Dynamics Analysis And Performance Study On Point-to-the-bit Rotary Steering Drilling Tools

Steerable rotary drilling technology,the representation of the highest level of drilling technology in the world,which is studied in almost every country, is a new sophisticated automated drilling technology. The key of this technology hasn't been developed in our country and has been set up a blockade against china by the western countries such as the United States, so it is very urgent for us to do research on this technology. In this paper, the new style structure and mechanical properties (the design principle, the working principle, the downhole operating principle and experiment principle etc. ) of the point-to-the-bit rotary steerable drilling tool which is been developing are described. Further, analysis and models of the downhole BHA working behavior, the kinematics and dynamics of this drilling tool are presented, and the bias unit prototype experiment is shown.Eight sections are included, namely: Introduction, structure and simulation design of the point-to-the-bit rotary steerable drilling tool, kinematics research on the point-to-the-bit rotary steerable drilling tool, dynamics research on the point-to-the-bit rotary steerable drilling tool, downhole BHA working behavior research on the point-to-the-bit rotary steerable drilling tool, downhole BHA working behavior research on the point-to-the-bit steerable rotary shaft, the bias unit prototype experimental research, conclusions and recommendations. On the basis of the completation of the structural design of the point-to-the-bit rotary steerable drilling tool and the lab experiment of the bias unit prototype, kinematics and dynamics characteristics of the point-to-the-bit rotary steerable drilling tool is lucubrated, the downhole BHA working behavior of it is analyzed, and the relationship between the steering control parameters of the rotary shaft and the guidance force on the bit is formulated, which became the theory foundation of the steering control research and the structural parameters optimization of the point-to-the-bit rotary steerable drilling tool, and the bias unit, the key section of the point-to-the-bit rotary steerable drilling tool, which has a new structural design , is prototyped and experimented in the lab. As a result, the rationality and feasibility of its new structural design is tested and problems shown in the test provide real reference value for further research and development of the point-to-the-bit rotary steerable drilling tool.As the last section of the paper, the conclusions of the research on the point-to-the-bit rotary steerable drilling tool and suggestions for the further development on it is made.