Title: Maximizing the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing: A Case Study of Tight Sand Development Project in Thailand

1. SPE-192047-MS
Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a
Mature Field by Hydraulic Fracturing: A Case Study of
Tight Sand Development Project in Thailand
Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
PTT Exploration and Production Plc.

2. KEY AGENDA
2
• Objectives
• Field Background & Tight Oil Development Scheme
• Case Study – Fracturing Campaign
• Summary & Conclusion
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

3. OBJECTIVES
3
• To present the scheme, and Its
supporting strategy used in
implementation
• Case history based on the first
Expansive-Scale Fracturing
Campaign, following its
successful pilot
The Ultimate Goal:
To sustainably develop the tight
reservoir unit, maximizing the
recovery of hydrocarbon trapped in
the low-permeability formations of
the Sirikit field, in its transition
towards the maturely aged life
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

4. BASIN OVERVIEW
4
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
 Located in the Northern part of Thailand
 Late Oligocene comprised of Alluvio-lacustine, Fluvio-
lacustrine, and Fluvial depositional environments
 Highly heterogeneous, multi-layered, thin-bedded
reservoirs with complex fault regime
y = 2E+06x6.9957
0.001
0.01
0.1
1
10
100
1000
10000
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
Permeability(mD)
Porosity (v/v)
S1 Porosity-Permeability Relationship
all
Yom
PTO
LKU
Sarabop_Khom
Power (all)

5. SIRIKIT FIELD OVERVIEW
5
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
 The field has been producing since 1980s.
 Total 115 Locations and above1000 wells drilled (nearly
400 currently active wells)
 Reservoir mechanism mainly solution gas drive and
aquifer support
 Various reservoir management plans were implemented;
 Waterflood, EOR
 Artificial lifts including G/L, Rod Pump, ESP, etc.
 Hydraulic Fracturing
 Oil rate 50 – 1,000 b/d per active wells in the field
contributing a significant part in domestic oil production.
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
1982 1987 1992 1997 2002 2007 2012 2017
OilProductionRate(BOPD)
Field Oil Production (BOPD)
Implement WF
(1995)
1st HF Pilot
(2006)
1st EOR Pilot
(2017)
Start Production
(1982)
Hydraulic Fracturing Waterflood
EORArtificial Lifts

6. SIRIKIT FIELD OVERVIEW
6
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
10 km
A
A’
 Tight formations are categorized by reservoir depth and properties
 Average porosity 3 -15% and permeability < 0.1 - 10 md
 Sand-shale interbedded, high lateral heterogeneity, complex faults
 Tight portion occupying 14% STOIP of the field (Current RF ~4.5%)
 Production history indicate fast decline which often considered as
secondary target for well planning

7. S1 TIGHT OIL EXPLOITATION
7
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
Campaign A (Pilot)
• 7 stages on 2 wells
• Prod. acceleration 4x-5x,
• Reserves gain
• Positive indication for technical &
economic feasibility
2006 to 2014 2016 2017
Early Days
• 17 Stages in various locations
• Technically proved producible
tight oil sand
Campaign B (Development)
• Extension in proven area
• Expansion to new area/formation
• Aim for sustainable implementation

8. S1 TIGHT OIL EXPLOITATION
8
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
Carried out HF in Proven Area (focus)
• Maximizing Gain / Economic Value
• Building & update Database
• Fine-tuning Practices
Unproven / New Area
• Feasibility / Evaluation
• Acquire data & Subsurface Study
• Determine the technique & Strategy
Production Restoration in Old Wells
• Gain extra benefit from
• Only qualified well w/ potentials
Generate Revenue
Turn Contingent to
Reserve
Extra chance
for income

9. 9
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
Full Adoption w/ continuing
Improvement
- maximizing Gain and Economic Value
- Optimizing and Streamlining Implementation
Execution in Unproven Area
- Feasibility / Evaluation
- Data Acquisition &Subsurface Study
- Area-specific Implementation Strategy
HF in Proven Area
- Maximizing Gain and Economic Value
- Database Development & Update
- Fine-tuning design and implementation
CONCEPTUAL TIGHT OIL DEVELOPMENT PLAN

10. 10
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
HYDRAULIC FRACTURING CAMPAIGNS
× 11 wells
9 new, 2 existing wells
× 16 stages
(1 – 2 stages/well)
1,750
mVD
2,350
mVD
Old /Existing Well
Unproven Area

11. FRACTURING STRATEGY DETERMINATION
11
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
Selection of Technique Implemented
 Work with reservoirs targeted
 Flexible – in terms of candidate selection to enable
dynamic nature of the project
** not every well drilled needs the fracture treatment **
 Low uncertainties – in terms of operation efficiency,
cost/time variance
 Time and cost effective
Strategic Plan & Challenges
 Long-term field-wide development plan
 Practical and Economically viable in Each
Phase Along the Process
 Field executions is sustainable in long run

12. FRACTURING STRATEGY DETERMINATION
12
Typical Sand Model in the Area
This Campaign
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

13. CONCEPTUAL WELL DESIGN AND OPERATION SEQUENCE
13
Fracturing Schematic Final Completion
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

14. ENGINEERING WORK PROCESS
14
Data Acquisition & Processing
• Integrated 3D geomechanics model
primarily used for fracture design
during the campaigns
• Post-Drill data collection & Pre-
treatment tests for extra piece of
information and Calibration
(IPTC-18833-MS)
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

