Dynamic Analysis Of Coiled Tubing Tension Between Drum And Injection Head

Coiled tubing has been widely used all over the world.In the actual working process,it will be affected by various factors and fail,thus reducing its service life.Through on-site investigation and literature review,it is found that various failure phenomena caused by tension are common among various factors that may lead to coiled tubing failure,and tension not only determines whether the coiled tubing can fulfill the required work requirements,but also relates to the production safety in its operation process.Therefore,it is necessary to study the tension characteristics of coiled tubing during operation.In this paper,the dynamic tension characteristics of coiled tubing between drum and injection head are analyzed in depth,mainly from the following aspects:Firstly,the basic circuits of hydraulic control system are briefly reviewed,and the working principle,structural characteristics and hydraulic control system circuits of drum and injector in coiled tubing machine are analyzed in detail.Finally,the dynamic analysis of coiled tubing between drum and injector is simplified and the hydraulic control of drum and injector is designed.Control system circuit.Then,combined with the actual working conditions of the coiled tubing between the drum and the injection head,and based on ANSYS finite element software,the finite element model including the drum,the injection head and the coiled tubing is established.The material properties,element types and related loads of the model are set up and calculated by finite element simulation.Using Origin data processing software,the corresponding curves of displacement difference and tension of coiled tubing between drum and injection head are drawn,and the relationship function between displacement difference and tension of coiled tubing between drum and injection head is obtained by fitting.Then,combined with the actual working conditions of coiled tubing and based on dynamic theory,the tension analysis models of coiled tubing winding on the drum and under the clamping force of injection head are established respectively,and the displacement calculation formulas of coiled tubing on the drum and injection head are obtained respectively.A dynamic simulation model of coiled tubing tension system including drum,injection head hydraulic control system and coiled tubing tension calculation model is established based on AMESim software.Finally,according to the different winding quantity of coiled tubing on the drum,three representative examples are calculated and analyzed,and the coiled tubing under different working conditions are discussed respectively.Based on the dynamic system simulation model of coiled tubing tension between drum and injection head established in AMESIM software,the parameters of each element in the model are set up according to the actual working condition of coiled tubing and the system simulation calculation is carried out.After the simulation is completed,the simulation results of each group are compared and analyzed.Through the above calculation and analysis,the following conclusions can be drawn:(1)Through the analysis of the hydraulic control system of the drum and the injection head in the existing coiled tubing machine,the hydraulic control system circuit of the drum and the injection head for the dynamic analysis of the tension between the drum and the injection head is simplified and designed.(2)Through the calculation and analysis of the three-dimensional finite element model of the drum,injection head and coiled tubing established in Ansys finite element software,the tension and related stress of the coiled tubing between the drum and injection head are obtained when the coiled tubing is subjected to step-by-step displacement load.The relationship between the displacement difference and the tension of the coiled tubing between the drum and the injection head is obtained by using Origin data processing software.(3)Based on the dynamic theory,the displacement and tension calculation and analysis model of coiled tubing winding on the drum and under the clamping force of the injection head are obtained,and the displacement difference between the drum and the injection head is calculated according to the specific conditions of the coiled tubing under different working conditions.(4)A simulation model of coiled tubing tension dynamic system is established based on AMESim software.The dynamic changes of the parameters of coiled tubing tension and other components in the system are obtained through the simulation calculation of grouped examples.The results show that when the speed control operation of injection head motor proportional speed control valve is moderately slow,the jitter of the dynamic tension curve of coiled tubing can be reduced.It can alleviate the vibration of coiled tubing in the working process.