Design Of Coal-bed Methane Drilling Rig Test Bench And Study On Mechanism Of Rock Breaking

As a new type of energy,the coal-bed methane(CBM)had attracted the huge attention of many countries because of its pollution-free,large storage capacity and heat combustion release amount.However,the natural occurrence of CBM had a variety of conditions,resulting in a high degree of difficulty in its exploitation,so during the mining process,the professional technical equipment had been extremely important.At present,the drilling technology for coal-bed methane mining is still relatively backward in China,and especially the drill is almost none for some needs of horizontal drilling areas.The domestic horizontal mining generally relies on introducing the foreign advanced equipment,which greatly increases drilling costs.Therefore,it is necessary to explore the characteristics of lateral drilling and horizontal drilling equipment suitable for domastic conditions.For the drilling rig,its working process is the coal seam or the rock formation destruction process,so the study of rock breaking mechanism is more conducive to the protection of the drilling tools and the improvement of the drilling efficiency.In view of the above problems.the main content of this thesis is as follows:Firstly,the characteristics of common drilling rigs and technical parameters were listed,and test bench was established for studying lateral drilling rock-breaking mechanism,which provided theoretical and experimental support for horizontal drilling research.Secondly,Under two load conditions,rock constitutive model and damage equation were made based on rock damage theory and physical mechanical properties,and the model's unity was verified by comparison.Under the conditions of confining pressure loading,rock breaking curves with the change of axial force were solved by MATLAB software.Finally,three-dimensional drilling teeth and rock model were established and imported into ANSYS for the finite element dynamic contact analysis.Then fraction in rock was researched at different cutting depths and speeds,which guided drilling parameters combination mode.It not only can improve drilling efficiency,but also can make an effective protection for drilling equipment.Drilling test rig has drilling parameters loading simulation system,coal seam confining pressure loading system,multi-signal integrated measurement and display functions,which embodies the innovation of the this paper.Drilling technology optimization,rock stress generation and expansion process study under different drill with different drilling parameters,research on correlation between teeth configuration of drill and particle appearance can be realized by the test rig.Besides it can make diversity analysis of rock sample and slogging effect,conduct diamonds drilling equipment's effectiveness and useful life experiment.The later research purpose is to reduce gas explosion,coal and gas outburst and flooding,and to solve the problems such as boreholes in the soft coal seam.