Application of hydraulic casing centralizer in sidetracked horizontal well drilling

When drilling the buildup section and horizontal section of conventional sidetracked horizontal wells, the drilling tools are difficult to be centralized, leading to uneven cement thickness, and poor cementing quality, resulting in water and sand production. The problem would lead to low production rate and short service time of sidetracked wells. In field application, centralizer is commonly used to improve the casing centralizing degree, but conventional centralizer has poor centralizing effect and would break wellbore. Therefore, a type of Hydraulic casing centralizer was developed. The tool has small original outer diameter, safe tripping process, large expended outer diameter, and great uprighting capacity, so it can greatly improve the centralizing degress of the completion string of sidetracked horizontal wells. Furthermore, the technique can improve cementing quality, enlarge service time of sidetracked horizontal wells, and increase production rate and economical effect. The tools are simple being applied in field, with no passive effect on normal drilling process. The tools have been applied on many wells in Liaohe and Jidong fields with good effect.