Design And Parameter Optimization Of Combined Drilling Equipment

As the demand for exploration and development continues to increase, the workload of drilling has greatly increased. At present, the drilling method is mainly the rotary drilling method of driving the drilling rod. This method is of great shortage. On the one hand, the drill pipe vibration will greatly reduce the life of downhole drilling tools; on the other hand, the drill rod span is too long, resulting in energy consumption is too large and operation efficiency is lower. In this paper, a scheme of drilling with combined drilling equipment is put forward,and the parameters are optimized. The main research contents are as follows:The combination drilling device consists of four parts: tractor, downhole motor, Anti-stall tool and drill bit. The structure and working characteristics of each part of the research,combined with the characteristics of drilling, determined the reasonable structure scheme:WWT type hydraulic tractor driven by drilling fluid; downhole motor for drilling low pressure,large torque of the screw drill tool; PDC bit; and the design of Anti-stall tool.In view of the structural scheme of the combined drilling equipment, a three-dimensional model of four major components was built. Including parts of the model, assembly model, as well as the assembly of the combined drilling equipment, the establishment of the part model,and Anti-stall tool for movement simulation.By connecting the thread with reference drilling tool, the structure of the connecting piece was designed. The load analysis and static analysis of the screw thread were carried out by numerical method and ANSYS finite element analysis software respectively. By optimizing the fillet radius of the stress dispersing slot in the thread structure, the optimum fillet radius is obtained, and the stress concentration at the connection thread is optimized.Optimize the hydraulic parameters of combined drilling equipment. On the basis of the traditional hydraulic parameters optimization, considering the pressure drop and the cyclic pressure consumption of the screw drilling tool, the drilling hydraulic parameter optimization method which is suitable for the drilling of the combined drilling equipment is determined.The optimization of drilling hydraulic parameters is verified by optimizing the design of concrete drilling examples.This paper has made effective work for further research of tractor in drilling, and provides a basis for optimizing hydraulic parameters of drilling in combined drilling unit.