Design And Calculation Of Control Mechanism In Rotary Steerable Drilling System Based On The Principle Of Eccentric Gravity

Complex wells like horizontal wells, extended reach welsl and multi-lateral wells flourish in worldwide with the exploration and production of low permeability reservoir, offshore hydrocarbon reservoir, methane, shale gas, etc. As conventional wells can hardly meet the demands, advanced Rotary Steerable Drilling(also called RSD) technology should be used to guarantee the precise well trajectory. Rotary Steerable Drilling, representing the world most advanced drilling technology, can greatly enhance penetration rate, reduce friction, lower risk of pipe-sticking, clean the wellbore and reduce drilling cost.To break the foreign monopoly of the RSD technology and improve the competitiveness of domestic drilling in the international market, study and research on the rotary steerable drilling tools is particularly important. The paper first summarizes three kinds of rotary steering drilling systems which are commonly applied in well site and analyze their work principle and control mode. Then, based on the Power Drive drilling system and eccentric gravity theory, this thesis puts forward a Three-valve control RSD tool whose tool face is controlled by three valves. Combined with CAD, Solid Works 3D software, overall structure and key components of the tool have been designed. And then the paper does some optimal computation and material optimization of the eccentric gravity block. Stepper motor’s control of the upper valve is analyzed to realize gaining angle, dropping angle and adjusting azimuth.