Abstract

Gas deliveries were started from the Offshore North West Java Sea (ONWJ) contract area to the domestic electricity generating facilities in Muara Karangand Tanjung Priok in September 1993. Unlike gas developments for the export market which are based on the exploitation of a single, large gas resource, the ONWJ gas developments consist of a large number of small, individual field developments, a complex pipeline delivery network, and a multitude of compression and gas processing facilities. The ONWJ contract area delivers two important products that are sold on the international market: crude oil and NGL's, and gas for the domestic market.

This paper addresses the strategic management of free gas reservoirs, associated gas reservoirs, and gas processing facilities to maximize recovery and to ensure adequate gas deliverability. A new, user-friendly, state-of-the-art, gas network simulation model running on IBM compatible PC was developed by ARCO to manage gas resources. The model merges a conventional gas field simulation model with a sophisticated tubing, pipeline-network, and facilities model to simulate the developments necessary for meeting the contractual gas sales and pressure requirements. The model has been used to optimize the field development schedule, anticipate the requirements of long lead-time facilities such as compressors, and evaluate the competitive benefits from alternative development and supply scenarios.

With fluctuations in crude oil and NGL prices, the model provides an extremely useful tool for planning the optimum sales strategy for maximizing revenue.