Tamboran Resources subsidiary Sweetpea also said it would take legal action to recover more than $40,000 per day from the station owner, cattle baron Rallen Australia, and any person that "aids" it if its fracking operations are delayed.

Traditional owners on Tuesday joined staff at Tanumbirini station, 735km southeast of Darwin, to "monitor" Sweetpea Petroleum's proposed work, which includes sinking bores and building roads.

They say they're safeguarding natural water supplies and sacred sites on the 5000 sq/km property in the Beetaloo Basin.

But in a legal letter sent to Rallen on Tuesday, Sweetpea said it has a legal right to access the station and it would be doing so from Wednesday.

"Sweetpea intends to take all reasonable precautions in ensuring that its intended access to Tanumbirini Station proceeds unhindered," the company said via its legal firm Squire Patton Boggs.

"Those precautions may include, but not be limited to, the engagement of relevant department officials and observers as well as security or law enforcement agents.

"We trust in those circumstances no one acting on behalf of Rallen, or at Rallen's behest, will act in any manner that is wrongful or without lawful foundation."

Sweetpea has an NT government issued approved access agreement to explore the property and previously gave notice to Rallen that it intended to enter it to start work on Wednesday.

Rallen opposes Sweetpea's plan, with director Pierre Langenhoven saying it was "unprecedented" for a gas exploration company to force its way onto a cattle station without the pastoralist's consent.

"Working side by side with traditional owners, we will act to protect the sacred sites, crucial water resources and land we care for together," he said.

Gudanji-Wambaya man Johnny Wilson said Sweetpea hadn't consulted traditional owners about its plans and "we are worried that this fracking will damage our sacred sites and pollute the water".

"Cattle is the backbone of our economy and provides food for us and all Territorians," the chair of Nurrdalinji Native Title Aboriginal Corporation said.

Native title holder Josephine John called on the NT's new chief minister, Natasha Fyles, to better protect the environment and ground water.

"We are a strong community, but fracking is killing our country and threatening our culture," the Nurrdalinji director said.

Tamboran said it would continue to defend its legal rights to explore the station.

"Tamboran Resources has been working closely with all stakeholders, including pastoral leaseholders and the Northern Land Council, in the preparation for our activities," a spokesman said.

The Beetaloo is one of a number of gas fields the previous Morrison government planned to develop to help boost the economy and secure Australia's energy supply.

It caused concern among many Territorians, who fear it could jeopardise efforts to meet the nations's emissions reduction target and contaminate groundwater in a series of linked aquifers.

The federal government granted Tamboran $7.5 million earlier this year under the program subsidising exploration. The company later failed to appear at a federal Senate inquiry into the funding program.

Rallen has six cattle stations with 70,000 head of cattle in the Beetaloo Basin. It's spent $200 million in the past four years developing the properties.

About 90 per cent of the NT's water supply comes from groundwater.

Australian Associated Press