Design And Performance Analysis Of Three - Cone Drill

The cost of drilling and drilling quality is directly affected by the quality of tri-cone rock bits, which is the main rock-breaking tool in the oil and gas development project. Since the advent of tri-cone rock bits, improving product quality has been constant pursuit of science and technology workers. According to the traditional design experience, the structure and parameters of rock bit are determined by the approximate calculation and trial and error, and the designed quality is low and the period is long to verify its performance through much trial and actual drilling experiment.Based on the geometry and kinematics theory of rock bit, the mathematical model of the optimal design is established with the analytic geometry of space, in which the structure of . rock bit is analyzed mainly in FORTRAN and VB development tools. And the rock breaking is simulated with computer to optimize the design parameters of the basic structural according to the rock-break characteristics. The three-dimensional design system of tri-cone rock bits is created with dynamic link library on base of SolidWorks software. From the design to performance analysis on the computer, high-performance rock bit is designed in a relatively short time. The thesis’s primary research works was as follows:1.In order to avoid the repeated broken bottom of the well and make the fluctuations of the number of teeth contacting with the bottom-hole as evenly as possible, the number of teeth contacting with the bottom-hole is comparatively designed and calculated between the teeth equidistant distribution and not equidistant distribution, which can effectively prevent teeth fracture and fall-off.2. For the insert bit, the direction of the teeth tooth top line is closely related to the broken area of the bottom. The teeth orientation is optimized and the comparative analysis of the broken bottom areas before and after is carried on to establish the reasonableness of this theory.3. The number of teeth contacting with the bottom-hole is an important factor affecting the mechanical speed and the wear life of rock bit. Its model is established and the distribution law is analyzed.4. Through the optimization of the structural parameters of tri-cone rock bits, the bottom-hole tracks and the comprehensive bar chart is drew to make the optimization results more intuitive.5. In the design of tri-cone rock bits, not only the limited space of the rock bit can be fully used by teeth surface structure, but also the interference between adjacent cone ring should be avoid. So the clearance between the adjacent cones is accurately calculated.6.Based on the optimization of parameters, the three-dimensional design system of tri-cone rock bits is created, and he three-dimensional parametric models of the cone and the teeth are established.With this method, the performance of rock bit could be predicted and analyzed at the design stage, evaluate design alternatives, and enhance scientific and reliability of rock bit design. It is of great significance to improve the design quality,shorten the research and development cycle of the new bits, and reform the design of the existing bits.