Exploration discoveries

	Vol. 230 No. 9
ARTHUR BERMAN, CONTRIBUTING EDITOR, bermanae@gmail.com

Africa. Chevron affiliate Cabinda Gulf Oil Company made a discovery with its 79-3XST1 well on Block 0 offshore Angola. The well tested 11.6 MMcfd and 2,550 bopd from 225 ft of net pay in Upper Pinda reservoirs. It was drilled to a 13,000-ft TD in 397 ft of water. Chevron operates with 39.2% interest. Partners include Sonangol EP (41%), Total E&P (10%) and Eni Angola Production (9.8%).

Sintezneftegaz Namibia discovered gas with its Kunene-1 well on Block 1711 in the Namibe Basin of offshore Namibia. Reserves are estimated at 14 Tcf. The well was drilled to a TD of 18,045 ft. Sintezneftegaz Namibia operates with 70% interest in partnership with EnerGulf (10%), PetroSA (10%), the Namibian national oil company Namcor (7%) and BEE (3%).

Tullow Oil made an oil discovery with its Ngara-1 well on Block 2 in the Albert Basin, in the Butiaba region of Uganda. The well found 26 ft of pay and was drilled to a 2,431-ft TD. It is located 2 mi south of the company’s Ngege-1 discovery.

Americas. Occidental Petroleum made a discovery with recoverable reserves of 150–250 million boe in Kern County, California. It is unclear from the company’s press releases exactly when this discovery was made, since six delineation wells have already been drilled. Nor is it clear what reservoirs contain the pay, except that there are multiple pay zones that consist of conventional reservoir rock with high porosity and permeability, and that may represent deepwater deposits. About two-thirds of the reserves are natural gas. Occidental has an 80% working interest in the area.

Shell has made a deepwater discovery with its West Boreas well on Mississippi Canyon Block 762 in the Mars Basin of the US Gulf of Mexico. The 100% Shell well was drilled in 3,000 ft of water.

Anadarko Petroleum made a discovery with its Vito well on Mississippi Canyon Block 984 in the US Gulf of Mexico. The well found 250 ft of pay in subsalt Miocene sands. The well was drilled to a 32,000-ft TD in 4,038 ft of water. Anadarko operates with a 20% interest in partnership with Shell (55%) and StatoilHydro USA E&P (25%).

Great Plains Exploration made an oil discovery with its Crossfire well at Pembina, Alberta, in western Canada. The well tested 2,023 bopd and 1.2 MMcfd from 39 ft of Nisku pay with an average porosity of 15%.

Pacific Rubiales has increased its reserve estimate for the Rubiales/Piriri Field in the Llanos Basin, Colombia, from 100 to 500 million bbl of oil. The field is located 290 mi west of Bogota in the Meta Department. Pacific Rubiales operates with 60% interest along with Ecopetrol, which has the remaining 40%.

Petrobras made an apparent discovery with its 5BRSA744RJS well in the Santos Basin, Brazil. The well was drilled to a TD of 13,659 ft on Block BS-500, 106 mi south of Rio de Janeiro. Petrobras operates the block with 100% interest.

Also in the Santos Basin, Petrobras made an oil discovery on Block BM-S-7 with its 9BRSA741SPS well. The well reached a TD of 15,175 ft near the Piracuca discovery, which is estimated to contain 550 million boe. Petrobras operates with 63% interest in partnership with Repsol, which holds the remaining 37% interest.

Repsol and Petrobras made another oil and gas discovery with their 1REPF4SPS well on Block S-M-789 in the Santos Basin, but no details were announced. Repsol operates with 40% interest in partnership with Petrobras (35%), Vale (12.5%) and Woodside Petroleum (12.5%).

Eni and Vale have made an indicated discovery with their 3ENI18RJS well on Block BM-S-4 in the Santos Basin. The well was drilled in 1,074 ft of water; no other information is available. Eni operates with 50% interest, and Vale holds the remaining 50%.

In Brazil’s onshore Reconcavo Basin, Petrobras made an apparent discovery with its 4BRSA751DBA well on Block REC-T-221. The well was drilled to a 5,811-ft TD.

Asia-Pacific. Santos discovered gas with its Burnside-1ST1 well on permit WA-281-P in the Browse Basin offshore Western Australia. The company said that the discovery has 100–500 million boe of potential from Brewster sandstone reservoirs. The well is located 280 mi offshore Broome and 25 mi from Ichthys Field in 700 ft of water. Santos operates with a 48% interest with partners Chevron Australia (25%), Inpex Browse (20%) and Beach Petroleum (7%).

Royal Dutch Shell discovered gas with its Concerto-1 well in the Browse Basin, Block WA-371-P offshore Western Australia. No other details were announced except that the discovery is large. The location is 10 mi from Shell’s Prelude Field.

Chevron Australia made two gas discoveries with its Clio-2 and Kentish Knock-1 wells in the Carnarvon Basin offshore Western Australia. The Clio-2 well found 375 ft of pay. It was drilled to a 14,400-ft TD and is located 90 mi offshore in 3,200 ft of water. The Kentish Knock-1 well found 110 ft of gas pay 185 mi offshore in 4,000 ft of water. It was drilled to an 8,300-ft TD.

CNOOC made a discovery with its Qinhuangdao (QHD) 35-4 well in the Bohai Basin of northeastern China. The well flowed 1,700 bopd and 0.4 MMcfgd from 85 ft of pay. It was drilled to a 7,267-ft TD in 85 ft of water, and is 24 mi west of QHD32-6 Field.

Elsewhere in Bohai Bay, CNOOC discovered oil with its JinZhou (JZ) 20-2N well. It tested 1,900 bopd and 0.35 MMcfgd from 110 ft of pay. The well was drilled to a 12,205-ft TD in 52 ft of water, and is located 2.5 mi from JZ20-2 Field.

PT Medco E&P made a discovery with its South Sebuku-1 (SS-1) well on the East Kalimantan Bengara I Block onshore Indonesia. The well tested at a combined rate of 10.9 MMcfd from two intervals within Tabul and Meliat reservoirs. It was drilled to a 5,029-ft TD, 9 mi from South Sembakung Field. PT Medco E&P operates with a 35% interest in partnership with PTTEP (40%) and Salamander Energy (25%).

Eurasia. Melrose Resources’ Kaliakra-2 appraisal well on Black Sea Block 3 found 67 ft of net gas pay in Paleocene reservoirs, at a location about 1 mi from the Kaliakra-1 discovery offshore Bulgaria. Reserves are estimated at 57 Bcf in the well, which was drilled to a TD of  2,679 ft.

Arthur Berman is a geological consultant specializing in petroleum geology, seismic interpretation and database design and management. He has over 20 years working for major oil companies and was editor of the Houston Geological Society’s Bulletin. He earned an MS in geology from the Colorado School of Mines.