As an upstream oil and gas company, AWE recognises our obligation to minimise the impact of our operations on the environment. AWE aims to ensure that our exploration and production activities are sustainable, and our approach to environmental management incorporates diverse locations and unique environmental conditions. We work hard to minimise our environmental footprint and adopt the highest standards of performance and protection of the environment including well decommissioning and site rehabilitation. A good example of this is the ongoing water monitoring that is undertaken at every stage of our operations in the Perth Basin.
Our operations are committed to recycling, minimising or eliminating waste generated at onshore and offshore sites, including drilling cuttings, hazardous, nonhazardous and general waste.
We are also committed to rehabilitating and restoring sites, as far as is practicable, to their original condition.
Well decommissioning involves the safe isolation and sealing of a well bore, the removal of the well head and the restoration of the well site back to its original land use. A well decommissioning program is under way in the north Perth Basin, and some new techniques to improve safety and efficiency have been successfully introduced.
A good example is the recent change to the technique used for cutting the well head, which is the last phase of well decommissioning and precedes rehabilitation. AWE now uses high pressure (45,000 psi) water/garnet jetting to cut the multiple layers of steel casing and cement just below the well head in a single operation, rather than the multi-stage cutting applied previously. The new technique is simple, takes less time and has reduced safety risks for employees and contractors.
The groundwater monitoring program at the Drover-1 exploration well in the Perth Basin, Western Australia, involved testing for 86 different analytes, sourced from four different locations. Out of a total of 344 tests, irregular readings were measured for methane at two locations.
Methane is non-toxic and non-poisonous and these results, while not harmful, were immediately reported to the regulatory authorities and the landowner. AWE then commissioned further testing and independent analysis of the results.
The independent analysis found that although methane readings at the two locations had increased:
The Department of Water subsequently confirmed that the levels of recorded methane posed no environmental or safety risk. The independent analysis confirmed that the methane was microbial and was not from naturally occurring reservoir gas or shale gas, and that the sources of the methane in the two wells were different. The elevated methane reading at the first location was consistent with the construction of a new water bore. At the second location, ongoing monitoring will confirm whether the methane levels have actually changed or whether the reading was a result of a testing anomaly. For a more information about Drover-1 groundwater monitoring, please go to: www.awemidwest.com.au/blog.
AWE’s Half Year 17 results: David Biggs, AWE’s CEO and Managing Director, discusses the company’s financial results, operating performance and outlook
Our strategy of building a portfolio of assets with diversity of product and geography provides us with a level of resilience and flexibility to manage change in volatile markets