Publications

Rahayu field was discovered in 1973 and it is a three-way closure anticline bounded by thrust fault bearing NW-SE at the west. The hanging wall is the only oil productive block with area coverage of 5x3 km and consists of 129 producers and 24 peripheral injectors. The main oil production comes from the Sierra group formation that consists of 3 main reservoirs, A, B and C. The A reservoir is subdivided into A1950 sand, A2020 sand, and A2050 sand. The B reservoir is subdivided into B2250 sand. The C reservoir is subdivided into C2420R, C2420S, C2420T, and C2420U. Those reservoirs are deposited in the Early Miocene age in an estuary environment setting. The reservoir depth ranges from 1900-2800 feet. Since 1997 enhanced waterflood method was started to improve oil recovery by converting producer well at the flank structure into injector wells. Those peripheral injectors surround the Rahayu field, even near the main thrust fault, in order to maintain reservoir pressure and also fluid displacement. Rahayu field is considered as a matured waterflood field and it needs alignment between peripheral injector-to-producer to make sure that the water is injected to the right reservoir. The main concern for this study is for all injectors that located along the thrust fault boundary. The main focus of this study was to make a robust interpretation for thrust fault outline and the subsurface location of injector and producer well trajectory along the fault surface.