The Principle And Mechanical Property Analyzing Of High Build-up Rate Rotary Steerable Drilling Tool

Rotary steerable drilling technology is a rotary-oriented drilling tool as the core of the cutting-edge automated drilling technology.At present,the development of unconventional oil and gas resources,especially the development of shale gas,is becoming more and more demanding of drilling technology.Conventional rotary steerable drilling tools have the problem of insufficient construction capability and high operating costs for drilling with large displacement wellbore clusters of horizontal wells required to meet unconventional oil and gas resources.A new type of high build rate rotary steerable drilling tool is designed for the challenges of unconventional oil and gas resources development.It has the advantages of high drilling speed,high drilling rig efficiency,high drilling efficiency and precise wellbore trajectory control.In addition to the advantages of large deflection ability,wide range of build-up rate,kick off point can be deeper and so on.In this paper,the structure of the high build-up rate rotary drilling tool is designed by analyzing the working principle of the push-the-bit and the push-the-bit rotary steerable drilling tool combining with the advantages of both.It also analyzed the working principle of high build-up rate rotary steerable drilling tool.Established the digital prototype tool by using the SolidWorks 3D model software and the strength of the pressure transmission device and the torque transmission device was analyzed by ANSYS finite element analysis software.Mechanical model of the bottom-hole assembly is built based on the vertical and horizontal bending method and the three-point fixed circle method.The calculation method of the bending force of the bottom-hole assembly is deduced;the calculation formula of the lateral force and the build rate of the drill tool are deduced.The theoretical build rate of the drilling tool is calculated by the limit curvature method and the maximum value is.By using the calculation example,the factors that influence the ability of build-up rate of bottom-hole assembly are analyzed,and the curvature of the drilling body,the bending angle of the curved shell and the inclination angle of the curved shell are obviously affected by the deviation ability of the lower drilling tool.Analyze the force of the control shaft,complete the dynamic analysis of the control shaft,and obtain the dynamic equation.Through the above work,the advantages of the high build-up rate rotary steerable drilling tools and the feasibility of the scheme are described,which provide the theoretical basis for the research and development of the high build-up rate rotary steerable drilling tool.