUTEDOCUMENTKnowledge E i t
Completion OpportunitiesCFT
EXECUTEDOCUMENTCapture Best Practices/ Lessons Learned
Capture Best Practices/ Lessons Learned
Maintain Performance Accountability
Maintain Performance Accountability
Environment
EVALUATE Completed Wells Ops.
Analyze TrendsAnalyze Trends
The Unocal Completions ProcessThe Unocal Completions Process
Get InformationAudit
Risk Manageme
Risk Identification
Post Project Review
ManagementProgram
Risk Assessment
Project Execution &Daily risk mitigation
Risk Mitigation
Communication
Fundamentals: Design Issues Key Design Issues:
Well Inflow / OutflowWell Inflow / Outflow Completion Selection NPV Optimization (economics) Design and Modelingg g
- Pre-Job Nodal Modeling (Prosper)- Tubular Stress Analyses (TDAS or WellCat)- Torque-and-Drag (Compass)
F S i l i (S i Pl )- Fracture Stimulation (StimPlan)- Erosion Calculations (Flux-rates)- Materials Selection (Metals, elastomers)- Formation Geology / Fluids and Filtrationgy
Execution / Pumping -Design and QC (operations, costs, etc)
Post-Job Evaluation Production
Kerja Ulang SumurKerja Ulang Sumur
Kerja Ulang Sumurj g
Materi terkaitMateri terkait komplesi sumurp
PERFORATING
OPTIMIZING FLUID FLOW
Casing
Cement
Damaged Zone(Permeability kd)
Undisturbed Formation(Permeability ku)
Goal : to establish effective (Permeability kd)
Crushed Zone(Permeability kc)
communication between the wellbore and the reservoir
Factors that influence fluid flow through the perforations :Factors that influence fluid flow through the perforations :- Perforating Geometry- Damaged zones around the wellbore- Crushed zones around the perforation
Diff ti l th t i t h f ti- Differential pressure that exist when perforating
PERFORATING GEOMETRY
Perforating geometry involves : Gun Phasing Shot density Perforation diameter Penetration depth
Perforation Diameter
PenetrationGun Phasing0.1 ent. hole PenetrationGun Phasing2.5 penetration
Cement
7 Casing7 Casing
Bore hole0.3 ent. hole6.0 penetration
FORMATION FRACTURING
OBJECTIVES
The objective of hydraulic fracturing for well stimulation is to increase well productivity by creating a highly conductive path (compare to reservoir permeability) some distance away from wellbore into the p y) yformation.
Fracture InitiationA hydraulic fracture treatment is accomplished by pumping a suitable fluid into the formation at a rate faster than the fluid can leak off into the rock. Fluid pressure is built up sufficient to overcome the earth compressive stress holding the rock material together. The rock thencompressive stress holding the rock material together. The rock then parts or fractures along a plane perpendicular to the minimum compressive stress in the formation matrix.
Fracture ExtensionAs injection of frac fluid continues, the fracture tends to grow in width
fl id i th f t t d th f t f kas fluid pressure in the fracture, exerted on the fracture face, works against the elasticity of the rock material. After sufficient frac fluid pad has been injected to open the fracture wide enough to accept proppant, sand is added to the frac fluid and is carried into the fracture p pp ,to hold it open after the job.
The growth upward or downward may be stopped by a barrier formation; downward growth may also be stopped by fallout of sand to ; g y pp ythe bottom of the fracture. The growth outward away from the wellbore will be stopped when the rate of frac fluid leakoff through the face of the fracture into the formation equals the rate of fluid injection into the fracture at the wellborefracture at the wellbore.
Mechanics of Fracturing vRegional Rock Stresses
h2v = Total vertical stress, psih1
Total vertical stress, psi= 0.007 D= average rock density, lb/ft= depth, ft
D
= 0.007 D Pr= formation pore pressure, psiPr
v h1 = Maximum principal horizontal matrix stressh2 = Maximum principal horizontal matrix stress
Horizontal Matrix stress depend on rock properties and pore pressure.
ZONE ISOLATION SQUEEZE CEMENTINGPACKERS
Squeeze Cementing - DefinitionSqueeze Cementing Definition
Injection of Cement Slurryinto the voids behind theinto the voids behind thecasing
Dehydration of cementyrequires: fluid fluid-loss, porous(permeable) matrix,differential pressure, time.
Injection below or abovefracture pressure
PACKERS
Objectives
All k ill tt i f th f ll i bj ti h thAll packers will attain one or more of the following objectives when they are functioning properly :
1. Isolate well fluids and pressure.p
2. Keep gas mixed with liquids, by using gas energy for natural flow.
3 Separate producing zones preventing fluid and pressure contamination3. Separate producing zones, preventing fluid and pressure contamination.
4. Aid in forming the annular volume (casing/tubing/packer) required for gas lift or subsurface hydraulic pumping systems.
5. Limit well control to the tubing at the surface, for safety purposes.
6 Hold well servicing fluids (kill fluids packer fluids) in casing annulus6. Hold well servicing fluids (kill fluids, packer fluids) in casing annulus.
