Priti Ubhayakar, Editorial Assistant
West Africa remains one of the most promising and most difficult offshore operating arenas. Huge successes off Angola are balanced with the deepwater production and logistics issues.
Infield’s prediction of new fields to come onstream in West Africa from now through 2013 calls for a five-fold increase in fields. The count for 2003 through 2007 saw 54 new fields, while the estimate for 2008 through 2013 calls for 271 more.
Following is some of what has made news in West Africa over recent months.
Angola
Esso Exploration Angola (block 15) Ltd. has initiated production from Kizomba C in 2,400 ft (800 m) of water 90 mi (145 km) offshore Angola. Kizomba C is designed to develop 600 MMbbl of oil from Mondo, Saxi, and Batque fields. Mondo is the only field producing at present. The other two are expected onstream later this year. Total plateau production from all three fields is targeted at 200,000 b/d of oil.
Daewoo Shipbuilding and Marine Engineering awarded KBR a contract to provide topsides engineering, procurement, and interface design for an FPSO on Total’s Pazflor project in Angola. Pazflor’s design is a purpose-built FPSO with a topsides weight of 32,200 metric tons (35,494 tons). It is designed with a processing capacity of 200,000 b/d of oil, 150 MMcf/d of gas, and a storage capacity of about 1.9 MMbbl of crude. The FPSO will be spread-moored in a depth of approximately 2,500 ft (762 m) atop 25 subsea oil wells, two gas injection wells, and 22 water injection wells.
A subsidiary of Total has finalized a five-year contract extension with Pride International for the dynamically positioned, deepwater drillshipPride Angola. The contract is expected to begin during July 2008 in continuation of the rig’s current contract.
Nigeria
Nexen received approvals to proceed on Usan field development. Usan is expected onstream approximately four years from the award of major contracts. Peak production is expected to be 180,000 b/d of oil. Associated gas will be re-injected into the reservoir. Nexen also announced that the government has approved the conversion of Oil Prospecting License (OPL) 222 into two Oil Mining Leases (OMLs 138 and 139), each covering half of the original area of OPL 222.
Star Deep Water Petroleum Ltd. (affiliate of Chevron Corp.) deployed WellDynamics’ SmartWell intelligent well completion technology in Nigeria’s Agbami field. The two-zone completion will balance production between zones and control water encroachment into the wellbore. The Agbami development plan consists of 20 oil producers, 12 water injectors, and six gas injector wells with flow control, permanent monitoring, or both. The single-wellbore completions are expected to produce from, or inject into, two distinct sand units. The completion consists of WellDynamics’ Direct Hydraulics with the Accu-Pulse downhole control system, multi-position HVC interval control valve (ICV) with customized flow trim, HF-1 packers and downhole gauges, as well as a multi-phase downhole flowmeter and an automated surface control system.
Mobil Producing Nigeria (MPN) awarded a five-year contract to a consortium of AMEC, JAGAL, and NETCO for the upgrade and expansion of offshore and onshore oil and gas production facilities in southeast Nigeria. The $220-million engineering, procurement, and construction management program is an arrangement comprising multiple contracts that will be implemented in Nigeria and will exceed the Nigerian Content Directive, according to AMEC. The consortium will provide project management, project services, and engineering design for the program. AMEC will provide project management and procurements skills, NETCO will provide engineering skills, and JAGAL will provide logistics and support services.
Afren entered into a farm-in agreement with Oriental Energy Resources to develop the Ebok field, offshore southeast Nigeria. Appraisal drilling is scheduled for 4Q 2008 to collect high quality oil samples, establish well deliverability, and acquire the reservoir data for optimizing the development plan. Pending appraisal wells, submission of a field development plan is anticipated in 2009. First commercial oil is expected in 1Q 2010.
Addax Petroleum has added to its Kita Marine discovery. The KTM-6 appraisal well is 2 km (1.2 mi) southwest of the successful KTM-2ST1 exploration well. Both wells penetrated separate but adjacent fault blocks. KTM-6 encountered an aggregate gross oil column of 173 ft (53 m) including individual gross oil columns of 94 and 52 ft (29 and 16 m) at depths of between 5,350 and 6,300 ft (1,631 and 1,920 m) subsea. Flow tests were not performed but pressure and fluid sample data indicate medium gravity oil.
TheAkpo FPSO is scheduled to sail from South Korea on May 10, 2008, to its installation site offshore Nigeria. The FPSO’s hull is being built by Hyundai Samho Shipyard – a first for the yard. The all electric vessel equipped with 150 MW Rolls Royce generators, is schedule to arrive in September 2008. Gas from Akpo will be exported via 16-in. (41-cm) pipeline lined with special coating to increase the flow rate by 20%. First oil from Akpo is expected in early 2009.
Drilling began on the Aje 4 well, according to Providence Resources. AJE Partners include: Yinka Folawiyo Petroleum (operator), Chevron Nigeria Deepwater (technical advisor), Vitol Exploration Nigeria, Energy Equity Resources Aje, and P.R. Oil and Gas Nigeria. The AJE 4 well is being drilled using Transocean’sDeepwater Pathfinder drillship.
BJ Process and Pipeline Services (BJ PPS) completed pipeline pre-commissioning services for the final segments of the West African Gas Pipeline (WAGP) system on behalf of Willbros West Africa Inc., an Ascot Offshore Services Company. The WAGP system measures 678 km (421 mi) and will gather natural gas from fields in the Escravos region of the Niger Delta for delivery to customers in Ghana, Togo, and Benin. The pipeline system comprises the existing Escravos-Lagos pipeline, a new onshore pipeline in Nigeria, a new offshore pipeline, and a recently built compressor station.
