Opportunities in Oil and Gas Fields
Questions
February 9, 2016
TABLE OF CONTENTS
A. Asset ...........................................................................................................................3
1. What is the size of the opportunity (size the prize)? ................................................................................3
2. Volumetric Evaluation............................................................................................................................3
3. Probabilistic Volume Estimates ...............................................................................................................3
4. Material Balance Application ..................................................................................................................3
5. Is the Opportunity Spread Out between multiple reservoirs or alone? ......................................................3
6. In what stage of field life does the opportunity lay? (Infant – No or limited depletion recovery; youth;
adolescent; young adult; middle age; mature; elderly) ...................................................................................3
7. How many wells does it lie within? .........................................................................................................3
B. Local Well Observations Development ............................................................................3
1.
2.
3.
4.
5.
6.
What is the average well spacing within the opportunity? ........................................................................3
What are the Wellbore Geometries? .......................................................................................................3
What are the Formation tops? ...............................................................................................................3
Is the reservoir Faulted?........................................................................................................................3
Has the opportunity been tested? ..........................................................................................................3
Well Logs over opportunity ....................................................................................................................3
1.
2.
3.
4.
Are 2D Geophysical Data available?. ......................................................................................................4
How about 3D Geophysical Data? ..........................................................................................................4
Coverage of Seismic Data? ....................................................................................................................4
Can Seismic be used to define the opportunity, or has it been used? .......................................................4
1.
2.
3.
4.
5.
6.
Surface Mapping ...................................................................................................................................4
Outcrop Samples ..................................................................................................................................4
Source rock maturity analyses ...............................................................................................................4
Other Surface Samples ..........................................................................................................................4
Faults ...................................................................................................................................................4
Are there Analogs?................................................................................................................................4
1.
2.
What are the project gates? ..................................................................................................................4
4
1.
2.
3.
4.
In Production? ......................................................................................................................................4
In Costs? ..............................................................................................................................................4
In the reservoir? ...................................................................................................................................4
Where Uncertainties exist will we need new data or can new processing be applied to old data? ...............4
C. Areal View by Seismic Data Development .......................................................................4
D. What Other Field Data can aid Development of Opportunity ............................................4
E. How rapidly can the Opportunity be Expanded or be closed if un-successful? ...................4
F. What are the Project Economic Factors and Risks? ..........................................................4
G. What are the storage and flow Risks from Petrophysical Analysis? ...................................4
1.
2.
3.
4.
5.
Determination of full-field petrophysical cut-offs .....................................................................................5
Generate summations, log displays, and other reports ............................................................................5
Interpretation of wireline formation testing results ..................................................................................5
Saturation Functions .............................................................................................................................5
Determine fluid contacts........................................................................................................................5
1.
2.
3.
4.
Seismic Interpretations .........................................................................................................................5
Structure Mapping on Key Geologic Surfaces ..........................................................................................5
Gross Reservoir Interval Isochore Mapping .............................................................................................5
Fault Interpretations .............................................................................................................................5
H. What are the Structural Framework Mapping Issues? .....................................................5
Page 1 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
I.
5.
Fold Geometries....................................................................................................................................5
What are the Reservoir Zones Uncertainties? ..................................................................5
1.
2.
3.
Net Reservoir Isochore ..........................................................................................................................5
Net:Gross Ratio Determination ..............................................................................................................5
Net Reservoir Petrophysical Properties ...................................................................................................5
1.
Reservoir Parameters ............................................................................................................................5
1.
2.
3.
4.
5.
6.
Existing Pressure Data ..........................................................................................................................5
Flowing Surveys ....................................................................................................................................5
Static Surveys .......................................................................................................................................5
Productivity Index .................................................................................................................................6
Gas Well Surveys ..................................................................................................................................6
Pressure Testing ...................................................................................................................................6
1.
2.
3.
4.
Wettability studies ................................................................................................................................6
Capillary Pressure .................................................................................................................................6
Relative Permeability .............................................................................................................................6
Residual saturations ..............................................................................................................................6
1.
2.
3.
4.
5.
6.
7.
8.
Production Data ....................................................................................................................................6
Reservoir Allocation ..............................................................................................................................6
Decline curve analysis and interpretation ................................................................................................6
Map Displays ........................................................................................................................................6
Interval tests and workovers .................................................................................................................6
Volumetric average pressure data ..........................................................................................................6
Reservoir surveillance sections ...............................................................................................................6
Mechanical status review .......................................................................................................................6
1.
Well Patterns ........................................................................................................................................7
1.
2.
3.
4.
5.
6.
7.
Fracture Identification ...........................................................................................................................7
Fracture Origin .....................................................................................................................................7
Fracture Morphology .............................................................................................................................7
Fracture Characterization ......................................................................................................................7
Identify and map fractures from seismic attribute analysis where possible ................................................7
Fracture Modeling .................................................................................................................................7
Fracture Stimulation Effects ...................................................................................................................7
1.
2.
3.
4.
5.
6.
7.
