Western Gas has secured regulatory approval from NOPSEMA to drill the Sasanof-1 exploration well on the North West Shelf.
The environmental plan was accepted after Western Gas had submitted the following documents for scrutiny.
• 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 for the Sasanof-1 well and the Well Operations Management Plan (WOMP) were submitted to NOPSEMA in early December 2021 for assessment.
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 207km northwest of Onslow, Western Australia. Sasanof-1 will be a vertical well and drilled to a total depth of approximately 2500 m in 1070 m of water, providing a low cost, high impact exploration well in a known and proven hydrocarbon province.
The Sasanof Prospect is on trend and updip of the liquids rich, low CO₂ Mentorc Gas and Condensate Field and nearby the Giant Gas Fields of Scarborough and Io-Jansz in the Carnarvon Basin.
ERC Equipoise Ltd (ERCE) has determined Sasanof has an estimated 2U Prospective Resource of 7.2 Tcf gas and 176 Million bbls condensate (P50), with a 32% Chance of Success. The high case 3U Prospective Resource estimate is for 17.8 Tcf gas and 449 Million bbls condensate
Western Gas Executive Director Will Barker said of the latest development: “Regulator acceptance of the Environment Plan for Sasanof is a major achievement for the Western Gas team and our service providers, XODUS and AGR. 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.”
