Research Of Working Performance For Controllable Bend Sub Based On The Rotary Steerable Drilling Technology

With the development of economy and society, oil has become an indispensable strategic resource in every country and the demands for oil has growth sharply. The oil industry urgent needs a new technology to improve efficiency that can meet the growing international demands. A new drilling technology which called rotary steerable drilling technology appeared in 1990 s. This new technology represents the most advantage drilling technology and is the development direction of modern drilling technology. However, China is still lagging behind in this new drilling technology and need to constantly strive to achieve a breakthrough.This paper improved mechanism design of the existing rotary steerable drilling system and point out a better model of Controllable bent sub, this paper is based on the new type of the point-the-bit rotary steerable drilling system, analyzed the key parts in controllable bend sub of this system, obtain a conclusion that the internal ball and its raceway is conjugated; calculated contact and friction stress of the internal ball and its raceway by using the Hertz theory; calculated the film thickness of the ball and its raceway by using the theory of elastic hydrodynamic lubrication and simulation it by MATLAB in the case of grease; finally, obtained different situations of ball and its raceway in the controllable bend sub that under different working conditions through the experiment of friction and wear by the CERT-2 high temperature tribometer.Pointed out the direction of development and give some advice through this paper at the end of this paper.