Optimization of Production Units Alternatives Considering Pressure Drop and Nonlinear Constraints

Abstract

The exploration and production of oil fields involves multidisciplinary teams and has several decision variables. These variables can be optimized in order to maximize the profits of the operating company assisting the process of decision making regarding the development of the oil fields. The problem addressed in this paper is to optimize simultaneously the number, location and sizing of Production Units, considering technical and operational constraints and pressure drop during the simulation of production. To evaluate the pressure drop we used multiphase flow tables in order to obtain the required pressure curves. Each alternative of Production Unit has a different set of multiphase flow table in accordance with the distances between the wellheads and their Production Unit. The evaluation of each alternative of Production Units takes into account the union of the reservoir model with its respective fixed configuration of wells using gas-lift as lifting method. The optimization process uses Genetic Algorithms with the goal of maximizing the net present value (NPV) of a project evaluating possible alternatives of Production Unit through numerical reservoir simulation. A case study was conducted to demonstrate how the simultaneous optimization of the decision variables works. The optimization result shows that the alternative founded when was optimized the sizing of Production Units -besides the quantity and location -obtained a NPV higher than that obtained by the alternative resultant of the location and the quantity optimization of replicants Production Units.