Research On Gas Pressure Measurement Technology For Super Long Boreholes

Gas pressure is one of the most important gas basic parameters in mine gas management.Existing pressure measurement technology cannot achieve long-distance pressure measurement,resulting in unclear gas in unexplored areas of the coal seam and affecting the scientific nature of gas disaster prevention and control.This paper discusses long-distance pressure measurement problems.Literature studies have shown that the current research hotspots for gas pressure measurement technology for super-long boreholes are mostly focused on the sealing of boreholes.Firstly,this paper summarizes the previous research results of drilling pressure sealing in boreholes,summarizes the factors affecting the determination of borehole gas pressure,and considers that bedding and cross-section drilling should be treated differently to solve the problem of sealing hole and high-pressure grouting.The law is better.Aiming at the safety,effectiveness and economy of super-long borehole sealing pressure measurement,a two-stage sealing method for measuring gas pressure in super-long boreholes is proposed.It is used in field measurement and the measured gas pressure is accurate.And the pressure measurement distance can reach more than twice the original technology.The two-stage sealing method is difficult to implement,the measurement cycle is long,and it is economically unreasonable.Based on this,it leads to the concept of “small air chamber pressure measurement” and solves the problem of long measurement period.According to the physical phenomena occurring in the field pressure measurement,the hypothesis of the volume of the pressure chamber and the balance time of the gas pressure was put forward,and the theoretical validity of the hypothesis was verified.According to the research content of the long-hole drilling pressure-sealing hole and the theory analysis of the pressure measurement of the small gas chamber,a similar simulation experiment system for gas pressure measurement in the coal seam was designed.The experimental results show that the smaller the pressure measuring chamber volume,the shorter the pressure balance time.This conclusion supports the "small air chamber pressure measurement" project concept.The paper also put forward the preliminary realization of the "small air chamber pressure measurement" project conception.Designing an automatic hole-sealing and pressure measuring device for super-long borehole drilling,which has the advantages of long pressure measuring sealing distance,controllable pressure chamber volume control,and rapid sealing of holes to reduce gas loss in coal seams.It is expected to achieve gas pressure in ultra-long boreholes.Accurate determination of the assay.In this paper,a two-stage sealing technique suitable for measuring gas pressure in super-long boreholes is obtained through theoretical research,and it is used in downhole pressure measurement to obtain good test results.After similar simulation experiments,the gas pressure chamber volume and gas pressure equilibrium time are verified.Relationship.Combining theoretical research with laboratory research,designing an automatic hole-drilling rig drilling tool with super-long borehole pressure for practical engineering value to complete the preliminary study of gas pressure measurement for super-long boreholes.