Risk Analysis in the Determination of the Best Exploitation Strategy Using a Calibrated Reservoir-Simulation Model

Abstract

ABSTRACT This paper introduces a new perspective in reservoir exploitation strategy using risk analysis. In a recent paper1, Acosta introduced an integrated systematic approach to determine the best exploitation strategy from a calibrated deterministic reservoir simulation model. The methodology presented in this work is a step forward, since the deterministic methodology is now combined with stochastic reservoir modeling and economic risk analysis, to improve the decision making process under uncertainty. A few calibrated reservoir simulation models generated from reservoir characterization techniques, using probabilistic modeling, are used to represent less likely, most probable and optimistic scenarios. Acosta's technique1, 2 is then applied along with an economic evaluation risk analysis program, to determine the optimum exploitation scheme for each scenario. This new workflow allows the determination of the optimum number of additional wells, their grid locations, as well of assisting to define the most appropriate enhanced recovery process. Key portfolio planning input, such maximum gross rates, production and injection infrastructure requirements, Capex and Opex profiles, are the results from this integrated technical and economical optimization approach. Reservoir management and strategic decision making process are improved, since both technical and economical risk analyses are considered. The most valuable plan is obtained for all options, along with their overall related uncertainties. Managers, therefore, can select the best alternative for field development, together with an assessment of the key parameters and knowledge to be determined, in order to reduce the project risk.