Western Gas has secured acceptance by NOPSEMA of its Environment Plan to manage activities for the Sasanof-1 exploration well on the North West Shelf.
Sasanof is a 2U Prospective Resource of 7.2 Tcf gas and 176 Million bbls condensate (P501), located nearby the Giant Gas Fields of Scarborough and Io-Jansz in the Carnarvon Basin, with 32 per cent geological chance of success. The high case 3U Prospective Resource estimate is for 17.8 Tcf gas and 449 Million bbls condensate.
Drilling is scheduled to commence in March/April 2022 using the Valaris MS-1 semi-submersible rig, following its relocation from nearby activities on the North West Shelf. Drilling costs are estimated at US$20-25 million.
The Sasanof-1 exploration well is in permit WA-519-P in Commonwealth waters about 207 kilometres northwest of Onslow, Western Australia. Sasanof-1 will be a vertical well and drilled to a total depth of approximately 2500 metres in 1070 metres of water, providing a low cost, high impact exploration well in a known and proven hydrocarbon province.
Western Gas’ Executive Director Will Barker said Regulator approval of the Environment Plan for Sasanof is a major achievement for the Western Gas team.
“It reflects a collaborative and focused effort and gives us the confidence to progress through the final stages of Regulatory approvals and detailed planning for the well.”
The Sasanof Prospect covers an area of up to 400 km2 and is on trend and updip of Western Gas’ liquids rich, low C02 Mentorc Field.
Sasanof-1 will be Western Gas’ first well drilled from its extensive exploration portfolio surrounding the existing Equus Gas Project that contains a discovered resource of 2 Tcf and 42 MMbbl (2C Gaffney Cline2). The Equus Gas Project has a historic exploration drilling success rate of 88%, with 15 discoveries from 17 wells.
Western Gas received acceptance by NOPSEMA of the following related documents:
- Sasanof-1 Exploration Drilling Program Oil Pollution Emergency Plan (Document No. WG-EHS-PLN-003, Revision 3, dated 22 November 2021)
- Sasanof-1 Drilling Program Operational and Scientific Monitoring Plan (Document No. 21309-21-BISR-1, Rev0_211015, Revision 0, dated 15 October 2021)
- Sensitive Information for WA-519-P exploration activities (submitted to NOPSEMA 3 December 2021)
The Safety Case Revision and Well Operations Management Plan, submitted to NOPSEMA in early December 2021, are currently being assessed by NOPSEMA.