Integrated Economic Model for Evaluation and Optimization of Cyclic Steam Stimulation Projects

Abstract

Abstract The development of any hydrocarbon resource should be planned to maximize the net present value (NPV) of the asset to stakeholders, subject to any imposed constraints. For example, in the evaluation of a single oil or gas well on primary production, assuming no additional constraints, maximization of the NPV may be obtained by maximizing recoverable volume, production rate, and realized product price, while at the same time minimizing capital and operating costs, royalties, and taxes. Maximization of the NPV of a thermal heavy oil project is significantly more involved than that of a single oil or gas well on primary production. This is due to the complex interplay of individual well production and injection profiles with field level production and injection constraints imposed by the central processing facility (CPF). In addition, for thermal heavy oil recovery methods such as cyclic steam stimulation (CSS), the scheduling of the production, soak, and injection cycles of the wells has a significant impact on the overall project NPV. This paper presents the results of a study to maximize the NPV of a greenfield CSS project by incorporating a recently developed horizontal CSS analytical model with a new surface model and economic evaluation model developed specifically for this purpose. The integration of the sub-surface, surface, and economic models allows for the optimization of input parameters simultaneously across the models to maximize the NPV of the entire project. The overall workflow and resulting optimized case will be summarized and discussed. In addition, stochastic simulation concepts are applied to the model to produce a distribution of results based on various input parameters. Stochastic simulations are already used in unconventional gas evaluations, and the authors believe that they will become an important tool to assist in the evaluation of thermal heavy oil projects due to the significant upfront capital cost and uncertainties associated with such developments.