Design Of Rotary Steerable Drilling System Bias Unit

Rotary steerable drilling technology is the representation of the highest level of drilling technology in the world, which is being strived to develop the state-of-the-art automated drilling technology in almost every country, and the core of this technology is rotary steerable drilling system. After the rapid development in recent decades, the point-to-the-bit rotary steerable drilling systems gradually become the future direction of the rotary steerable system for its excellent performance. Because of the late start in the field of rotary steerable drilling technology in our county, combined with foreign technology blockade against our country, both of which leads our country to lag behind in the foreign advanced level. Especially in the point-to-the-bit rotary steerable drilling system research, the domestic is only at the theoretical and experimental study stage, and no molding system appears. Therefore, in order to narrow the gap with foreign technical level, it is necessary to do breakthrough research for this technology.This paper consists of four parts:introduction, design of the bias unit mechanism, steerable behavior mechanics of the bias unit, conclusions and recommendations. On the basis of research and analysis of the original bias tools’ oriented principle, this paper designs a bias tool. This tool can take advantage of the naturally present drilling fluid pressure which provides the impetus for the bias unit, and it also can realize controllable orientation through the control operations. This paper has completed the mechanical design drawings of bias unit, the main components selection and strength check, which has also completed the 3D parametric designs and the virtual assembly of the components by using SolidWorks mechanical design software. The mechanical analysis of the bias institutions has been done by using of the theory of mechanics of materials and engineering fluid mechanics, and established the mechanical model of the bias unit after doing research on the relationships in the steerable control parameters, which lays the foundation for the subsequent optimization of the design and theoretical studies of the bias unit. Finally, this paper points out the urgent need for the bias unit design, and put forward the guiding suggestions for the next in-depth study.