Coal Seam Gas Field Management: Well Performance and Production Forecasting During Shutdown and Recovery Operations

Abstract

This paper presents the results of a study into the post-shutdown recovery behaviour of coal seam gas (CSG) wells and its application to estimating long-term field turndown capacity incorporating the impact of well performance recovery postshutdown. Queensland, Australia is currently host to a number of CSG to liquefied natural gas (LNG) projects under development. These projects aim to develop Queensland's vast CSG resources to supply domestic and international gas markets. However, the need to build field deliverability prior to the availability of export gas markets presents a significant challenge. CSG wells must be dewatered while gas production may be constrained. The ability to manage and forecast production performance in field turndown scenario is therefore critical. A study of production data from CSG production interruption events was conducted to determine how wells reacted to turndown of gas production rates. The study considered various production management strategies including partial choking and complete shut in of selected producers. Implications of the work include identification of criteria for selecting wells that are suitable for long-term turndown, the formulation of operational guidelines for minimising adverse post-shutdown production impacts, and estimation of long-term field turndown capacity through the application of the study results to a field production model.