Study on Relation Between Effective Extraction Radius and Study Area Shape and Borehole Spacing

In order to solve the problems in the process of determining the effective extraction radius of borehole, for example, the influence of the study area shape on the effective drainage radius measurement of borehole, quantitative relation between borehole spacing and effective extraction radius in large-area borehole construction on the site, the corresponding problems are corrected by theoretical derivation. The results showed that different study areas correspond to the calculation formulas with different effective drainage radius, and the corresponding effective drainage radius formula is deduced in case of the rectangular and cylinder study areas; in large-area construction of gas extraction borehole on the site, due to influence of extraction overlapping of neighboring boreholes, the effective extraction radius enlarges relative to single borehole, being about 1.34 times of the effective extraction radius R of single borehole.