Volume 3, issue #8 - 12-03-1998

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Drilling went beyond 10 km in UK's Wytch Farm

Jan. 26, 1998 Anadrill has played a major role as directional drilling, measurements-while-drilling and mud logging contractor for the BP and partners' Wytch Farm extended reach drilling project in achieving the world's longest stepout while drilling the field's M11SPY well.
Anadrill also provided well planning services with associated drilling engineering support at Wytch Farm.
The 33,181-ft (10,114-m) stepout was the first to break the 10 km barrier and exceeded the previous record by 6,729 ft (2,051 m). The M11 well, which took 173 days to drill and case, reached a total depth of 34,967 ft (10,658 m). True vertical depth at total depth was 5,266 ft (1,605 m).
As directional drilling and MWD contractor, Anadrill provided downhole tools and services, including PowerPak(a) motors, CDR(a) Compensated Dual Resistivity tool with annulus pressure measurements, ADN(a) Azimuthal Density Neutron tool and Powerpulse(a) MWD tool with downhole weight-on-bit, torque and multiaxis shock measurements.
The logging-while-drilling string in the hole on the final run also set a record for the deepest MWD triple-combo transmission, breaking the old record, also held by Anadrill, by nearly a mile. All recorded data were successfully retrieved, breaking the recorded LWD record by more than 4,000 ft.
The M11 well is the 14th extended reach well drilled since BP and its partners began the Wytch Farm project in April 1993. It was drilled as part of the Stage III development of the offshore section of the field's Sherwood reservoir, for which BP received the Queen's Award for Environmental Achievement in April 1995.
"The enthusiasm and energy imported by our contractors, such as Anadrill, on this project have been truly impressive. Without it I doubt we could have even contemplated going for the 10-km target," said BP Drilling Project Manager Paul Tooms.
"At times it was pretty tough going on M11. But we have learned so much that doing it again would be a lot easier and cheaper. Indeed it has opened up possibilities that we hadn't previously considered seriously."
The Wytch Farm oil field, located on the South Coast of England, is the largest onshore oil field in Western Europe, producing some 100,000 bpd from the Sherwood Triassic and Bridport Jurassic sandstones. Half of the recoverable reserves extends offshore, under Poole Bay.
BP originally planned to develop the field's offshore reserves by building an artificial island at a capital cost of $ 260 million, with the first oil forecast for 1996. However, in late 1991, the company concluded that extended reach drilling could reduce capital expenditures by 50 % and advance the first oil by three years to 1993 and opted for that alternative.
Tooms added, "Demonstrating that it is possible to drill to such an extended reach opens up options to reach oil deposits economically elsewhere in the world -- the implications are huge."
The Wytch Farm oilfield is operated by BP Exploration on behalf of its partners, ARCO British Ltd, Premier Oil Exploration Ltd, ONEPM Petroleum, Clyde Petroleum (Dorset) Ltd and Talisman North Sea Ltd.
Anadrill's core product lines are directional drilling and MWD/LWD. Anadrill is an operating unit of the Schlumberger Oilfield Services.