Publications

Nurbani is one of the most unique carbonate fields located in the shallow western flank of Sunda Basin, a part of CNOOC SES block. Hydrocarbon accumulation represents the shallowest oil in the basin and this field was selected due to heavy oil with viscous crude of average 15º API. The hydrocarbon accumulations have been delineated by eight (8) exploration wells, the first drilled on 1983, when a thick carbonate reservoir from Baturaja – Gumai Formation (Miocene) was discovered. The drill stem test (DST) ranged from 150 – 1370 BOPD and permeability from the wells ranged between 450 – 16.320 mD. Nurbani field development was initially planned to function in two phases. The Initial phase started with two wells drilled: Nurbani Alpha and Bravo. The Second phase will be conducted if the result of the first phase is promising for comprehensive field development. The two development wells were drilled in 2003 with unfavorable results. Nurbani Alpha as a vertical well, drilled near Nurbani-08, which has DST result 1370 BOPD. In fact, Nurbani Alpha total fluid production collected less than 200 barrels with a trace of water. Nurbani Bravo drilled horizontally and successfully penetrated oil zone. However, during 3 the days’ testing period, 100 % of this well’s yield was gas. This paper focuses on the fluid contact differentiation, reviews the unfavorable result of development wells using a 3D model, and proposes a proper production method to optimize heavy oil production performance in upcoming time.