Contact Analysis And Parameter Optimization Of Bidirectional Self-locking Slip Of Snubbing Service

In order to adapt to the development of various complex stratigraphic oil and gas fields in our country,snubbing service oil production and drilling depth deepening,the performance of the power slip system directly affects the efficiency of drilling equipment.So the paper study snubbing service self-locking slip structure and optimize the slip gear tooth to ensure safety,improve drilling efficiency,which are of great social and economic value.In this paper,through the study of bidirectional self-locking slip,the structure parameters of slip gear tooth,contact stress distribution and bidirectional self-locking slip bearing test were analysed.Finally,the bidirectional self-locking slip gear tooth structure was optimized.The main contents include the following points:(1)Through consulting relevant literature both at home and abroad,it summarized the application and research status of the power slips.It introduced the working principle of snubbing service lifting device and three power slip system scheme,and analyzed structure characteristics of the new bi-directional self-locking slip system,and main parameters of slip gear tooth was carried on the preliminary design.(2)Slip string contact finite element model was established,and the finite element method of the slip gear tooth contact stress was analyzed,the results show that slip gear tooth contact stress in the circumferential direction present "sine curve",and the axial distribution was not uniform,the maximum contact stress occured in the middle,on both sides of the contact stress was small.At last,it analyzed respectively to slip gear tooth contact stress in different load conditions and different slip gear tooth materials.(3)The bidirectional self-locking slip bearing test-bed was set,through using the combined method of finite element model and experimental analysis to study,and the simulation results and experimental results were compared.Results show that slip tooth plate edge stress change rule of measuring points were basically identical under the four kinds of load conditions,and the results of the finite element model calculation and the field test were same,and the error of the slip gear tooth test results and the simulation results met the requirements of engineering analysis.The accuracy of the finite element slip string contact calculation method was proved in this paper.(4)Through using the Optimal Latin Hypercube Design(OLHD)method to design scheme of slip gear tooth agent model,and Kriging method,the RBF method and RSM method were used respectively to measure the build agent model,and the three agent model error precision was analyzed.Results show that the RBF model was more suitable for agent model of bidirectional self-locking slip gear tooth.Finally,the RBF model and MIGA optimization algorithm were applied to the bidirectional self-locking slip gear tooth,and the minimum slip load uniformity coefficient was the optimization goal,and slip tooth board space,tooth apex Angle and Angle were limited.Compare results of the before and after optimization analysis,results show that the optimized bidirectional self-locking slip gear tooth under the precondition of satisfying certain constraints the slip bearing coefficient to the minimum.A reasonable optimization design method of bidirectional self-locking slip gear tooth was provided.In this paper,snubbing service bidirectional self-locking slip structure and main parameters of slip gear tooth were analyzed.Slip string contact finite element model was set up,and the contact stress of slip gear tooth was analyzed.Through constructing bidirectional self-locking slip bearing test stand,the accuracy of the slip string contact simulation method based on the finite element model were validated.At last,the agent model of bidirectional self-locking slip gear tooth structure was optimized,which enhance the security of snubbing service device.