Reservoir Management Process

The reservoir management process is concerned with developing an oil field and establishing short-term and long-term production strategies that will recover the maximum amount of oil in the most economical method. The reservoir management process has three main phases.

Pre-Development Phase

Evaluation of the reservoir is accomplished by one of four methods: geophysics, drilling and core recovery, well testing and logging techniques. Here the tools required for formation evaluation during the pre-development phase are identified and the results interpreted. As more wells are drilled and supplemental data in the form of core analyses become available, the interpretations evolve into typically more complete solutions, which can be utilized with increased confidence.

Development Phase

At the reservoir development stage, down hole rock properties (porosity, permeability and initial fluid saturation) and fluid properties (viscosity, density and formation volume factor) from the few available wells are used to construct the initial model. Reservoir simulation mathematical models are constructed to investigate various development questions:

• How many wells are required and where should they be placed to sustain a desired production rate?
• What size and capabilities must the surface facilities have?
• How will the produced gas and water be handled? Is reservoir pressure support, in the form of water or gas injection, necessary?

Each of these questions has an obvious bearing on project economics. It is at this point that different field development scenarios are evaluated.

Operating Phase

When the field comes on-stream, there is actual performance data (pressure and production) with which to further calibrate the model. The understanding of rock and fluid behavior is an ever-evolving process that requires repeated model revisions. These calibrated simulation models are then used for updating the annual development strategy and to forecast performance.