Application of EOS to Optimize the Design of an Early Production Scheme of an Onshore Oil Field in Abu Dhabi

This study is aimed at optimizing the design of surface facilities of an early production scheme for an onshore Abu Dhabi oil field. The current design of separation facilities is modular, and thus improvements in performance are possible with a better understanding of PVT properties of the oil produced. This is performed by optimizing the multistage separator process for the range of properties of oil processed by the facilities. This paper describes the characterization of the crude oil processed by the facility using the 3-parameter Peng-Robinson Equations of state to describe the phase behavior and fluid properties using reservoir fluid data and an analysis of production data. After characterizing the fluids from each production well in the reservoir, the streams are mixed and the overall characterization of the total reservoir crude oil is used to optimize the design of the current facilities. This overall characterization of the crude oil is checked and compared to field analysis from the current operating facility. Current production facilities consist of one production separator followed by a free water knockout tank. Results show that optimum separation requires a multi-stage scheme versus the two-stage scheme being used now. Up to 2-3% increase in oil volumes produced may be achieved by using an optimized 3-stage separator design consisting of high and medium pressure production separators followed by the free water knockout tank.