Real-Time Gas Lift Well Optimization Using Surface Read Out (SRO) System in Bunyu Field

Abstract

Gas lift optimization is required to sustain production in Bunyu Field. There are 35 gas lifted wells from total of 61 production wells, which contribute to2916 BOPD from the total production of 6000 BOPD or around 49% of the total production. The performance of these wells are pivotal to ensure production target is achieved. An optimum gas injection rate in each well is essential to maximize the oil production by reducing the Flowing Bottom Hole Pressure (FBHP). Previously, a conventional downhole Pressure – Temperature (P-T) gauge was used to record well response to gas lift injection rate variation to determine the optimum point. However, this method is considered time consuming since the adjustment to determine the optimum gas injection rate can only be done after the data has been downloaded and being analyzed . Thus, the measurement program should be repeated several times until the optimum gas injection rate is determined. This paper presents an approach to optimize the production of gas lifted well by selecting the optimum gas injection rate using a real-time downhole data monitoring system, called Surface Read Out (SRO). This system is used to evaluate the changes in the downhole pressure and temperature in a real-time. When the downhole P-T gauge reaches the perforation depth, a Multi-Rate Test (MRT) is carried out with variation in gas injection rate to find the optimum rate. Optimum gas injection rate is then determined based on the lowest FBHP observed and the highest production test result during the MRT. This optimization method has been proven effective to quickly increasing well production because gas injection rate adjustment can be done during the measurement program based on the real-time analysis. In addition, calibration of well performance model based on the actual Gas Lift Performance Curve (GLPC) of the MRT result can provide more accurate production forecast.