Jeremy Beckman • London
Rig shortage constrains Norwegian activity
Norwegian sector operators should drill 35-40 exploration wells in 2008, up from 33 last year, according to the Norwegian Petroleum Directorate. However, the numbers would be higher if more rigs were available: lack of capacity, the NPD says, has caused numerous license commitment wells to be postponed.
Recently, the NPD identified 23 rigs under contract on the Norwegian shelf, two-thirds of these taken by StatoilHydro. Wells of late seem to be delivering results – the best may be a gas/oil zone in mid-Jurassic sandstones which was drilled as an extension of a producer well on StatoilHydro’s Alve field in the Norwegian Sea. Farther south, the same operator found gas in the Natalia structure, drilled by the semisubWest Alpha 5 km (3.1 mi) northwest of the Midgard field. NPD estimates Natalia’s recoverable reserves at around 1.5 bcm (53 bcf).
In the North Sea, StatoilHydro made two small finds in the Oseberg area, both prospective tieback developments. Elsewhere in this sector, the jackupMaersk Guardian found oil and gas in Jurassic and Mid-Triassic sandstones for BG Norge in the Pi-North prospect; and Det norske’s wildcat on the Draupne structure encountered oil with a small gas cap. Det norske estimates prospective oil of at least 65 MMbbl, sufficient for Draupne to serve as a potential field center, also tying in the nearby Hanz and West Cable discoveries.
More SGB fields onstream
Shell has started operations at two new fields in the UK southern gas basin. It has developed Caravel and Shamrock with Monotower platforms, both fabricated at the HSM yard north of Rotterdam. The Monotower is an in-house Shell design powered by wind and solar energy. At peak, the two fields will export a combined 220 MMcf/d to the Bacton terminal on the Norfolk coast.
In the same sector, Dana Petroleum has government approval for Babbage, another platform-based development. Plans involve an initial three wells with an option for two more after first gas, scheduled for early 2010. Production will be transported via a 28 km (17.4 mi) pipeline to BP’s West Sole complex, and onwards to the Dimlington terminal in Humberside. Another Dana-operated gas project, the Barbara/Phyllis joint development in the central North Sea, is at the pre-sanction phase.
In the far northern UK sector, Dana has discovered oil in a Brent reservoir while drilling the West Rinnes structure and a subsequent side track into East Rinnes in block 210-24a. The oil quality is similar to that being produced at the company’s nearby Hudson field. Dana plans to re-interpret existing seismic data using the new well data,with a view to identifying further prospects for exploration.
Majors extend deepwater frontiers
Seismic ships are setting a course for the eastern Atlantic. Scan Geophysical’sM/V Geo Searcher is about to start an 8,500 km (5,281 mi) long-offset 2D survey offshore Portugal for a consortium of Petrobras, Galp, and Partex. The survey will employ a 10,000 m (32,808 ft) long MSX solid (gel-filled) streamer system and a 4,000 cu in. source array designed for low frequency output.
TheMalene Ostervold recently completed a 2D seismic acquisition campaign for Milesian in Ireland’s Celtic Sea.
Around 200 km (124 mi) off Ireland’s southwest coast, ExxonMobil and Providence Resources have contracted theM/V CGG Princess for a 2D survey over frontier licenses 1/08 and 2/08. Both were awarded in March under the Porcupine basin licensing round, and cover a total of 13 blocks, including the large Drombeg prospect, in water depths of 2-3,000 m (6,561-9,842 ft). Nearby the partners also have acquired and processed long-offset 2D seismic reflection data over the Dunquin and Goban Spur structures.
Milesian Oil & Gas recently concluded a 2D campaign in another new license in the Celtic Sea off southern Ireland. Here Wavefield Seismic’sMalene Ostervold acquired 495 km (307 mi) of seismic over the Amergin and Eremon structures, both identified from existing seismic data. Milesian assesses Amergin as a potential 63 MMboe prospect.
Polymers could boost Captain output
Chevron is examining polymers as a means to enhance recovery from its Captain heavy-oil field in the UK central North Sea. The company’s long-term aim is 50% recovery by the end of field life, each extra percent of production representing around 10 MMbbl.
A team in Aberdeen is working with the group’s Energy Technology Company (ETC) in Houston to evaluate a polymer flood followed by application of alkali surfactant polymers to improve sweep efficiency. Polymers thicken injection water, pushing increased amounts of oil ahead of it on its passage through the reservoir, while surfactant with alkaloids separates and mobilizes further oil from the reservoir sand.
The team has been studying successful and unsuccessful applications of polymer flooding. Past failures can be attributed to incomplete reservoir management, poor modeling of process mechanisms at field scale, or unavailability of appropriate polymers and surfactants in required quantities, they say.
Chevron also is drawing on the experience of its IndoAsia business unit, which has been working on a surfactant/polymer EOR project for the Minas field in Indonesia, expected to go to field trials in 2011. ETC and Aberdeen are working to characterize the various polymers that might be suitable for Captain, as well as to develop reservoir simulation models. Their aim is to run a pilot on a single injector well during 2009.
Island offloads Dutch licenses
Island Oil & Gas is selling various interests in the Dutch North Sea to Delta Hydrocarbons for $25 million. These include Island’s 83.33% interest in the Q13a production license, containing the undeveloped Amstel oil field, and 100% of the recently awarded Q13b exploration license which houses another undeveloped oil field, Zaan.
Island plans to use the proceeds to inject capital into its projects offshore Ireland and elsewhere, but insists it is open to acquiring further licenses in the Netherlands.
