ESS/EST Marginal Field Development in E-South Area, Offshore Northwest Java

Abstract

Abstract The south area of giant E field, Offshore Northwest Java, contains 5 proven structures: ESW, ESS, EST, ESP and ESR. Only the ESW structure was developed, while the other structures had not been developed by conventional methods due to marginal economics. Development of those marginal fields was accomplished with innovative methods applied by a multidisciplinary team. A three well platform, a cluster, was installed and a multilateral well with two targets in the ES-31 sand in the EST area was drilled through one of the conductors. A second well was drilled with Main/Massive and Talang Akar objectives, and the last well was drilled horizontally to the ES-31A sand in the ESS area. The multilateral well can provide considerable improvement to the total productivity index over the vertical wells and single-horizontal wells. In the presence of permeability barriers such as faults, the multilateral well can also reduce the risk of production uncertainty. The optimum horizontal length and number of branches were determined by balancing incremental production against the drilling and well completion cost. This project was the first application of multi-lateral technology for ARCO Indonesia. The successful application of multilateral techniques has provided an economic means to develop other marginal fields in Offshore North West Java in ARCO Indonesia.