Microbial anomaly distribution in Chen22 block, Chenjiazhuang oil field, Bohai Bay Basin

We collected 469 soil samples above Chen22 block in Chenjiazhuang oil field in the Bohai Bay Basin in order to study the microbial anomaly distribution above oil reservoirs. Methane-oxidizing bacteria and hydrocarbon oxidizing bacteria in the soil samples were cultured, and the number of bacteria detected was counted by using the MPN method. There was a good alignment between the upper abnormalities of the two indicative microorganisms and the position of wells on the connecting-well profile which had an obvious background area on the north and south ends. It showed that the two kinds of microorganism were effective indicators for the hydrocarbon microseepage of reservoirs. Combined with geological and drilling information, the response between the abnormal distribution of microorganisms and the underlying reservoir was researched by an accurate survey on the area. The distribution of underground reservoirs could be predicted by detecting microbiological anomalies, which also had a certain guiding significance to well drilling.