Elastomeric Cement Slurry System

By adding elastomeric toughening materials to cement slurry, the cement stone's elastoplasticity is improved without affecting the conventional performance of the cement slurry. The elastic modulus can be reduced to less than 7 GPa, increasing impact toughness by 23% and flexural strength by 10%. Under triaxial stress conditions, the cement stone strain exceeds 3.5%, exhibiting higher tensile strength and significantly increasing the Poisson's ratio. The cement ring can withstand more cycles of alternating stress, maintaining good bonding with the casing, which is advantageous for improving well cementing quality and cement ring sealing integrity. In recent years, this approach has been applied in the cementing of horizontal shale gas wells in 52 instances, with no occurrences of annular pressure.