DRILLING REMAINS BRISK OFF NORTHERN EUROPE

Drilling activity remains high off northern Europe, drawing in newly built rigs and units from other parts of the world. Midway through the region's peak summer drilling season there were 138 rigs available in northern Europe-eight more than at the same time last year. Of these, 13 were idle (seven semis, five jack ups, and a drillship). Ninety-four of the rigs were drilling, six more than last year. The rest were being used as accommodation or production units or were undergoing

Sept. 2, 1991

7 min read

Drilling activity remains high off northern Europe, drawing in newly built rigs and units from other parts of the world.

Midway through the region's peak summer drilling season there were 138 rigs available in northern Europe-eight more than at the same time last year. Of these, 13 were idle (seven semis, five jack ups, and a drillship).

Ninety-four of the rigs were drilling, six more than last year. The rest were being used as accommodation or production units or were undergoing conversion or maintenance.

Britain continues to dominate the drilling activity. Sixty of the 94 drilling units were in U.K. waters, five more than in summer 1990. Norway accounted for 15 active rigs, compared with 11 at the same time last year.

In Holland, the number of active rigs-all jack ups-fell to 13 from 15 last year. The Danish effort was almost unchanged, with six rigs this year vs. five in 1990.

Ireland had a single drilling unit. There was no drilling in French or German waters.

All the new rig capacity in northern Europe has gone into exploration and appraisal drilling. Fifty-two rigs at midsummer were working in these categories, compared with 49 last year. The number of rigs drilling development wells increased to 42 from 39.

The drilling effort has benefited from regular releases of acreage, principally in Britain and Norway.

Britain awarded 74 new blocks in its 12th licensing round. Successful applicants agreed to work programs involving 167 wells. The 12th round coincided with the first frontier round, which awarded 6 tracts in the lightly explored Atlantic west of Scotland.

The government offered preferential terms for tracts in these deep waters. Operators are not required to make any drilling commitment in the early years, but subsequent relinquishments will be governed by the level of drilling in initial license periods.

Activity in the frontier area was boosted by the decision of operators in multiblock Clair field to run a jointly funded appraisal program including a horizontal well and hydraulic fracturing of a vertical well. Both wells, operated by BP Exploration and Elf U.K., are being completed this summer.

Clair is a large, heavy oil accumulation that looked like a prospect for development in the next century. However, the joint program funded by eight companies could lead to an extended test program on both wells next summer.

ELF'S DEEP WELL

One of the longest and deepest wells drilled in the U.K. sector recently tested 13 MMcfd of gas and 3,300 b/d of condensate. Elf (U.K.) Ltd. 22/30c-8 was drilled to 18,855 ft in 10 months, the second deepest well ever drilled in U.K. waters.

The discovery is 3 miles north of Ultramar Exploration's large Franklin gas-condensate find, where an appraisal program is in progress. Initial estimates of reserves from Elf's find are 1 tcf of gas and 200 million bbl of liquids.

BP Exploration is drilling the first diapir salt dome play in the North Sea in Quadrants 22 and 23. BP has discovered six oil and gas-condensate fields, and 1991 drilling has brought total reserves to about 660 million bbl of oil equivalent.

In the southern U.K. North Sea, Conoco has proved up more reserves around its Murdoch prospects in Quadrant 44, while to the west ARCO British made a promising find in the lightly explored area between the Esmond/Forbes/Gordon complex and the main producing field farther south. The 43/24-1 well tested 34 MMcfd. The structure contains an estimated 300 bcf of gas reserves.

Enterprise Oil made a discovery in Block 48/22 in another lightly explored area southwest of Lancelot field. It tested 27 MMcfd of gas.

Outside the North Sea, Hamilton Bros. Oil & Gas made a discovery in Block 110/13 in the Morecambe Bay area off Northwest England. Its 110/13-5 tested 70 MMcfd and 80 MMcfd of gas from two intervals from a structure in the northern part of the block. Hamilton, now wholly owned by BHP Petroleum, previously had found a large gas structure in the eastern part of the block.

Drilling has resumed in the English Channel. Occidental Petroleum (Caledonia) drilled a tight hole on Block 98/16 about 7 1/2 miles off Dorset. The well is close to BP Exploration's offshore extension of onshore Wytch Farm field.

NORWEGIAN SURGE

Exploration activity has surged off Norway, especially in the North Sea. And recent acreage allocations should reverse a slump off mid-Norway and in the Barents Sea.

Norsk Hydro, concentrating its efforts in the North Sea, is ready to move north again. It plans to use all four semisubmersibles it has under charter for exploratory drilling, instead of just two, as it has recently.

One well will be drilled in the lightly explored More area just north of the 62nd Parallel, where the first well in the second half of last year had noncommercial hydrocarbon shows. A well is also planned for the Barents Sea.

Esso Norge, the most active of the non-Norwegian companies in Norway's northern Arctic waters is also returning to the area for a well on either Block 7122/1 or 7122/4, awarded in the 13th round. Late this year Esso will spud a second well on its acreage in the Nordland area north of Haltenbanken.

Interest in the nearby Nordland 11 area increased following a small Jurassic gas-condensate find by Den norske stats oljeselskap AS (Statoil) on Block 6507/3.

The noncommercial find was the first indication that hydrocarbons are present in this area.

DANISH ACTION

Interest in Danish waters focuses on the area around Harald field and the median line with Norwegian waters.

A unit of Statoil took nearly 11 months to drill and test the Amalie-1 well on Block 5604/26. It drilled the well to 17,449 ft to test gas and condensate from a Jurassic horizon.

But the well found oil in a separate horizon at about 13,000 ft. Test results haven't been disclosed. Statoil plans to conduct more 3D seismic work and to drill an appraisal well next year.

Provided the promise of the oil zone is repeated by the appraisal well, Statoil could be sitting on one of the biggest liquids reservoirs in Danish waters.

The discovery well is close to Harald field, operated by Dansk Undergrunds Consortium, and the Lulita prospect discovered across the median line in Norwegian waters earlier in the year by Norske Shell.

In the central producing area, attention has focused on the Skjold Flank-1 well, which has been drilled to 13,120 ft to test the Middle Jurassic below the producing Upper Cretaceous/Paleocene chalk reservoir.

DUTCH DISCOVERY

Most Dutch sector drilling has been around the main gas fields and few offshore oil prospects.

Placid's N/7-2 gas discovery close to the eastern border with German waters found an interesting eastern extension of Ameland Nord field.

But Placid's attempt to find reserves in the O quadrant in the far southern part of Dutch waters was not successful.

Exploration should get a boost from the eighth licensing round announced earlier this summer. The Ministry of Economic Affairs said 114 blocks that were open on June 6, 1991, will be included in the round. Applications must be received before Apr. 1, 1992, and awards are expected before the end of the year.

Drilling is about to resume in the German North Sea after a break of several years.

At the end of last year ARCO Germany acquired a 100% stake in two licenses covering 29 blocks in the central and eastern parts of the German sector to supplement its holdings to the south. Since 1988, ARCO has been shooting seismic surveys in the German sector. It expects to begin drilling on Block L/3 in September or October.

Previous drilling in this area found small gas accumulations with high nitrogen content. ARCO has developed a model that it hopes will reduce the risk of finding the high nitrogen content gas.