Section R. 325.1633a - Construction of wells; groutingRule 133a.
(1) Shale traps, cementing baskets, packers, or other devices must not be used to suspend grout above an open annular space. Excessive development, washing, shoveling of cuttings, or other similar activities must not be used to induce collapse of the borehole wall or to reduce the amount of open annular space surrounding a permanent casing.(2) Neat cement or bentonite grout must be placed through the permanent casing or a grout pipe from the bottom of the annular space upward to the ground surface in a continuous operation without interruption. The density of grout flowing from the annular space at the ground surface must be the density of the grout being pumped in.(3) A permanent casing must be installed in a borehole that has a diameter of not less than 2 inches larger than the nominal size of the permanent casing, except as provided in subrule (4) of this rule and R 325.1635.(4) When grout is placed through a grout pipe outside the permanent casing, the borehole diameter must be not less than 2-7/8 inches larger than the nominal casing size.(5) An annular space between a permanent casing and temporary casing must be grouted during temporary casing removal by pumping neat cement or bentonite grout, or by pouring bentonite chips, bentonite pellets, or granular bentonite, into the annular space. Granular bentonite must not be poured into an annular space that contains drilling fluid or water.(6) Neat cement must be allowed to set a minimum of 24 hours when standard type I, type IL, type Ia, type ILA, high-early type III, or type ILHE cement is used. If bentonite is added to neat cement, the grout must be allowed to set a minimum of 48 hours before drilling operations are resumed.Mich. Admin. Code R. 325.1633a
1994 AACS; 2023 MR 10, Eff. 5/26/2023