10,323
edits
Changes
Jump to navigation
Jump to search
mLine 13:
Line 13: − + − + − + − | − Line 42:
Line 40: − + Line 84:
Line 82: − + − | − Line 94:
Line 90: − + Line 103:
Line 99: − + Line 132:
Line 128: − + Line 139:
Line 135: − + Line 169:
Line 165: + + Line 181:
Line 179: − + Line 190:
Line 188: − − [[file:evaluating-stratigraphically-complex-fields_fig1.png|thumb|{{figure number|1}}Example of electrofacies map showing distribution of SP log patterns. (From <ref name=pt06r35>Galloway, W. E., Cheng, E. S. S., 1985, Reservoir facies architecture in a microtidal barrier system—Frio Formation, Texas Gulf Coast: The University of Texas Bureau of Economic Geology, Report of Investigations, v. 144, 36 p.</ref>.)]] − * [[Monte carlo and stochastic simulation methods]] − + − * [[Geological cross sections]] − * [[Correlation and regression analysis]] − + − * [[Statistics overview]] Line 223:
Line 215: +
Stratigraphically complex fields (view source)
Revision as of 20:49, 19 January 2022
, 20:49, 19 January 2022added Category:Methods in Exploration 10 using HotCat
| isbn = 0891816607
| isbn = 0891816607
}}
}}
Stratigraphically complex fields are those that exhibit a high degree of vertical and lateral heterogeneity that is directly controlled by the environment of deposition (Table 1). This heterogeneity occurs at all scales (see [[Geological heterogeneities]]). It can result in a highly variable distribution of rock properties within one reservoir and the division of a single stratigraphic interval into multiple reservoirs that act as independent, self-contained compartments.
Stratigraphically complex fields are those that exhibit a high degree of vertical and [[lateral]] heterogeneity that is directly controlled by the environment of deposition (Table 1). This heterogeneity occurs at all scales (see [[Geological heterogeneities]]). It can result in a highly variable distribution of rock properties within one reservoir and the division of a single stratigraphic interval into multiple reservoirs that act as independent, self-contained compartments.
==Degree of hetrogeneity==
==Degree of hetrogeneity==
{| class = "wikitable"
{| class = "wikitable"
|-
|-
|+ {{table number|1}}Tentative, relative depositional heterogeneity ranking of reservoir facies based primarily on Texas petroleum fields
|+ {{table number|1}}Tentative, relative depositional heterogeneity ranking of reservoir facies based primarily on Texas [[petroleum]] fields
|-
|-
! Depositional Environment
! Depositional Environment
! Heterogeneity Rank
! Heterogeneity Rank
|-
|-
| ''' Siliciclastic Systems '''
| colspan=2 | ''' Siliciclastic Systems '''
|-
|-
| Submarine slope/fan/canyon fill, silty to muddy
| Submarine slope/fan/canyon fill, silty to muddy
| 8.0
| 8.0
|-
|-
| Fluvial or deltaic sandstone on carbonate shelf
| Fluvial or deltaic [[sandstone]] on carbonate shelf
| 8.0
| 8.0
|-
|-
| 2.0
| 2.0
|-
|-
| ''' Carbonate Systems '''
| colspan=2 | ''' Carbonate Systems '''
|-
|-
| Evaporitic flats (sabkhas)
| Evaporitic flats (sabkhas)
| 8.5
| 8.5
|-
|-
| Open shelves, extensive diagenesis
| Open shelves, extensive [[diagenesis]]
| 8.0
| 8.0
|-
|-
| 8.0
| 8.0
|-
|-
| Karstic unconformity zones
| Karstic [[unconformity]] zones
| 8.0
| 8.0
|-
|-
* Questionable correlation of depositional packages between wells
* Questionable correlation of depositional packages between wells
* Presence of numerous vertical [[permeability]] barriers at a variety of scales
* Presence of numerous vertical [[permeability]] barriers at a variety of scales
* Complex [[porosity]]-permeability and [[capillary pressure]] relationships (a broad scatter in the data indicates different lithofacies and pore types)
* Complex [[porosity]]-permeability and [[capillary pressure]] relationships (a broad scatter in the data indicates different [[lithofacies]] and pore types)
* Anomalous changes in pressure gradient
* Anomalous changes in pressure gradient
