Summary

In today's competitive economic climate, cost-effective production technology is required by producers of marginal petroleum reservoirs to survive and prosper. Field management based on reservoir characterization and simulation studies can assist the producer in efficient exploitation of hydrocarbon reserves. In the past reservoir simulation and management were restricted to large oil companies and to producing fields considered “core assets”. Today, PC-based reservoir simulation is economically and technically feasible for the small independent producer. The objective of the study is to demonstrate the use of modem and cost-effective tools for reservoir characterization and simulation in a typical mature oil field in Kansas. The Schaben Field, located in Ness County, Kansas, was chosen as part of a US Department of Energy Class 2 project. This field was discovered in 1963 and continues to produce oil from Mississippian dolostones and limestones.

Integrated reservoir characterization forms the foundation for the development of a descriptive reservoir model and provides the framework for simulation. The descriptive reservoir model integrates existing and newly acquired well data. Simulation input parameters were generated from the reservoir model and were used to simulate the reservoir performance from discovery to 1996. Regions with potential for incremental oil recovery were identified by the analysis of the reservoir performance and from the distribution of the remaining mobile oil in place. The simulator was used to predict the performance of potential infill wells drilled in these areas.

General application of PC-based simulators such as BOAST3 to large-scale or full-field simulation has been restricted by hardware and software limitations. Recent advances in the computational speed and memory capabilities have drastically reduced the simulation run time. The development of powerful and “user-friendly” spreadsheet, relational database, gridding and mapping software have provided the front and back-end tools to efficiently assemble and manipulate simulation input data and to generate useful maps and charts from the simulation output.

The Schaben field simulation study addresses a number of producibility problems in Meramecian and Osagian dolomite reservoirs of Kansas. Mississippian reservoirs are a major source of Kansas production and account for approximately 43% (21 MMbbls in 1994) of the state's annual oil production. Results from this study were used to design field management and future infill drilling plans in the Schaben field. It is hoped that this study will provide a model for improving field management of similar reservoirs in Kansas and in the Mid-continent.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas