Evaluation on reservoir development strategy-gas cap water injection and gas cap blow down

Abstract

How to get maximum hydrocarbon value from the reservoir without spending huge Capital Expenditure (CAPEX) such as new facilities or new wells has always been considered in managing a reservoir. This study evaluate of the scope of maximizing profit portfolio by Gas Cap Blowdown (GCBD) to recover optimum associated gas and Gas Cap Water Injection (GCWI) to increase the recovery of the unsweep oil underneath gas cap. Case study is East Bunga Kekwa reservoir in I-60 sand which located in PM3-CAA-B46 CN area in Malay Basin. Currently reservoir being develops by 3 Oil Producers and 2 Water Injector for pressure support and to increase sweep efficiency. However, effects of hysteresis have to consider for this studies. Therefore, history matching process by using drainage-imbibition curve have been conducted and managed to improve the matching of a few parameters such as bottomhole pressure, Gas Oil Ratio and Water Cut. The result of the studies predict that by conducting gas cap blowdown cases and concurrent gascap blowdown and gascap water injection cases may reduce the Oil recovery but increase Gas recovery as well as reducing the company gross income. On the other hand, by having Gas Cap Water Injection cases may increase both oil and gas recovery which on this studies showing the incremental of oil recovery factor from 22% to 23% and gas incremental of ~9bcf and total gross monetary incremental is 186.5mmusd as compare to do nothing case.