* Variable oil and water chemical composition
* Variable oil and water chemical composition
* Multiple [[fluid contacts]] at different structural elevations
* Multiple [[fluid contacts]] at different structural elevations
* Irregular reservoir distribution (such as a dry hole surrounded by producers)
* Irregular reservoir distribution (such as a [[dry hole]] surrounded by producers)
* Anomalous fluid relationships (such as a gas zone underlying an oil zone or an oil zone downdip of water)
* Anomalous fluid relationships (such as a gas zone underlying an oil zone or an oil zone downdip of water)
* Irregular and/or highly directional waterflood response
* Irregular and/or highly directional waterflood response
==Evaluation==
==Evaluation==
[[file:evaluating-stratigraphically-complex-fields_fig1.png|thumb|300px|{{figure number|1}}Example of electrofacies map showing distribution of SP log patterns. (From Galloway and Cheng.<ref name=pt06r35>Galloway, W. E., Cheng, E. S. S., 1985, Reservoir facies architecture in a microtidal barrier system—Frio Formation, Texas Gulf Coast: The University of Texas Bureau of Economic Geology, Report of Investigations, v. 144, 36 p.</ref>)]]
Recognition and three-dimensional characterization of reservoir heterogeneity in a stratigraphically complex field requires a well-by-well analysis of the following:
Recognition and three-dimensional characterization of reservoir heterogeneity in a stratigraphically complex field requires a well-by-well analysis of the following:
* Understand the basic regional and local geological setting.
* Understand the basic regional and local geological setting.
* Describe lithofacies and interpreted depositional environment(s) (see “Lithofacies and Environmental Analysis of Clastic Depositional Systems”).
* Describe lithofacies and interpreted depositional environment(s) (see [[Lithofacies and environmental analysis of clastic depositional systems]]).
* Determine the relationship between lithofacies/depositional environment and reservoir distribution and quality.
* Determine the relationship between lithofacies/depositional environment and reservoir distribution and quality.
* Determine reservoir distribution.
* Determine reservoir distribution.
* Use reservoir simulation model to manage field.
* Use reservoir simulation model to manage field.
* Refine reservoir description and calibrate reservoir simulation model.
* Refine reservoir description and calibrate reservoir simulation model.
==See also==
==See also==
* [[Introduction to geological methods]]
* [[Introduction to geological methods]]
* [[Lithofacies and environmental analysis of clastic depositional systems]]
* [[Lithofacies and environmental analysis of clastic depositional systems]]
* [[Subsurface maps]]
* [[Subsurface maps]]
* [[Flow units for reservoir characterization]]
* [[Flow units for reservoir characterization]]
* [[Effective pay determination]]
* [[Effective pay determination]]
* [[Multivariate data analysis]]
* [[Cross section]]
* [[Evaluating structurally complex reservoirs]]
* [[Evaluating structurally complex reservoirs]]
* [[Conversion of well log data to subsurface stratigraphic and structural information]]
* [[Conversion of well log data to subsurface stratigraphic and structural information]]
* [[Evaluating tight gas reservoirs]]
* [[Evaluating tight gas reservoirs]]
* [[Reservoir quality]]
* [[Reservoir quality]]
* [[Carbonate reservoir models: Facies, diagenesis, and flow characterization]]
* [[Carbonate reservoir models: facies, diagenesis, and flow characterization]]
* [[Fluid contacts]]
* [[Fluid contacts]]
* [[Geological heterogeneities]]
* [[Geological heterogeneities]]
* [[Evaluating fractured reservoirs]]
* [[Evaluating fractured reservoirs]]
* [[Evaluating diagenetically complex reservoirs]]
* [[Evaluating diagenetically complex reservoirs]]
==References==
==References==
[[Category:Geological methods]]
[[Category:Geological methods]]
[[Category:Methods in Exploration 10]]