Empyrean Energy to develop Topaz, offshore China

June 10, 2022
Empyrean Energy PLC will enter the second phase of exploration and drill the Topaz prospect, PLC Block 29/11 permit, based on success of the Jade exploration well within Pearl River Mouth basin, offshore China.

Empyrean Energy PLC will enter the second phase of exploration and drill the Topaz prospect, PLC Block 29/11 permit, based on success of the Jade exploration well within Pearl River Mouth basin, offshore China.

The drilling objective for Jade was to test for hydrocarbons down to 2,860-m TD (OGJ Online, Apr. 11, 2022).

Comprehensive post-well analysis from Empyrean and China National Offshore Oil Co. (CNOOC) geochemical and basin modelling experts confirmed the Jade well carbonate reservoir parameters are better than pre-drill estimates with total thickness of 292 m and porosity in the range of 25 to 27%. In addition, the Jade well penetrated thick and effective regional seal facies and reservoir top was encountered within the depth conversion range. These parameters can now be more confidently mapped across Empyrean's 3D data set. Reservoir, seal, and trap validity of the Topaz prospect has been enhanced by the Jade well data.

Topaz has the potential for oil charge from two kitchen-source rocks. The recently identified Baiyun North Sag and Baiyun East Sag have been bio-marked as the proven source rock for CNOOC light-oil discoveries to the immediate West of Block 29/11.

Baiyun North Sag is within Block 29/11, immediately south and down dip of the Topaz prospect, and has all three key elements required for successful oil migration. It is a deep sag that is in the timing and depth window for oil generation, and Empyrean has identified a suitable deep fault for efficient vertical migration that reactivated at the peak time of oil expulsion about 10 million years ago. A thick carrier bed exists for lateral migration to the Topaz prospect. This carrier bed has been confirmed during the drilling of the Jade well and is mapped on Empyrean's 3D data set.

Gas shows within the gas cloud zone in the overburden at the Jade well are now interpreted to have migrated from Baiyun North Sag via reactivation of a nearby fault, about 800 m away, rather than coming from basinal faults extending into Baiyun East Sag which is about 20 km away. The identification of this nearby fault that extends into the Baiyun North Sag is now the most likely explanation for the gas shows in the Jade well. This interpretation enhances the prospects of Baiyun North Sag as a potentially valid additional source rock and, in turn, the likelihood of the Topaz prospect having access to two mature source rock-kitchens.

Additionally, a CNOOC regional migration map indicates that Topaz has potential for being charged from the proven Baiyun East Sag via spill from CNOOC discovery well LH 23-1d.

Empyrean is operator of Block 29/11 and has 100% working interest during the exploration phase. In the event of a commercial discovery, partner CNOOC may assume 51% participating interest in the development and production phase. The second phase of exploration requires payment to CNOOC of $250,000 with work obligation to drill an exploration well within 2 years.

About the Author

Alex Procyk | Upstream Editor

Alex Procyk is Upstream Editor at Oil & Gas Journal. He has also served as a principal technical professional at Halliburton and as a completion engineer at ConocoPhillips. He holds a BS in chemistry (1987) from Kent State University and a PhD in chemistry (1992) from Carnegie Mellon University. He is a member of the Society of Petroleum Engineers (SPE).