Geology & Geophysics

The two-month survey will be conducted early 2025. (Image source: Adobe Stock)

Shearwater Geoservices Holding AS has announced the award of a 4D seismic monitoring contract for the Jubilee field in Ghana, operated by Tullow Ghana Ltd

The two-month survey will be conducted early 2025, utilising capacity from Shearwater’s high-end fleet, supported by the company’s state-of-the-art technology offering and extensive operational experience. This will be the first contract conducted by Shearwater Ghana, in conjunction with local partner Destra Energy; and will include considerable local content participation.

Irene Basili, CEO of Shearwater says, “Our leading towed streamer technology is an ideal fit for the Jubilee field, enabling repeatable surveys to provide Tullow and partners with high-quality data in support of better-informed reservoir optimisation. We look forward to executing this project as part of our long-standing commitment to our clients in Ghana and West Africa.”

The agreement will allow TGS to manage and license more than 132,000 sq kms of seismic data, both 2D and 3D. (Image source: TGS)

By agreement, Tanzania’s Petroleum Upstream Regulatory Authority (PURA) has given energy data and intelligence company TGS full access to the region's extensive offshore subsurface data 

The agreement will allow TGS to manage and license more than 132,000 sq kms of seismic data, both 2D and 3D. 

Tanzania boasts strong play diversity, proven through exploration success across much of the stratigraphy, from Early Cretaceous to Miocene reservoirs. The comprehensive dataset comprises of regional seismic as well as well data, unlocking insights into the basin's evolution and structural history.

It will help identify hydrocarbon plays, allow for prospect-specific analysis, mapping of robust trapping configurations, and help understand the maturity and distribution of source rocks.

Besides exclusive rights to license all of Tanzania’s offshore mainland data, TGS is also free to acquire new seismic data and reprocess existing data. 

The company can support upcoming licensing rounds, which is expected to start next year. Tanzania is now ranked third in sub-Saharan Africa for future investment, anticipating 6% GDP growth by 2025, with million-dollar investments in infrastructure, and LNG, among other sectors. 

Attractive exploration target

David Hajovsky, EVP of multi-client at TGS, said, “Tanzania remains an attractive exploration target with its world-class gas fields and excellent sands proven across multiple source intervals. By providing access to high-quality seismic data ahead of potential future licensing activities, TGS will empower exploration and production companies to evaluate opportunities in this under-explored but highly promising region of East Africa.” 

TGS has also signed an agreement recently with the national oil company of Liberia (NOCAL) for data access expansion in the region. 

TGS plans to reprocess approximately 15,616 sq kms of legacy 3D seismic data in the Liberia Basin. (Image source: TGS)

Energy data and intelligence provider TGS has collaborated with the National Oil Company of Liberia (NOCAL) to expand data access offshore Liberia

TGS will work to rejuvenate the existing legacy 2D and 3D datasets in Liberia's prospective Liberia and Harper Basins, aspiring to reach high subsurface clarity. 

This will help build a unified velocity model in depth, utilising cutting-edge imaging algorithms to produce the final migrated seismic data, which can prove crucial for prospectivity studies in Liberia's offshores.

The company has initiated this campaign since 2022, after the Liberia Petroleum Regulatory Authority (LPRA), in cooperation with NOCAL, opened direct exploration licensing negotiations for all offshore blocks over the Harper and Liberia basins in 2021. An already reprocessed 2D legacy seismic of approximately 12,097 kms is available for industry licensing.

Benefitting exploration

"At TGS, we are proud of our longstanding and successful partnership with Liberia, which we believe presents considerable offshore hydrocarbon opportunities. This high-quality 2D seismic data will be essential in promoting future licensing rounds offshore Liberia under a direct negotiation approach. It also allows E&P companies to further evaluate exploration opportunities in an under-explored but proven petroleum system adjacent to prolific hydrocarbon provinces," said David Hajovsky, executive vice-president of global multi-client at TGS.

Since Liberia's Petroleum Law came into effect in 2019, investment conditions were relaxed and more time frame for exploration was allowed. The reprocessed products by TGS add to the exploration prospects in the region with its consistent, continuous data set of several vintages, providing uninterrupted seismic attributes of higher confidence at target levels across the entire margin.

TGS has now taken on to the second phase to reprocess an additional 12,675 line kms over the Liberia and Harper Basins, bringing the total to over 24,700 kms.

Additionally, the company plans to reprocess approximately 15,616 sq kms of legacy 3D seismic data in the Liberia Basin. 

A thorough geophysical scanning might have more to reveal from the historic wells drilled and operated on the Tobias field in KON-11. (Image source: Adobe Stock)

Exploration and production company Corcel PLC has noted the suspension of drilling and well testing activities in KON-11, with focus now shifting on collecting and studying geological and geophysical data from the area

This comes following multiple weeks of challenging well testing and engineering efforts that involved reactivation of the fractured carbonate reservoirchallenging well testing and engineering efforts that involved reactivation of the fractured carbonate reservoir, but with minimum yeild results. A thorough geophysical scanning of the region, however, might have more to reveal from the historic wells drilled and operated on the Tobias field in KON-11.

The block partners are hence considering subsurface conditions to understand the natural fracture system characteristics, trying to identify formation damage and residual issues with water inflow. 

Key commercial asset

Reaffirming Angola as a key commercial asset, Corcel executive chairman Antoine Karam said, "While initial results in Angola have not allowed immediate reactivation of the Tobias Field as originally hoped, the block partners are undertaking a detailed review of how to best utilise and exploit the two wells recently completed and further develop the full potential of the block. The company and its block partners believe KON-11 continues to offer significant developmental potential and that these early testing results are by no means a definitive outcome.

"Activities are accelerating at the company's operated block, KON-16, which we believe offers substantial upside and an attractive exploration risk/return profile.

"While the company continues to actively review new projects as part of the normal course of business, Corcel's interests in Angola remain key commercial assets for the company and we and our block partners believe that further development will add significant value to our respective businesses as our three blocks are advanced.

"Meanwhile, the company intends to host an investor event covering its current plans and strategy in the near term, with further details to be provided."

The company is positive about the identified potential of the Tobias reactivation effort, and KON-11 more broadly, remains significant, and that these early results will both usefully inform next steps and lead the block partners to ultimate commercial production in the block.

Activities at KON-16 during 2024 are expected to focus on G&G studies as well, including review of existing seismic data, a review of the historic Tuenza-1 well which had oil shows in the pre-salt level and associated petrophysical analysis. The immediate goal of these efforts is to prepare an updated prospect and lead table for consideration by the block partners.

The company believes that KON-16 offers sizeable upside in the form of 1,029 MMbo unrisked recoverable leads in the pre-salt, where the Tuenza-1 well (1960) was historically drilled on the block and oil and gas was found bleeding from the core in the Cuvo formation.