The US oiler last week filed a Supreme Court writ alleging Woodside had not lived up to its side of the agreement, it was reported this morning.

Last December Apache announced the $2.82 billion sale of its share of the Wheatstone LNG plant near Ashburton North and the associated Brunello and Julimar fields in the Carnarvon Basin to Woodside, along with its interest in the Kitimat LNG project in Canada and the associated Liard Basin gas fields in a separate transaction.

Apache claims that Woodside has refused to refund a number of cash calls in March that it paid during the period when ownership was being transferred to Woodside, and it believes should have been refunded under the sale and purchase agreement.

Neither party is talking publicly about the spat.

The rest of Apache's WA assets, including a promising upstream portfolio and the Devil Creek, Varanus Island and Macedon gas production assets, were part of a $2.1 billion sale to a consortium of Macquarie Capital Group and Brookfield Asset Management that formed Quadrant Energy.

Quadrant, which is run day to day by Apache's former local management, is also involved in a tussle with Santos over the Spar joint venture.

Santos has lodged action in the Supreme Court complaining about Apache's operatorship, and claiming there were irregularities in the sale of the Apache Energy business unit to Quadrant's owners.

Santos says the pre-emption notices issued by Apache included a transaction value for Spar, and not a contemporary market value as stipulated by the joint operating agreement.

That set the price for Spar at a level that Santos complains deterred it from using its pre-emptive rights.

The court agreed, although the issue is still being finalised.