Wyoming Administrative Code › Agency 020 - Environmental Quality, Dept. of › Sub-Agency 0007 - Land Quality - Non Coal › Chapter 8 - EXPLORATION BY DRILLING › Section 8-2 - General Drill Hole Abandonment Requirements

Current through July 13, 2024
(a) All drill holes
				sunk for the purpose of conducting exploration by
				drilling
,
including those drilled within a permitted
				mine operation, shall be capped, sealed or plugged in the manner described
				hereinafter.
(b) Drill holes that
				have artesian flow of groundwater to the surface shall be plugged with
				cement-based sealant material, as specified and in the manner described below,
				to prevent fluid communication and adverse changes in water quality or
				quantity.
(c) Drill holes that have
				encountered any ground water or saturated stratum shall be sealed utilizing
				sealant materials and emplacement methods as prescribed hereinafter to prevent
				fluid communication and adverse changes in water quality or quantity.
(d) "Sealant materials" are materials that
				are stable, have low permeability and possesses minimum shrinking properties
				such that they are optimal sealing materials for well plugging and drill hole
				abandonment. Sealant materials shall be either:
1) a fluid mixture of water plus a
				cement-based or bentonite-based material, or
2) a dry bentonite- based material, either
				chips or pellets specifically designed for sealing drill holes. Sealant
				materials shall meet the technical requirements for making a proper seal, shall
				meet applicable recognized industry standards and shall be prepared according
				to manufacturer's directions for specific site requirements. The following are
				approved sealant materials:
(i) Neat Cement
				Slurry must consist of a mixture of Portland Cement and not more than 6 gallons
				of clean water per bag (1 cubic foot or 94 pounds) of cement;
(ii) Sand Cement Slurry must consist of a
				mixture of Portland Cement, sand, and water in the proportion of not more than
				1 part by weight of sand to 1 part of cement with not more than 6 gallons of
				clean water per bag of cement (1 cubic foot or 94 pounds);
(iii) Concrete Slurry must consist of a
				mixture of Portland Cement, sand and gravel aggregate, and water in the
				proportion of not more than 1 part by weight of aggregate to 1 part of cement
				with not more than 6 gallons of clean water per bag of cement;
(iv) Cement/Bentonite Slurry must consist of
				a mixture of cement and bentonite in the proportion of not more than 6.5
				gallons of water and 3 to 5 pounds of powdered bentonite per 94-pound sack of
				Portland cement;
(v) High Solids
				Bentonite Slurry means an inorganic mixture with a slurry density of 9.4
				lbs./gal. minimum (20%) by weight of solids bentonite, with polymers, water, or
				other additives for the yield/rate control, which forms a low permeability seal
				(not greater than 1 x 10-7 cm/sec), and is mixed to the manufacturer's
				specifications; and
(vi) Nonslurry
				Bentonite must consist of chipped or pelletized bentonite varieties
				specifically designed to be used to seal drill holes.
(vii) Abandonment Gel means a mixture of
				bentonite with polymers and other additives and water in the proportion of one
				(1) barrel of water to 15 pounds of abandonment material with a minimum slurry
				density of 8.6 lbs./ gal. Abandonment Gel used to seal boreholes shall meet the
				following specifications when using American Petroleum Institute Standard
				Procedures for Testing Drilling Fluids:
(A)
				Ten minute gel strength of at least 20 lbs. / 100 sq. ft.
(B) Filtrate volume not to exceed 13.5
				cc.
(C) Minimum Marsh Funnel
				viscosity of 60 sec. / quart.