In Q3 and Q4 2013, Woodside Energy Ltd (Woodside), on behalf of the North West Shelf Project participants, undertook the second and third stages of the Greater Western Flank Phase One (GWF-1) drilling (GDA01 and GDA02 development wells) and completions campaign in Commonwealth waters within Production Licence WA-5-L, located about 130 km northwest of Karratha in Western Australia.
The completions were conducted using the Atwood Oceanics Atwood Eagle, a semi-submersible mobile offshore drilling unit.
Prior to the commencement of the completions campaign, Woodside conducted an environmental risk assessment and then implemented a range of mitigation and management measures to ensure potential environmental risks, including the potential marine pollution resulting from loss of containment of chemicals or hydrocarbons, were appropriately addressed.
Scottech Fluid Treatment Unit
Woodside's strong commitment to positive environmental outcomes and the sustainable development of hydrocarbon resources required the use of the latest fluids treatment technology and systems during its drilling and completions campaign. Scottech Oilfield Services, leaders in fluids treatment technology, had worked with Woodside on a number of occasions, and were able to provide the services Woodside required.
When approached by Woodside to help with fluids treatment during GWF-1, Scottech were in the process of introducing to the Australian market a new piece of equipment used to treat fluids in the oil and gas industry.
Scottech's fluid treatment unit is a totally new solution, recently brought to Australia by OTS, Norway, the parent company of Scottech Oilfield Services. The Fluid Treatment Unit has been developed to meet the stringent requirements of the 'zero discharge' regulation in the Norwegian sector of the North Sea, where it has been widely used and proven. It is anticipated that this higher level of regulation will be introduced into Australia, which has led to interest in the waste water/slop oil treatment equipment by Australian Operators.
The fluid treatment units are setting world-best environmental practice and enabling a lower discharge level. This is providing cost savings through minimised logistics – including vessel tank cleaning and onshore treatment and reduced time.
The Fluids treatment unit is able to process oil-contaminated brines, seawater, surfactants, freshwater, and surface-generated water. The unit consists of a mechanical separation system, which generates three distinct waste streams: dried solids, oil, and water. Any recovered hydrocarbons are stored and the treated, clean water can be discharged, if allowed by local permits.
During the campaign, the fluids treatment unit treated approximately 13,000 bbl of fluids, resulting in an average of 5 – 25 ppm prior to discharge.
Woodside is now planning to retain the unit for use on-board the Atwood Eagle during their next two year campaign starting July 2014.