An oil and gas exploration method based on a microbial gene, comprising the following steps:
- S1) determining a sampling site in an exploration area;
- S2) determining a sampling site in a forward-modeling area, wherein the forward-modeling area is established with a known oil containing well, and/or with a known gas containing well in the exploration area;
- or wherein the forward-modeling area is established with a known well within an area that is adjacent to the exploration area;
- wherein the sampling site of the forward-modeling area is above the known oil and/or gas containing well in the exploration area, or wherein the sampling site of the forward-modeling area is above the known well within an area adjacent to the exploration area;
- S3) designing a scheme for sampling the forward-modeling area, wherein the sampling scheme involves collecting and preserving a soil sample from one or more sampling sites above each well in the forward modeling area;
- wherein the soil samples include microorganisms and each collected soil sample is preserved with a preservation agent comprising of the following components:
- a Tris-HCl solution pH 8.0 comprising a 0.5% (w/v) cetyltrimethylammonium bromide (CTAB), a 2% (v/v) ethanol, a 1% (v/v) β-mercaptoethanol, 0.75 mM ascorbic acid, 0.25 mM ascorbyl palmitate, 10 mM ethylenediaminetetraacetic acid disodium salt, 0.5 mM NaCl, and 1 mg/L DNase inhibitor;
- S4) extracting DNA from the preserved soil samples of the one or more sampling sites in the forward modeling area;
- S5) subjecting the extracted DNA from each soil sample from the forward-modeling area to a high-throughput sequencing (HTS), and reading operational taxonomic unit (OTU) values of species at each sampling site;
- and
- S6) identifying gas-indicating effective bacteria and/or oil-indicating effective bacteria at each sampling site within the exploration area;
- calculating oil indexes and/or gas indexes according to the OTU values of the soil sample at each sampling site within the exploration area, and/or the OTU values of the gas-indicating effective bacteria in a known well that is a dry well and in a known well that is an oil well;
- and/or the OTU values of the oil-indicating effective bacteria in a known well that is a dry well and in a known well that is an oil well;
- comparing the values of the oil indexes and/or the gas indexes to determine effective oil indexes and/or effective gas indexes at each sampling site within the exploration area;
- and
- establishing an isopleth of oil and gas-indicating microorganism values at each sampling site across the exploration area using the values of the effective oil indexes and/or effective gas indexes at each sampling site.