BP West Java offshore operations include over 140 unmanned wellhead platforms which are frequently the sites of infill drilling and workovers using jack-up rigs. Although operational SIMOPS controls have been systematic for years, only recently has attention been directed towards the technical integrity of the platforms themselves. Most of the unmanned facilities are over twenty years old and of variable condition. Potentially severe consequences could result from a platform hydrocarbon leak during SIMOPS, made worse by the high density of drilling personnel working on site and in the rig offices and accommodations.
For this reason, a program was instituted to assure the technical integrity of unmanned wellhead platforms as a prerequisite for well SIMOPS. The work program includes thorough inspections of platform hydrocarbon pressure systems, including attached risers, as well secondary structures such as gratings, hand-rails and stairs, process safety protective and other critical electrical and instrument systems. When necessary, time consuming repairs must be executed before SIMOPS, but in some cases, mitigations are sufficient based on a risk-based rationale. The program has been a considerable challenge to implement due to the hectic pace of well operations, but has certainly reduced major accident risks associated with SIMOP activities and therefore resulted in a safer work environment.
The West Java oil and gas fields lie north of Indonesia's Java Island, in close vicinity to Jakarta. BP operates these fields as a production sharing contractor for the Indonesian people and their oversight agency BPMIGAS. Geographically, the extensive infrastructure of 218 offshore structures, 375 subsea pipelines and floating oil storage / export facilities occupies an area roughly 250 kms by 100 kms. A vast majority of the procution facilities are aged beyond 20 years, with many over 30 years old. Although production is modest at ~30 MBOD and ~300 MMSCFD, the gas in particular supplies about 25% of Jakarta's electric generation feed requirements and about 50% of industrial gas users in the area. The asset is therefore vital to Indonesia and its robust economy. General layout of the field is shown in Figure 1. About 140 of the West Java field structures consist of unmanned wellhead platforms on which over 900 oil and gas wells are located. These sites are frequently subject to wellwork and infill well drilling by contracted jack-up rigs. In recent years, 30–40 wells are worked and about 10 new wells drilled annually. Incremental production is critical to sustaining field life and in meeting oil and gas delivery commitments to customers and the nation.