Underbalanced coiled tubing sidetrack successful

Journal Article · Mon Dec 18 04:00:00 EST 1995 · Oil and Gas Journal

OSTI ID:153738

Adam, J; Berry, M ^[1]

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1. Nederlandse Aardolie Maatschappij B.V., Assen (Netherlands)

The technique of drilling through a completion string, underbalanced, with coiled tubing eliminated some of the problems encountered with overbalanced drilling in a group of offset wells. This project confirmed that performing drilling operations in live wells can be carried out safely and effectively. Dalen is a sour gas field in the eastern part of The Netherlands and produces from vertical fractures in the Zechstein carbonate reservoir. The proposal for Dalen 2 was to abandon the lower section of the original hole and subsequently sidetrack conventionally to the top of the reservoir, run and cement a 5-in. liner, complete the well with a 5-in. monobore completion, and install the christmas tree. This part of the operation would be performed with a workover hoist. Thereafter, a 3 3/4-in. hole would be drilled through the completion and into the reservoir, underbalanced with coiled tubing. The drilling proposal had to address a number of key issues: creating underbalanced conditions; handling sour gas production at surface; handling and treating drilling fluids at surface; removing drilled solids from the returned fluid system; and deploying a long coiled tubing drilling bottom hole assembly (BHA) into a live well. The paper discusses planning, legislative issues, well preparation, the drilling program, and lessons learned.

• OSTI ID: 153738
• Journal Information: Oil and Gas Journal, Journal Name: Oil and Gas Journal Journal Issue: 51 Vol. 93; ISSN OIGJAV; ISSN 0030-1388
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ACIDIZATION
CEMENTING
CONSTRAINTS
DIRECTIONAL DRILLING
DRILLING FLUIDS
FIELD PRODUCTION EQUIPMENT
GEOLOGIC FRACTURES
HYDROGEN SULFIDES
NATURAL GAS PROCESSING PLANTS
NATURAL GAS WELLS
NETHERLANDS
POLLUTION REGULATIONS
WASTE PROCESSING
WELL CASINGS
WELL DRILLING