Controls on microbial response above typical oil and gas reservoirs in the Junggar Basin and implications for exploration
Year: 2026
Type: article
Abstract: Introduction Microbial hydrocarbon exploration, which is based on the theory of light hydrocarbon microseepage, has played an increasingly important role in oil and gas exploration. However, the microbial response characteristics above different types of hydrocarbon reservoirs and their geological controlling factors remain poorly understood, severely constraining the predictive effectiveness of microbial prospecting. Methods In this study, butane-oxidizing bacteria were selected as indicator microorganisms to systematically investigate their distribution characteristics above structural, lithologic, and stratigraphic hydrocarbon reservoirs in the Junggar Basin and to elucidate the dominant geological controls. A total of 1,607 soil samples were collected at depths of 20–25 cm from two study areas. Microbial values (MV) were determined using a gradient dilution–selective cultivation–colony counting method. Combined with correlation analysis and seismic profile overlay, the relationships between MV anomalies and geological conditions of hydrocarbon reservoirs were established. Results and discussion The results indicate that the microbial anomaly distributions are consistent with the predominantly near-vertical migration theory of light hydrocarbons. Structural reservoirs exhibit large-scale, high-intensity MV anomalies, which closely coincide with anticline cores. Lithologic reservoirs are characterized by irregular, band-shaped MV anomalies, whereas stratigraphic reservoirs show clustered anomalies near pinch-out zones. The mean MV is strongly positively correlated with hydrocarbon enrichment ( R 2 = 0.8035) but only weakly correlated with reservoir pressure ( R 2 = 0.0308) and crude oil density ( R 2 = 0.0515). Light hydrocarbons in the reservoir could still migrate to the surface even when covered by thick mudstone caprocks. Hydrocarbon enrichment in subsurface reservoirs plays a critical role in shaping the surface distribution of hydrocarbon-oxidizing bacteria. The microbial response models established for different types of hydrocarbon reservoirs provide robust theoretical support and technical references for hydrocarbon prediction in geologically complex areas.
Source: Frontiers in Microbiology
Authors: Li Ding, Linfeng Wu, Shuai Luo, Yubing Wu, Hui Wu, Hai Mei
Institution: Peking University
Language: English
Subfield: Geology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223112139