Bi-setting and Leak-proof Cement Slurry Technology of Whole Well Sealing of Horizontal Wells

To improve the cementing quality of shale gas leaking horizontal wells,a leak-proof and bi-setting cement slurry system of whole well sealing of horizontal wells was developed.The performance of cement slurry system was studied and evaluated in laboratory.The result showed that the cement slurry not only had high strength of set cement,but also had rapid velocity of static gel strength development and short thickening transition time.In addition,it had stronger anti-channeling and good plugging effects.It was of great significance for ensuring the cementing quality and subsequent completion operation.This cement slurry system has been used in the horizontal well cementing in Jiaoshiba Area and it is successfully used for cementing in 3 horizontal wells with serious leakage.Also all the cement slurry is returned to the ground successfully.After waiting on cement for 48 h,well test of logging indicates that the cementing quality of the horizontal segment is very well.