Developing Realistic Depletion Plan of Senoro Field using Coupled Reservoir - Surface Network Simulation

Abstract

Based on current approved development plan of Senoro gas field, the field will be produced at rate 300 MMSCFD (net) to fulfill the gas demand. Existing study based on black oil reservoir simulation conducted on developing depletion plan of Senoro Field give an unexpected result of plateau time which is only 11.7 years while the field has gas delivery contract for 13 years. This possibility of shortfall gas tends to risk the company to get a penalty as termed in the contract.Further analysis of the existing development plan also shows that the gas depletion plan is not yet optimal. It is indicated by the unbalance recovery factor between southern and northern reservoir area as it is shown by a significant difference of its reservoir pressure at the end of contract year. Furthermore, the design of production network planned for Senoro Field also indicating huge pressure losses will be encountered by the southern area wells.To solve the problem, a new study has been conducted to optimize the development plan. The method used in this study is dynamic coupling simulation by connecting reservoir simulation and surface network system into a single package of simulation run. This study has successfully optimized the Senoro field depletion plan to achieve the target 13 years of plateau time. Strategies used to achieve the target are by rescheduling well, utilizing pressure booster in southern area, installing gas compressor after 9th years of production, introducing horizontal well S-22hw to substitute well S-22, and reducing the number of well to 19 from the original plan of 21 wells.