Sidetracking technology of new three-stage well structure in Tahe Oilfield

 67 wells have been drilled since a new three-stage well structure was tested and promoted in the Tahe Oilfield in August of 2011. Considering the sidetracking needs of these wells, a sidetracking technology program is presented in this paper. First, mudstone is drilled with 165. 1 mm bit and cemented with 139. 7 mm casing. Second, to reach design depth with 118 mm bit. Meanwhile, the feasibility of 139. 7 mm casing cementing and the directed drilling technique support of sidetracking slim hole are discussed. The optimized sidetracking technique program is proved feasible, and can meet the sidetracking requirements of new three-stage well structure in the Tahe Oilfield.