The geomicrobiological method (GMB) is used in combination (or independently) with geochemical studies to identify and localize accumulations of hydrocarbon fluids at depth. The method has been widely developed abroad and it is used in various climatic (including in the permafrost zone) and geological conditions, both on land and at sea.
The method is based on the assumption of the formation of a “bacterial filter” (hydrocarbon-oxidizing biocenosis) in the zone of hydrocarbon gas migration over oil and gas accumulations in the upper part of the section (G. Mogilevsky, 1937). Geomicrobiological studies are carried out on surface air, snow cover, surface, and underground waters, soils, soils, and rocks. The geomicrobiological indicators used in patients with GPNG are usually divided into direct and indirect. Of particular importance is the method in places with low concentrations of hydrocarbons, which is determined by the higher sensitivity of microorganisms in comparison with the sensitivity of existing gas analytical instruments.
The research methodology of the samples consists of a quantitative and qualitative assessment of methanotrophic bacteria, including the determination of the genetic and taxonomic composition of bacteria based on the analysis of the 16S rRNA gene using the sequencing method (NGS).
Estimation of the number of aerobic methanotrophic bacteria is determined by two methods:
- FISH hybridization (hybridization method with fluorescently-labeled probes).
- Cultivation using agar media.
The geomicrobiological method is also widely used to solve oilfield problems due to the dependence of the intensity of bacteria development in the upper part of the section on hydrocarbon reserves and reservoir pressure on the productive horizon.
- to identify and localize places of gas leaks in the field and gas storages;
- intensification of oil production in low-yield wells, contouring the boundaries of productivity and water cut of reservoirs;
- methane control in coal mines.
In solving environmental problems, the HMB method is used to determine the degree of gas saturation and gas-generating ability of bulk soils (construction sites and solid waste landfills) based on the study of the activity of methanogenizing and methane-oxidizing microflora.