By Macson Obojemuinmoin, in Lagos
General Hydrocarbons Limited has moved the platform rig Blackford Dolphin to a location in deepwater Nigeria for a multi-well campaign on the Oyo oil field and adjoining prospects.
It will start operations by the second week of April 2023.
The company is particularly excited about the potential of a deep prospect in the vicinity of the Oyo North West Structure. The prospect, a robust, four-way closure hemmed in by a roll over fault, is called ‘Ewo Deep’. Top officials at GHL describe it as “The Big Ewo”.

An analogue of the Big Ewo, in another part of OML 120
Although GHL wants to establish revenue inflow by re-entering and hooking up some of the producer wells that have been shut in for the past five years, there is also the proposition that “access to development funding will be enhanced if Ewo proves to be what it seems”, company sources say.
The Oyo field and associated prospects are located in Oil Mining leases (OML) 120 & 121. The field was producing before the acreages were revoked from Erin Energy, its previous operator.
GHC also wants to drill new prospects that had been identified and listed in the prospect inventory. Company sources insist that the available seismic and petrophysical data have been extensively reviewed and the locations high graded. “Schlumberger has worked on the studies, Baker Hughes has taken a comprehensive look and (the Nigerian subsurface consultant) D’Harmattan has been part of these studies”, GHL sources, who want to remain unnamed, tell Africa Oil+Gas Report. “GCA (Gaffney Cline & Associates, a firm of ‘Competent Persons’) has evaluated what Schlumberger and others have done”.
Africa Oil+Gas Report’s skepticism is borne out of the fact of the chequered history of OMLs 120 and 121. Production from the Oyo field, the only producing property in the acreages, fell rapidly almost as soon as first oil gushed out in December 2009, crashing from 22,500Barrels Per Day (BOPD) to 4,000BOPD in the space of 10 months. By November 2014, the six well field was delivering less than 1,000BOPD. Two wells drilled in 2015: Oyo- 7 and Oyo -8, took the field to over 10,000BOPD, but Erin Energy was severely indebted at the time and was so burdened by litigations and other woes it keeled over into bankruptcy. The Nigerian state moved in to revoke the assets in 2019. The company lost its Ghanaian asset the same way two years after. It is noteworthy that Oyo -7 and Oyo-8 are two of the locations that GHL

Oyo Field Performance Profile
proposes to re-enter in the course of the campaign. No one says that there is any new seismic acquisition or processing. The lingering question is: If the ‘Big Ewo’ was sitting there all along, how come no one ever drilled it, in all the 30 years since the acreages were first awarded?
The planned drilling and re-entry in Oyo field &Co would be GHL’s first field operations since its incorporation in 2007. The company, owned by Nigerian investors, was discretionally awarded the OMLs 120 and 121 in 2020, several months after the revocation from the previous asset holder. It was one of the last discretionary awards of acreages under the laws that governed the country’s petroleum industry at the time. In the Petroleum Industry Act (PIA), which is the new overarching legislation of the industry, no company will access an acreage outside of the process of a bid round.