Analysis Of Influencing Factors Of Deflecting Ability Of Rotary Steering System And Optimization Design Of Key Parameters

Rotary steering drilling technology has many advantages,such as fast drilling speed,small friction torque,and easy control of well trajectory.It has become an important technical means for drilling in complex structural wells,such as ultra deep well,large displacement horizontal well and cluster well.The real-time control of well trajectory is one of the main functions of the rotary steering drilling technology,and the deflecting ability of rotary steering system is the core of its control function.Therefore,it is necessary to study the factors that affect the deflecting ability of the rotating steering system.Firstly,based on the theory of continuous beam,the mechanical models of the BHA of the push-the-bit and point-the-bit are built up.The formulas for calculating the side force and angle of bit are derived.Taking Visual Basic as the platform,the software of mechanical analysis is compiled.Secondly,according to the evaluation method of trend deviation angle,a bit oriented model considering the rock drillability and the bit anisotropy is established.With this model,the BHA is connected with the bit and the fo rmation.The influences of the of the BHA structural parameters,the drilling parameters,the bit and the formation characteristic parameters on the deflection ability of the rotary steering system are analyzed.Finally,in view of the problem of insufficient slope of rotary steering system in Tazhong oilfield.According to the analysis,the key parameters which affect the ability of the deflection of the rotary steering system are optimized,and good results are obtained.