The model of aquifer’s horizontal elastic displacement caused by water injection is difficult to solve because adequate description of its boundary conditions is unavailable. According to the anti-symmetric characteristics of constant-rate pumping and injection flow in Theis confined systems

it is assumed that their infinite boundaries of bulk flux should be also anti-symmetric and then the solution of aquifer’s horizontal elastic displacement with constant-rate water injection is derived. The results show that the skeletal solids movement velocity and its accumulated displacement

radial strain and tangential strain are expressed in constant-rate injection process as negative ones as they are expressed in constant-rate pumping process. In the injection process

there are two types of radial deformation areas: extension one is near to the well and compressive one is far from the well. The maximum displacement exists along the line dividing the two areas. If the confining beds of the aquifer are relatively stable

the relative displacement of the aquifer caused by water injection is enough to make well casings of water and oil wells deformed or even damaged. The aquifer keeps extension in tangential direction and the maximum tangential strain locates in the borehole wall

which can lead to radial tensile fractures of well adjacent rock.