Billions of dollars in international investment have flowed into West Africa in the last few years, expanding exploration drilling and moving a number of world-class fields into production.
Investment in West Africa’s offshore is growing and could be the largest in the world by 2011 if Douglas-Westwood Ltd.’s forecast is accurate. The company contends that West Africa will not only be the world’s largest offshore market, but will be the largest deepwater and subsea market as well.
Angola
Possibly the biggest news offshore West Africa in 2006 was Dalia going onstream.
Discovered in September 1997 in block 17, 135 km (84 mi) offshore Angola in 1,200-1,500 m (3,937-4,921 ft) water depth, Dalia contains an estimated 1 Bbbl of recoverable oil. It was the largest deepwater development to be brought onstream last year and is among the largest projects of its kind in the world.
In fact, Angola was in the spotlight for much of 2007. In early January, Sonangol and Total E&P Angola announced the ultra-deepwater Salsa-1 discovery, the sixth exploration well on block 32. The discovery is in the southeastern part of block 32, 15 km (9 mi) southwest of the Mostarda-1 discovery.
Further exploration drilling is underway, and more is planned across the block.
In late January, Chevron subsidiary Cabinda Gulf Oil Co. and partners had a significant oil discovery in deepwater block 14 in the Lower Congo basin.
Shortly after Chevron’s announcement, BP had a discovery with the deepwater Terra well in block 31. The Terra well, which lies in 2,328 m (7,638 ft) water depth 411 km (255 mi) northwest of Luanda, is BP’s twelfth discovery on this block. Terra is 30 km (19 mi) northwest of BP’s Titania discovery, which was announced in last October.
It was Total’s turn next with oil discoveries from its eighth and ninth exploration wells on ultra deepwater block 32.
Drilled in 1,977 m (6,486 ft) water depth, the Manjericão-1 well tested more than 5,000 b/d of oil from Oligocene oil bearing reservoirs. This discovery is in the central part of block 32. The discovery demonstrates additional resource potential in the previously unexplored central area of block 32.
Total’s Caril-1 well, drilled in 1,673 m (5,489 ft) water depth, also encountered oil. The discovery is in the northeastern part of block 32. Further exploration drilling is under way and planned across the block.
Angola’s offshore will likely lead the region in the coming year as well. Sonangol is offering new exploration acreage this year, some of which lies in ultra deepwater beyond block 31.
Nigeria
Nigeria’s deepwater was not as productive over the last year as Angola’s, but a number of companies will soon begin drilling obligatory exploration wells on blocks awarded in 2005.
Devon Energy plans to drill its third and final obligation well in OPL 256 and its first well in OPL 242. Shell is planning a drilling campaign in OPL 245; Petrobras will begin drilling OPL 315, and Chevron will drill OPL 247. Chevron will also appraise the Obo discovery in the Joint Development Zone that Nigeria shares with São Tomé and Príncipe.
ExxonMobil is working on appraisal activity at the Uge 1 discovery in deepwater OPL 214. And Eni will drill more appraisal wells on the Oyo field in OML 120.
The shallow-water HD project is Shell’s primary focus offshore Nigeria this year. The project encompasses HD, HA, and satellite fields that will produce 140,000 b/d of oil as well as gas for NLNG.
Shell is also developing the deepwater Bonga South West field separately from Bonga Main, which is already in production.
Last year saw some significant milestones offshore Nigeria, one of which was Shell’s discovery at Bonga North in OPL 212 in early May. Also in May, Chevron drilled the first oil discovery in OPL 214 about 113 km (70 mi) offshore. The well encountered more than 100 m (328 net ft) of oil, making it one of the most recent, sizeable deepwater discoveries in the Niger Delta.
Around the same time, Exxon Mobil Corp. affiliate, Esso E&P Nigeria Ltd. started production from the deepwater Erha development. The development includes Erha and Erha North, which was to come onstream in 3Q 2006.
In July, Addax Petroleum began the a field development program on the Nda Field in OPL-90 adjacent to the Okwori field about 90 km (56 mi) offshore as a subsea tieback to the Okwori FPSO.
