COILED TUBING RIG DRILLS CANADIAN HOLE

March 6, 1995
Coiled tubing drilling (CTD) operations have spread to Canada with the first reported successful reentry to drill a horizontal well bore. Shell Canada Ltd. in January reentered its 12-33 well in Alberta's House Mountain field and used a coiled tubing unit to drill a 970 ft horizontal section through Devonian Slave Point pay at 2,100 m true vertical depth. Shell in late February was accumulating production data to fully weigh the results of the CTD procedure compared with those of horizontal

Coiled tubing drilling (CTD) operations have spread to Canada with the first reported successful reentry to drill a horizontal well bore.

Shell Canada Ltd. in January reentered its 12-33 well in Alberta's House Mountain field and used a coiled tubing unit to drill a 970 ft horizontal section through Devonian Slave Point pay at 2,100 m true vertical depth.

Shell in late February was accumulating production data to fully weigh the results of the CTD procedure compared with those of horizontal wellbores drilled with conventional rotary rigs.

However, Shell's contractors on the job-the Dowell and Anadrill units of Schlumberger Oilfield Services, Houston-said the CTD application was a technical success.

Shell used a conventional rig to pull the well's production tubing, then set a whipstock and drilled out of the old vertical hole with a 3X in. bit to the targeted zone. Once in the interval, Dowell replaced the conventional rig with a coiled tubing unit and drilled the horizontal section underbalanced using brine and nitrogen as the drilling medium.

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