The two appraisal wells, Cash-2 and Maple-2, would be drilled in AC/RL7 where a possible floating liquefied natural gas project has been flagged, to appraise the field and provide better definition of the hydrocarbon reserves.

Late last year, it was reported PTTEP would form a $US1 billion joint venture with Linde Group and SBM Offshore to develop an FLNG vessel for the Cash-Maple field.

Under the JV, Linde and SBM would provide technical design advice and study the FLNG project in detail while PTTEP would continue drilling for gas and assessing reserves.

In a submission to the federal Department of Environment, Water, Heritage and the Arts, PTTEP said the two wells would be drilled by Diamond Offshore's Ocean Patriot semi-submersible, beginning in April.

Cash-2 will be drilled 2.3 kilometres northeast of Cash-1 to target the northern part of a faulted anticlinal feature developed at the Jurassic-Triassic level.

The primary objective reservoir in Cash-2 is the Jurassic Montara and Plover formations.

Following Cash-2, the Maple-2 well will be drilled.

PTTEP said that wellsite had not yet been finalised, but the well was expected to encounter both gas and condensate.

No oil is expected to be found.

The two wells will be drilled to a depth of 4200 metres and are expected to take 45 days each.

PTTEP also said the drilling program would be managed in accordance with its health, safety and environmental policy and Diamond Offshore's HSE policy.

Earlier this month, PTTEP was given approval to keep its Australian licences following the release of an independent review of the company's Montara action plan, which found it had effectively responded to the issues raised in the Montara Commission of Inquiry report and set the company on the path to achieving industry standards for both good oil field practice and good governance.

Though the company has been allowed to keep its licences, it has been put "on notice" for 18 months to ensure all aspects of the plan are implemented.

PTTEP holds an 80% interest in AC/RL7 and is currently negotiating the purchase of Cue Energy's 20% stake.

Cue has previously said it expected the sale to be finalised in the first quarter.

AC/RL7 lies about 700km west of Darwin and 200km southwest of the Bayu-Undan field.

Meanwhile, Calgary-based Bengal Energy has announced PTTEP is planning to drill an exploration well in AC/P24 of the Timor Sea in the second quarter.

The well would be drilled to a depth of 1650m at the Kingtree location (formally referred to as the Marshall Withers location) which lies on trend with the Challis-Cassini oil field.

Bengal said the location was defined on multiple 3D and 2D seismic data, and sat east of the original Katandra oil discovery.

If successful, Bengal believes it could potentially enable the joint development of both fields.

PTTEP is operator of AC/P24 with a 60% interest while Bengal holds 10%. Nippon Oil has the remaining 30%.