15. ENGINEERING WORK PROCESS
15
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

16. KEY OPERATION VIEWPOINTS
16
Material Quality Control
• Proppant Sieve Test
• Water Analysis / Fluid Compatibility
• Hydration test / Gel Break Test
Operation Quality Assurance
• Readiness to Operate
• Data Acquisition & Measurement System
• Contingency Plan
• Real-time Monitoring, risk identification &
mitigation
• Slurry Quality Verification
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile
Operational Practices
• Safety, regulation, waste management
• Baseline assessments
• Community Engagement
• Operating time window arrangement to
avoid the impact on local community.
• Sound barriers installation at the site &
Regular noise level measurement

17. FRACTURE TREATMENT JOBS OVERVIEW
17
0.52
0.76
0.93
1.23
1.26
0.35
0.64
0.78
0.89
0.88
0.26
0.56
0.64
0.62
0.70
0.00 0.50 1.00 1.50
Formation Pressure
Fracture Gradient
Formation 1st…
0.00 0.50 1.00 1.50
psi/ft
Average typical Fracture Treatment jobs performed
• 99.3 klb proppant /stg. 20/40 ISP+ tail-in RCP (31%) @Max 5-7ppa
• 37% pad Ratio.; 1,415 bbl. x-link frac slurry (per stg.) @ 20 bpm
• Borated X-linked System; Live/Encapsulated Breaker
• Treating Pr. : up to 5,902 psi, MainFrac Pump: 50-110 mins/stg.
0.0
0.5
1.0
LZ-2-1
LZ-3-1
LZ-3-2
LZ-4-1
LY-1-1
LX-2-1
LX-3-1
LX-3-2
LX-4-1
LX-4-2
LT-1-1
LT-2-1
LT-2-2
TE-1-1
TE-1-2
FG (psi/ft)
Pc (psi/ft)
Frac Gradient, Closure Stress, Reservoir Pressure
Range of Fracture/Stress Data
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

18. PRODUCTION PERFORMANCE REVIEW
18
• Total rate of 5x-6x original non-frac potential
• Large variation of oil rate (strongly linked to local
reservoir quality)
• Most wells indicates good fracture performance
(negative skin, high FOI),
• Some with slightly low efficiency than others
potentially due to
– Poor containment,
– Potential choke skin from debris
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

19. PRODUCTION PERFORMANCE REVIEW
19
Detail Analysis and Reservoir Study have led to
 Update Well performance prediction model
 Solid Criteria for candidate selection for area
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

20. FRACTURE TREATMENT JOBS OVERVIEW
20
• In the proven area, all new wells achieved 100% planned
pumping volume., 13/14 jobs in the area achieved the design Xf
• Shorter Half-Length on existing well, compared to others
• Both jobs in Unproven Area terminated earlier than plan
• No LTI during executing the frac job;
No environmental concern or complaint from
the community; No NPT from improper
planning or equipment failure
• Compared to previous campaign, time and
cost utilization on average per-stage have
improved significantly
X
0.51X
0.35X
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

21. EXAMPLE: Time & Cost Effectiveness and Potential Improvement
21
1. Indicative of the operation performance on
a well, compared to the overall average
2. The best possible time could be done,
considering each set of activity had been
performed at its best ( )
3. The opportunity for further cost reduction
(Opportunity for further time and cost optimization)
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

22. SUMMARY & CONCLUSIONS
22
1. A development scheme strategically initiated to
address tight oil targets of a conventional oil
field in its mature stage has been presented –
with focus on (I) extension in proven area;
(II) expansion to new area/formation; and
(III) restoration of old well production.
2. It’s fundamentally enabled by utilizing the
hydraulic fracturing, strategized by the set
of criteria and proceeded with strong and
systematic engineering work process
from design through the field operation and
the analysis.
 The right “Frac Technique & Field implementation
strategy” is the key to make this scheme work.
Flexibility and Reliability are the critical focuses.
 The more efficient the work process, the better the
scheme works out.
 Challenges:
– Positive economic realizable in each phase
– Able to be sustainably implemented in long-
term “field-wide” Scale.
SPE-192047-MS • Maximising the Opportunity in Multi-Layered Tight Sand Reservoirs in a Mature Field by Hydraulic Fracturing:
A Case Study of Tight Sand Development Project in Thailand • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile

23. SUMMARY & CONCLUSIONS
23
1. A development scheme strategically initiated to
address tight oil targets of a conventional oil
field in its mature stage has been presented –
with focus on (I) extension in proven area;
(II) expansion to new area/formation; and
(III) restoration of old well production.
2. It’s fundamentally enabled by utilizing the
hydraulic fracturing, strategized by the set
of criteria and proceeded with strong and
systematic engineering work process
from design through the field operation and
the analysis.
3. While the ideal oil rate was not achievable in
every single job being performed, the first
campaign fully implemented following its pilot:
4. Significant progress in understanding of the reservoir
introduced to the project and improvable areas in
field execution identified from the analysis will make
its continuation even more robust, paving its path
securely towards the sustainable future.
proved to be economic; seamlessly integrated
into the overall field development plan; and
executable in a sustainable manner.
SPE-192047-MS • Theerapat Suppachoknirun, Marut Wantawin and Thanita Kiatrabile