It’s Not How You Start, But How You Complete That Counts!

Authors: Ray Johnson, Jnr. and Steve Scott

Date Published: June 2005

Number of Pages: 20

Reference Type: Magazine Article

Abstract:

Since its formation in 2000, Queensland Gas Company Limited (QGC) has been exploring the coal seam gas (CSG) resources of the Walloon Subgroup (SG) in the Surat Basin. Through this period, a great number of core and exploration wells were drilled to understand and define the gas resource size and potential commerciality.
Unfortunately, many early wells used completion techniques that limited the success of producing this reservoir. Whilst openhole completions were trialled early, they were met with limited success based on fines influx. Next, cased and cemented wells using hydraulic fracturing were attempted to stimulate the coals, reduce fines influx and increase gas production. These wells were ineffective and many experienced problematic wellbore failures, further hampering production optimisation. Finally, an openhole completion, under-reamed with a pre-perforated casing segment isolated from overlying cemented casing was trialled and achieved commercial success at flow rates representative of DST testing from earlier exploratory efforts. This paper describes the results of prior effotis and the improvements obtained from implementation of this new completion method.

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Tags: Qld