In general, the injection of water into the ground can help to increase the pore pressure in the rocks, which can reduce the shear stress on faults and thus decrease the likelihood of earthquakes. This technique, known as "induced seismicity mitigation," has been used in some cases to mitigate the risk of earthquakes caused by fluid withdrawal or the injection of fluids for enhanced oil recovery. However, it is important to note that induced seismicity mitigation requires careful planning and monitoring, as the injection of water can also lead to increased seismicity if not properly managed.
In the case of using excess water from oil and gas operations to reduce seismicity in agricultural areas, several factors would need to be considered. First, it would be necessary to assess the specific geological conditions in the area where the injection would take place, as the effectiveness of induced seismicity mitigation can depend on the local geology. Second, it would be necessary to determine the appropriate volume and rate of water injection, as too much or too rapid injection could lead to increased seismicity. Third, it would be important to monitor the effects of the injection, both in terms of seismicity and other potential impacts such as changes in groundwater levels or soil stability.
Overall, while it is possible that using excess water from oil and gas operations could help to reduce seismicity in some agricultural areas, it is important to carefully assess the specific conditions and potential impacts before implementing such an approach. Consultation with experts in hydrogeology, seismology, and other relevant fields would be crucial to ensure the safety and effectiveness of any such project.