Research On Mechanical Properties Of Φ73mm Guided Drilling Tool Assembly

Coiled tubing steering drilling has become the mainstream of drilling technology due to its advantages of low cost,less pollution,and high degree of automation.It has been widely used in the fields of sidetracking and directional wells in old wells abroad.The research is still in the initial experimental stage.Steering drilling tool assembly is one of the core technologies of coiled tubing directional drilling.It plays an important role in controlling the well trajectory.Its mechanical properties directly affect the control effect of the coiled tubing steering drilling tool assembly on the well trajectory during drilling.This article first introduces the commonly used methods of analyzing the mechanical properties of the steering drill tool assembly,focusing on the vertical and horizontal bending method,and using the vertical and horizontal bending method to simplify the mechanical model of the steering drill assembly,and the structural angle of the single-bending screw is equivalent to under the premise of lateral concentrated load,based on the composition structure and basic working principle of the proposedΦ73mm guided drilling tool assembly with rotary joint,according to the vertical and horizontal bending method,the variable diameter stabilizer is regarded as a sliding hinge bearing with eccentric displacement,and establishment the two-dimensional and three-dimensional mechanical model of the Φ73mmguided drilling tool assembly,and analyzes the lateral force and rotation angle of the bit,the variable deviation force and rotation angle of the well slope bit,and the variable azimuth force and rotation angle of the azimuth surface bit.According to specific calculation examples,the mechanical analysis of theΦ73mmguided drill tool assembly is carried out,and the drill bits of the near-bit stabilizer,variable diameter stabilizer,weight-on-bit,borehole curvature,middle stabilizer,and upper stabilizer on the straight screw steering drill assembly are studied respectively.The influence of lateral force,the influence of structural bend,weight-on-bit,near stabilizer,and borehole curvature on the lateral force of the bit of the single-bend screw guided drilling tool assembly is studied at the same time.The results of the obtained calculation examples can be used to improve the steering drill.Provide reference for combined deflecting ability and optimized mechanical properties of the Φ73mm guided drilling tool assembly.In order to verify the mechanical model,a simulation test plan was designed based on similar theory,and a simulation test was carried out.A test bench for testing theΦ73mm guided drill tool assembly was designed according to a ratio of 1:1,and hydraulic cylinders were selected to provide the drill pressure for the steering drill tool assembly.In order to increase the scope of application of the test bench and facilitate installation and later maintenance,the base and simulated wellbore were standardized and modularized,and the main components of the test bench were analyzed by finite element analysis.Finally,the mechanical properties of the Φ73mm guided drill assembly are comprehensively analyzed by analyzing the relationship between the weight on bit,the structural bending angle and the lateral force of the bit in the simulation test,and combining it with the analysis of the numerical mechanics model.