Other West Africa players
Tullow Oil outlined its drilling program forGhana. In June 2007, the company drilled the Mahogany-1 well on the West Cape Three Points block in the deepwater Tano basin, followed by the Hyedua-1 well on the adjacent Deepwater Tano block. Proven recoverable resources from the field are estimated at 170 MMbbl of oil, while the ultimate upside potential is estimated to be in excess of 1 Bbbl.
Up to five appraisal wells are planned on the field in 2008 using two rigs. The company hopes to increase the proven resource base of the field and collect additional geological and engineering data to support development planning and activities. The first exploratory appraisal well, Mahogany-2, began in March.
Tullow has been designated as the field operator, with the support of the government of Ghana. A phased development is planned with a first oil target of 2010. Screening studies indicate that the most suitable development scheme will involve an FPSO suited to fast-track development.
Tullow also plans to drill further exploration wells in the vicinity of its Jubilee discovery. The first well was drilled in February 2008 on the Odum prospect in the West Cape Three Points block. Further high-impact prospects have been identified in the deepwater region and at least two of these, Teak and Tweneboa, are expected to be drilled within the next 12 months. Each of these prospects has upside potential in excess of 0.5 Bbbl of oil.
In addition to the deepwater program, Tullow plans to drill its second well on the shallow water Tano license during 2008. The first well, drilled in September 2007, was unsuccessful. The second well to be drilled on the Ebony prospect targets a geological play similar to the Odum discovery.
The company made an oil discovery with the Odum-1 exploration well off Ghana in 955 m (3,133 ft) of water. The well, drilled to 3,387 m (11,112 ft) deep, encountered a gross oil column of 60 m (197 ft) and 22 m (72 ft) of net pay. Samples from the reservoir indicate an oil gravity of approximately 29° API. Odum-1 will be completed and suspended as a future development well. The drillshipSonga Saturn will move to Mahogany-2, the next appraisal well on the Jubilee field. Meanwhile, due to persistent borehole instability, Tullow has decided to suspend the Ngassa-1 exploration well and plans to re-drill it from an alternate location.
Devon Energy Corp. agreed to sell its oil and gas business inCote d’Ivoire to Afren for $205 million, subject to government approval. The assets include Devon’s interests in offshore producing block CI-11, offshore undeveloped block CI-01, and the onshore Lion gas processing plant. Devon’s current net production from Cote d’Ivoire is approximately 3,000 boe/d.
PGS, in co-operation with Petroci, completed acquiring, processing, and interpreting over 6,500 km (4,039 mi) of new 2D seismic data collected offshoreCote d’Ivoire. The data are available for licensing from PGS. The dataset covers the entire deepwater of Cote d’Ivoire, from the maritime border with Liberia in the west to Ghana in the east. Acquired with an 8,500-m (27,887-ft) cable to allow for imaging of the full sedimentary section, the data were processed using Kirchoff pre-stack time migration. PGS says the completed interpretation of the multi-client 2D data shows prospects and leads in both the deeper syn-rift section and also in the shallower post rift. The data also indicates a thicker sedimentary section that had previously been expected, providing much more extensive potential source than had been mapped to date.
SOCO Exploration and Production Congo S.A. agreed to farm-out 8.5% of its interest in the Marine XI block, offshore theRepublic of Congo, to Petrovietnam Exploration Production. The deal is subject to government approval. SOCO EPC will remain the operator with a 29% working interest. The Marine XI block is in water depths up to 110 m (361 ft), and covers 1,400 sq km (541 sq mi). A multi-well drilling program is scheduled for the second half of 2008.
Total began redeveloping the Anguille field inGabon. Anguille is 20 km (12 m) offshore Port-Gentil in a water depth of 30 m (98 ft) in the Grand Anguille Marine concession. Discovered in 1962, Anguille came onstream in 1966 and produced 7,500 b/d of oil in 2007 prior to redevelopment. According to Total, the redevelopment project will improve the oil recovery factor from 13% to 23% by increasing the number of drainage points and by enhancing well productivity using hydraulic fracturing and massive waterflood.
Phase 1 of redevelopment is under way, using existing facilities. Around a dozen wells will be drilled in 2007 and 2008, and the associated surface facilities will be debottlenecked. Running from 2009 to 2011, Phase 2 entails installing new offshore infrastructure and decommissioning obsolete process units, building an onshore plant (power generation, fluid treatment, gas compression), and drilling an additional 30 wells.
The project will eliminate gas flaring on the field by 2011, as well as coastal discharges of production water. Production is expected to increase from 2008, peaking at over 30,000 b/d of oil in 2013-2014. The development cost is an estimated $2 billion for additional proved and probable reserves of around 150 MMbbl.
Bowleven signed a contract with Sedco Forex International to drill one well with the jackup rigTrident IV. The rig will be used to re-drill the IF exploration well in block MLHP 2 offshore Cameroon. Operations were expected to begin by now.
Noble Energy completed a successful test on block I, offshoreEquatorial Guinea. The I-4 well, on trend with the Belinda discovery on block O offshore Equatorial Guinea, encountered a high quality Miocene reservoir that yielded flow rates of 1,634 b/d of condensate and 28.9 MMcf/d of natural gas, or approximately 6,450 boe/d, according to Noble. The well was drilled to 9,721 ft (2,963 m) TD in 2,226 ft (678 m) of water. This was the final well of the six-well program drilled by the drillship Songa Saturn.
Elixir Petroleum acquired an interest in, and has been appointed operator of, block SL-4, offshore the Republic ofSierra Leone. The 4,429-sq km (1,710-sq mi) block is one of six awarded offshore exploration blocks in the region. The company plans a 3D seismic program for the area to begin in 3Q 2008.
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