Simple methodology predicts optimum pressures of multistage separators

To achieve good separation between gas and liquid mixtures from the crude oil production system and to maximize hydrocarbon liquid recovery, it is necessary to use several separation processes at decreasing pressures and to adjust the pressure set points to improve product separation and recovery at minimum cost. This study presents a simple methodology for optimizing separator pressures in the crude oil production unit. The new proposed methodology determines the optimum pressures of separators in different stages of separation and, consequently, optimizes the operating conditions. In this study, the optimum pressures of separators in a 3896 Kgmole/hr oil production unit were determined. As a result, the oil recovery was increased about 6 Kgmole/hr (80 bbl/day), and the quality of total produced oil was improved by 0.3 API.