Borehole sealing technology of gas pressure measurement in two stage variable diameter borehole with subhorizontal passed through strata drilling
LI Haowei
LIU Hai
WANG Zhaofeng
ZHAN Mengqing
Abstract：In order to solve the borehole sealing technical problems occurred in the gas pressure measuring process under the condition of the subhorizontal passed through strata drilling,based on the conventional borehole sealing technology and the cement self shrinkage effect,a two stage variable diameter pressurized borehole sealing technology was provided.With the two stage variable diameter of the borehole,a baffle welded at the variable diameter location and a distance to the borehole outlet reserved for the second sealing,in combination with the high pressure grouting technology applied to the borehole,a technique method to the borehole sealing and pressure measuring was realized.The technology was applied to the seam pressure measurement in No.1075 gas drainage gateway of Liulong Mine in Baise Group.The site test data were high efficiently and accurately measured and obtained.The study results showed that the two stage variable diameter pressurized sealing technology could effectively seal the top sectional notch of the sealing section of the subhorizontal pressure measuring borehole,could have a high leakproofness hole sealing and could provide the guarantee to accurately measure in-situ gas pressure of the seam.
Keywords：subhorizontal drillingseam gas pressurevariable diameter hole sealinghigh leakproofness hole sealing
Publication Date：2017-01-01