This document discusses re-entry horizontal drilling for enhanced oil recovery in Indonesia. It begins by outlining drivers for enhancing oil recovery through re-entry drilling such as declining production from existing wells. It then provides background on Indonesia's oil production history and challenges in meeting production targets. The document describes Geoglide's services for directional drilling, well planning, and risk reduction for re-entry horizontal wells. It discusses factors to consider such as well selection, drilling unit selection, horizontal drilling technology options, and information needed to plan a re-entry horizontal drilling project. The conclusion emphasizes that EOR projects require cost-effective and low-risk solutions.

1. RE-ENTRY
HORIZONTAL
DRILLING
for
ENHANCED OIL
RECOVERY
Brod Sutcliffe
Oleg Schkoda
15th December 2011
RE-ENTRY
HORIZONTAL
DRILLING
for
ENHANCED OIL
RECOVERY
Brod Sutcliffe – DIrector
Andika Mahardika – Operation Manager
Geoglide Well Positioning
UMW –Hydraulic Work Over Unit

2. 2
Drivers for Enhancing Oil Recovery
through Re-entry Drilling
• Are your wells dead or producing at marginal rates ?
• Is the gas & water disposal cost spiraling ?
• Are there bypassed reserves in your reservoir ?
• Can you determine where these reserves are ?
• Are your existing wells in re-usable condition ?
• Are there formations you wish to avoid ?
• Drilling unit availability ?

3. 3
Indonesian Oil Production
• First oil – 1883, Telaga Tiga, N Sumatra
• Cepu refinery opened in 1890
• Pertamina formed in 1968
• Peak oil in 1995: 1,600,000 BOPD
• Steady production decline
• 2011 (est) : 903,000 BOPD
• Dozens of mature fields
• Reserve estimate:
up to 8 BBOIP

4. Meeting Indonesian Oil Production Targets
• The job is getting more difficult
• Production shortfall widened in 2011
• Production vs Consumption shortfall
widening
Source: IEA, 2015

5. 1. Field Screening
- Economic evaluation
- Residual producible reserve volumes & location
- Current well production
- Condition of well & production facilities
- Existing seismic and well monitoring
- Select a candidate field for more detailed study
2. Assess Wells
- Production logging data (availability, economic viability)
- Thru-casing logging
- Casing condition logging
- Modeling of scenario per well
- Define remedial action plan
EOR Re-entry Drilling Candidate Selection

6. 6
Geoglide Services for Re-entry Drilling
• Directional drilling, MWD, LWD & directional surveying services
• Fishing & casing exiting services (with technical partners)
• Reservoir & geological consultation
• Directional well planning & anti-collision
• Drilling engineering
• Drilling optimization
– Vibration management
– Downhole pressure management
• Geo-mechanics & formation pressure management
• Geo-steering
• Risk analysis & economics

7. 7
• Leverage of existing production facilities & infrastructure
• Risk relatively low due to reservoir knowledge
• Access bypassed & un-swept reserves
• Extend well life and cumulative production
Increase recovery factor / life of mature field:
Drivers for Re-Entry Horizontal Wells
• Exploit pre-existing well (well-
head, slot, casing)
• Leverage off existing well
information and history
• Manage surface area / structure
Utilize pre-existing wells to avoid the cost/risk of drilling
through the over-burden

8. Three levels of engagement:
EOR Options
1. No re-entry
- Optimization of production through surface production
facilities adjustments / modifications
3. Re-entry & re-drilling or sidetracking
- Re-drill well beyond damaged or coned zone
- Sidetrack to access bypassed reserves
- Apply benefits of horizontal completions to fields
drilled with old technology / techniques
2. Re-entry & re-completion
- Work-over, stimulation, re-completion

9. EOR Re-entry Drilling Key Criteria
• Economics – bypassed reserves are marginal, so we need to keep
the cost down !
– Reduce drilling unit footprint
– Reduce POB, support costs
– Reduce equipment cost
• Reduce risk
– Confidence of finding reserves (Reservoir & Geology)
– Technical (right technology with high repeatable success rate)
– Minimize complexity
– Planning – more planning = lower execution cost / risk
– Use highly experienced people
– Reduce HSE exposure & environmental impact

10. EOR Re-entry Drilling Unit Selection
• Primary considerations: Cost & Risk
• Options
– Conventional J/U
• Fairly expensive and often difficult to position
due sea-bed infrastructure
– Light weight purpose designed platform rig
• Ideal where large campaign is firm
– Hi-spec HWU
• Ideal to prove concept or
execute small programme
– CTDU
• Higher cost & risk
• Availability (also barge support requirement ?)