Mobility Ratio of displacement process? ..................................................................................................7
Vertical Equilibrium or no cross-flow and the following? ..........................................................................7
Can k be derived from Petrophysical Data? .............................................................................................7
Miscellaneous Data ...............................................................................................................................7
Geostatistical Evaluation ........................................................................................................................7
Property Distribution .............................................................................................................................8
Volumetric Analysis ...............................................................................................................................8
J. Fluid Properties Determination Uncertainties? .................................................................5
K. What is the Quality of the Dynamic Data Pressure Survey Data? ......................................5
L. What is the Quality of the Multiphase Flow Properties? ....................................................6
M. What is the Quality of the Production, Pressure, and Secondary Product Data? ................6
N. Are other Engineering Data for Water or EOR Injection Available? ...................................7
O. Fractured Reservoir Characterization .............................................................................7
P. Other Generalized Data? ...............................................................................................7
Page 2 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
A. Asset
1. What is the size of the opportunity (size the prize)?
2. Volumetric Evaluation
a. Oil Volumes
i.
Original oil in place
ii. OOIP and STOIP
iii. OOIP comparisons to historical estimates
b. Gas Volumes
i.
Original free gas in place
ii. Original solution gas in place
c. Transition Zone Volumes
i.
OW transition volumes
ii. Swept zones and saturation estimates
3. Probabilistic Volume Estimates
a. Assignment of uncertainty in volumetric estimates
b. Results of Monte Carlo estimation methods
4. Material Balance Application
a. Drive Mechanisms
b. Pressure History
c. Volume Estimates
i.
In place volume estimates (see Volumetric Evaluation)
d. Aquifer Strength
i.
Aquifer size
ii. Aquifer properties
5. Is the Opportunity Spread Out between multiple reservoirs or alone?
6. In what stage of field life does the opportunity lay? (Infant – No or limited depletion
recovery; youth; adolescent; young adult; middle age; mature; elderly)
7. How many wells does it lie within?
B. Local Well Observations Development
1. What is the average well spacing within the opportunity?
2. What are the Wellbore Geometries?
3. What are the Formation tops?
a. Chronostratigraphic tops
b. Lithostratigraphic tops
4. Is the reservoir Faulted?
a. Have Fault cuts been observed in wells?
b. What other evidence of faulting exists from performance date
5. Has the opportunity been tested?
a. Wireline formation testing
b. Drillstem testing
c. Production testing
6. Well Logs over opportunity
Page 3 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
a.
b.
c.
d.
Conventional open-hole wireline logs
Cased hole logging services
Image logs and other special surveys
Dipmeter logs
C. Areal View by Seismic Data Development
1.
2.
3.
4.
Are 2D Geophysical Data available?.
How about 3D Geophysical Data?
Coverage of Seismic Data?
Can Seismic be used to define the opportunity, or has it been used?
D. What Other Field Data can aid Development of Opportunity
1. Surface Mapping
a. Geological
b. Geochemical data
c. Special Studies / Maps
2. Outcrop Samples
a.
b.
c.
d.
General description and classification
Petrographic thin sections, descriptions, and classifications
SEM studies
Chemical and mineralogical analyses
3. Source rock maturity analyses
a. Thermal maturation analyses
b. VR data
c. Basin modeling
i.
Basin modeling studies in 2D and 3D
ii. Maturation profiles
iii. Migration studies
4. Other Surface Samples
a. Groundwater samples and analyses
b. Surface seep samples and analyses
c. Geochemical surveys and analyses
5. Faults
6. Are there Analogs?
E. How rapidly can the Opportunity be Expanded or be closed if un-successful?
1. What are the project gates?
2.
F. What are the Project Economic Factors and Risks?
1.
2.
3.
4.
In Production?
In Costs?
In the reservoir?
Where Uncertainties exist will we need new data or can new processing be applied to
old data?
G. What are the storage and flow Risks from Petrophysical Analysis?
Page 4 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
1.
2.
3.
4.
Determination of full-field petrophysical cut-offs
Generate summations, log displays, and other reports
Interpretation of wireline formation testing results
Saturation Functions
a. Leverett “J” functions
b. Other fluid saturation parameters (Thomeer, etc.)
5. Determine fluid contacts
a.
b.
c.
d.
Free water level
Oil-water contact
Gas-oil contact
HPW, LKO, etc.
H. What are the Structural Framework Mapping Issues?
1. Seismic Interpretations
a. Attribute Analysis
2. Structure Mapping on Key Geologic Surfaces
3. Gross Reservoir Interval Isochore Mapping
4. Fault Interpretations
a. Fault Plane Mapping
b. Fault Cuts in Wells
c. Fault Displacement Analysis
5. Fold Geometries
a. SCAT Analysis
I. What are the Reservoir Zones Uncertainties?
1. Net Reservoir Isochore
2. Net:Gross Ratio Determination
3. Net Reservoir Petrophysical Properties
J. Fluid Properties Determination Uncertainties?
1. Reservoir Parameters
a. Oil and gas volume factors for volumetric reserves determination
i.
