Devil Creek Development Project (DCDP)

In early 2008, Apache Energy and its joint venture partner Santos announced the go-ahead for the Devil Creek development project (DCDP), a greenfield gas development about 40km southwest of Dampier in Western Australia.

The project, requiring an investment of about $900m, consists of an unmanned offshore gas production platform, an offshore gas supply pipeline, an onshore gas supply pipeline, a gas processing plant and a sales gas export pipeline.

In December 2011, Santos announced first gas production from the Reindeer field through the Devil Creek platform. The gas was delivered through the Dampier-to-Bunbury natural gas pipeline (DBNGP) for distribution.

Devil’s Creek platform specifics and location

The offshore platform sits in the Apache-operated Reindeer field, which was discovered in 1997 and lies 85km northwest of Dampier in permit WA-209-P. Apache has a 55% interest in the field, which has reserves quoted at more than 390bn cubic feet and an expected life of ten to 14 years.

In contrast, the DCDP is expected to have a life of 20 to 30 years, so although gas is initially being supplied by Reindeer, the project will have the capacity to tie in future prospective gas fields.

The platform is connected to the mainland by a 92km-long pipeline. Installation of the pipeline was completed in July 2011. From the shoreline crossing, which was created using horizontal direct drilling to minimise its environmental impact, an onshore 16in pipeline takes the raw gas another 11km to the Devil Creek gas plant, for processing to remove produced water, after which it is compressed and fed into the DBNGP.

The installation of the pipeline and horizontally directional drilled (HDD) shore crossing began in January 2010. By April 2010, rock dumping works were carried out at Reindeer and the trestles were installed. Installation of the platform was completed in February 2011.

Produced water is expected to be less than 500bpd in the first eight years, rising to 2,500bpd thereafter.

The produced water treatment and disposal system consists of two degassing vessels, two 200m³ storage tanks, plus two hydroclones and stripping column systems designed to handle about 10,000bwpd. The system’s evaporation ponds have a total capacity of about 100,000bwpd.

A second commercial product derived from the gas stream is gas condensate, which is stabilised, stored in two 20,000-barrel tanks and exported in 400-barrel tankers to Kwinana in metropolitan Perth.

Gas plant aspect of Australia’s Devil Creek development project (DCDP)

The gas plant itself consists of two gas processing trains to provide initially up to 100Mmscfd of dry natural gas and 80,000l a day of gas condensate, although the facilities are being designed to process up to 200Mmscfd and 160,000l a day of condensate.

The gas plant broke ground in September 2009. The civil works for the plant started in February 2010 and by June 2010, the process equipment modules shipped from Thailand were installed at the plant.

To meet construction requirements, a facility to accommodate 300 transient workers has been built. Gas plant operations require a variable permanent workforce of 20 to 30 people.

The original timeline for the project was to have included engineering and procurement, plus fabrication and assembly, to start in Q2 2009, followed by construction from mid-Q3 2009, then commissioning by Q3 2010 and first gas around Q4 2011. But in December 2008 the JV partners decided to defer the onshore and offshore aspects of the project because of the global downturn.

Consequently Apache Energy terminated several contracts but continued to progress the necessary regulatory approvals.

A month later, Apache announced a deal to supply about 154Bcf of gas from Reindeer over seven years to CITIC Pacific’s Sino Iron project in Western Australia, beginning in the second half of 2011, and the DCDP was reactivated. As a result the project schedule was revised, with the construction of the pipeline shore crossing that was originally scheduled for Q1 and Q2 2009 being deferred for about 12 months. Horizontal drilling of the shore crossing and tie-in with the onshore gas pipeline were completed in August 2010.

In November 2011, Santos signed a six year contract with Murrin Murrin Operations to supply 14.8PJ of gas for its Murrin Murrin nickel and cobalt project in Western Australia.

Contracts awarded by JV partners Apache Energy and Santos

In March 2009 Apache signed a $45m contract with Clough Projects Australia for the engineering, procurement and fabrication of the gas plant. The work included engineering, design works, procurement of all permanent materials and equipment, plus fabrication and assembly of all modules for the onshore facility.

Clough subcontracted Udhe to carry out the detailed design of the project. Leighton Stealth was contracted to provide installation and project management services for the 16in gas pipeline. Installation of the onshore pipeline of the project was carried out by Orion Pipeline Services.

John Holland was contracted to construct the non-process buildings of the gas plant including the warehouse, administration facilities and other utilities. The offshore pipeline and platform were installed by SapuraAcergy.

DrillTec and ARV carried out the drilling works for the installation of the offshore gas pipeline.