Mich. Admin. Code R. 324.807
Current through Vol. 24-23, January 1, 2025
Rule 807.
During Class II well injection operations, a permittee shall ensure that the surface injection pressure does not exceed a pressure determined by the following equation:
Pm = (fpg - 0.433 sg)d where Pm = surface injection pressure fpg = fracture pressure gradient of the injection interval (if unknown, assume 0.800) sg = specific gravity of the injection liquid (if unknown, assume 1.2) d = depth of the top of the injection interval in feet (true vertical depth). The value for fpg may be determined by an instantaneous shut-in pressure or data derived from step rate testing. Other information to derive fpg values may be used with approval of the supervisor or authorized representative of the supervisor.
Mich. Admin. Code R. 324.807