Abstract: This article combined the two methods between flow method of gas drilling and drilling gas pressure drop method, by comparison site construction continuous observation and analysis of advanced testing and stress testing bore holes to determine the Zhu Jiadian No. 4 Seam coal seam drilling of the effective pumping discharge radius for thin seam gas drainage drilling layout and parameter optimization provides the basic parameters.

Key words: thin seam, drainage drilling, gas effective drainage and pumping radius