Discoveries support UK's good reputation

Tie-in of the Haltenpipe line to a pipeline laid from Norway's west coast was recently performed remotely by an ROV deployed from a construction vessel. The 28-degree slope at the junction point, in 350 meters of water, was too dangerous for a diver in a hyperbaric welding chamber. After the two pipes were aligned for the connection, the Morgripe coupling (system pictured) was hydraulically actuated to mechanically lock the pipes together. The connection passed external and internal pressure tests.

Britain is the nation most favored for new exploration/production ventures, according to the 1996 league table from consultants Roberston Research International. In a survey of 111 oil companies, the UK fended off Venezuela, Indonesia, and Algeria due mainly to its attractive fiscal environment for producers and progressive licensing arrangements.

Until recently, however, the exploration end-product didn't justify that tag. But four newly announced finds have revived the UK sector. In particular, BP/Shell's Suilven north of the Foinaven and Schiehallion Fields in block 204/9. The well was drilled in 850 meters of water by the semi Ocean Alliance a year ago. Although it wasn't tested, hydrocarbons were confirmed by the log and core data.

Further appraisal is needed to establish commerciality. Britain's government responded by rushing forward two new blocks north of Suilven for licensing. There have been numerous tight hole wells west of the Shetland over the past year. This more positive announcement may arrest flagging interest in the region.

British Gas continued the good work with a rare UK oil find in central North Sea block 15/23d. The Santa Fe 135 encountered a 266-ft gross oil column in Upper Jurassic sandstones, testing over 7,500 b/d on a 32/64-in. choke, with 9 mcf/d of associated gas. The HT/HP well was suspended in February for re-entry later on. British Gas is discussing a fast-track development with operators of nearby fields. To the north is Texaco's Galley, itself at the planning stage for production via a semi.

Phillips bolstered the J-block assets value following appraisal of the 1996 Jade discovery. The new well was drilled from a nine-slot spacer frame placed on the seabed in November in anticipation of a quick development. With a TD of nearly 17,000 ft, the latest HT/HP well practically mirrored the results of its predecessor - a 1,300 ft thick hydrocarbon column with no water contact. Two intervals were tested, both flowing copious gas and condensate. A subsea tieback to the Judy/Joanne platform looks the likely solution, probably onstream late 1998. The gas would not be impacted by the litigation with Enron over supplies from Judy/Joanne.

Finally, Mobil declared test rates of 30 mcf/d from well 48/12d-9, drilled by the Rowan Halifax jack-up five miles west of Mobil's Galahad platform in its southern sector stronghold.

Ramform shapes up for Banff

Conoco, which is close to first oil from its MacCulloch Field production vessel, has chosen more unconventional designs for its next UK developments. PGS has reconfigured the delta-shaped Ramform seismic boat for FPSO service on the Banff oil and gas field in block 29/2a. As with MacCulloch, Conoco is also contracting out engineering and production management, this time to PGS and Atlantic Power.

Banff, discovered in 1991, was recently subjected to an extended production test through two new producer wells. 5MM bbl were gleaned over six months, with good flow rates achieved. Again as with MacCulloch, Conoco is aiming for a very tight track, with first oil due in June 1998. However, MacCulloch is currently six months behind schedule.

Brovig Offshore's anti-pollution vessel Crystal Sea finally looks to have landed an assignment for Conoco's 40MM bbl Buckland Field, after a period on the sidelines. Assuming Buckland comes onstream next year as well, Conoco UK should fortify its position as the pacesetter for replacing spent Conoco Corp. oil reserves.

Elf keeps Dutch run going

Following an ultra-lean period for exploration on the Dutch Shelf, the gloom has suddenly lifted. Twenty-seven offshore exploration and appraisal wells completed last year yielded one oil and 10 gas strikes. Now Elf Petroland has announced two further gas finds on blocks K1a and K4a.

Well K1-3, the first drilled on this block by Elf, located a sizable payzone in lower Permian sandstone. The yield is estimated at 3 mcm/d, which could be exploited quickly via a connection to Lasmo's Markham platform.

Carboniferous discovery well K4-10 was Elf's fourth consecutive success in block K4a, with production potential of 1.4 mcm/d. Elf is already into a subsea development in this block, through the completed discovery well K4-6, which is due onstream this fall. A second find in the block will be tapped next year using an unmanned satellite platform.

NPD highlights small field potential

PDOs for at least 19 small Norwegian fields will be issued over the next two years, according to Norway's Petroleum Directorate. Their combined reserves are put at 1.5 billion bbl of oil and 240 bcm of gas, over half of which could be developed through existing infrastructure. NPD points to enabling technologies such as multiphase pumping, ERD and subsea wells and floaters to counter the larger water depths. In total, NPD has challenged operators to develop 108 small finds to sustain Norwegian production above 3MM b/d beyond 2005.

Prospects include Heidrun North, discovered eight km north of the main Heidrun Field in 1990. Three development options are under review, including a standalone production ship. Should a planned appraisal well raise reserve estimates to 50MM bbl, as expected, production could start in 1999.

More nations in line for Norwegian gas

Statoil has confirmed that a T-piece will be included on the Europipe II gas trunkline from Kaarsto to Emden. This will allow a 120-km, 28-in spur line to be laid to Nybro on the west Jutland coast, conceivably carrying 2 bcm/yr through the Danish network to Sweden.

One part-candidate for the exports could be a Statoil discovery in block 34/1, close to Gullfaks. A recent appraisal of the 1994 strike, tentatively named Kvitebjorn, tested 28 mcf/d and over 3,000 b/d condensate. The resultant reserves upgrade suggests it is nearly twice as big as the nearby Huldra Field, says Statoil, which is thought to house 22 bcm of gas.

Ekofisk's redevelopment has necessitated rerouting of gas exports from Amoco's Valhall to Emden, Germany through a new line that connects to the Norpipe trunkline. Due to Norpipe's higher pressures, Amoco has commissioned a 550 ton compressor module from ABB and Heerema Tonsberg for installation on its new Valhall wellhead platform.