Cooper Energy Ltd. reported March 25 that Jolly-1, the first of two deep wells targeting the Casterton formation within the Penola Trough of the onshore Otway Basin in South Australia, is being plugged and abandoned after cutting cores in the Casterton formation and Lower Sawpit shale and also identifying the potential for a new deep basin gas play in the Penola Trough.
Jolly-1 was drilled to a total depth of 13,208 feet (4,026 meters) in PEL 495 and recovered 87 feet (26.7 meters) of conventional core from the Lower Sawpit and 169 feet (51.7 meters) from the Casterton formation, which was the primary target of the well. Elevated mud gas readings were observed during the drilling of the well over a gross interval of 1,115 feet (340 meters) of the Lower Sawpit shale (from 11,253 feet to 12, 368 feeet, or 3,430 meters to 3,770 meters) which contains extensive sandstone intervals.
Exploration Manager Andrew Thomas said, “The presence of gas shows over an interval of approximately 1,115 feet (340 meters) in this well is very significant and indicates that a substantial deep basin gas play may be present in the Penola Trough. This represents an additional play for the joint venture to pursue in the Penola Trough and complements the potential associated with the Casterton formation. We are looking forward to evaluating both opportunities further with Bungaloo-1, the next well in the program.”
The rig will move to PRL 32 to drill Bungaloo-1 immediately after completing operations at Jolly-1. Bungaloo-1, located 8.6 miles (14 kilometers) northwest of Jolly-1, has a prognosed total depth of 12,063 feet (3,677 meters).
Bungaloo-1’s primary target is the Casterton formation and the Lower Sawpit shale is now a secondary objective. Conventional cores are programmed to be obtained from shales in the Casterton formation at Bungaloo-1 which, together with those recovered from Jolly-1, will be analyzed in the coming months for information on the distribution, maturity and characteristics of the Casterton formation in the Penola Trough.
Participating interests in the PEL 495 and PRL-32 are Cooper Energy, 30%, and operator Beach Energy, 70%.