While proclaimed as Class A reserve in 1908 for its unique fauna, found nowhere on the mainland after the island was cut off around 8000 years ago, WAPET (now Chevron) has been actively exploring the island since the 1950s, and made the Barrow-1 gusher, in 1964.

WAPET, founded in 1952 as a joint venture between Caltex and Ampol, marked Australia's first ever (if small) oil flow at Rough Range and, after a decade of assessing the potential for oil on Barrow Island, struck black gold with its first well and that paved the way for commercial production in 1967.

The oil field is now mature, having produced most of its estimated 250 million barrels from more than 430 wells drilled, and the exploration focus since the 1970s has been the potential for big gas discoveries in the Carnarvon Basin around Barrow Island.

The first discovery was West Tryal Rocks-1, northwest of Barrow Island in 1973 and, in 1980 the Gorgon discovery was made.

West Tryal Rocks remains undeveloped, but Gorgon is now helping underpin the Gorgon LNG project, which produced its first gas this week.

Forty years later exploration has resulted in more than 40 trillion cubic feet being found in the Greater Gorgon area, and the imposition of a three-train plant, but Chevron's role as a steward of the island's natural resources remains largely unchanged, although the rules are noticeably stricter than they were in the 1960s.

The initial field activities occurred well before the proclamation of environmental protection legislation in Australia, and WAPET had no model on which to base its management program, but it still managed to avoid the introduction of exotic plants and animals, so much so that the island's full suite of native species remains intact, and the conservation values of the nature reserve have been maintained.

Controversial decision

These days Chevron is in charge of quarantine and upholding the rigorous environmental program required to give the big US company its licence to operate on the island.

However, a straw poll of the public more than a decade ago - when the idea of piping the gas to an LNG plant on the otherwise nearly pristine island rather than bringing it to the mainland - would have found many against the idea, and incredulous that protecting the island during development was possible.

While the next 40-plus years of operations will tell if developments the size of Gorgon and nature can live side by side, a lot of ink and blood have been spilled getting to Gorgon to its first LNG cargo, for what has always been a challenging deep water project with high C02 contents of between 12-15%.

With the discovery of Gorgon and the giant Io-Jansz gas accumulation in 2000, thoughts turned to the best way to develop the gas, and at the time the Environmental Protection Authority opposed the use of Barrow Island as a gas hub, saying the risks to the biodiversity conservation values of Barrow Island were simply too great.

The WA Labor Party, under Geoff Gallop, had other ideas, much to the chagrin of WA Greens and other environmental groups such as the Conservation Commission of WA, who argued there was no sense in which other factors could balance out the environmental unacceptability of the initial Gorgon LNG proposal.

Over their protests, the Gorgon Gas Processing and Infrastructure Project Agreement was signed between the joint venturers and the state government in 2003, and ratified by the WA Parliament through the Barrow Island Act 2003.

By 2005 Chevron and its partners had calcified on using Barrow Island, having rejected other options such as a pipeline to the North West Shelf venture, a standalone mainland plant, and review of a 1990s plan for a North Rankin/Goodwyn style 6MMtpa LNG project.

Work starts

The Kellogg Joint Venture started engineering and design work on the downstream assets following the Gallop government's approval of an expanded footprint to disturb the reserve outside the existing area of the WA Oil assets.

At the time Chevron and its partners dreams were of selling gas into China, then the emerging, rapidly growing ‘dragon economy' that kicked off the last super-cycle, and the west coast of the US, which was in free panic that US gas would run out by the early 2010s.

The partners had even signed a 2003 Memorandum of Understanding for the supply of LNG to North America through an offshore LNG import terminal off the coast of the under construction Energia Costa Azul Baja Mexico, which would take 50% of Gorgon's output into the first LNG receiving terminal on the North American West Coast, and Shell's proposed LNG import terminal in Ensenada, west Mexico.

The joint venture was also aiming to sign what could be one of the biggest LNG deals in the industry's history with China National Offshore Oil Corporation, which would see the Chinese purchase a significant equity stake in the project, as well as buying significant volumes of LNG for delivery into China.

At the time Gorgon was envisaged as a 10 million tonne per annum project, sending gas to the US by 2010.

Obviously, that never happened.

Instead largest importer of liquefied natural gas, Japan, became the first customer to sign up for Gorgon gas purchasing 1.2MMtpa from Gorgon through major utility Tokyo Gas Company from 2010 over 25 years.

By 2007 the WA government had given its environmental approvals, the culmination in a four-year approvals process.

The WWF still expressed deep disappointment in the decision by then-federal environment minister Malcolm Turnbull to approve the Gorgon gas project on Barrow Island, arguing only the mainland makes sense.

The schedule slipped as Gorgon grew to three 5MMtpa trains with a budget tipped at $18 million, although by the time 2009 rolled around the budget had locked it at around $US32 billion, or around $A50 billion in the money of the day.

Chevron, which called Gorgon "the next Snowy River" and "a project whose time had come", was even talking about an expansion to five trains and 25MMtpa within the approved 300 hectare footprint.

Cost blowouts, schedule delays and the global financial crisis put pay to that idea, but with state and Commonwealth approvals giving the company a "highly conditional" okay - albeit with design changes such as moving gas flaring further inland and dimming the lighting to avoid upsetting the island's turtles - the three-train option moved ahead.

Turtles are dramatically disorientated by artificial light, which makes it harder for them to reach the sea quickly from their beach nests, so sodium vapour lights were also chosen.

With a $1 billion CO2 sequestration project approved by then-environment minister Peter Garrett and ExxonMobil signing what was described as Australia's largest ever trade agreement with PetroChina, $50 billion for a further 2.3MMtpa of Gorgon gas, beyond the 2MMtpa procured from Shell, the final investment decision was taken in 2009.

That happened in the US on September 14, roughly one month later, with an estimated spent of $A43 billion.

While the proposed fourth train had fallen out of favour by 2013, design work had increased throughput to 15.6MMtpa, and, struggling with the limitations of space, the JV asked for permission to disturb an extra 32 hectares (0.32sq.km) to the project's original 300 ha (3sq.km) footprint, primarily so it could increase its laydown area and debottleneck its operation.

A bitter debate saw the Barrow Island Amendment Bill 2013 pass the WA parliament.

By that time cost to build the project has increased from US$37 billion at sanction in 2009 to US$54 billion, and the schedule had slipped from early 2015 to mid-year.

It since slipped into early 2016.

Chevron has blamed the high Australian dollar, high wages, low productivity, weather delays and the logistical challenges of building a gas plant on the A-Class reserve at Barrow Island as the major

reasons for the delays and cost overruns.

With quarantine and accommodation headaches, someone probably crunched the numbers on taking the gas the 100-odd km further to near Onslow, where Chevron is developing the Ashburton North precinct for its Wheatstone two train development, but if those numbers have ever been calculated none of the JV partners are talking.