In the early stage of shale gas block in southern Pingqiao

the annular pressure phenomenon of casing production existed in high pressure shale gas wells

so that the elastic and ductile cement slurry system is optimized to improve the cementing quality and improve the long-term sealing ability of cement ring. Comprehensive analysis for the reason of this phenomenon is made

and through the physical simulation device

the sealing ability evaluation experiment of cement ring is carried out to reveal it. By interphase filling technology

the brittleness of cement is improved. Meanwhile

nano-emulsion filling technology is used to realize void filling and reduce porosity of cement and micro-ring gap. After the optimization of cement slurry system

the elastic modulus of cement slurry and the residual strain of cement slurry are reduced more than 10 % and 30 % respectively. As for as the field application of 6 wells in site

the cementing quality rate is 100 %

and the casing annulus pressure phenomenon has not happened yet. The application of low residual strain elastic ductile cement slurry system provides new technical method and means for shale gas wells to prevent annulus zone pressure

which have a good reference significance and popularization value.