Exporation/Development Briefs

The government of Chad and Griffiths Energy International Inc., private Calgary independent, entered into a production sharing contract for the DOB (Mangara) and DOI (Badila) concession on 2,744 sq km in the Doba basin in southern Chad.

In March, Griffiths Energy said a subsidiary signed a production sharing contract with the government for the Chari-Ouest (Borogop) and Chari-Doseo concession on 20,000 sq km in southern Chad in the Doseo and eastern Doba basins.

Griffiths Energy said it would exploit the Mangara-Badila concession first because of its proximity to the Chad-Cameroon crude oil pipeline.

CAMAC Energy Inc., Houston, and PetroChina CBM Co. have spud the ZJS-3 coalbed methane well on the 175,000-acre Zijinshan contract area in Shanxi Province east of Yulin in China's Ordos basin.

The well is at 3,300 ft and projected to 4,500-5,500 ft. Mud logs have shown gas readings from several penetrated sands, CAMAC Energy said. The companies plan to flow test this well, drill two more wells, and reinterpret seismic in 2011.

Repsol YPF will join Colombia's state Ecopetrol in exploring two offshore blocks in the Caribbean and Gulf of Venezuela.

Repsol will earn a 50% interest in blocks RC-11 and RC-12 in the Guajira basin, known to be gas prone. The blocks cover 1,860 sq km and 1,345 sq km, respectively.

RC-12 is a two-segment block that lies partly in the Caribbean. The other section hugs the Guajira Peninsula in the western Gulf of Venezuela.

Repsol earlier this year took a 30% interest in the sprawling Tayrona block west and south of RC-11. About 75 miles east of RC-12 off Venezuela's Paria Peninsula, ENI SPA and Repsol are delineating the 2009 supergiant Perla gas-condensate discovery on the Cardon IV block (OGJ Online, Feb. 25, 2011).

To the southwest of RC-11 lie Chuchupa, Ballena, and Riohacha gas fields just off Riohacha. Chuchupa was discovered and placed on production in the 1970s.

Gross production from Al Baraka field on the Kom Ombo block in upper Egypt is averaging an estimated 900 b/d of oil, said Sea Dragon Energy Inc., Calgary, cooperator of the concession with Dana Gas Egypt.

Proved and probable reserves at the field rose to 5.2 million bbl as the result of successful drilling in 2010 compared with 600,000 bbl at acquisition in late April 2010.

Hydraulic fracs were conducted at the Al Baraka-3, 6, 7, and Al Baraka SE wells. The four wells are producing a combined 296 b/d after frac compared with 115 b/d before. Al Baraka-6 and 7 appear to be contributing the bulk of the production increase and are deemed successful while the Al Baraka-3 and SE have shown only modest production gains.

Sea Dragon is working with the service provider to design an optimal frac program going forward based on the results of the four recent fracs.

Harvest Natural Resources Inc., Houston, expects the Transocean Sedneth 701 semisubmersible to spud the Ruche Marin-A exploratory well on the Dussafu PSC off southern Gabon in late April.

The second 3-year exploration phase will be extended until May 27, 2012, at which time the partners can elect to enter a third exploration phase. Harvest has 66.667% interest and is operator of the 680,000-acre block.

It will drill the well to 10,100 ft measured depth in 380 ft of water to test multiple stacked presalt targets.

An appraisal well has confirmed potential of the Sankofa oil and gas discovery to become the first development of nonassociated gas off Ghana, according to Eni SPA.

The company, operator of the Offshore Cape Three Points license, said the Sankofa 2 appraisal well tested high-quality gas at a constrained rate of 29.5 MMscfd and 52° gravity condensate at a rate of 1,000 boe/d.

Drilled in 864 m of water about 55 km offshore, the well confirmed 35 m of net gas and condensate pay in Cretaceous sands with "excellent reservoir characteristics," Eni said. The well also encountered a 6 m oil leg, "which will be the object of further studies."

Vitol Upstream Ghana Ltd. operated the block at the time of the Sankofa 1 discovery in July 2009. The well, about 35 km east of Jubilee oil field, encountered 36 m of net oil and gas pay.

Eni acquired majority stakes in and became operator of the Offshore Cape Three Points and Offshore Cape Three Points South blocks in September 2009 (see map, OGJ, Mar. 15, 2010, p. 34). Interests in both blocks are Eni Ghana Exploration & Production Ltd. 47.22%, Vitol Upstream Ghana 37.78%, and Ghana National Petroleum Corp. 15%.

