The document summarizes a workshop on geological guidelines for oil and gas field development and production. The workshop covered: - Background and objectives of clarifying synergy between geologists, geophysicists and engineers and demonstrating integrated geological-reservoir models. - Content of geological and geophysical studies including regional geology, reservoir mapping, 3D modeling, and reserve estimations. - Key concepts including controls on reservoir quality, heterogeneity identification by integrating reservoir architecture and fluid flow trends, and approaches to reserves estimations and classifications. - The importance of an integrated approach combining different data sources and analyses to characterize reservoirs and reduce uncertainties.

1. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG
WORKSHOP PEDOMAN STUDI GGR
compiled by:
HADI PRASETYO
hprasetyo@bpmigas.com
1
GEOLOGICAL CONSIDERATION FOR
DEVELOPMENT AND PRODUCTION
OF OIL & GAS FIELDS

2. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 2
AGENDA:
Background & objectives
G & G study content
Principal concepts & examples
Conclussions
Q & A

3. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 3
 In order to support the increase of reserve and discover
HC trap or help secondary recovery activity, qualified
human resources are needed who are able to utilize,
interpret and model geologic-reservoir conditions through
integrated thought.
 To clarify the synergy between geologists, geophysicists
and petroleum / production engineers.
 To demonstrate the essence of a geological-reservoir
model that incorporates, integrates and reconciles various
types of geological and engineering information.
Background & objectives

4. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 4
G & G Study content
 Regional geological framework
 Geological framework of project area:
structure & depositional environment model; reservoir
zonation & correlation; gross isopach maps.
 Petrophysic / log evaluation
 Geology-reservoir maps:
net-porous; net-pay; iso-porosity; iso-permeability; storage
capacity (h*phi); flow capacity (k*h); HC pore-volume maps.
 3D Geology Reservoir model
 HC in-place / reserves estimations
 All of above items must be supported by Laboratory analysis

5. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 5
Developing GGR model:

6. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 6
AGENDA:
Background & objectives
G & G study content
Principal concepts & their examples
Conclussions
Q & A

7. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 7
SYNERGY………….
JPT, May 1977

8. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 8
EXPLORATION – PRODUCTION CYCLE
(R.M SNEIDER, 1997)
CONCEPTS, DATA,
ANALOQUE FIELDS
PROSPECT
DEFINITION
FAIRWAY
DELINIATION
BASIN ANALYSIS
APPRAISAL AND
PLANNING
DEVELOPMENT *)
PRIMARY *)
SUPPLEMENTARY
RESERVOIR
MANAGEMENT
DISCOVERY

9. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 9
Reducing uncertainty:

10. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 10
GEOLOGIC CONTROLS ON PRODUCTION
(Davies, D.K.,1986)
FUNDAMENTAL
CONTROLS
FIRST ORDER
GEOLOGIC CONTROLS
SECOND ORDER
GEOLOGIC CONTROLS
THIRD ORDER
GEOLOGIC CONTROLS
FOURTH ORDER
GEOLOGIC CONTROLS
POROSITY PERMEABILITY SATURATION
COMPOSITIONS
LITHOLOGY, MINERALOGY:
GRAIN-MATRIX-CEMENT
TEXTURES
GRAIN-SIZE, SORTING,
PACKING, FABRIC
DEPOSITIONAL
ENVIRONMENT
DIAGENESIS STRUCTURE
REGIONAL TECTONO-
SEDIMENTARY FRAMEWORK
PORE GEOMETRY
PORETHROAT SIZE, POREBODY SIZE, FRACTURING,
SURFACE ROUGHNESS

11. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 11
PERMEABILITY
POROSITY
INCREASING
VISIBLE
POROSITY
INCREASING
GRAIN
SIZE
INCREASING
MICROPOROSITY
(Evans et al, 1997)
Significant controls on the quality of sandstone reservoir

12. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 12
RESERVOIR QUALITY
ROCK
COMPOSITION
DEPOSITIONAL
ENVIRONMENT
POST-BURIAL CHANGES
DIAGENESIS
M A N
(Davies, D.K.,1986)
SIGNIFICANT CONTROLS ON THE QUALITY
OF RESERVOIR ROCKS

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RESERVOIR CHARACTERIZATION

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(Gunter et al., 1997 in Cavin, 2007)
Reservoir Characterization

15. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 15
Core photograph of
sandstone with characters
med-coarse grain, cross
bedded, congl’tic, sharp
base contact and calcite
cemented at the base.
0.001
0.010
0.100
1.000
10.000
100.000
1,000.000
10,000.000
0 5 10 15 20 25 30
Porosity, %
Hz.Permeability,
mD
Core photograph
of sandstone
shows slightly
bioturbated,
v.fine-fine grain,
with calcite
cemented at the
upper part
(white).
Plot Porosity vs. Hz-Permeability
Core photo illustrates v.fine – fine
grained sandstone with moderately
intensity bioturbation.
Porosity (%)
Hz.
Permeability
(mD)
Feldspathic greywacke, v.fine-fine grain,
18% clay matrix, hz-permeability = 73 mD.
Sublitharenite, med-coarse grain, congl’tic, <5%
clay matrix content , hz-permeability = 1900 mD.
2168-
2171
2149-2152
2137-2140
Thin-section photomicrograhs
Lower
Upper
Reservoir zonation & their characters

16. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 16
0
5
10
15
20
25
30
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Clay
matrix
-
petrografi
(%)
He-Perm. hz (mD)
PLOT Kh vs. Clay matrix
Cross-bedded sandstone
Highly bioturbated sandstone
Depositional
environment controls
on reservoir quality

17. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 17
Depositional environment & Diagenesis controls on reservoir quality
Core photograph
Thin section photomicrograph Scanning Electron Micrograph

18. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 18
PORE TYPE AND RESERVOIR POTENTIAL PROBLEMS
(Pittman, 1977)

19. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 19
After Poupon et.al (1970); Pittman (1977); Munson (1988)
EFFECT OF AUTHIGENIC PORE CLAYS ON
POROSITY AND PERMEABILITY
DISCRETE- PARTICLE KAOLINITE
PORE-LINING CHLORITE
PORE-BRIDGING ILLITE
GRAIN
GRAIN
GRAIN
GRAIN
GRAIN
SEM photomicrographs

20. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 20
Flow
Units
Gamma Ray
Log
Petrophysical
Data
Pore
Types
Lithofacies
Core
1
2
3
4
5
Core
Plugs
Pc
φ Vs. k
High Quality
Function moves up and right, and
becomes less “L” shaped as reservoir
quality decreases
Pc(Sw) Depends on k,φ
ROCK CHARACTERS vs. CAPILARY PRESSURE
Sarwarrudin et.al (?)

21. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 21
SO.....RESERVOIR CHARACTERIZATION =
TO IDENTIFY RESERVOIR
HETEROGENEITY.....?

22. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 22
APPROACH FOR IDENTIFYING RESERVOIR
HETEROGENEITY (1)
DETERMINING RESERVOIR ARCHITECTURE:
• analyzing geological data (log, core, SWC, cuttings & drilling records).
• depositional system  a basic of reservoir zonation & correllation.
• reservoir zonation  genetic unit.
• well log stratigraphic correlation  sequence stratigraphy
• isopach maps  gross, net porous, net pay, phi, Sw, storage & flow
capacities, HC-pore volume.
• structure  depth structural map; compartementalization.
ESTABLISHING FLUID-FLOW IN THE RESERVOIR:
• documenting history oil, gas, and water production.
• maps of: initial-curent-cummulative production & water-cut by well basis /
reservoir unit.

23. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 23
APPROACH FOR IDENTIFYING
RESERVOIR HETEROGENEITY (2)
INTEGRATING RESERVOIR ARCHITECTURE AND FLUID FLOW TRENDS:
• correllation between reservoir facies / zones, structural setting and
production trends, must be found.
• to form the basic for interpreting compartments within a reservoir.
• establishing a framework for engineering analysis  volumetric estimating,
flow simulation, Decline Curve Analysis (DCA) & history matching 
comparison of reservoir pressure & petrophysic porperties.
Engineering Analysis:
• It should be coincide with geological & fluid flow analyses.
• Compartments dimension could be tested by history matching and DCA,
compartment boundary estimated by flow simulation & also by pressure test.

24. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 24
Reserves Estimations & Definitions:
 The estimation of oil & gas reserves is
not an exact scienc,
 ......always uncertainty in making these
prdiction,
 .....the magnitude of the uncertainty
dependent on the quantity & quality of
the data & on the experience and
knowledge of the evaluator,
 .......is a continuous process throughout
the life of a producing oil-gas field,
 ...the uncertainty decreases with time,
until the economic limit is reached and
the ultimate recovery is realized.
(Arps, 1956)

25. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 25
Reserves estimation & classification:
...uncertainty that is presented by deterministic method

26. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 26
Reserves estimation & classification:
...uncertainty that is presented by probabilistic method

27. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 27
Reserves estimation & classification:

28. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 28
AGENDA:
Background & objectives
G & G study content
Principal concepts & examples
Conclussions
Q & A

29. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 29
AN INTEGRATED APPROACH FOR RESERVOIR CHARACTERIZATION

30. Workshop Pedoman Studi GGR, 21 Oktober 2009, BANDUNG 30
Questions? Comments?
Terima kasih........Thank you