LNG construction surges forward

10. the-wheatstone-platform-topsides-load-out-and-sail-away-were-completed-successfully-01By Emma Brown

July 6, 2015

ENERGY giant Chevron has operated in Australia’s oil and gas industry since 1952.

Today, Chevron is the largest holder of exploration permits across Australia – with a strong presence offshore northwest WA and in the Great Australian Bight –  and is positioning itself as one of the number one suppliers of Australian liquefied natural gas (LNG). With construction surging ahead at its   Gorgon and Wheatstone projects the company is ticking off major milestones in the development of Australian LNG.

Wheatstone Project

The Chevron-operated Wheatstone Project is one of Australia’s largest and most significant resources developments, set to play an important role in providing natural gas for the 21st century.

Construction began on the $37 billion Wheatstone Project, about 200kmnorth of Onslow in WA, in late 2011 and is now almost 60 per cent complete. The project is on track for completion in late 2016.

Once complete, Wheatstone will comprise an onshore facility at the Ashburton North Strategic Industrial Area west of Onslow; a 200 terajoule per day domestic gas plant; and two LNG trains with a combined processing capacity of 8.9 million tonnes per annum.

In May 2015, the Wheatstone Project reached an important milestone with the installation of the platform topsides at the offshore gas processing plant, 225km offshore from Ashburton North, near Barrow Island.

The achievement was one of the largest single integrated float-over installations in Chevron’s history.

Wheatstone Project platform manager Michael Watkins said in a promotional video that a lot of work had gone into ensuring the operation was a success.

“You’re dealing with one of the biggest platforms in the world; the engineering that goes into this has taken a couple of years at least, to get all of these plans together,” he said.

Mr Watkins said in preparation for the load-out, the 37,000t structure had to be jacked up 20m on four jacking towers.

“We lower off the topsides onto the deck support frame and then that combined structure will then be loaded out – a total weight of nearly 45,000 tonnes – on to the Hereema 851 vessel.”

Mr Watkins said the topsides were transported at full height to float above the legs of the steel gravity substructure (SGS).

Once it arrived in Australia the anchor and mooring patterns were set up around the SGS, and the barge was aligned and moved in on mooring lines between the SGS legs before being lowered off via ballasting of the barrage to its final location.

With the offshore gas processing plant now in place, the subsea equipment, including wellheads and subsea trees, is being installed.

Hook-up and commissioning activities are now underway at the site.

Construction on the rest of the project has progressed steadily through the year. Equipment and modules are being delivered and installed at the plant site; the roofs of LNG Tank 1 and Tank 2 have been raised; and construction of the two condensate storage tanks is underway.

The materials offloading facility is a hive of activity with the breakwater nearing completion and the 1.2kmproduct loading jetty is continuing to make headway.

Wheatstone is a joint venture between Chevron Australia (64.14 per cent), Kuwait Foreign Petroleum Exploration Company (13.4 per cent), Woodside Petroleum (13 per cent),  PE Wheatstone (8 per cent) and Kyushu Electric Power Company (1.46 per cent).

 Gorgon Project

The Chevron-operated Gorgon Project is more than 90 per cent complete and on schedule to deliver its first LNG in the next few months. LNG exports are expected to behin before the end of the year, and domestic gas will be delivered nto the market this year.

Based on Barrow Island, the Gorgon Project is one of the world’s largest natural gas projects and largest single-resource development in Australia.

The project will develop the Gorgon and Jansz-Io gas fields, between 130km and 220km offshore northwest WA ..

The completed project will include a three-train, 15.6mtpa LNG facility and a domestic gas plant with the capacity to supply 300TJ of gas per day to WA.

The project will also include facilities to inject and store carbon dioxide into a deep reservoir unit more than 2km beneath Barrow Island. The aim is to inject between 3.4 and 4 million tonnes of reservoir carbon dioxide each year, reducing greenhouse gas emissions from Gorgon by about 40 per cent.

The project aims to

It comprises of a LNG facility with three processing units, a domestic natural gas plant and a carbon dioxide injection project.

In May, 2015 the first of  five gas turbine generators (GTG) at Gorgon were commissioned.

“The Gorgon Project has achieved an important milestone with the successful start-up of the first GTG, a critical element in the gas plant start-up sequence,” Chevron Australia managing director Roy Krzywosinski said.

“This is a fantastic achievement for all those involved in this technical accomplishment.”

Gorgon development director Scott Young said domestic gas was introduced from the Dampier to Bunbury Natural Gas Pipeline via Gorgon’s domestic gas pipeline, and used for a number of commissioning activities such as starting-up the first gas turbine generators.

“The GTG will be used to provide power for commissioning activities and powering up of the process equipment in the utilities, monoethylene glycol and inlet areas,” Mr Young said.

“Over the past few months the teams onsite have been preparing for the introduction of hydrocarbons by conducting safety muster drills and erecting signage around key areas.

“With the plant now ‘live’ we will all continue to work to work together to ensure the project continues to be delivered safely.”

The enormous generators stand at eight-storeys high and weigh 2200t. Once all five GTGs are operational, they will provide up to 584 megawatts of electricity – a close equivalent to the capacity of the Kwinana Power Station in WA.

During its construction phase, the Gorgon Project has made a significant contribution to the Australian economy. More than $31 billion has been spent on Australian goods and services and 10,000 jobs have been created.

Gorgon is a joint venture between operator Chevron (47.3 per cent), ExxonMobil (25 per cent), Shell (25 per cent), Osaka Gas (1.25 per cent), Tokyo Gas (1 per cent) and Chubu Electric Power (0.417 per cent).

North West Shelf  

Even though Chevron’s major Australian LNG projects are still under construction, the company has a wealth of experience with LNG. It is an equal one-sixth foundation participant in the North West Shelf Venture (NWSV).

This project, on the Burrup Peninsula near the Port of Dampier in WA, was Australia’s first LNG project and has been operating for more than 30 years.

Today the project injects about $800 million annually into local businesses and produces LNG for industrial, commercial and domestic use.

Its operations comprise production from five major oil and gas fields and a number of smaller fields including the North Rankin, Goodwyn, Peresus, Angel and Echo Yodel natural gas fields and the Wanaea, Cossack, Lambert and Hermes crude oil fields. The facilities include three fixed offshore platforms, one floating production, storage and offtake vessel and Australia’s largest onshore gas processing facility.