Japan's Mitsui has boosted its onshore exploration portfolio in Western Australia's Perth basin where it is developing the large Waitsia gas field.

Mitsui's subsidiary AWE agreed to acquire Norwest Energy’s 27.945% operator interest in Block EP413 for A$100,000 conditional upon completion, said Norwest.

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AWE will also pay for all costs and assume liabilities associated with Norwest's interest in the permit, effective from 23 February 2021.

The permit contains the Beharra North oil lead, which Norwest said recently could be de-risked if Metgasco's planned Cervantes-1 oil exploration well is a success.

Metgasco said in its latest quarterly that it is hoping to drill the Cervantes-1 well in the third quarter this year in Block L14, immediately to the north of EP413.

Meanwhile, the stage two development of the Waitsia gas field - one of the largest ever discovered onshore Western Australia - progressed into the engineering, procurement and construction phase earlier this year.

Site construction is planned to begin in the first half of 2022.

The phase two project is designed to produce 250 terajoules (235 million cubic feet) per day of gas.