Patent ID: 7444780

Claim:
A method for producing fertile indigenous top soil at a well site employing spent water-based drilling mud recovered at the well site wherein the fertile indigenous top soil possesses similar microbial and enzyme characteristics as soil at the well site, the method comprising the steps of: providing an apparatus having a hopper, the hopper provided with at least one compartment having a mixing assembly, at least one air supply conduit for supplying air into the at least one compartment; and a discharge assembly for removing the fertile indigenous top soil from the at least one first compartment; moving the apparatus to a position near the well site; admixing effective amounts of spent water-based drilling mud, mature compost, organic fertilizer, and top soil in the at least one compartment of the hopper to provide a mixture having a pH in the range of from about 7 to about 9.5, the mixture containing spent water-based drilling mud, from about 30 to about 150 volume percent mature compost, from about 5 to 20 volume percent organic fertilizer, and from about 5 to 20 volume percent top soil from the well site wherein each of the volume percent is based on the volume of the spent water-based drilling mud present in the mixture; admixing from about 5 to about 15 volume percent gypsum, based on the volume of spent water-based drilling mud present, into the mixture so as to break up and reduce adhesive characteristics of clay particles present in the spent water-based drilling mud; activating the mixing assembly so as to stir the mixture for a period of time effective to form a substantially homogenous mixture; drying the substantially homogenous mixture so as to produce fertile indigenous top soil possessing similar microbial and enzyme characteristics as the top soil surrounding the well site; and removing the fertile indigenous top soil from the at least one compartment of the hopper.