Abstract:
Coal seams contain all kinds of light hydrocarbons. When coal seams are burned, the integrity of overlying strata is destroyed, which provides a good channel for hydrocarbon escape from the coal seam. This process conforms to the principle of light hydrocarbon microseepage. Then, microseepage associated microbial hydrocarbon detection technology is introduced to test its recognition ability of coal seam burning area. In Haojialiang Coal Mine of Jurassic Coalfield in northern Shaanxi, two survey lines were tested and butane bacteria was selected as microbial detection index. After microbial analysis process such as soil sampling, microbial culture, and colony count, combined with geological drilling results, microbial values were calibrated and grouped into abnormal and background values. The microbial response characteristics of light hydrocarbon microseepage in coal burning area were studied. The microbial values in the fully burned area were background low values. In the transition area, the continuous high anomaly microbial values can be seen, while in the normal coal seam area, the microbial anomaly is mainly medium low value. Therefore, the microbial response model of coal burning area was established. The geological results of coal seam burning area explained by microbial hydrocarbon detection technology are consistent with the combustion boundary interpreted by magnetic method, and verified by drilling holes as well. The application of microbial hydrocarbon detection technology in the field is simple and environmentally friendly, and most of the work can be completed indoors. Therefore, it is more suitable for the detection of coal seam burning areas similar to the ecologically fragile area in northern Shaanxi, and has significant practical significance and economic value.