Afren drilled an appraisal well for Okoro in shallow-water OML 112 in Dec. 2006, which sparked the decision to pursue a nine-month development drilling program on Okoro and Setu that is to begin in 3Q 2007. A fast-track development plan is in place to produce first oil in early 2008.
The Bilabri field in OML 122 is also on a fast track. Operator Equator has leased theBW Endeavour FPSO for a three-well, 30,000 b/d operation that is to come onstream this year.
Other West African players
Total’s Moho-Bilondo project is the key project offshore Congo. In early April 2007, Total made two oil discoveries in the northern area of the permit, 80 km (50 mi) offshore.
The Moho Nord Marine-1 discovery well encountered a 140-m (459-ft) column of oil, and the Moho Nord Marine-2 well, about 1.5 km (1 mi) away, encountered two connected reservoirs.
Appraisal is under way for the additional reserves in the three oil reservoirs, and development plan studies have already been launched.
The wells are part of the second phase of the campaign to add resources to the current Phase 1 Moho-Bilondo development. An earlier discovery, Mobi Marine 2, will be connected to the Moho-Bilondo floating production unit.
Launched in late August 2005, the initial Phase 1 development plan for Moho-Bilondo consists of 12 subsea wells tied back to a floating production unit, with a peak output of 90,000 b/d of oil. Production is scheduled to begin in 2008.
Last December, Hess Corp. and partners Tullow Oil and GEPetrol began production from the Okume complex offshore Equatorial Guinea. First oil was achieved on Dec. 14 at the Okume B platform. Production will grow during 2007 to reach 60,000 b/d peak production in 2008.
While Hess moves to production, Devon Energy and partners are making progress with exploration drilling in block P offshore Equatorial Guinea. In March, 2007, the group announced the P-1 well on the Jupiter prospect demonstrated that the major elements of the hydrocarbon system are in place.
Though P-1 was unsuccessful, wells P-2, P-2 sidetrack, and P-3 encountered commercial hydrocarbons. Information from the wells is being analyzed along with other regional information. Based on the current estimates, the Green Sand discovery holds 33 MMbbl of gross recoverable oil reserves.
Devon is carrying out a feasibility study to evaluate the commercial viability of the project. Studies also are ongoing to evaluate information acquired from the block to support decisions on further exploration and appraisal activities within the area.
In Sept. 2006, FirstAfrica Oil completed its initial development drilling program offshore Gabon in the East Orovinyare field. Initial production is expected in 3Q 2007 at more than 7,000 b/d of oil.
And last December, Total added an exploration and production sharing contract for the Diaba license to its West Africa holdings. The 9,075-sq-km (3,504-sq-mi) license lies in 100-2,500 m (328-8,202 ft) water depth 50 km (31 mi) off southern Gabon.
The three-phase exploration program includes a 2,000-km (1,243-mi) 2D seismic survey, a 700-sq-km (270-sq-mi) 3D survey and an obligation well.
At the southern end of West Africa, Tullow Oil began drilling again offshore Namibia in late 3Q 2007 on the potentially giant Kudu gas field.
Exploration and analysis to date suggest reserves of at least 3 tcf, with potential for up to 9 tcf. The parts of the reservoir drilled so far have achieved good flows, but Tullow wants to test other sections in a different geological setting.
Depending on the outcome of the two-well appraisal program, development could be expanded from the present option of fueling a gas-to-power project on the border with South Africa, to an export project, possibly involving LNG.
East Africa
Drilling is picking up offshore Kenya. In mid-December 2006, Australia’s Woodside Energy Ltd. set 51-mm (20-in) casing at 2,944 m (9,659 ft), 751 m (2,464 ft) below the seabed and resumed drilling at the Pomboo No. 1 well in license L-5 in the Lamu basin.
Woodside acquired 40% interest in the Kenya L-5 license along with three other blocks from Dana Petroleum Plc. subsidiary Dana Petroleum (E&P) Ltd. in May 2003. The blocks cover 47,500 sq km (18,340 sq mi) in water depths to 3,000 m (9,842 ft).
In April 2006, Aminex entered into a seismic option agreement with Upstream Petroleum Services Ltd. over blocks L9 and L10. Under UPSL’s technical evaluation agreement, 570 km (354 mi) of new 2D seismic were acquired over the area as well as geochemical seabed coring and additional seismic on prospective leads.
The area covered by this agreement is about 5,000 sq km,(1,931 sq mi) involving land and near-shore acreage of original Kenyan blocks L9 and L10.
Last December, Australia’s Origin Energy began the early stages of its Kenyan exploration program with a 3,200 km (1,988 mi) seismic survey in Lamu basin blocks L8 and L9.
Offshore Tanzania, EnerGulf submitted its proposed production-sharing agreement for the 8,000-sq-km (3,089 sq mi) Tanga block last January, but although the company believes the block has potential for several significant petroleum accumulations, no further activity has yet taken place on the block.
In 2Q 2006, Aminex began acquiring a new 2D survey in the Area B transition zone of the Nyuni license. Aminex acquired 330 km (205 mi) of 2D marine seismic over this area in 2005. The aim of the survey was to firm up drilling targets for exploration wells.
Last April, East African Exploration Ltd. farmed in to the block, agreeing to earn its interest by acquiring new transition zone 2D seismic data over Area B.
In March 2007, Dominion Petroleum Ltd. signed a PSA for exploration block 7, which covers 8,500 sq km (3,232 sq mi) in the Indian Ocean east of Dar es Salaam. The PSA has an initial exploration period of four years, during which Dominion will spend at least $8.75 million on surveys and will drill one well.
Offshore Mozambique, Anadarko Petroleum Corp. signed an exploration and production concession contract last December for Offshore Area 1 in the Rovuma basin.
The block includes 90,000 onshore acres and stretches eastward 56 km (35 mi) offshore into 1,800 m (6,000 ft) water depth. The block’s boundary borders Tanzania to the north and extends southward 160 km (100 mi).
Anadarko has identified multiple leads across the area and is planning a five-year initial exploration term, with options to extend that phase another three years.
More money is moving into this region, but until there is a world-class find, East Africa will remain a side note to West Africa’s melody.
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Africa’s bit players
Dana Petroleum and partners are forging ahead with a drilling campaign offshore Mauritania. The most recent qualified success took place last December, when the group made an oil discovery on block 7. Though the discovery was not commercial, it was encouraging enough to ensure Dana’s continued exploration activity in the under-explored area.
Another considerably under-explored province is offshore Senegal, where there have been nearly 50 wells drilled in the last 50 years. Almost half of the wells were in the Casamance basin. Most of the discoveries have been oil, with primary production coming from the Dome Flore and Gea fields, jointly operated by Senegal and Guinea-Bissau. Thirteen wells have been drilled in the Dome Flore block, with several penetrating heavy oil deposits. Two wells have hit lighter crude.
The primary activity off Senegal is a seismic survey First Australian Resources Ltd. began in February 2007. The survey will be the largest 3D survey conducted in the area, comprising 2,050 sq km (792 sq mi), including prospect C1 in the southwest corner of the Sangomar offshore block.
The new survey follows Edison’s recently completed 1,500-sq-km (579-sq-mi) survey in the Rufisque Deep offshore block. The Rufisque Offshore Profond license covers the northernmost inshore section of the Senegalese offshore area and adjoins Mauritanian block 1.
In early 2005, Woodside acquired exploration acreage off Liberia in the country’s first offshore licensing round.
Woodside’s acreage adjoins blocks held by joint venturer Repsol in neighboring Sierra Leone. Woodside and Repsol each hold a 50% interest in two blocks immediately west of Liberia in Sierra Leone, giving them interests in five adjoining blocks across the two countries.
Woodside’s initial four-year work commitment in Liberia includes acquiring 600 km (373 mi) of 2D seismic data and 1,600 sq km (618 sq mi) of 3D data.
In Dec. 2002, Tullow and Addax Petroleum signed an exploration license with the Cameroon Government for the shallow-water Ngosso area, which contains small oil discoveries, including Narendi, Odiong, and Oongue. A 3D survey, covering 207 sq km, was completed in 1Q 2006. There is a chance that two wells will be drilled this year, most likely in 4Q.