11. Delivery - Risk Reduction
• Planning
– Reservoir studies & assessment to locate un-swept reserves
– Ask “will a horizontal drain optimize recovery ?”
– Bottoms-up planning – design well around the production drain
– Design completion (hardware, fluid, longevity, accessibility)
– Connect the drain to the plumbing – i.e. existing host well
• Optimize hole size for casing size & expected P-rate
• Directional profile – radius (i.e. optimize curve length to minimize over-
burden drilling but allow accurate well placement, lateral length & completio
– Rig availability
• Minimal (cost-effective) size, foot-print

12. Delivery - Risk Reduction
• Planning continued
– Knowledge management
• Offset well review – drilling performance
• technology used
• drilling problems experienced and how solved
– Conduct well planning & engineering
• Formation pressure regime
• Geo-mechanical stability
• Direction plan, torque, drag, hydraulics
– Develop scope of work, time-depth curve, spread cost, AFE
• define casing exit method, drill bits, FE programme, fluid,
steerable BHA design, completion design
– Develop contingencies.

13. Delivery
• Preparation
– Assign a highly experienced project team &
field crew
– Communication
– Develop & distribute well-defined
Operations Programme
– Pre-spud meetings
– Team building
– Secure supply chain (mobilization)
– Contingency
– Prepare well plans,
– Finalized BHA design & bit selection

14. Delivery
• Execution
– Kill & secure well
– Fish completion & set base plug
– Assess well condition – casing, cement
integrity
– Run Casing Caliper-CCL-CBL-GR log
– Precise depth matching
– Squeeze cement if required
– Run, orientate & secure one-trip
whipstock w/ milling BHA (or section mill)
– Cut window
– Ensure window is clean & all junk
removed POOH

15. Delivery
• Execution
– Run drilling BHA
• For SR wells a special curve BHA will be run with a slide-only SR motor
prior to running a conventional steerable BHA for the lateral
– Monitor torque, drag & hydraulics
– Reduce drilling risk
• Light BHA to minimise differential sticking
• PWD for hole cleaning and pressure management
• Tri-axial vibration to ensure LWD reliablity
• Mechanical thruster to assist slide steering and extend lateral reach
– Ensure accurate well placement
• WPR resistivity for geosteering
• EM MWD if UBD

16. Horizontal Drilling – What Radius is Best ?
1,000m
2,000m
up to 10,000m
30 - 60°/30m
58 – 29m radius
860 – 290m radius
Long
Radius
Medium
Radius
Short
Radius
2° - 6° / 30m
290 – 58m radius
6° - 30° / 30m
300m
60 - 220°/30m
29 - 8m radiiUltra Short
Radius
Horizontal Well Radius Definitions

17. Radii versus Distance Drilled
Radius Curve Length DLS
8 12.6 214.8
12 18.9 143.2
18 28.3 95.5
25 39.3 68.7
30 47.1 57.3
45 70.7 38.2
100 157.1 17.2
200 314.2 8.6
300 471.3 5.7
400 628.4 4.3
500 785.5 3.4
1000 1,571.0 1.7
DLS Curve Length Radius
200 13.5 8.6
100 27.0 17.2
60 45.0 28.6
30 90.0 57.3
12 225.0 143.2
8 337.5 214.8
3 900.0 572.9
(m) (m)(m) (m)(deg/30m)(deg/30m)
Ultra-short radius (USR) – USRD + Geoglide
Short radius (SR) - Geoglide
Medium radius (MR) - Geoglide
Long radius (LR) - Geoglide

18. Radius Drivers: Medium versus Short
ShortRadius
ShortRadius
MediumRadius

19. Horizontal Drilling Technology
Long Ultra-ShortMedium
Build Rate (deg/30m (deg/100’))
Curvature
Tool Type
Pipe Rotation
Completions
MWD Type
Std Motors
USR / Articulated
Collar
Conventional
Slide Drill - No Rotation
Ti & Composites
Conventional - No Restrictions
Special
Short Bit-Bend
Short
6 30 60
950
290
190
58
95
29
Radius (ft.)
Radius (m)
Probe MWD
Flex MWD / Steering Tool
Premium - Limited Rotation
220
25
8
• Limitations versus radius:

20. 20
EOR Re-Entry Drilling – Information Needed:
• Desired radius (either radius or DLS) and reason (less cost, trying to avoid
a tricky formation, or water, etc)
• Hole size for curve
• Hole size for lateral (generally the curve and lateral will be the same)
• Length of lateral required
• Lithology across the curve (any water bearing layers, unstable shales, etc)
• Lithology of reservoir (e.g. clean sand, carbonate, fractures, shale lenses,
etc)
• Nature of reservoir (any gas / water to be avoided)
• Reservoir pressure
• LWD requirements in curve (typically just GR, but resistivity is available)
• LWD requirements in lateral; any geosteering capability needed
• Downhole temperature

21. 21
EOR Re-Entry Drilling – Information Needed:
• Drilling fluid type; any underbalanced drilling planned ?
• Completion design
• Any ESP requirements
• For a re-entry: Casing exit details (casing size(s), casing condition, cement
condition, window method preferred)
• Anticipated rig capacity
• Estimated AFE, days / well, spread cost
• Anticipated production / well
• Number of wells planned
• Project start date, tender date, etc
• Tender type – full IS, SRD package, individual services, lump sum, $/m,
$/day, incentives, penalties

22. 22
CONCLUSION
• EOR projects are economically marginal requiring very cost effective,
low risk solutions and technologically acceptable
• Working with a light weight rig or HWU can deliver with confidence !
THANK YOU