Billionaire Gina Rinehart is about to control most of Western Australia's new gas from 2030

Gina Rinehart has broken a deadlock that kept one of Western Australia's largest undeveloped gas fields in the ground for years, and the terms of the settlement tighten her grip on the state's future gas supply.

Hancock Energy will lend Strike Energy $30 million to develop West Erregulla, the Perth Basin field the two companies own equally, about 230 kilometres north of Perth. Strike's share of the gas will be processed through Belisama, the $850 million plant Hancock is building nearby. The loan requires consent from Macquarie, Strike's existing financier, which has separately extended a further $30 million.

Strike called it a major breakthrough. Its shares rose 9.5% to 12 cents.

The field had been stuck. Saul Kavonic, an analyst at MST Marquee, said years of misalignment between the two owners had left development going nowhere, and identified the asset as the most valuable in Strike's portfolio.

What changed was the people on the other side of the table. Two former Fortescue executives joined Strike's leadership two months ago, with Nev Power replacing John Poynton as chairman and Shelley Robertson taking over as chief executive from Peter Stokes. Kavonic said Robertson's arrival was decisive, describing a more constructive relationship with Hancock that finally moved things forward.

Power was explicit about the relationship. He said he had known Rinehart for many years and looked forward to working with her and the Hancock team.

The processing arrangement matters more than the loan. Belisama was approved by the Western Australian Planning Commission this month, after the Environmental Protection Authority passed it without assessment, and it was designed principally to handle the fields Hancock bought from Mineral Resources for $1.1 billion in 2024. It will produce up to 210 terajoules a day, run for 20 years and employ 40 people. Hancock has four years to substantially begin construction before the approval lapses.

Adding West Erregulla to that plant puts Rinehart on both sides of the field: co-owner of the gas and owner of the infrastructure that processes it.

Kavonic put the consequence plainly. Once Belisama is running, Hancock will control most of the uncontracted new gas volumes in Western Australia from 2030, making it the most influential gas supplier in the state.

The timing works in her favour. The state market is expected to tighten from the middle of 2029, which is when West Erregulla is scheduled to deliver first gas. Robertson said there were certainly customers out there and no shortage of people to talk to, and that she felt reasonably comfortable Strike would fill the ticket.

A final investment decision is targeted for the 2028 financial year. Analysts put the cost of developing the field at about $200 million.

Rinehart has been pushing the state and federal governments while she builds. She said on Monday that Hancock was ready to commit the capital needed for new Western Australian gas supply, but that projects of this scale need stable and sensible government policies that encourage investment. Hancock chief executive Garry Korte said extending the state's 20% cap on onshore gas exports beyond 2030 was crucial to underpinning further investment in high-risk exploration and drilling.

Those are not abstract requests. The Belisama investment decision had been targeted for the end of September and is now in doubt while Hancock waits to see how the federal government's gas reservation scheme will apply in Western Australia. The company has said that question needs resolving before it commits the full $850 million.

Rinehart is Australia's wealthiest person, and Hancock has been expanding its energy division as the group moves beyond iron ore.