Seismic technology

HIGH-CHANNEL-COUNT SURVEY FOR CLEARER IMAGING

In oil and gas, seismic survey is a crucial stage of seismic exploration. It is the key to analyse the potential of any prospective exploration area. Many international companies are investing heavily in Africa – to update and upgrade technological advancements at this crucial E&P stage.

IN MARCH 2021, seismic equipment and reservoir monitoring instruments manufacturer Sercel announced that its highperformance equipment is currently being deployed on another 3D megacrew survey in North Africa.

The crew is operating with an 80,000-channel 508XT land acquisition system, complete with QuietSeis digital sensors, and 10 Nomad 90 Neo broadband vibrators in challenging desert terrain. Combined with the superior seismic data performance of QuietSeis, super-heavy Nomad 90 Neo vibrators are the ideal choice for a high-productivity broadband survey programme, providing a wider frequency range, high energy output and excellent sweep quality.

Emmanuelle Dubu, Sercel CEO, said, “It is especially exciting to have our latestgeneration digital equipment deployed on this high-channelcount onshore survey. Our 508XT acquisition system and Nomad 90 Neo vibrators are exactly the right combination for high-performance surveys, delivering unparalleled subsurface data quality for clearer seismic imaging.”

Africa has actually been seeing a momentum of seismic acquisitions across the continent in past years. In December 2020, the USA-based VAALCO Energy announced the acquisition of three-dimensional (3-D) seismic data at the Etame Marin block offshore Gabon. According to Cary Bounds, CEO, “Our new 3D seismic survey is a vital tool in helping us unlock the remaining 116 million gross barrels of oil reserves and resources identified on the license. The new seismic data will help us optimise every location to drill and potentially identify new locations to add to our drillable inventory. Additionally, our recent announcement of the acquisition of Sasol’s interest at Etame combined with the new 3-D seismic survey underscores our confidence in the long-term potential at Etame.”

To add more to this momentum, in October 200, Polarcus Limited was awarded 3D seismic data acquisition services in West Africa with an expected duration of two months.

Seismic activity is accelerating in Equatorial Guinea as the country intensifies its E&P Activities in 2021. Last year, Trident Energy started a 4D seismic survey over the Block G assets which contain the Ceiba and Okume fields offshore Equatorial Guinea. With this, the country will see three exploration wells drilled in Trident Energyoperated Block G in 2021.

CGG, the geosciences leader, has a number of activities going on in the African region. In East Africa, CGG is working on survey to help explorers better understand the petroleum potential of undertested offshore regions. As stated in the company’s website, it is aiming to intersect crucial oil and gas wells in the area and provide structural constraint to the imaged data.

In South Africa, the company is working on Durban and Zululand basins. Located off South Africa’s East Coast, the deepwater potential has still not been explored. As stated by the company, the basins have possible analogues to the Rovuma and Mafia Basins located offshore Mozambique and Tanzania to the north and the conjugate North and East Falkland Island Basins.

Additionally, last year, the company announced the final 3D PSDM seismic dataset from its 15,400 sq km multi-client survey of the outer Zambezi Delta in Mozambique. The ultramodern data was acquired over blocks Z5-C and Z5-D and surrounding open acreage as part of a multi-client programme agreed between CGG and Mozambique’s Instituto Nacional de Petroleo (INP). 

Sercel's broadband seismic vibrator truck, Nomad 90 Neo.