Publications

Discoveries in the deepwater Kutei Basin, Miocene interval, such as Gendalo, Ranggas and Gehem, triggered focused exploration activity in the area. Subsequently, gas discoveries were made in the Pliocene interval of Jangkrik Complex such as the following: Jangkrik in 2009,Jangkrik NE in 2011 and the Merakes field in 2014. Detailed 3D Seismic interpretation and core description from Jangkrik, Jangkrik NE, and Merakes wells were used to describe the characteristics of the deepwater sedimentation in Kutei Basin. The Jangkrik & Jangkrik NE reservoirs are interpreted as channel complexes deposited in confined upper slope environment. Whereas the Merakes reservoir is described as a lower slope fan featuring channel-levee deposits affected by large-scale instability processes and subaqueous erosions resulting from cross-cutting relationship of submarine channels network. The reservoir body is cut by younger mud-filled channel erosion separating a feeder area, where the Merakes well was drilled, into the main fan area. In general terms, seven facies have been recognized from three Pliocene core samples: Facies A, B, C, D, E, F, & G. In the Jangkrik NE well core, the predominance of facies A, B, C and G is indicative of a more proximal depositional environment as compared to the other well cores. The abundance of facies G indicates segregation of coarse grained material over a short-distance and high energy mass transport on a steep slope. In the same upper slope environment, the Jangkrik well core is dominated by facies D, E and F which are more “mature” depositional facies. These are characterized by “cleaner” facies, with minimum amounts of conglomeratic elements, which indicate a more distal deposition compared to the Jangkrik NE well core. In the Merakes well core, facies C, D, and F are dominant, while facies G is minimum. Compared to the other two wells, the Merakes core sample shows the most "mature" sequence. It was deposited in the most distal environment where mud or siderite clasts are rarely found.