Nigerian independent oil firm completes survey in western UgandaSince the Ngassa prospect lies entirely under the lake, two deviated wells, Ngassa-1 and Ngassa-2 were drilled on land at the periphery to access the reservoirs.
May 29—Nigerian outfit, Oranto Petroleum Limited (OPL), has successfully completed a Two Dimensional (2D) seismic data acquisition survey over the Ngassa block in the Albertine Graben.
OPL contracted IMC Geophysical Services Limited from the United Kingdom to undertake the survey, which commenced on 15th April, 2019, and was completed on 18th May, 2019.
“The survey involved the acquisition of 326 line kilometres of off shore (on Lake Albert) 2D seismic data over the Ngassa Contract Areas. 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,” Dozith Abeinomugisha, Director Exploration at the Petroleum Authority of Uganda (PAU) said.
The two stratigraphic licenses of Ngassa Deep Play and Ngassa Shallow Play Contract Areas were awarded to Oranto Petroleum Limited from Nigeria in October 2017 by the Minister of Energy and Mineral Development, for a period of four years. This is the first time Uganda undertook stratigraphic licensing, where two licenses are issued vertically over the same block. This is to ensure that all potential oil and gas zones in the area are fully evaluated through implementation of the work programmes aproved by the Petroleum Authority of Uganda.
The Ngassa block lies on the eastern banks of Lake Albert, within the villages of Tonya A, Tonya B, Kijjangi, Mbegu, Kaiso and Kyehoro, in Hoima and Kikuube districts. The Ngassa block, which was initially part of Exploration Area 2 licensed to Tullow Uganda Operations Pty Limited, reverted to the government after the expiry of Tullow’s appraisal period. The block is covered by good quality 2D seismic data acquired between 2003 and 2008. A third of the block is covered by 3D seismic data.
Since the Ngassa prospect lies entirely under the lake, two deviated wells, Ngassa-1 and Ngassa-2 were drilled on land at the periphery of the main structure between 2007 and 2009, respectively, in order to access the reservoirs. Oil and gas shows were encountered by the two wells; however, a large part of the prospect was untested. This implies that additional exploration work was required to fully assess the potential of the prospect.
“Oranto Petroleum Limited will now process and interpret the acquired data. The results will inform the subsequent activities during the next two year phase of the exploration period. 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,” Abeinomugisha said.
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. OPL has also undertaken other technical studies as part of the exploration work programme, including reprocessing of the existing seismic data, Amplitude versus Offset (AVO) and petrophysical studies over the Ngassa 1 and 2 wells to evaluate the quality of the reservoir horizons penetrated by these wells as well as studies related to a drilling solution on Lake Albert.
Abdul Byakagaba Bazara, the OPL General Manager, described the exercise as a big success. “We have received great support from Government, the local leaders and communities in the area where we are operating. The UPDF and Uganda Police have provided us with security throughout this exercise, which has been undertaken without incident,” he said.
A Joint Security Team that comprised the Uganda People’s Defence Forces (UPDF), Uganda Police Force (UPF) and the Internal Security Organisation (ISO) led by Brig. Michael Nyarwa, the Commandant of the UPDF Marine Unit, oversaw the security for the exercise.
“We secured the operations on land, water and air, and our team also worked closely with the local community for intelligence gathering,” Brig. Nyarwa said.
Bazara said, “Over 70 pc of the workforce employed during the survey were Ugandans. In addition, OPL has subcontracted Uganda firms to provide legal services, security services, camping, catering and general maintenance services.”