A Study On Improving Sidetrack Hole Cementing Quality

The technology of sidetracking in the primary well bore is one of the ways of reducing the well drilling cost and the time spending on well drilling, extending the old well life, it also can increase the crude oil productivity. This article states the study on effective ways to improve cement quality for slim hole after well sidetracking, the most difficult things of well cementation for slim hole of sidetrack well is:the size of slim hole is very small, casings can not keep in the center of annulus, the efficiency of cement replacement is very low; the cement sheath after cementing is not thick enough. The poor cementing of sidetrack well will influent well production. After long-term production the formation pressure of old well is non-uniform, fracturing, waterflooding extraction also make the situation of down hole is very complex. Nowadays the side tracking for old well became more popular and comparing others it is a very effective and economic way to improve the old well productivity. But the problem of cementing for slim hole of sidetracking well as mentioned above become more critical, we have to study on how to overcome the difficulties in cementing of sidetracking well. This paper will state the study on the ways using for improving cementing of slim hole, such as:delayed cementing, opening hole, water plugging, pretreatment of formation, etc.