Western Gas has executed the formal contract with Valaris for the MS-1 semi-submersible rig to drill the Sasanof-1 exploration well in WA-519-P. 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.