Cost Effective Development of Remote Deepwater Northwest Australian Gas Fields

摘要

In the search for new gas reserves, exploration and production companies have acquired significant acreages in increasingly remote, deep water offshore Northwest Australia (NWA). Recent discoveries tend to be individually smaller accumulations, some with significant faulting and most with varied reservoir compositions, pressures and temperatures. The regional challenge posed is to achieve cost effective developments in these marginal environments. The paper will describe how results from recent development studies illustrate demonstrable relationships between functional design choices and facilities Total Installed Cost (TIC). Challenging these choices through the application of front end loading techniques allows the necessary balancing of competing development drivers to achieve a viable development. The observations and learnings associated with recent NWA studies, described in this paper, may be applied to remote, deepwater fields in other areas of the world. The results of the analytical work showed that demonstrable relationships can be developed between individual design choices and field facilities TIC. The cumulative effect of many design choices creates significant differences in overall estimated TIC. The major benefit of identifying these differences is to highlight the importance of the relationship between various technical and commercial development requirements and TIC. Understanding these relationships assists the field developer in making the appropriate choices required to achieve sanction for these marginal developments. Where complex geographical (remote, deepwater), geological (heterogeneous, distributed reserves) and technical (challenging flow assurance, high reliability) characteristics combine in development planning for gas fields, the result is regularly marginal or sub-economic. The results and observations above highlight the import conclusion that a successful marginal development requires the balancing of competing drivers. This understanding can be applied to add value to other developments, early in the conceptual design, where defining the facilities functional requirements has the greatest impact on the feasibility of a project.