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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
Modeling
a Fractured Reservoir for a Brown Field by Integrating
Geologic and Production Data
1 Schlumberger Logelco, Egypt. DCS-CS
2 Schlumberger DCS Denver
3 General Petroleum Company (GPC)
Ras Gharib field, located in the Gulf of Suez, Egypt, is a structurally complex field with a large number of faults and complex stratigraphy. Ras Gharib field has been producing since 1930s. The field operator has realized the need for a reservoir model to predict reservoir performance so as to optimize the recovery of the remaining reserve. Previously only limited reservoir characterization was performed, and the reservoir models that were built were unable to match the field production data despite significant modifications of petrophysical properties of the models. The field development plans couldn’t confidently rely on these models, as they didn’t have an adequate history match to the production data.
The factors that negatively affected the previous models were first screened. For
example, it was realized that the main producing unit of the reservoir is highly
fractured, and the fact that no fracture property was modeled in the previous
models significantly affected the mismatch to the production history data.
A new modeling
workflow was developed to improve the fracture characterization
of the reservoir with limited data. Faults were identified and faulting-induced
fractures were inferred from the fault patterns in the field. The descriptive faultpatterns
were further quantified and validated using the production data.
Because no image logs were available, production logs were used as feedback
to model the fracture properties. As drilling mud losses were recorded as a
qualitative indicator, a quantitative methodology based on an enhanced
geostatistical technique was developed to integrate them with the production
data and faulting-induced fracture properties.
As a result of using a highly integrated modeling
workflow that incorporates the
fracture characterization and property
modeling
, the reservoir model has shown
very good early history match to the field production data. This has helped
determining the remaining reserves, and is to be used for the next phase
development planning of the field.