Research On Cementing Technology Of Shale Gas Horizonal Well

Shale gas horizontal well cementing, as one of the petroleum industry focuses, has beenstudying both in China and abroad. It’s also a reason for restricting the speed of China’s shalegas exploration and development. Shale gas reservoirs often have the characteristics of lowporosity and low permeability, and hydraulic fracturing and other stimulation treatments areoften taken to connect nature fractures, so the demand for cementing quality is very high. Atpresent, shale gas horizontal well cementing is confronted with a lot of technical difficulties,such as, difficult running casing, bad casing centralization, low cement displacementefficiency, poor performance of cement ring, and so on.Based on a comprehensive review on the technology of shale gas horizontal wellcementing and an analyses on the key technologies of shale gas horizontal well cementing,this paper explores the effective ways to improve the cementing quality from three aspects:the technology of casing running and centralization, the technology of improvingdisplacement efficiency, and the cement slurry system. It comes to some main conclusionsthat:①Casing running ability can be improved by the use of the technology of floatingcasing running and the elastic and rigid centralizers which are installed on the casing stringevery20meters along can keep the casing at the center of borehole.②The Oil-based pre-padfluid of QZY can be used to raise slurry displacement efficiency of the horizontal well inshale gas reservoirs.③It has hit upon a low-density foam cement slurry system and aconventional density cement slurry system, which are suitable for the cementing of thehorizontal well in shale gas reservoirs. The study results are applied for the cementing of thehorizontal well in shale gas reservoirs, and have obtained good effects.