The Reindeer Raw Gas Pipeline (RRGP) is part of the Devil Creek Development Project (DCDP), a greenfield project which recovers and processes gas reserves from the Reindeer Gas Field, located in WA-209-P, approximately 80 km northwest of the Port of Dampier, Western Australia.
The project is a joint venture between Apache Corporation and Santos; the Reindeer Gas Field is 55 per cent-owned by Apache as operator, with Santos holding the remaining 45 per cent interest.
The DCDP was first sanctioned in March 2008, however, it was deferred in December of the same year as a result of the global financial crisis. The project subsequently restarted with the signing of a gas sales agreement with the foundation gas customer, CITIC Pacific’s Sino Iron, in January 2009.
Piping Reindeer gasArticle continues below…
The RRGP transports gas from the normally unmanned Reindeer Wellhead Platform through a 105 km offshore and onshore pipeline which connects to the Devil Creek Gas Plant. The gas plant is in the immediate vicinity of the North West Coastal Highway (NWCH), approximately 10 km inland from Forty Mile Beach.
While the DCDP is initially providing up to 100 MMcf/d of dry natural gas and 80 kL/d of gas condensate, the facilities have been designed to process up to 200 MMcf/d of gas and 160 kL/d of condensate. After the raw natural gas has been processed at the Devil Creek Gas Plant, it will be delivered to the Dampier to Bunbury Natural Gas Pipeline (DBNGP). The gas condensate will be exported south from the project area via heavy haulage tankers along the NWCH and further south to Kwinana.
The 105 km, 406 mm diameter RRGP consists of three components:
- A 92 km offshore section, from the Reindeer Wellhead Platform to shore;
- A 2 km shore crossing at Gnoorea Point, Forty Mile Beach; and,
- An 11 km onshore section.
The pipeline was constructed from X65 pipe and has the capacity to transport 300 MMcf/d of gas.
A concrete-weight coating for on-bottom stability was applied to the entire offshore section and part of the onshore section, while the remainder was coated with three-layer polypropylene.
Liasing with the indigenous and beach communities
October 2007 saw the completion of a 12-month Aboriginal heritage site survey and recording program conducted by Apache within the DCDP area.
Devil Creek Production Manager Neil Fairweather says “Field survey work was undertaken by a team of archaeologists including ethnographic consultation with representatives from the two Aboriginal groups with a connection to the Devil Creek area, the Wong-goo-tt-oo and Yaburara Coastal Mardudhunera groups. A total of 54 discrete locations within the project area provided evidence of previous occupation by Aboriginal people.”
In early July 2009, Apache received consent from the WA Minister for Indigenous Affairs to use DCDP land areas lying to the north of the NWCH.
“Working in conjunction with the project archaeologist, Aboriginal heritage monitors commenced the collection and relocation of artefacts in accordance with an agreed management plan and in a manner consistent with the ministerial conditions,” says Apache Government and Public Affairs Manager David Parker.
“Within the 17 known Aboriginal heritage sites within the project area, in excess of 1,200 individual artefacts including grindstones, mullers, flakes and cores were collected and recorded during the salvage program.
“All artefacts have been returned to the local landscape at a location selected by senior members representing the traditional owners, the Wong-goo-tt-oo and Yaburara Coastal Mardudhunera people,” Mr Parker says.
In December 2007, Apache launched a survey for users of Forty Mile Beach, which was designed to provide the company with a better understanding of how many people used the area and what it was used for, in addition to gathering information on the community’s thoughts about the Devil Creek project.
“Based on feedback from the survey, Apache put in place a number of community benefit arrangements,” says Mr Parker. “These included the provision of funds to the Shire of Roebourne for the enhancement of recreational facilities at Forty Mile Beach, which is a popular camping area for seasonal travellers.”
A stakeholder consultation group was also formed for the duration of the project to provide updates and discuss key issues directly with the community.
Complex components in pipeline construction
Construction of the raw gas pipeline began in January 2010 with the commencement of work on the shore crossing at Gnoorea Point, which passes under the beach and associated boat ramp to avoid disrupting or compromising the recreational values of the area. Pipelaying works began in March 2010 and concluded on program in March 2011.
“All works were carried out under the Apache and contractors’ safety management systems,” says DCDP Project Manager Roger Lewis.
Mr Lewis says that the RRGP has three notable differences to other pipeline projects: the fact that it crossed the Pluto Pipeline, that the offshore section was laid in water depths ranging from 4–60 m, and that the horizontally directional drilled (HDD) shore crossing was used as a landfall in an environmentally sensitive area.
Pluto Pipeline crossing
The offshore section of the RRGP crosses over the Pluto Pipeline, approximately 70 km to the north of Gnoorea Point in 50 m water depth. The crossing works involved the installation of concrete support mattresses, trestles and a rock berm over the Pluto Pipeline.
The trestles were installed by TS Marine using the Havila Harmony vessel, while rock dumping was performed by the Jan de Nul/Van Oord joint venture using the Simon Stevin. This crossing began in March 2010 and was completed within a month.
The offshore section began construction in October 2010 and was finished in March 2011, with offshore pipelay carried out by SapuraAcergy using the Sapura 3000 installation vessel for the deepwater section, and the Leighton Stealth for the shallow water section. Pipe was laid at a rate of approximately 2 km per day, using the latest automated welding and pipelay techniques.
HDD shore crossing
The HDD program at the Gnoorea Point shore crossing allowed the gas pipeline to be buried approximately 20 m below the seabed, from just behind the shoreline to 1.85 km offshore.
The HDD method was selected because it minimised disturbance and impacts to the seabed and dunes at Gnoorea Point; it allowed unimpeded future public use of the access ramp at Gnoorea Point; and it allowed future use of the existing ‘Shore-Based Marine Facility’ for the purpose of launching offshore pipelines.
The HDD shore crossing was contracted to DrillTec, who began the crossing in January 2010 and completed it by August of the same year. The onshore section of the pipeline was contracted to Aibel, who was subcontracted by John Holland Group, and was under construction from January to May 2010.
Onshore environmental management
“During the environmental impact assessment for the project, injury or death of fauna from the installation of the 11 km onshore pipeline was identified as one of the highest environmental risks during DCDP construction,” says Mr Lewis.
To address this risk, Apache adopted management measures during the installation of the pipeline to reduce impacts to fauna, which included:
- Limiting the section of open trench to a maximum of 2.5 km at any one time;
- Providing fauna shelters, such as hessian sacks, and fauna ladders (material or wooden posts that animals can climb up) in the trench; and,
- Twice-daily inspections and removal of trapped animals by specialist fauna handlers.
Fauna removal from the onshore pipeline trench undertaken in February and March 2010 resulted in over 600 animals being rescued and released alive. 95 per cent of these animals were reptiles, including dragons, geckos, skinks, legless lizards and snakes.
First gas was delivered to the DBNGP in December 2011 and the gas plant was officially opened in February 2012.
Commenting on the significance of the DCDP at the gas plant’s official opening on 25 February, Apache Managing Director Tom Maher said “For more than 15 years, WA has relied on only two major facilities to supply domestic gas – the North West Shelf and Varanus Island. Now that Devil Creek is online, the state now has greater energy security with a third gas processing plant.”