Recent progress in the theory and technology of microbial prospecting for oil and gas

Abstract

Microbial prospecting for oil and gas (MPOG) is a surface exploration technology derived from the principle of light hydrocarbon micro-seepage from oil and gas reservoirs. The light hydrocarbons (C1-C5) in oil and gas reservoirs permeate the overlying sedimentary layer in the way of micro-seepage, which induces the growth of microorganisms specializing in the consumption of light hydrocarbons in near-surface soil. As a result, the microbial concentration and community structure in oil and gas areas will be different from that without underlying oil and gas reservoirs. By analyzing the abnormal characteristics of microbial concentration and community structure, the oil and gas enrichment areas and oil and gas reservoirs are predicted. In recent years, the research team has established sample acquisition and pretreatment techniques for different geomorphology and surface types, and combined with traditional culturing and molecular biology methods, the precise diagnosis of oil and gas from the perspective of both hydrocarbon indication microorganism quantity and community structure is realized. The artificial simulation results lasting three years show that there are obvious differences and responsive relationships between the microorganisms and community structure under the acclimation of different hydrocarbon components. The strains found are consistent with the actual oil and gas reservoir, providing a theory basis for microbial exploration. In addition, the correlation among environmental conditions, hydrocarbon geochemistry and hydrocarbon microbial group distribution was studied using different oil and gas reservoir types and different geographical conditions. The rule of microbial community in situ of oil and gas reservoir samples was analyzed, and a database of oil and gas indicators in typical oil and gas basins in China was preliminarily constructed. The results showed that the surface microbial anomaly was closely related to the location of oil and gas reservoirs, and can reflectthe characteristics of oil and gas reservoirs of different types. Combined with petroleum geology and geophysical data, the microbial exploration technology can effectively predict the favorable enrichment areas of oil and gas. This paper also presents nine development trends of MPOG.

Keywords

• microbial prospecting
• microbial community
• database
• artificial simulation