DIRECTIONAL DRILLING TECHNOLOGY FOR LIAN 30-1

Lian 30-1 is a directional well with a designed horizontal displacement of 2108.73m, and its target is located at the bottom of Jinghang Channel. ZJ45 rig and conventional directional drilling technologies were used, with such equipment as dual stand pipe, high-frequency linear shale shaker, dual centrifuges equipped. Casing program, well profile and cementing design were optimized, and such advanced drilling technologies as wired MWD, wireless MWD, steering drill, reversed drill string, composite metal ionic polymer drilling fluid for sloughing control, PDC bit were also applied. This well was successful drilled, with its total measured depth drilled to 3590 m and TVD to 2762.56 m, max. inclination is 51.10° and drilling period of 47 days, and no drilling accidents or troubles were encountered. The drilling practice of Lian 30-1 proved that the conventional drilling technology and equipment is capable of drilling directional well with horizontal displacement of less than 2500 m, as only as proper techniques are conducted.