Abstract: Methods of conducting ureolysis-induced calcium carbonate precipitation with a heat-treated cell preparation, methods for preparing the heat-treated cell preparation, and related materials. The methods of conducting ureolysis-induced calcium carbonate precipitation include precipitating calcium carbonate at a location by introducing urea, calcium, and a heat-treated cell preparation comprising active urease enzyme to the location. The urease enzyme hydrolyzes the urea to ammonium carbonate, and the calcium reacts with the carbonate to form a calcium carbonate precipitate at the location.

Abstract: The invention is a method of increasing hydrocarbon recovery through the biomineralization sealing of fractured geological formations followed by refracturing, including preparing a composition with biochemical components that is delivered into a geological subsurface through a cased well bore. Nutrient solutions are delivered into the geological subsurface through the well bore, thereby metabolizing the nutrient solutions with the biochemical components to create a mineralizing byproduct. Mineralizing solutions are delivered into the geological subsurface, delivering the composition, nutrient solutions and mineralizing solutions to targeted geological formations having existing formation fractures, through casing openings. Mineralizing solutions react with the mineralizing byproduct to produce minerals, which crystallize in the existing formation fractures, sealing and strengthening the existing formation fractures and resulting in sealed fractures.