Inclination measuring and deviation correction technology of pressure released gas drainage borehole in external dislocated high level gateway

In order to solve the drilling trace of pressure released gas drainage borehole offsetting the original design trace of the borehole,based on the inclination m easured results of the original designed borehole,an angle compensation and correction method and the evaluation index of borehole correction effect were provided.The i nclination measured results of the original designed No. 151 and 152 boreholes showed that the deviation distance of the borehole final location was 4.203 m and 4.481 m i ndividually and after the angle compensation and correction method conducted,the deviation distance of the borehole final location was 1.363 m. After the deviation correct ion conducted,the max value and average value of the borehole gas density was increased by 15.3% and 11. 6% individually higher than before the deviation correction con ducted,and the continued drainage time was increased by 1 ~ 6 days.The deviation correction effect showed that the method could solve the borehole deviation problem ba sically and could improve the pressure released gas drainage effect.