Research On Mechanical Behavior Of Hydraulic Twister Based On Horizontal Well Reverse Fishing

With the development of oil and gas resources drilling and production technology at home and abroad,the degree of exploration and development of oil and gas fields is getting higher and higher.Horizontal Wells are widely used in the process of exploitation,but because of the well structure,the stuck accidents are frequent and difficult to deal with effectively.The conventional upside-down fishing tool is a mechanical upside-down tool,which cannot meet the requirements of horizontal well upside-down fishing due to the high friction resistance,low torque transfer efficiency and wear caused by the friction between the pipe string and the well wall when the top drive is adopted in the horizontal well.By placing the power source close to the falling fish,the problem of low torque transfer efficiency in horizontal Wells can be effectively solved.Therefore,it is of great significance to develop the hydraulic reverse buckle.Domestic research on hydraulic reverse locking tools is relatively backward,especially the horizontal section torque augmenting mechanism.In order to break the technical blockade of hydraulic reverse locking tools abroad,this paper studies the torque augmenting mechanism,combines the advantages of mechanical and hydraulic torque augmenting mechanism,studies the hydraulic torque augmenting mechanism suitable for horizontal well reverse fishing,and conducts mechanical analysis on the power unit and deceleration mechanism of the hydraulic torque augmenting mechanism.The power transmission characteristics of hydraulic torque twister are studied.The main research contents of this paper are as follows:(1)Taking 2 7/8 "drill pipe as the main reverse target,the operation condition,rated working load and volume of the torque twister were analyzed,and the power unit and deceleration mechanism of the torque twister were determined by comparing the main advantages and disadvantages of domestic and foreign downhole reverse tools and retarders.The working principle of hydraulic torque twister is described in detail and the key structural design parameters are analyzed.(2)The dynamic model of torque generator is established based on Lagrange equation,and the motion state of rollers is analyzed in the working process.The main parameters affecting the dynamic performance are studied.The phenomenon of overlap interference of gear pair of reduction mechanism and the principle of gear minor modification are studied.Based on the meshing characteristics of gear pair,the parameters that affect the power transmission efficiency of gear pair and the multi-tooth meshing effect of gear pair were studied,and the load distribution model under the multi-tooth meshing effect was obtained.(3)Based on the finite element analysis theory,the contact mechanics analysis of torque generator was carried out to study the relationship between the maximum contact stress and the lift Angle of spiral groove.The results show that the best spiral groove lift Angle is 38°.By changing the driving force of the roller,the relationship between the maximum contact stress and the driving force is analyzed,and the maximum load and torque that can be borne by the torque generator system are obtained.The reduction ratio of the reducer is determined to be 51.(4)Based on the White shark optimization algorithm,the optimization model of gear minor modification parameters was established,and the optimal modification parameters were obtained when the gear pair modulus was 1 and 2 and the tooth crest height coefficients were different.Based on the theory of finite element analysis,the meshing models of single tooth and full tooth were respectively analyzed by establishing the optimized meshing models.The results show that under the same load,the gear pair with modulus of 2 and top height coefficient of 0.6 has better meshing strength.The multi-tooth meshing effect was explored through calculation and analysis.The research showed that there were three pairs of teeth engaged in meshing under working conditions,and the main meshing tooth bore 58% of the total load.The multi-tooth meshing effect greatly improved the bearing capacity of the gear pair,so the power transmission capacity of the gear pair with less tooth difference met the operation requirements.