Empyrean eyes drilling ops for big prospect off China in 2024

AIM-listed oil and gas exploration company Empyrean Energy is setting the stage to drill a high-impact prospect next year in Block 29/11 located in the prolific Pearl River Mouth Basin, offshore China, approximately 200 km southeast of Hong Kong.

COSL-owned NH9 rig was used to spud the Jade prospect; Source: Nevsky Shipyard

Following the Jade well drilling program, comprehensive post-well analysis by Empyrean and CNOOC confirmed the Jade well-intersected carbonate reservoir with better parameters than pre-drill estimates with a total thickness of 292 m and porosity in the range of 25 to 27%. The AIM-listed player claims that the well failed due to a lack of access to effective migration pathways.

As the oil migration to the Topaz prospect has been identified as the key risk, the company’s pre-drill exploration efforts are focusing on mitigating this risk, with the reservoir, seal, and trap validity of the prospect enhanced by the Jade well data. Empyrean notes that the combination of 3D seismic data with the confirmed well data and post well analysis has resulted in the improved validity of the Topaz prospect as “a robust and large drilling target” with approximately 891 million barrels in place.

Currently, the company is conducting two further technical projects that capitalize on the 3D seismic acquired over the permit, shared regional 3D seismic that CNOOC has, and additional physical well data of both firms. These projects are designed to help address and mitigate the remaining primary geological risk at Topaz – oil migration into the Topaz trap.

Furthermore, Empyrean, together with CNOOC, is completing a regional oil migration study. The regional data includes temperature, pressure, the timing of oil maturation, and successful oil migration pathway mapping. The project will map oil migration from the proven source rock southwest of Block 29/11 that charges the four CNOOC oil discoveries, immediately west of Block 29/11 and Topaz, and extend this into Block 29/11 and map these migration pathways to Topaz.

Similar work will also be conducted from a new source/kitchen located entirely within Block 29/11 and oil migration pathways will be mapped to Topaz. According to Empyrean, this project is expected to be completed in the immediate future.

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In addition, the company is conducting a 3D simultaneous seismic inversion project focused on Topaz, utilizing the oil properties, reservoir temperature, reservoir pressure, and water salinity data from CNOOC oil discovery wells combined with reservoir porosity and mineralogical data from Empyrean well logs and core to maximize the effectiveness of the inversion project outcomes.

Moreover, Empyrean underlines that this project is being conducted in two phases. While the aim of Phase I is to assess whether an oil-bearing reservoir case can be distinguished from water water-bearing reservoir in the elastic property domain of seismic inversion, Phase 2 involves inverting the entire 3D seismic data and will generate several datasets for the elastic properties.

The company highlights that these datasets will be analyzed for high grading of the Topaz prospect while the 3D seismic inversion project is expected to be completed in the immediate future. During the exploration phase, Empyrean holds 100% interest in Block 29/11 in China and serves as the operator of the block. If a commercial discovery is made, its partner, CNOOC, may assume a 51% participating interest in the development and production phase.

Patrick Cross, Empyrean’s Non-Executive Chairman, commented: “In China, planning and further de-risking work is currently being finalized with the aim to ultimately drill the Topaz prospect in 2024. These activities, largely focused on oil migration into Topaz, are expected to be completed in the immediate future.”