DRILLING & PRODUCTION

A coiled tubing conveyed electric submersible pump deployed in the UK by XLT of Aberdeen incorporated a high voltage power cable inside the tubing. The well was live during the insertion of the 2-3/8-in. tubing.

Pump, power cable deployed in live well with coiled tubing

A coiled tubing conveyed electric submersible pump was deployed in a live UK well that incorporated a high voltage power cable inside the tubing. The well installation was conducted by XLT of Aberdeen.

The pump assembly was run with 2-3/8-in. coiled tubing. The system employed a separate downhole packer with a polished bore receptacle so the assembly could be landed and retrieved without excessive loads. The well depth was 3,000 ft and included a 50 deviation. Installation time for the project was 16 hours.

The coiled tubing shields the power cable and other electrical components from differential wellbore pressures and chemicals in wellbore fluids. The shielding allowed the contractor to eliminate the conventional metal wrap for the cable and utilize a type of less expensive cable.

The system was developed as a joint industry project, sponsored by the European Commission, Amoco, Agip, BPX, Edison Oil, Pentex Oil, BIW Connectors, Quality Tubing, and Dowell Schlumberger.

Controlling water use key to managing drilling location waste

The volume of location water at a drilling site that needs handling in an environmentally safe manner is easily as large as the drilled cuttings and as much as 30 times the hole volume. Bill Piper of Amoco Environmental Health & Safety cited the problem for drillers in the April issue of The Brief, a joint industry publication for drilling.

A drilling rig uses 300-1,000 bbl of wash water every day. Piper suggested the following rules to help drillers control waste water generated for both land and offshore sites:

1. Keep cleaner fluids separated from dirtier fluids. Storm water should be kept separate in tanks where regulations constrain run-off. Don't combine oil based wastes with water based wastes.
2. Re-use storm water for mud make-up water or rig washing. Rig wash water can be re-used often.
3. Use the dirtiest water to wash shaker and centrifuge slides, desanders, and desilters. Re-use this water often and add water only as a last resort.
4. Use rig vacuums rather than washing, pistol grips shut-offs on hoses, and high pressure, low-volume washing systems.
5. Develop a detailed plan for handling wastewater volumes at the outset, especially the volumes developed during surface hole drilling.

Gamma ray MWDis run through 12-meter radius

A gamma ray sensing measurement-while-drilling (MWD) unit successfully transited a 12-meter radius (short radius) in a trial application in the US Gulf of Mexico. The short-radius transit is believed to be the first for a gamma ray unit anywhere, according to the developers - Baker Hughes Inteq.

Conventionally, a gamma ray unit cannot withstand the stresses of a short radius turn. A gamma ray ray unit detects naturally occurring radiation in the production formation to strategraphically position the drilling string during the drilling process.

Build four platforms, get fifth one free!

Amoco UK is seeking to build minimum platforms in groups to keep costs down, and is reviewing potential developable fields for that concept. Amoco's projects manager says the savings would equal a free fifth platform, if four were built together.

The cost reduction applies to Amoco's depth-insensitive Amoss (Amoco minimum offshore supporting structure) platform design, which features a submarine quadrapod jacket which supports a single column through the wave zone. Each jacket weighs about 1,050 tons and supports a 400-ton deck. For similar depth applications, the Amoss structures weigh about one-third of conventional structures.

Amoco is installing Amoss units on the Davy and Bessemer Fields in the southern North Sea, and plans to order three more for the Indefatigable Field later this year, with the possibility of more for four other gas developments. Mobil plans to employ the technology for its Galahad development.

Ramform concept examined for testing, early production

Tentech of Kristiansand, Norway is examining the ramform design concept for use in an extended well testing and early production vessel because of the excellent motion characteristics and high up-time in high sea states.

The ramform type of vessel features a wedge shape, with the widest portion of the vessel aft. The aft section is two-three times as wide as other vessels of similar lengths, which is the key to its stability in rolling seas.

The ramform design will emerge later this month as a seismic data collection ship. The design's good motion characteristics, high noise suppression, and great width aft to accommodate a large number of streamers were instrumental in its selection by PGS.

The design was originated by Norwegian naval architect Roar Ramne as a submarine hunter. The Tentech-Ramform vessel is designed to accommodate up to 200,000 bbl with corresponding processing capabilities.

Drilling records:

• Horizontal run: Shell used a Neyrfor-Weir 4-3/4-in. SBS steerable turbine drilling motor to push a six-in. diamond bit through 3,289 ft horizontally in a Leman Echo 49/26 well, beating a 2,724-ft record set offshore Texas.
• Vertical run: Amoco Trinidad drilled to 10,108 ft in the South East Galeota 15 well in 5.9 days with two PDC bits aboard the Rowan Gorilla IV.
• Horizontal penetration: Shell averaged a penetration rate of 28.4 ft/hr with a six-in. diamond bit and a Neyrfor-Weir turbine, beating out an earlier similar bit record of 26.6 ft/hr.

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