Empyrean confident in ‘world-class carbonate reservoir’ in block off China

  • Exploration & Production
Block 29/11, Pearl River Basin, Offshore China; Source: Empyrean

Results from a seismic inversion analysis for Empyrean’s Jade and Topaz prospects, located in Block 29/11 in the Pearl River Mouth Basin, offshore China, gave Empyrean confidence it has a world-class carbonate reservoir with excellent porosity and permeability at both prospects.

Block 29/11 is a large block – 1806 square kilometres – located in the prolific Pearl River Mouth Basin, approximately 200km southeast of Hong Kong.

Empyrean is the operator with 100 per cent of the exploration rights of the permit during the exploration phase of the project. In the event of a commercial discovery, CNOOC will have a back in right to 51 per cent of the permit.

Empyrean Energy on Thursday announced the results of its seismic inversion project, designed to assess the reservoir quality and reservoir rock composition at its Jade and Topaz prospects at Block 29/11.

As previously reported, the company engaged China Offshore Services Limited (COSL) to carry out data processing and technical work for the seismic inversion project.

Following this, the company has undertaken a detailed analysis and assessment of the dataset.

‘Excellent quality carbonate reservoir’

The company on Thursday reported that comprehensive analysis of the seismic inversion data has now been completed, and validates the interpreted presence of excellent quality carbonate reservoir facies at both the Jade and Topaz prospects with porosities interpreted to be in a highly favourable range of 20-30 per cent.

The main aim of the seismic inversion project was comprehensive reservoir characterisation, with particular focus on the Jade and Topaz prospects, by combining existing well log data with 3D seismic data to generate an acoustic impedance dataset.

Analysis of this nature has been used to successfully interpret the physical rock properties of reservoirs globally – in particular lithology, porosity and thickness of reservoir.

In order to achieve the most comprehensive and robust result from the Seismic Inversion Project, the Company approached China National Offshore Oil Corporation (CNOOC) to gain access to the log data of a crucial well, LH-23-1-1d, located approximately 12 km southwest of the Jade prospect in a permit operated by CNOOC.

CNOOC agreed to provide the data, resulting in increased technical confidence in the results of the seismic inversion project. The LH-23-1-1d well intersected both carbonate and sandstone reservoirs with oil pay.

In order to combine well log data with the 3D seismic data, the company worked closely with the COSL team.

During this process, well data from the LH-23-1-1d well proved crucial in establishing the close relationship of impedance data extracted from the seismic data to the lithology, porosity and thickness of reservoir in existing wells.

Comprehensive and systematic analysis of the acoustic impedance dataset resulted in separating Zhujiang carbonate facies from the underlying Zhuhai sandstones facies.

In addition, the lateral distribution of high-quality carbonate reservoir has been mapped. This more detailed work validates the earlier interpretation from seismic thickness analysis and supports the interpreted presence of a thick carbonate reservoir with porosities in a range of 20-30 per cent at the Jade and Topaz prospects.

Empyrean CEO, Tom Kelly, stated: “The seismic inversion analysis has greatly enhanced our interpretation and gives us further confidence that we have a world-class carbonate reservoir with excellent porosity and permeability at both the Jade and Topaz prospects.

These prospects are technically ready to be drilled and we will work hard to ensure they feature in a recovering oil market. The excellent relationship and cooperation with COSL and CNOOC has once again been demonstrated by access to crucial well data”.

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