Seismic data from the Angoche Basin

The following are some of the main data highlights coming from work in 2015 between the Mozambican National Petroleum Institute (INP) and Schlumberger (SLB), which comprises the acquisition of 15,000 square kilometres of broadband seismic data in the Angoche Basin. INP is Mozambique’s upstream hydrocarbon regulator.

The survey is optimally located to help oil and gas companies reveal the hydrocarbon potential offshore Angoche, especially with an upcoming licensing round. According to SLB, the survey provides a significant improvement in both data quality and coverage to highlight the prospectivity of the region and reduce risk in the exploration and development phases.

What does the data consist of?

  • 15,000 square kilometres of data acquired using IsoMetrix marine isometric seismic technology, providing true 3D broadband data;
  • Long-offset data with 8-kilometre streamer;
  • Final PSTM volume processed through modern broadband processing workflows, including adaptive deghosting (enhancing the low-frequency information in the data) and the application of adaptive subtraction within the 3D surface-related multiple elimination (SRME) aimed at areas of high-frequency diffracted multiples;
  • High-quality depth imaging of more than 2,500 square kilometres of seismic data using a combination of adaptive and least-squares full-waveform inversion and iterations of tomography updates; this accounted for the complexity of the overburden, including mass-transport flows, channels, and thin layers;
  • AVO products that demonstrate the value of broadband processing on angle-dependent amplitudes and derisk deepwater exploration;
  • 4,990 square kilometres of high-resolution shallow hazards cube: 2-ms sampling with 6.25-m × 12.5-m bins to functionally assess possible closures or spill points and better delineate fault planes;
  • Final migrated volumes now available for licensing, which shows enhanced seismic data quality.

Mozambique’s 6th Licensing Round

On November 24, 2021, the Mozambican Ministry of Mineral Resources and Energy (MIREME) launched the 6th Public License Round for the Concession of 16 Areas for Exploration and Production of Hydrocarbons, which ran for 12 months and comprised two phases namely:

The Prequalification phase, which was for a period of 4 months, from November 2021 to March 2022, aimed to determine the companies that meet the legal, financial, technical and safety, health and environment requirements, required under Appendices A and D; and

The Qualification phase, which was for a period of 8 months, from April 2022 to November 2022, due to the extension of the License Round period by another 3 months, from August 31 to August 11 November 2022, in response to the request submitted by potential bidders.

The objective of this phase was to determine which companies gathered the best technical terms (minimum work program), financial terms (gains for the state from an economic point of view, institutional support, social and human capital training), required under the terms of Appendices B and C.

Initial interest in Mozambique’s Angoche Basin

In November 2022, Mozambique’s National Oil Company (NOC), Empresa Nacional de Hidrocarbonetos (ENH), stated that both Eni and the China National Offshore Oil Corporation (CNOOC) had declared mutual interest in further development of the Mozambican oil and gas sector. The IOCs submitted proposals to explore areas under the 6th Licensing Round for the concession of areas for oil and gas exploration and production; Eni showed interest for the area A6-C, in Angoche, and CNOOC for the areas S6-A, A6-G, A6-D, S6-B and A6-E, located in Angoche and Save, respectively.

It should be noted that the 2 companies propose to form a partnership with Mozambique’s National Oil Company, distributing the participating interest as follows:

  1. A6-C – Eni operator (60%), and ENH partner (40%);
  2. S6-A – CNOOC operator (70%), and ENH partner (30%);
  3. A6-G – CNOOC operator (79.5%), and ENH partner (20.5%);
  4. A6-D – CNOOC operator (77.5%), and ENH partner (22.5%);
  5. S6-B – CNOOC operator (77.5%), and partner ENH (22.5%); and
  6. A6-E – CNOOC operator (80%), and partner ENH (20%).

Mozambique’s 6th Licensing Round results

After the aforementioned interest shown by both Eni and CNOOC, in November 2022 the IOCs were awarded 6 blocks (1 for Eni and 5 for CNOOC), based on the proposals submitted; no bids were made for 10 of the 16 offshore blocks that were offered during the 2021 launch of the licensing round.

Interestingly enough, these 16 blocks included 2 blocks in the Rovuma Basin, off the coast of the northern province of Cabo Delgado, which are adjacent to Areas 1 and 4, known to host over 100 trillion cubic feet of gas (proven).

INP highlighted that the work programmes proposed by Eni and CNOOC for the first period of exploration will allow investments of around USD $370 million, including the drilling of at least 4 wells.

Eni’s presence and the first well expected in the Angoche Basin

Additionally to Eni’s new A6-C Block in the Angoche Basin, the IOC is also present in 2 other blocks in the same basin.

In January 2021, Eni was set to drill the Raia-1 exploration well in Block A5-A in the Angoche Basin, which would be the first of the company’s 6 commitment wells in this Block. This Block is located just offshore Angoche in water depths between 300 and 1,800 metres. The Block consists of Eni (34%), Sasol (25.5%), Qatar Energy (25.5%), and ENH (15%).

Eni is also present in the A5-B Block to the south, with an equity of 10%, in water depths of 1,700 and 2,500 metres. Both of these Blocks were awarded in October 2018 during the country’s 5th Licensing Round.

If any of Eni’s commitment wells in A5-A are due to be drilled during the first expiration phase, the first well could be drilled before October 2023. This is exciting news, not only because it’s the first well in the Angoche Basin, but also because it will give IOCs a clearer picture of what to expect throughout the newly awarded offshore blocks, and continue to attract investment.

About the Author: Felipe Gaitán Michelsen