Publications

Pase field is located within the Pase Block in the onshore of North Sumatra Basin. Gas was discovered in 1983 by the Pase A-1 exploration well. The field has been producing from Tertiary sediment and pre-Tertiary basement fracture reservoir since 1998. The objective of this study is to examine the reservoir characteristic of pre-Tertiary basement fracture and its implication to production behaviors of the Pase field. Pase reservoir covers an area of 6.672 in acres and contains gas column in excess of 300 feet. The geology of the area is situated on the southwestern flank of the Lhok Sukon high where tectonic is strongly influences fracture occurrences. Reservoirs fracture were analyzed using wide range of data sets ranging from seismic, well and production test. Geocellular modeling is generated and incorporated with curvature surface to describe the relationship between the degree of curvature surface and fracture intensity. Reservoirs pore space occurs both in matrix and fractures which is predominantly with low porosity. Whereas, permeability is highly variable, higher in fracture but lower in matrix. Linier correlation has been observed among fracture intensity, porosity, permeability, and degree of curvature surface. The higher the curvature degree, the higher fracture intensity, and the better the porosity is. It is confirmed by the Pase A-1, Pase A-5 and Pase A-6ST2 well location. Those production wells situated near to the axis of fault related folding where the extensional fracture may possibly swarm. To date cumulative production up to190 BCF and continue flowing. The study reveals that the Tertiary sedimentary cover and the pre-Tertiary basement have been fractured where fracture deliver significant gas production. Production profile suggests that an initial steep decline derived from fracture production, while lesser decline may attribute to the matrix production. The successes of pre-Tertiary basement fractured reservoir have driven an insight of basement fracture potentiality within the Arun and Lhok Sukon high corridor.