HORIZONTAL SLIM-HOLE DRILLING WITH COILED TUBING - AN OPERATORS EXPERIENCE

What is believed to be the first horizontal well drilled with directionally controlled coiled tubing recently was completed in the Austin Chalk formation. An existing well was sidetracked out of 4 1/2-in. casing with a conventional whipstock. An average build rate of 15-degrees/ 100 ft was achieved in the curve, and a 1,458-ft vertical section was drilled with 2-in. coiled tubing, downhole mud motors, wireline steering tools, a mechanical downhole orienting tool, and 3 7/8-in. bits. This paper discusses the orienting and directional tools and techniques developed during this operation. It also describes improvements made for the second well.