Research On The Applicability Of Gas Pressure Measurement Technology For Directional Drilling Machine While Drilling

Coal seam gas pressure is a key parameter in gas drainage,gas disaster prevention and risk identification of coal and gas outbursts.However,in the actual production work,due to the limitations of the current gas pressure measurement method,the gas pressure measurement cannot be successfully completed at the expected location,which hinders a series of work to be carried out downhole.With the rapid progress of directional drilling technology,information engineering technology,etc.,remote pressure measurement while drilling technology is expected to be developed.Under the condition of no suitable roadway,the directional drilling machine while drilling parameter measurement technology is applied to mine gas pressure measurement.Long-distance,accurate and effective pressure measurement.This graduation thesis takes the gas pressure measurement technology of directional drilling rig as the object,and conducts a prospective study on its applicability.The results are as follows:First,analysis of the development trend of pressure measurement technology.On the basis of traditional measurement technology and remote in-situ measurement technology,the technology of measuring coal seam gas pressure with directional drilling machine will be rapidly developed and put into use.The traditional measurement technology is based on ordinary drilling rigs forming a hole and sealing the hole at close range for pressure measurement;the remote measurement-whiledrilling technology is also based on the directional drilling machine to form a hole and the remote hole bottom sealing and pressure measurement.Different from the remote in-situ measurement technology,it can seal the hole at the bottom of the hole at any time as needed.The remote in-situ measurement technology has matured,and the remote measurement-while-drilling technology is still in the research and development stage.Second,the feasibility analysis of remote measurement while drilling technology.The predecessor of this technology,the remote in situ measurement technology,has the following characteristics:(1)Overcome the shortcomings of traditional measurement technology that can only be measured at a short distance;(2)Realize long-distance drilling hole bottom sealing;(3)Based on the directional drilling rig,sensor pressure measurement,cable transmission,and orifice data acquisition are realized.Compared with the remote in-situ measurement technology,the remote measurement-whiledrilling technology needs the following improvements in the sealing technology and process:(1)Change the tedious process of withdrawing,disassembling,loading and drilling,and complete all the processes at one time,and no longer withdraw and disassemble the measuring pipe,bottom-hole motor and drill bit of the directional drilling rig;(2)The gas pressure measuring tube and the sealing drill pipe should be installed in a suitable position in advance,and the sealing capsule of the sealing drill pipe is an important factor to test the feasibility;(3)In the drilling process,the test gas pressure link is added,and the hole forming and work efficiency are also factors that cannot be ignored to test the feasibility.Feasibility analysis believes that the feasibility of remote measurement while drilling technology is generally feasible,and the details need to be improved in practice.Third,the basic analysis of the existing technology.The gas pressure measurement technology for directional drilling rigs mainly relies on coal seam gas pressure measurement technology,directional drilling technology and measurement parameter technology while drilling,all of which are mature.The key lies in integration: in the design of the pressure measuring device,the pressure measuring pup joint and the sealing capsule are threadedly connected to form a gas pressure measuring device while drilling;then select the most suitable gas pressure sensor according to the specifications,size,transmission performance and other requirements of the gas pressure sensor;secondly,the structure design of the sealing capsule is completed through the scheme comparison;the orifice monitor includes the carrier communication module,the main control module and the gas measurement module;finally According to the overall design idea of the device,the technical process of measuring gas pressure while drilling with directional drilling machine is discussed and researched,through the further improvement of the active gas pressure measurement method,the first and second gas passages designed by the pressure measurement while drilling device of the directional drilling machine can interact with each other to realize the functions of gas compensation and sealing pressure measurement,complete the preparation of the pressure measurement process,and form a complete pressure measurement system.Fourth,comparative analysis of measurement methods.Long-distance measurement of gas pressure is the most difficult problem to be solved by traditional gas pressure measurement methods,mainly in the following two aspects: One is that the drilling performance of ordinary conventional drilling rigs is limited,and it is difficult to achieve long-distance drilling;the other is to measure the gas pressure of coal seams from a long distance.Because there is no suitable roadway,the construction is difficult,and the coal seam cannot be drilled for normal coal seam parameters.It is determined that the actual production work cannot continue,and it falls into an "infinite loop" state.The disadvantage of the long-distance in-situ measurement of gas pressure is that the pressure measurement device cannot be recovered and reused.When measuring the coal seam gas pressure again,a new pressure measurement device needs to be used,which greatly increases the pressure measurement cost.Difficult to accept.The gas pressure measurement technology for directional drilling rigs can effectively,quickly and conveniently carry out long-distance gas pressure measurement and the pressure measuring device can be reused to reduce the cost of pressure measurement.The determination of gas occurrence law in a region can also realize remote measurement of coal seam gas pressure without suitable roadway for measurement.The pressure-measuring-while-drilling technology of directional drilling rigs has the advantages of long gas pressure measurement distance,good borehole sealing,and short pressure measurement period,which improves its application value.Fifth,research on the scope of application and technology path.On the basis of the finalization of the test device,conduct applicability research to determine the applicability of gas pressure measurement while drilling technology for gas drainage,gas comprehensive control,gas outburst identification,etc.The limitations of pressure and the feasibility of pressure measurement while drilling determine its applicable field of pressure measurement in coal mines.The paper has 24 figures,11 tables,and 78 references.