Geological Evaluation and Reservoir Characterization

• Field Development Studies - require an accurate determination of productive hydrocarbon pore volume. Computations of productive hydrocarbon pore volume vary depending on the recovery mechanisms such as (1) solution gas drive, (2) waterflooding, or (3) gas injection. Consequently, appropriate net pay cutoffs must be determined for the specific producing mechanism. Variations in the vertical and areal distribution of pore volume, permeability, and fluid saturation strongly affect fluid movement and hydrocarbon recovery under alternate development programs. In addition, geological zonation plays a crucial role in relative fluid movement through the reservoir. The identification, correlation, and mapping of these zones or flow units enhance the accuracy of reservoir prediction and frequently play an important role in selecting new drill sites for production or injection wells. Basic mapping can be done with either Petrel or GeoGraphix, while 3D earth models are constructed in Petrel.

• Petrophysical Analysis - involves the determination of rock properties including porosity and water saturation on a foot-by-foot basis. Petrophysical analysis integrates core measurements with old and new style open and cased hole log analysis to ensure that the most reliable estimates of hydrocarbon pore volume are computed. Complex petrophysical problems such as shaly sands and complex carbonate mineralogy are solved with the PETCOM PowerLog software.

• Core Interpretation - is a direct analysis of physically-measured rock properties including porosity, permeability, and fluid saturations. Special core analysis involves a determination of the interrelationship between pore structure, matrix wettability, saturations, and fluid flow. Reliable estimates of oil, gas, and water production depend on data from core tests such as gas/oil and oil/water relative permeability, capillary pressure, wettability, and residual oil saturation.

• Formation Evaluation Programs - provide for the appropriate laboratory core tests and field production and transient pressure tests which yield meaningful reservoir description data necessary for reliable production forecasts. These tests, when combined with the appropriate choices of open and cased hole logs, can provide data necessary to confidently characterize reservoir properties.

• Exploration and Evaluation Programs - utilize geologic and engineering data to define drilling prospects, establish appropriate risk factors, and estimate reserve potential. These evaluations integrate all relevant data including subsurface measurements, geophysical records, production data, pressure tests, fluid analysis, and environment of deposition.

• Basin Studies - are directed toward unraveling the stratigraphic and depositional complexities of specific reservoir trends. They typically include a description of the depositional system, definition and prediction of reservoir facies, diagenetic controls on reservoir quality, and insight into potential drilling and completion problems.

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