Application of Reservoir Management Techniques to the East Randolph Field, Portage County Ohio: Reservoir Engineering Study
Authors: Salamy S.P. , Young M.A. , Safley L.E. , Wing J.L. , Thomas J.B. 
Published: December 2007

The developed geologic model and the collected and analyzed data were used as the basis for a numerical reservoir simulation study to history match the production and pressure performance, and to predict the effect of different oil recovery techniques. A phased approach was utilized to simulate the study area by first performing a single well simulation to determine the sensitivity of the simulation results to various reservoir parameters. Results of the single well simulation and the developed geologic model were then used to model the performance of the full field. The field was simulated to examine the potential for infill drilling and an infill well was drilled and cored. The impact of waterflooding and gas repressurization were also evaluated.

Exploration in the Cambrian Rose Run Formation in Ohio resulted in the 1992 discovery of a prolific oil reservoir, the East Randolph field. In the last two and a half years the reservoir produced 450,000 STB and 1,200,000 MCF, and the average reservoir pressure declined from 3,100 psi to 2,200 psi.

Declining reservoir pressure, high producing GORs, and operational problems dictated the need for developing a comprehensive reservoir management strategy to improve the operational economics and optimize the oil recovery in the field. Under the Department of Energy Reservoir Management Demonstration Program, a team composed of professionals from Belden & Blake and BDM-Oklahoma was organized to study the potential for improving recovery through infill drilling, waterflooding, and gas repressurization.

Further development drilling has confirmed new reservoir limits, and volumetric and material balance analyses indicated potential OOIP exceeding 10 million barrels (compared to the original estimate of 4.4 million barrels). Based on core and log data, a three-layer geologic model was developed to describe the reservoir with the top layer primarily a gas producing zone and the bottom two layers as oil producing zones. Pressure buildup tests, PVT samples, and core relative permeability data were utilized to understand the fluid behavior and develop the reservoir model.

Program Objectives

BDM-Oklahoma, on behalf of DOE, solicited brief proposals to perform cooperative or cost shared research in developing and implementing reservoir management plans in pursuit of its goal of improving reservoir management understanding through demonstration and technology transfer. Three development projects submitted by small operators of oil reservoirs were selected on the basis of the regional significance of the projects, their potential for economic success, the demonstrated degree of problem identification, the availability and quality of data for addressing the key problem(s), the suggested approaches for solution, and the teaming arrangements suggested by the operators.

Once a project is selected, a multidisciplinary team develops a detailed joint work statement delineating the scope of the project, its individual subtasks, the schedule of proposed activities, the need for additional data collection, and the goals and responsibilities of team members. Regular meetings of teams and subteams make optimization of the ongoing work possible through modifications of work plans. Teams are composed of experienced engineers, geoscientists, and other professionals representing BDM-Oklahoma, local operators, service companies, research organizations, state surveys, etc.