The Sankofa wells are on a block adjacent and to the east of the West Cape Three Points block, where a group led by Kosmos Energy Corp. recently encountered oil, gas, and condensate pay in the Teak-2 exploratory well east of Jubilee field (OGJ, Apr. 4, 2010, Newsletter).

A group led by Oilex Ltd., Perth, will drill a proof-of-concept horizontal well to a tight sand in Cambay field in India and conduct 2 months of tests following an eight-stage frac stimulation.

Cambay-76H, to spud in May, is to have a 610-m lateral in the areally extensive Eocene Y zone reservoir at 1,800 m on the 161 sq km Cambay production sharing contract area. A rig is being moved from another location in Gujarat.

A data package for Cambay field "tight" reservoirs has been submitted to a US independent reserves certifier that expects to complete the certification process in May. Vertical wells have yielded gas-condensate from Eocene at subcommercial rates on the block, which is 10 km from India's gas grid.

Cambay PSC participating interests are Oilex Ltd., operator with 30% interest, Oilex NL Holdings (India) Ltd. 15%, and Gujarat State Petroleum Corp. 55%.

Tately Budong-Budong NV, a subsidiary of Pexco NV, is moving to drill the second exploratory well on the 1.4 million acre Budong Budong block on northern West Sulawesi, Indonesia.

Harvest Natural Resources Inc., Houston, which holds 47% interest in the block, said the first well, Lariang LG-1 in the Lariang subbasin, was spud Jan. 6, 2011, and encountered multiple oil and gas shows in the secondary Miocene objective. Total depth is 5,311 ft.

Wireline logs and samples of reservoir fluids confirmed the presence of hydrocarbons, trap, and seal thus greatly derisking the license's exploration potential, Harvest added.

High formation pressures and control difficulties required the use of more casing strings than originally planned at shallower depths. At 5,300 ft, heavy drilling mud losses and the high formation pressures led to the decision to discontinue operations and plug and abandon the well for safety reasons. The primary Eocene targets, expected at 7,200 ft measured depth, were not reached.

The rig is moving to the Karama KD-1 prospect to 8,100 ft in the Karama subbasin 50 miles south of LG-1.

Niko Resources Ltd., Calgary, has cemented 7-in. liner at 3,558 m measured depth at the Qara Dagh-1 exploratory well which has indicated prospective pay in two formations in Iraqi Kurdistan, said participant Groundstar Resources Ltd., Calgary.

The well will drill ahead from liner depth in the Upper Shiranish formation through Shiranish into the Kometan formation at 4,200 m MD.

Preliminary analysis by Niko Resources of a logged interval at 2,522-3,558 m MD indicates possible prospective pay of up to 143 m in the Lower Tanjero and Upper Shiranish formations, Groundstar said. The top of the Shiranish formation has been interpreted to be at 3,420 m.

The operator has applied for a one year extension to the first phase of the first exploration period.

The Qara Dagh block is in the Zagros fold belt 60 km southeast of Taq Taq oil field and 60 km east of supergiant Kirkuk oil field. It is adjacent to a Heritage Oil Corp.-operated block with a recent oil discovery. Groundstar has 6% beneficial interest in Qara Dagh.

Pemex Exploration & Production signed a final agreement with the Sea Dragon de Mexico affiliate of Seadrill Management AS to provide the West Pegasus, formerly Seadragon I, ultradeepwater semisubmersible for work in the Gulf of Mexico off Mexico.

West Pegasus was recently delivered from the Jurong Shipyard in Singapore and proceeded for mobilization to Mexico on Apr. 1. Operations are to start in the third quarter of 2011.

The 5-year assignment in Mexico has a fixed operating day rate for the first 2 years, and the day rate will be adjusted annually thereafter based on market conditions. Estimated contract value is $850 million excluding mobilization fee assuming a constant day rate over the 5-year term.

Harvest Natural Resources Inc., Houston, expects to spud the first of two exploratory wells by yearend on 955,600-acre Block 64 in the Ghaba salt basin in south-central Oman.

The block, also known as Al Ghubar or Qarn Alam, is near Barik, Saih Rawl, and Saih Nihayda gas-condensate fields. Harvest committed to drill two wells in 3 years ending in May 2012 with a $22 million outlay.

The company has reprocessed and integrated multiple existing 3D seismic databases, and detailed geological and geophysical interpretation is under way to refine the prospects and define drilling locations. Well planning and procurement of long lead items is expected to start in the second quarter of 2011.

Harvest has 100% working interest in the block during the exploration phase, and Oman Oil Co. will have the option to back-in for as much as a 20% interest in the block after the discovery of gas.

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