Drilling technique of Well BY-1HF for shale reservoir

Well BY-1HF is the first exploration well drilled in shale formation in He’nan Oilfield. Based on the information of ad-jacent wells and technical difficulties, the wellbore structure, drilling fluid and cementing technique are designed. Firstly, the pilot hole is drilled, and then backfilled and side tracked. Water based polymer drilling fluid is used in the side tracked section, and serious hole instability is encountered when drilling long distance mud shale formation. The new techniques of rotation directional tool, white oil based drilling fluid and sectional tie-back cementing were used in the third drilling section, which ensured the drilling safety, wellbore quality and cementing quality, and raised drilling speed. The footage of 1 122 m is drilled with only 6 days and one trip, and the horizon-tal section is 1 044 m with average overcut rate of 3.88%. The tripping, drifting, logging and casing running processes are successful, and the cementing work is qualified.