Tracy Dulle • Houston
Offshore to see more EOR
A study released in May says a major campaign of enhanced oil recovery (EOR) in offshore fields will be crucial to sustain the world’s future oil supply.
Less than 25% of the world’s offshore oil reserves have been produced to date and that opens the door for a big EOR push, according to theFuture Oil & Gas Supply: A Quantitative Analysis by the Oil & Gas Journal Research Center. Petroleum consultant Dr. Rafael Sandrea, who led the study, says EOR is more cost-effective in adding reserves than exploration or acquisition.
Another major aspect of the report is an assessment of the production potential of global offshore oil. Offshore has been the main source of growth for world oil production. Onshore production has been flat essentially during the last two decades, the report says.
North Sea/Europe
StatoilHydro has discovered hydrocarbons in two wells in the Oseberg area in the Norwegian sector of the North Sea. The first discovery was made in a long-reach exploration well from the Oseberg C platform, targeting the Cook formation in the Theta structure.
“The well is designed to be converted to a producer within 45 days after discovery, giving an extremely quick turnover from prospective resources to producible reserves,” says Trond Eide, Oseberg Petech project leader.
StatoilHydro’s Oseberg C platform in the North Sea, where hydrocarbons have been discovered in two wells. Photo courtesy of Helge Hansen, StatoilHydro.
“Work is currently under way to determine the optimal production solution,” says Bjørn Inge Braathen, leader of the exploration team working in the Oseberg area. Depending on the development solution, preliminary expected volumes are around 5 MMbbl of oil.
Oil and gas was also found in the Delta S2 structure in the Oseberg South area. The Delta S2 discovery targeted the Brent Group, and is believed to contain about 16 MMbbl of recoverable oil equivalents. Well 30/9-21S was drilled byTransocean Winner. At print, the rig was drilling a second branch to test the nearby Richards prospect.
According to the company, the Delta S2 discovery may be tied back to the nearby Delta template within a few years, and continued exploration success in the area may trigger new development solutions.
StatoilHydro also has confirmed gas and condensate on the Alve field in the Norwegian Sea around 16 km (10 mi) southeast of the Norne field. Based on a preliminary estimate, the discovery includes 3-5 bcm of gas. A thin oil zone was also proven below the gas.
Extension drilling was carried out and is due to come onstream in January 2009.
The drilling of well 6507/3-5S has been completed, and the well will be temporarily plugged. A completion of the previously proven reservoir is planned for fall 2008.
BG Norge, operator of North Sea production license PL292, proved a gas and oil accumulation in reservoirs of Jurassic (Sleipner formation) and Triassic (Skagerrak formation) age with exploration well 15/12-19. The well was tested at approximately 750 cu m/d (4,717 b/d) of oil.
The overall resource potential is being evaluated and field development planning is under way.
The well was drilled with theMærsk Guardian jackup in a water depth of 86 m (282 ft) to TVD below sea level of 3,169 m (10,397 ft). The rig was scheduled to move to PL 274 to drill exploration well 1/3-11 for Dong.
Following the restart of the Forties pipeline system, Nexen has resumed production from its North Sea fields, which include Buzzard and Scott/Telford. Production is ramping up in accordance with directions from the pipeline operator.
The Forties pipeline was shutdown following a two-day strike by workers at the Grangemouth refinery in Scotland, which provides essential utility services to the operation of the Forties pipeline at BP’s Kinneil plant.
West Africa
Total E&P Congo has brought the Moho-Bilondo field in the Republic of Congo onstream. Discovered in 1995, the field contains estimated reserves of about 230 MMbbl of oil.
Moho-Bilondo is the first producing deepwater development in the Congo The reservoirs will be developed with nine producing wells and five water injectors in two subsea clusters.
Plateau production is forecast at 90,000 b/d in 2010. Insulated umbilicals and flowlines will bring the oil to the FPU, from where it will be exported via a new 16-in. (41-cm), 80-km (50-mi) pipeline to the Total-operated Djeno onshore terminal.
In addition, the Moho Marine Nord 1 and 2 wells, drilled in 2007 in the northern part of the license, revealed significant additional resources of good quality oil, according to Total. New development studies have been launched.
Moho is 9 mi (15 km) off the Congolese coast in the Haute-Mer concession in 2,300 ft (700 m) of water.
Partners on the project are Société Nationale des Pétroles du Congo (15%) and Total E&P Congo (operator and 53.5%), and Chevron (31.5%).
PA Resources has completed drilling appraisal well I-5 on the Benita structure in block I, Equatorial Guinea. The well determined the net oil pay to be over 13 m (43 ft) and defined the oil-water content.
The well was designed to determine down dip reservoir limits and to provide an opportunity to flow test the oil zone. The well was to appraise the extent of the earlier discoveries of oil and gas in the wells I-1 and I-2.