Boi and Sg
b. Recovery factors
i.
Variable by zone or facies?
K. What is the Quality of the Dynamic Data Pressure Survey Data?
1. Existing Pressure Data
a. Fault block isolation indication
i.
Tracer test results
b. Support for determination of fluid contacts
i.
Pressure profile analysis
c. Formation pressure testing results and analyses
2. Flowing Surveys
a. Tubing head pressure surveys
b. Bottomhole pressure surveys
3. Static Surveys
a. Tubing head pressure surveys
Page 5 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
b. Bottomhole pressure surveys
4. Productivity Index
5. Gas Well Surveys
a. Multi-rate test results and interpretations
6. Pressure Testing
a.
b.
c.
d.
e.
f.
Pressure Buildup Tests
Stimulation Activities
Drawdown Tests
Fall-off tests
Injectivity tests
Parting pressure tests
L. What is the Quality of the Multiphase Flow Properties?
1. Wettability studies
2. Capillary Pressure
a. Drainage capillary pressure
b. Imbibition capillary pressure
3. Relative Permeability
a.
b.
c.
d.
Water-oil relative permeability
Gas-oil relative permeability
Gas-condensate relative permeability
Relative permeability hysteresis
4. Residual saturations
a. Residual oil saturation
b. Residual gas saturation
M. What is the Quality of the Production, Pressure, and Secondary Product Data?
1. Production Data
a. PLT and Injection Log Visualization in 3D
b. Bubble Maps
i.
Compare historical production to simulation results and predictions
c. Vertical Lift Data
i.
Needed to calculate FTHP for simulation
2. Reservoir Allocation
a. Production allocation
b. Injection allocation
3. Decline curve analysis and interpretation
4. Map Displays
5.
6.
7.
8.
a.
b.
c.
d.
e.
EUR maps
Drainage radius maps
Cumulative fluids maps
Field status maps
Water and/or gas advance maps (time-dependent)
Interval tests and workovers
Volumetric average pressure data
Reservoir surveillance sections
Mechanical status review
Page 6 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
N. Are other Engineering Data for Water or EOR Injection Available?
1. Well Patterns
a. Pattern Performance
b. Volumetrics
c. Injection/Flood design and performance appraisal
O. Fractured Reservoir Characterization
1. Fracture Identification
2. Fracture Origin
a. Determine stress field directions
3. Fracture Morphology
4. Fracture Characterization
a. Orientation
b. Density and intensity
c. Porosity and Permeability effects
5. Identify and map fractures from seismic attribute analysis where possible
6. Fracture Modeling
a. Construct DFN models
i.
Validate fracture permeability in DFN model
b. Calculate dual porosity and/or dual permeability model parameters
7. Fracture Stimulation Effects
P. Other Generalized Data?
1. Mobility Ratio of displacement process?
2. Vertical Equilibrium or no cross-flow and the following?
a. Sequence and Areal Distribution
i.
If there is any deviation from the stratigraphic sequence defined above, we will need to have
those exception defined.
b. Key Surfaces
i.
Any key surfaces (geophysical markers, unconformity surfaces, etc.) need to be identified.
c. Layering Constraints
d. Edge Effects
i.
How should erosional and non-depositional limits be handled (if any are present)?
3. Can k be derived from Petrophysical Data?
4. Miscellaneous Data
a. Boundary Conditions / Limits
i.
Are there geographic limits to the study area?
b. Contacts
i.
Oil-Water
ii.
1)
2)
Highest proven water
Lowest proven oil
1)
2)
Highest proven oil
Lowest proven gas
Gas-Oil
c. Special Data
5. Geostatistical Evaluation
a. Data analysis and quality control
Page 7 of 8
Opportunities in Oil and Gas Fields
Questions
February 9, 2016
i.
Use geostatistical tools to evaluate data quality, screen unrealistic data outliers, isolate
individual wells that have spurious data, etc.
b. Variogram analysis
i.
Use facies distribution summary to build variograms for each facies type
6. Property Distribution
a.
b.
c.
d.
Porosity
Permeability
Fluid Saturations
Facies Distribution
i.
Use SIS or object-modeling to distribute facies
e. Flow Zone Indicators
7. Volumetric Analysis
a. Determine petrophysical parameters to be used in volumetric reserves determination
b. Quality control
i.
Check for zero-volume or negative volume cells in grid
c. Determine original in-place volumes
i.
Gross reservoir volume
ii. Net reservoir volume
iii. Net hydrocarbon volume (OOIP and OGIP)
iv. Recoverable reserves (if recovery factors are available)
d. Monte Carlo Simulation
i.
Create multiple realizations to capture uncertainty in:
ii.
iii.
iv.
v.
1)
2)
3)
4)
Fluid contacts
Saturation profiles
Pore volume and pore distribution
Other uncertainty
Perforations, liners, open-hole completions
Recompletions
Plug-backs
Other
Page 8 of 8