Design And Simulation Of Screw Drilling Tools For Gas-Drive Hydraulic Motive

As a new downhole power drilling tool for gas drilling directional wells and horizontal wells,the structure performance of gas drilling screw is directly related to the gas drilling efficiency.Due to the compressibility of circulating medium for gas drilling screw,the output torque value of the existing gas drilling screw drill in the working process is low and the speed and torque output is not stable,which makes drill shutdown of high-speed rotation of the"speed" phenomenon after the drilling tool releasing and results in poor performance,low life,not reliable,efficient and safe gas drilling directional drilling.Therefore,it is of great significance to study and design a new type of gas screw drilling tool for gas drilling horizontal well and directional well.Based on the existing screw drill and screw drill gas as the main object,and combined with the principle of automobile engine valve and piston rod,this paper designs a new type of gas-gas drive screw drill hydraulic gas drilling screw,and conducts the simulation research,the main research contents and the results are as follows:(1)The current development status of domestic and foreign gas screw drill and screw drill and the structure,performance and the advantages and disadvantages of the existing gas screw drill are comprehensively analyzed.Anew kind of gas screw drill design concept in motor assembly increased upper valve structure mainly includes a valve mechanism and a piston bar mechanism,control gas through the gas distribution mechanism of entry and exit through the piston rod mechanism of gas energy into the liquid energy,provide hydrodynamic sustained,steady flow for motor rotor,avoid motor speed phenomenon,completed the structure design and conceptual entity model of screw drill gas model is put forward.(2)Based on the design concept of new type gas screw drill and combined with structure of engine gas distribution mechanism,this paper put forward two design schemes of screw drill gas distribution device,gas distribution device arrangement including valve mechanism and piston rod mechanism.According to the actual conditions and the size of borehole radial space gas drilling,and ultimately determine the structure and arrangement form the gas distribution mechanism of gas distribution device,three-dimensional solid model of all parts of the new gas screw drill is built based on the SolidWorks software.(3)Based on the 3D model of gas based PDM model,the composition of various parts of the structure and its working principle,and introduces the structure of the new gas flow inside the screw drill is described.And the performance analysis model of gas screw drilling theory,including the analysis and evaluation of performance characteristics of gas distribution mechanism theory and the actual work characteristics and actual conditions are carried out,which provides a theoretical basis for the safe use of new gas screw drill.(4)A finite element mechanical model of the new gas screw drill is established.Based on the Abaqus software,the finite element strength analysis of the key parts of the new gas screw drill is carried out under the actual working conditions,and suggestions and suggestions for improvement of the structure are put forward.(5)Based on the SolidWorks software,the CFD model of computational fluid dynamics model of screw drill in the gas is established.The model is imported into Abaqus software to mesh,then the CFD mesh model into ANSYS-Fluent computational fluid dynamics.The flow field analysis is carried out under different conditions,providing a theoretical basis for the optimization design of runner.