EXPLORATION IN WEST JAVA: PLAY CONCEPTS IN THE PAST, PRESENT AND FUTURE, EFFORTS TO MAINTAIN RESERVES GROWTH

摘要

Hydrocarbon exploration activities in the West Java Province have been active since the period prior to Indonesian Independence. Play concepts both conventional and unconventional have been applied. It is considered that these concepts can be classified in to 5 stages.rnThe first stage involved the play concept that was based on oil seepages and surface mapping. This concept has been applied since 1871 and early exploration drilling was conducted in areas which had oil seepages in the surrounding area. Futhermore this concept was supplemented by surface mapping to identify geologic structure.rnThe second stage play concept was associated with the identification of the High Trend. This concept has been applied since about 1960 when Pertamina first started to operate in the West Java region. Exploration was focussed on the identification of prospect located on High Trends. This approach was successfully in discovering several fields i.e. Jatibarang, Cemara, Kandanghaur, Tugu, Cilamaya, Pamanukan and Gantar.rnThe third stage was the development of the play concept of prospects created as a result of a Thrust Fault System. This concept has been applied since about 1980 and has been utilised to focus on identification of prospects generated by compressional. Fields discovered using this play concept included Pasirjadi, Subang, Jatirarangon and Cicauh.rnThe fourth stage involved the concept of the Basin Deep or Sub-Basin. Exploration was focussed on the identification of prospects on Sub-Basin. The concept is to identify clastic reservoirs whoch were deposited within a rift system in the basin deep or sub-basin. This concept have been applied since about 1995. Some wells discovered were Wanajaya-1, Melandong-1, Tb.Kelapa-1 and Karangbaru-1.rnThe fifth stage is the play concept of the Present and the Future. For the future exploration play concept are adjusted to more fully understand the geologic features and petroleum systems are more comprehensive and detailed, and also use modern appropriate technologies. All of the above concepts are compiled, analyzed and combined, to search for opportunities for both conventional and unconventional exploration play concepts aimed at finding oil and gas reserves. Exploration targets are not only in new prospects but also in brown fields. Therefore, by application of these concepts it will bernpossible to maintain reserves growth in West Java.