Ghana’s government has approved the $1.1-billion Phase 1A development of theJubilee field, according to Tullow Oil.
This involves adding five new production wells and three water injectors, and expanding the subsea facilities network, all over an 18-month period. Drilling should start in February.
Phase 1 of Jubilee was completed in October when the last of initial 17 initial wells was completed and brought onstream. Production from the field peaked at 88,000 b/d of oil last year before falling back to 70,000 b/d at year-end.
The cause of this decline is a technical issue related to the design of the well completions. Remedial work to recover lost well productivity is under way, with a side track of the J-07 production well incorporating a new completion design.
Tullow says the well was flow tested to the rig at rates of up to 15,000 b/d and started production to the FPSO in early January. Output is being raised gradually to assist monitoring of the new completion’s performance over the next two to three months.
This re-design will likely be used in thePhase 1A wells and in side tracks of a further three Phase 1 wells during 2012. Tullow estimates the total cost of the recompletions at $400 million.
During 2012, the company expects Jubilee’s overall production to ramp up toward the plateau rate of 120,000 b/d as the remedial program takes effect and the new Phase 1A wells come onstream.
However, the final outcome may depend on the well performance, the downtime required to execute the recompletions, and the scheduling of available rigs for other exploration and appraisal commitments.
Late in December, Tullow, on behalf of the Jubilee partners, acquired ownership from Modec of theKwame Nkrumah FPSO. However, Modec will continue to provide operations and maintenance services under a new contract.
As for ongoing appraisal activity, the Owo-1 discovery well in the Deep Water Tano block was re-drilled in December to allow testing and coring. The Owo-1RA well will now be flow tested and pressure response monitored by pressure gauges deployed in the Enyenra-2A well, 7.2 km (4.5 mi) to the south, and inEnyenra-3A, 6.5 km (4 mi) to the north.
The aim is to determine the level of reservoir connectivity to assist in selection of the development scheme. Later this month, Enyenra-4A will be drilled a further 6.8 km (4.2 mi) south of Enyenra-2A in an attempt to determine the southern extent of the Enyenra field.
Tullow says the partners expect to submit a plan of development for theTweneboa/Enyenra/Ntomme (TEN) project to the government this summer alongside a formal declaration of commerciality. They would then aim for first production 30 months after securing sanction.
INTECSEA is performing FEED (Front-end engineering design) for the subsea infrastructure in London while a design competition is in progress for the FPSO FEED involving three contractors. This work is being conducted in Singapore, and Tullow has established a local project office to support the work and future construction of the floater.
During 2012 Tullow expects to drill up to three exploratory wells on the Deep Water Tano block. Prospects include Wawa-1, targeting hydrocarbons that may have migrated into a potential trap up-dip from the TEN oil and gas-condensate fields; Turonian Deep-1, a multi-objective prospect below the TEN fields; and Sapele-1, to test a prospective turbidite lobe immediately south of Jubilee.
In the adjoining West Cape Three Points license, which contains Jubilee’s eastern section, theTeak-3 well drilled by operator Kosmos in November confirmed a northern extension of the Teak discovery across a major fault.
There will be at least one further appraisal well, Teak-4, and a flow test this year. The plan for the so-called “Mahogany East Area” is under discussion with the government.
Elsewhere in the region, Tullow says all four main gas compressors are now operational on the Espoir fields off Cote d’Ivoire and gas exports have been restored to full capacity. An eight-well drilling should start this fall on both West Espoir and East Espoir, designed to rejuvenate Espoir production and extend the life of the field.
Following the Cote d’Ivoire government’s lifting of Force Majeure for Tullow’s deepwater exploration blocks CI-103 and CI-105, the company plans to drill one well in each block during the current quarter.
The semisubEirik Raude is en route from Ghana to drill the Kosrou and Paon prospects. Tullow is monitoring discussions between the Ghanaian and Ivorian governments concerning demarcation of their maritime border.
Last October Tullow signed the new C-10 exploration PSC offshoreMauritania, giving it an operated equity of 59%. This 10,000-sq km-plus (3,861-sq mi) license is equivalent to much of the former PSC A and B licenses, and carries a two-well commitment in the first three years.
This year Tullow planning various activities across its Mauritanian licenses including 3D seismic acquisition and drilling.
The company has also been granted extensions to the remainder of the previous PSC A and B and increased its equity in these concessions to 67.3% and 64.1% respectively. They contain the Banda, Tevet, and Tiof oil and gas discoveries. Tullow is now operator and is progressing development of Banda with concepts under review.
Offshore Namibia in southwest Africa, Tullow signed a new Petroleum Agreement for the Kudu gas field in October 2011 and the following month the Minister of Mines & Energy issued a new 25-year production license.
Design concepts have been agreed for the offshore development and associated onshore power station, and FEED tenders will be ready for issue once commercial arrangements have been finalized.