COMPLETION FLUID
FungsiFungsi C/WO FluidsC/WO Fluids
Fungsi utama: Stabilize the wellbore & control sub-
surface pressurepFungsi lain: Suspend equipments and transport solids Suspend equipments and transport solids Sebagai medium untuk well logging Pelumasan Displace other fluidsp
JENIS FLUIDA C/WOJENIS FLUIDA C/WOJENIS FLUIDA C/WOJENIS FLUIDA C/WO
SolidsSolids Free Brine Systems (Clear Fluid)Free Brine Systems (Clear Fluid) SolidsSolids--Free Brine Systems (Clear Fluid)Free Brine Systems (Clear Fluid)
SolidsSolids Laden FluidsLaden Fluids SolidsSolids--Laden Fluids Laden Fluids Drilling FluidsDrilling Fluids Lease Water or SeawaterLease Water or Seawater Lease Water or SeawaterLease Water or Seawater
SolidsSolids--Free Brine SystemsFree Brine Systemsyy
NaCl dan KCl brines biasanya dibuat ydengan melarutkan kristal garam kering dengan air karena densitas maximum
d d l f d h b lyang dapat dicapai relatif rendah; bila dijual dalam bentuk larutan biaya angkutan menjadi mahal karena adanyaangkutan menjadi mahal karena adanya tambahan berat air.
NaBr biasanya dibuat dari garam kering NaBr biasanya dibuat dari garam kering atau tersedia dari supplier dalam bentuk larutan pekat dengan densitasbentuk larutan pekat dengan densitas sesuai dengan kebutuhan.
FORMATION DAMAGE
DamageDamage Zone
Basic Causes of DamageC i h f i fl id i h b i f F i DContact with a foreign fluid is the basic cause of Formation Damage. This foreign fluid may be a drilling mud, a clean completion or workover fluid, a stimulation or well treating fluid, or even the reservoir fluid itself if the original characteristics are alteredreservoir fluid itself if the original characteristics are altered.Most oilfield fluids consist of two phases liquid and solids. Either can cause significant formation damage through one of several possible mechanismspossible mechanisms.
Plugging Associated with SolidsOccurs on the formation face, in the perforation, or in the formation :Weighting materials, clays, viscosity builder, fluid loss control material, lost circulation materials, drilled solid, cement particles, perforating charge debris rust and mill scale pipe dope precipitated scale etcdebris, rust and mill scale, pipe dope, precipitated scale, etc.
Large Solids (perforating tunnel, face of an open hole zone, face of natural or created fracture or in fracture channel) Small Solids (may be carried for some distance into the pores) Solids Precipitated (scale or asphaltene/paraffin)
Plugging Associated with Fluid Filtrategg gThe liquid filtrate may be water containing varying types and concentrations of positive and negative ions and surfactants. It may be a hydrocarbon carrying various surfactants. The liquid is forced into porous zones by differential pressure, displacing orThe liquid is forced into porous zones by differential pressure, displacing or commingling with a portion of the virgin reservoir fluids. This may create blockage due to one or more of several mechanism that may reduce the absolute permeability of the pore, or restrict flow due to relative permeability or viscosity
ff teffects.
Classification Of DamageTh h i th t lt i f ti d b llThe numerous mechanisms that result in formation damage may be generally classified as to the manner by which they decrease production : Reduced absolute permeability of formation results from plugging of pore channels by induced or inherent particles.y p Reduced relative permeability to oil resultss from an increase in water saturation or oil-wetting of the rock. Increase viscosity of reservoir fluid results from emulsions or high-viscosity treating fluidsviscosity treating fluids.
100 kd = 50 md Relates productivity loss to degree and depth of damage The important
1
10
c
t
i
o
n
R
a
t
e
b
b
l
/
d
a
y
Permeability of undamaged reservoir = 100 md
kd = 1 md
kd = 10 md and depth of damage. The important point is that with radial flow, the critical area is the first few feet away from the well bore.
0.01
0.1
0 5 10 15 20 25
P
r
o
d
u
c
y g
Formastion thickness 10 ftWell bore radius 0.25 ftDrainage Radius 500 ftOil Visosity 0.5 cpDrawdown 53.6 psi
0 5 10 15 20 25
Radius of damaged zone beyond well bore, ft
Cement
7 CasingBore hole
Mengapa komplesiMengapa komplesi sumur penting ?p g
Fundamentals: Why Discuss Inflow?Fundamentals: Why Discuss Inflow?
60%
Andrew
First Year productionabove expectation
Ram Powell
0
20%
Arkwright OverspendUnderspend
Ram Powell
-20%
- 40% 40% 80%
ETAP
LiuhuaChirag
Cusiana ph 2 Harding HugotonW. Seno
-60% Schiehallion
Pedernales
CupiaguaHugoton
-100%Foinaven
Pedernales First Year production
below expectation
Hi t i ll th i d t h t b t t di ti t d ti itHistorically, the industry has not been great at predicting cost, productivity or risk. We must do better to handle Deepwater projects
Completion Options Completion Options LifeLife--ofof--Well IssuesWell IssuesClassic Failure Rate
40
45
50Completions are not much different from other commodities (e.g., cars)
20
25
30
35
40
#
F
a
i
l
u
r
e
s
S d C l F il B A d C l i
0
5
10
15
0.1 1 10 100
Time
Sand Control Failure By Age and Completion Type
7080
a
i
l
SOC Time
3040506070
P
W
e
l
l
s
T
h
a
t
F
a SOCCHGPOHGPFP FPs cost more but last
longer
01020
0 5 10 15 20
%
o
f
G
P longer
Screen-only cost less but fail more frequently
Years on ProductionRef G. King Completion Database dated 2004.
Questions ?
PR-1
1. Apa yang dimaksud dengan komplesi2. Sebutkan jenis jenis komplesij j p3. Apa yang dimaksud dengan kerja ulang4 Sebutkan key issues pada komplesi4. Sebutkan key issues pada komplesi
sumur
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