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Nigerian Firm Oranto Petroleum Concludes Appraisal Survey For Uganda’s Ngassa Block

A United Kingdom-based firm IMC Geophysical Services LTD, has concluded Two Dimensional (2D) seismic data acquisition for Uganda’s Ngassa block.

The prospective oil field was auctioned to Nigerian firm Oranto Petroleum in October 2017. The block lies on the eastern banks of Lake Albert.

Oranto contracted the Shifield-headquartered firm  to undertake the survey, which began in mid April this year and went on until May 18.

Ngassa was part of Exploration Area 2 licensed to Tullow Uganda Operations Pty Limited but reverted to the government after the expiry of Tullow’s appraisal period.

Director Exploration at the Petroleum Authority of Uganda (PAU) Dozith Abeinomugisha told local media in Kampala that  the “conclusion of this exercise represents an important step by the licensee in fulfilling its obligations for the first two-year exploration phase that runs from October 2017 to October 2019.”

“The survey involved the acquisition of 326 line kilometres of off shore (on Lake Albert) 2D seismic data over the Ngassa Contract Areas,” Abeinomugisha said.

Before Oranto’s exercise, 32 seismic surveys had been undertaken in Uganda’s oil-rich Albertine Graben, resulting in the acquisition of about 7,000-line kilometres of 2D seismic data and about 2,000 square kilometres of 3D seismic data.

Two-thirds of this block is covered by good quality 2D seismic data while the remaining third is covered by 3D seismic data acquired between 2003 and 2008.

The acquired data will be analysed together with the pre-existing 2D and 3D data to better define the north-eastern part of the Ngassa mega prospect.

Uganda awarded two stratigraphic licenses of Ngassa Deep Play and Ngassa Shallow Play Contract Areas for a four-year period, ending 2021.

It was the first time East Africa’s prospective oil producer undertook stratigraphic licensing, where two licenses are issued vertically over the same block. Officials say the move was intended to ensure that all potential oil and gas zones in the area are fully evaluated through implementation of work programmes approved by the Petroleum Authority of Uganda.

Oranto has also undertaken other technical studies as part of the exploration work programme, including reprocessing of the existing seismic data and petro-physical studies over the Ngassa 1 and 2 wells to evaluate the quality of the reservoir horizons penetrated by these wells.

Although the two wells encountered oil and gas, much of this block was not tested, meaning that there was need for additional exploration work to fully assess the potential of the block, officials say.

“We expect Oranto Petroleum Limited to revert to the PAU by October, 2019, with a detailed work programme for drilling at least one exploration well on Lake Albert within the next two years,” said Abeinomugisha.

The acquired data will be analysed together with the pre-existing 2D and 3D data to better define the North Eastern part of the Ngassa mega-prospect.

Oranto country General Manager Abdul Byakagaba Bazara, described the exercise as a big success for Uganda.

“We have received great support from the government, the local leaders and communities in the area where we are operating,” he said.