Research On The Design And Mechanical Properties Of A New Type Of Composite Cable For Electric Submersible Pump Oil Extraction

The composite cable as the key part of the Cable Deployed Pumping System(CDPS),took spiral wound fiber bundle to stablize its structure,with the polymer to overlay cladding.Power transmission,hydraulic control and pump equipment suspension can be well realized by this special structure,Besides,it can also take the place of oil pipe for pulling and running electric submersible pump.As the cable hang a pump,it can be put into production.Thus,it can speed up the recovery process greatly,shorten the pump inspection period and reduce the running cost.At present,the design and manufacture of composite cable mainly rely on human experience and experimental results,but it cannot be scientifically predicted and guided through the theoretical model and numerical analysis,which seriously restricts the development of composite cable and CDPS system.Therefore,this research was carried out to study the mechanical performance of the composite cable,and the main research contents are presented as follows:(1)Based on domestic and foreign research and system operating conditions,the cross section design of the composite cable was finished.The writer has studied the material selection,structure parameters and electrical parameters calculation.Moreover,the cable production process has been proposed based on the structural characteristics of cable.(2)The typical operation processes of the composite cable were analyzed.And theoretical model was established to study the elastic properties of the cable based on the micromechanics of composite materials.Then constitutive relation of cable structure was discussed on the basis of multi-layer stress distribution method.Then,the writer put forward the axial stiffness formula of cable,analyzed the stress of the cable under the clamping,and estimated the ultimate tensile load of the system.Meanwhile,the method of calculating the stress and deformation of the composite cable was provided.(3)The basic mechanical properties of composite cable materials were tested.Axial bond slip test was carried out to analyze the internal bonding properties.The horizontal tensile test and the clamping test were designed for the two key loads of cable.Experiments showed that the theoretical analysis method was reliable,which could provide guidance for numerical modeling.(4)Numerical model under the critical load was established according to the structural characteristics of the composite cable.Comparing with the experimental and theoretical calculation results,load and boundary conditions were reasonable in the numerical model.Under various working condition,the mechanical properties,stress and strain of cable can be obtained by numerical means,which illustrate the rationality and reliability of cable structure.The paper completed design of a composite cable with CDPS,and put forward theoretical research method of cable structure.Then experimental study of the cable material and the key mechanical behavior were fulfilled.It also analyzed the cable by means of numerical simulation.The research showed that the theoretical method and the numerical model were consistent with the experiment,and the designed composite cable can meet the load requirements.It provided an effective research method for designing and optimizing the composite cable.