Western Gas on track with drilling programme on North West Shelf using Valaris rig

Stage set for Western Gas to drill ‘one of the most anticipated exploration wells’ in Australia

After confirming a rig slot to start mobilisation next month, Australia’s Western Gas has set all the wheels in motion to drill the Sasanof-1 high-impact exploration well on the North West Shelf.

Valaris MS-1 rig; Source: Valaris

Back in February 2022, Western Gas confirmed it had secured all necessary government approvals required to drill the Sasanof-1 well, following the acceptance of its proposed Well Operations Management Plan (WOMP). At the time, the firm explained the start of operations was expected in the second quarter of 2022.

This acceptance came on the heels of the approval of Western Gas’ Environment Plan and the Safety Case Revision for the use of the Valaris MS-1 semi-submersible drilling rig. The green light was granted by the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) in December 2021.

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In an update on Wednesday, Western Gas informed that the Valaris MS-1 rig would start mobilisation from the Port of Dampier to the Sasanof-1 well between 9 to 16 May 2022. The Australian player confirmed that its drilling programme was on track with all approvals secured, service and supply contracts awarded, and long lead time equipment now in Western Australia.

Will Barker, Executive Director at Western Gas, remarked: “With the rig mobilisation date confirmed, the stage is now set for one of the most anticipated exploration wells on the North West Shelf in many years. Success on the scale of the independent resource estimates would be a game-changer for Australia’s largest gas producing basin, adding a vital new and independent gas supply for domestic energy security and export volumes to meet increasing global LNG demand.”

The rig contract for MS-1 was executed with Valaris in November 2021 and the rig is expected to take approximately four days to reach the Sasanof-1 well, which is approximately 200 km northwest of Onslow, Western Australia. Afterwards, the rig and support vessels will start the laying of the anchor spread prior to the spudding of the exploration well.

Furthermore, the company says that onshore logistics preparations are now underway to ready equipment for the drilling campaign, with all long lead items acquired, key consumables ordered, and ready for delivery when required.

According to Western Gas, the well will be drilled vertically to a total depth of 2500 metres in 1070 metres of water while the drilling program is anticipated to take approximately 26 days from the date of rig mobilisation from Dampier port.

Covering an area of up to 400 km2, the Sasanof Prospect is estimated by ERCE to contain a 2U Prospective Resource of 7.2 Tcf gas and 176 Million bbls condensate (P50), with a high case 3U Prospective Resource estimate of 17.8 Tcf gas and 449 Million bbls condensate (P10).

This will be the company’s first well drilled from its exploration portfolio surrounding the existing Equus gas project with a discovered resource of 2 Tcf and 42 MMbbl and a historic exploration drilling success rate of 88 per cent with 15 discoveries from 17 wells.