Method of gravity assisted microbiologically enhanced oil recovery by improving the distribution of nutrients introduced into oil producing rock formations

摘要

A method of improving oil recovery includes the step of selecting an oil containing rock formation having geologic structures and well completions with vertical permeability that allow a structurally high water injection point. Through a series of analyzes a nutrient water mixture is determined and injected at the injection point to stimulate resident microorganisms through gravity dispersion of nutrient materials. A period of limitation is allowed to permit changes in the size or hydrophobic properties of the microorganisms. Through interaction with the stimulated resident microorganisms, oil, trapped in a pore space, is freed to accumulate with upward gravity separation for production.