Ensco rig mobilizing for Dorado well drilling

The Ensco 107 jack-up drilling rig has begun mobilization from Singapore to drill Quadrant Energy’s Dorado-1 well off Australia.

The Dorado-1 well is located within the WA-437-P exploration permit in the North-West Shelf of Australia. The equity interest holders are Quadrant Northwest (operator) with 80% interest and Carnarvon Petroleum with the remaining 20% interest.

According to Carnarvon’s statement on Monday, the rig is expected on location in mid-May 2018 with drilling anticipated to begin before the end of May.

Quadrant Energy signed a contract for the Ensco 107 rig to drill the Dorado-1 exploration well back in November 2017. Drilling of the well is expected to take around 60 days to complete and be at the top of the primary objective in around 35 days.

The primary objective of the Dorado-1 well is to assess the gas and liquids potential in the Caley member. The Dorado well is less than 20 kilometers from and updip of the successful Roc-1 and Roc-2 wells.

The Roc-2 well also tested the deliverability of the reservoir through a well test that achieved around 55 million scf/day of gas and an associated condensate rate of 3,000 barrels per day.

The Dorado structure at the Caley interval is estimated to contain a gross mean recoverable prospective resource of 545 Bscf of gas and 30 million barrels of associated condensate (125 million barrels of oil equivalent, gross, Pmean).

Carnarvon said that multiple secondary targets were identified by Carnarvon in the Crispin and Milne members and these would also be assessed by the Dorado-1 well.

The shale-filled Dorado canyon which incised into the Caley and Milne sediments creates a large trap geometry in the target levels, bounded to the west, south, and east. The company added that similar shale-filled canyon trap geometries proved very effective in a number of gas fields in the Gippsland Basin in Victoria.

Based on the results at Roc and Phoenix South, Carnarvon and Quadrant consider the Dorado prospect as a probable gas prospect with significant associated condensate.

“[…] it should be noted that this structure may contain a substantial oil accumulation. This is due to the known presence of oil-prone source-rocks in the section at Roc, and the possibility that gas at Roc has displaced the oil up dip into Dorado,” Carnarvon added.