SHELL Petroleum Development Company (SPDC)'s Forcados Yokri field is set to contribute 140,000 barrels per day to Nigeria's crude oil output as efforts to restore the field to its previous production level gathers momentum.
A recent edition of the company's in-house journal, Shell Bulletin disclosed that a campaign to hook up wells drilled in the area, has just commenced with two clusters of ten wells linked to the old estuary flowstation.
It was disclosed that 15 more wells are expected to be hooked up and this would result in a return to the field's production peak of 140,000 b/d.
However, the 10 wells already hooked up has resulted in a gain of more than 40,000 barrels of crude oil per day.
The company's Head of Development, Southern Swamp, Olatunji Adu, while speaking on the project, pointed out that if all the development opportunities are exploited and optimised, the scope of the field's possible contribution to the company's growth aspirations is enormous.
It was disclosed that two potential upside opportunities have been identified in two horizontal wells in this first open-up campaign and they include Forc-139 and Forc-137T.
Conservatively, Forc-139 and Forc-137T were planned to produce 5800/6000 b/d, but are now believed to be capable of producing 10000/7500 b/d.
The Shell Bulletin also disclosed that analysis of data acquired during the drilling campaign in the field as well as the results of the Forcados Yokri exploration well (FY-128) have identified potential reserve upsides in the field.
Mr. Olatunji disclosed: "Well test results showed opportunities for higher production rates in some of the wells opened up. At the beginning, the open-up campaign was delayed by poor weather conditions, industrial strike action and boat seizure/hostage-taking by communities in the Forcados area.
"Despite these problems, the first phase of the clean-out and testing campaign was actualised. We are in the process of hooking up more wells with a focus to opening up all those already drilled."
The Forcados Yokri oil field is located about 50 km southwest of Warri and the Forcados part of the field was discovered in 1968, production commenced in July 1970, while the Yokri extension was discovered in 1971.
It was disclosed that the fields have 'expectation oil-in-place and ultimate recovery' of about 2.7 and 1.7 billion barrels respectively.
In 1974, crude oil output from the Forcados Yokri field peaked at 140,000 b/d, only to fall to 80,000 b/d due to natural water encroachment, pressure depletion and vertical lift problems, the bulletin disclosed.
Following this development, an Integrated Petroleum Engineering Study was carried out in 1993 and 1994 with focus on the main reservoirs in the field for underdeveloped oil reserves. A dedicated project team took over the Forcados Yokri Integrated Project (FYIP) in 1998.
The FYIP was then given the mandate to actualise the development opportunities identified in the previous studies and in the subsequent drilling campaign that followed between year 2000 and 2002, twenty five wells were drilled in four new multi-well cluster built by indigenous contractors, as well as three stand-alone wells.
It was disclosed that a lack of flowlines and deferments in installation of the well jackets and decks of the new clusters, delayed the opening up of the 25 wells and this resulted in a locked-in potential of about 134,000 b/d.
While it is expected that the ongoing hook-up exercise will free up the locked-in potential, it was disclosed that proper integration of well performance and accurate dynamic modelling of the maturing field played a key role in ensuring that many of the wells are coming on potential as predicted.