Research on key sealing technique for intelligent drill string

In order to solve the problem of electric transmission safety technique through intelligent drill string in electric drilling and in view of the problems like automatic sealing while makeup and breakout of intelligent drill string and leaking of core component at high pressure, a rotating dynamic/static sealing structure for core component applicable to intelligent drill string was chosen according to service environment and technological requirement, and finite analysis was conducted to the main factors like initial compressibility, medium pressure, rotation speed of needle rotation shell and outlet rotation shell which affect the sealing performance, and the rotating sealing performance of the sealing structure was further improved. Finally, its rationality and using effect were proved by experimental tests. The result shows that the sealing ring has a good sealing performance when initial compressibility is 17%; the double-triangle slip ring acts as a retainer ring, so this sealing structure can stand a high pressure of 10 MPa; the sealing performance of the sealing ring is the best when the rotation speed of needle rotation shell or outlet rotation shell is below 2 rad/s. Using the combined sealing of O-ring with triangle slip ring and optimizing the related parameters of this sealing structure has effectively addressed the problem of key sealing of intelligent drill string, and hence ensures effective and rapid transmission of electrical signals and power of electric drill,which further promotes the development of intelligent drill string.