Reseach On Coal Bed Methane Multi-branch Horizontal Well Composite Cavity-forming Operations And Visualization Of Underground

With the help of analysising and comparing three ways to build a cave by CBM(Coal Bed Methane)multilateral horizontal wells,considering the domestic situation and construction operations,a composite cavity-forming operation method of CBM multi-branch horizontal well has been given here.That method is a combination of high-pressure water jet and mechanical build a cave.In other word,use high-pressure water jet to pre-perforating the wellbore firstly,and then build a cave by mechanical cutting coal.Properties and parameters of coal rock are described here.Besides,material parameters are statisticed,which help to provide support with theory and data to the subsequent simulation.This paper discuss the efficient coal-breaking mechanism of composite buildikng a cave based on the coal-breaking theory of the two ways including high-pressure water jet and machinical mading carve.Mentioned to composite building carves technology,It is a main reason for reducing the mechanical resistance and improving construction efficiency to use high-pressure water jet to break rock up front.Taking advantage of ANSYS software to do numerical simulation on the stress distribution of the coal rock during perforating,and to analyze the influence on stress distribution made by some factors such as borehole radius,the way of arranging holes,and so on.Based on ANSYS/LS-DYNA software and the implicit-explicit solution method,the explicit dynamic model of tool cutting coal rock was established.Several model examples were created whose situations such as borehole layout schemes and whether tool cutting through perforations were various.Suggestions on the arrangement of perforation were proposed after comparing the calculation results.Due to the necessity of coal-bed gas mining informationization and the shortcomings of traditional education and training,the virtual reality technology were used to design and develop the visualization system for coalbed gas composite cavity.With the help of virtual reality technology and Virtools development platform,a three-dimensional model was established using 3ds Max software,which could construct virtual scene and complete the design and development of coalbed methane system.The key technology and the realization process of visualization system are introduced in detail,which can be taken as the reference example of visualization system development.The visualization system can be used as teaching training and science popularization transmission,which can not only save the training cost but also break through the restrictions of time and place.