Following the delineation and development of a field, the recovery of oil by cyclic steam stimulation and other thermal methods is controlled by actions taken at the surface. A number of operational variables effect the optimal management of steam stimulation programs. Generally these variables relate to the generation and allocation of steam for injection at production wells. Because the number of variables can be large, the management of steam stimulation programs is seen to require that solutions be found to constrained multivariate optimization problems.
In this paper, a novel and integrated approach is presented to the optimal management of cyclic stimulation programs. The approach combines the use of technologies to simulate the flow of steam in networks and wellbores with an industrially tested variant of the Successive Quadratic Programming algorithm (SQP) for process optimization. Examples are presented that illustrate the ability of the integrated approach to optimize the allocation of steam in distribution systems for which (1) the objective is to minimize the loss of thermal energy in surface piping and wellbore tubing, and (2) the objective is to increase the value of oil production that follows stimulation. Extensions of the approach to more realistic allocation problems are found (i) to require the inclusion of steam generation costs in the formulation of optimization problems, and (ii) to require the incorporation of mechanistic reservoir models for the stimulation of oil production by steam injection.