TheSedco 700 drilled the well to TD 3,075 m (10,089 ft). Noble Energy was preparing to flow test the well, after which the rig will drill on a Miocene prospect named Diega in block I.
Asia
SOCO has updated its drilling operations. In Cuu Long basin off southeast Vietnam, SOCO International’s Te Giac Den 1X sidetrack has reached 5,096 m (16,719 ft) MD. The Hoang Long joint operating company was running logs prior to setting casing.
The Te Giac Trang appraisal well has reached its target of 3,437 m (11,276 ft) and is being logged prior to testing.
Three development wells have been drilled on the Ca Ngu Vang oilfield and another well partially drilled and suspended pending installation of an unmanned platform. Once the platform and topsides are in and the drilling rig finishes the TGT-6X appraisal well, where it was redeployed to allow platform installation, the three existing development wells will be tied-back and completed.
The rig then will finish drilling and completing the fourth well before starting the planned four production and two injection drilling program. Major facilities, equipment orders, and installation were proceeding apace to meet the planned onstream date within approximately 60 days. The jacket is set and the first of the two pipelines was being installed.
At Bualuang field off Thailand, a wellhead platform has been installed and five producer wells and one water injection well have been drilled. An FPSO has arrived and should be ready for production by the end of the quarter.
After completing drilling of the Kambuna field development program, production tests were under way on the three production wells.
The first test on the Kambuna-2 well offshore North Sumatra, Indonesia, tested at a stabilized rate of 33 MMcf/d of natural gas, says operator Serica Energy.
Kambuna-2 tested the Belumai reservoir over a 97-ft (30-m) interval from 7,245 to 7,342 ft (2,208-2,238 m) below mean sea level and produced gas at a maximum stabilized rate of 33 MMcf/d on a choke. The flowing wellhead pressure during this test was 1,870 psi (12.9 MPa). Production was limited by the test equipment.
A second test was carried out at production rate more representative of that required from the well when full field production begins, Serica says. During this test on a choke of 48/64 in., Kambuna-2 well produced gas at a stabilized rate of 19 MMcf/d together with 2,000 b/d of 53º API condensate, at a flowing wellhead pressure of 2,280 psi (15.7 MPa).
Further production tests are scheduled on Kambuna-3 and Kambuna-4 this month.
Serica holds 65% in the Kambuna field project.
Middle East
The crude oil reservoir Ras Budran in the Gulf of Suez, 4 km (2.5 mi) off the coast of Sinai, is celebrating 25 years of production, says operator RWE Dea AG.
SUCO was founded as a joint venture between RWE Dea as operator and the Egyptian General Petroleum Corp. Production began in 1983 at 60,000 b/d of oil. To date, 267 MMbbl of crude have been produced.
Last year the production concessions for the oil production areas in the Gulf of Suez were renewed for another 10 years, with additional capital spending earmarked for more development.
Australia
Australia’s Minister for Resources and Energy Martin Ferguson has announced the award of nine offshore exploration permits representing a $425 million investment.
Five permits were awarded off Northern Territory in the Bonaparte basin. Permit NT-P76, which is eligible for the Designated Frontier Area tax incentive, was awarded to SIPC Australia Pty Ltd., while Apache Northwest Pty Ltd. and Total E&P Australia were awarded permits AC/P42 and AC/P43 in equal partnership. Finder Exploration Pty Ltd. was awarded AC/P44 and AC/P45.
Three permits were in the Browse basin. Total E&P Australia won WA-408-P. A consortium including Santos Offshore Pty Ltd., Chevron Australia (W07-5) Pty Ltd., and Inpex Browse Ltd. was awarded WA-410-P, while Santos, Inpex, and Beach Petroleum Ltd. won permit WA-411-P.
Permit WA-409-P in the Carnarvon basin went to Cue Exploration Pty Ltd. and Gascorp Australia Pty Ltd.
A total of 14 bids were received for the nine areas.
Australia’s National Offshore Petroleum Safety Authority (NOPSA) issued a Prohibition Notice preventing petroleum operator Australian FPSO Management Pty Ltd. (AFM) from using a process plant on its offshore facility at Woollybutt field, about 42 km (26 mi) west of Barrow Island, Western Australia, until safety issues are resolved.
The Prohibition Notice follows a recent inspection by NOPSA Occupational Health and Safety Inspectors of AFM’s FPSO,Four Vanguard.
NOPSA is concerned that critical safety systems related to shut down and emergency depressurization within the process plant are not able to meet the standards.
This followed an incident on April 9 onFour Vanguard, when free hydrocarbon gas was detected onboard.
NOPSA is a commonwealth statutory agency that regulates the health and safety of the Australian national offshore petroleum industry through the Petroleum (Submerged Lands) Act 1967.
