Design And Simulation Of The Closed Loop Controlled Bend Sub

In1990s, with the development of petroleum industry, rotary steerable drilling technology came out, which overcame many disadvantages of conventional drilling technology, such as the limitation of the hole depth because of the great frictional resistance; the incapability of special oil well such as horizontal well, multilateral well; poor well cleaning and so on. Rotary steerable drilling technology has advantages of high drilling efficiency, high quality of well bore, good adaptation of complex drilling environment, and more intelligence. Thus, it has been the main focus of world drilling technology.This paper introduces the structure and the working principle of some typical rotary steerable drilling tools. A new kind of RSS-"point the bit" is discussed, and its guide principle is detailed. CAD software Pro/Engineer is used to build up the three-dimensional model of the guidance parts. These parts are assembled together by certain relationship. Kinetic simulation software ADAMS is used to simulate the guide motion of the controlled bend sub, which verifies the rationality of the model design. Finite element analyzing software ANSYS is used to analysis the stress of the key part of bend sub, and get the features of its stress distribution, which verifies the reliability of the tools design.