NOVELTY - Stimulating microbial methane production in petroleum-bearing subterranean formation, involves analyzing components of formation, detecting microbial consortium comprising methanogenic and methanotrophic microorganisms, characterizing methanotrophic microorganisms for determining ecological environment that promotes microbial degradation of petroleum and generation of methane by the microorganisms, and modifying the formation environment.    USE - (M1) is useful for stimulating microbial methane production in a petroleum-bearing subterranean formation (claimed).    DETAILED DESCRIPTION - Stimulating (M1) microbial methane production in a petroleum-bearing subterranean formation, involves analyzing one or more components of the formation to determine characteristics of the formation environment, detecting the presence of a microbial consortium comprising a methanogenic microorganism, within the formation, assessing whether the formation microorganisms are currently active, determining whether the microbial consortium comprises one or more methanotrophic microorganism, characterizing one or more microorganisms of the consortium, one of the members of the consortium being a methanogenic microorganism, and comparing the members of the consortium with a known microorganism having one or more known physiological and ecological characteristics, characterizing one or more methanotrophic microorganisms of the consortium (if present), and comparing the members of the consortium with a known microorganism having one or more known physiological and ecological characteristics, using information obtained from the above steps, for determining an ecological environment that promotes in situ microbial degradation of petroleum and promotes microbial generation of methane by a methanogenic microorganism of the consortium, and if methanotrophic microorganisms are present, for determining and ecological environment that demotes in situ microbial degradation of methane by a methanotrophic microorganisms of the consortium, and modifying the formation environment based on the determinations, if methanotrophic microorganisms are present, to stimulate microbial conversion of petroleums to methane, while minimizing methane destruction by adverse processes.    DESCRIPTION OF DRAWING(S) - The figure is a graph representing the computer simulation of extent of biodegradation and methane production throughout an entire oil column.