The Performance Of Friction And Wear Of Coiled Tubing/built-in Cable During Oil Recovery

In this paper,the friction and wear tests of the coiled tubing/built-in cable under the lubrication condition is carried out firstly,then the morphology of the tubing and cable are characterized by metallographic microscope and scanning electron microscope.The friction and wear rules and wear mechanism of the tubing under different working conditions were obtained.These will provide important theoretical basis and technical guidance for the future coiled tubing in oilfield production.Firstly,measuring the weight loss of the tubing and calculating the thickness reduction,wear rate and residual internal pressure strength based on the weight loss of the tubing,the variation rules under three working conditions(contact load,grit content and grit size)in the low viscosity crude oil and the high viscosity crude oil were obtained.Under low-viscosity crude oil,the influence of contact load,grit content and grit size on the wear of the tubing is reduced in turn;during three working conditions,the change of contact load has the greatest influence on the residual internal pressure resistance of the tubing.However,under high-viscosity crude oil,the influence of grit content,contact force,and grit size on the wear of the tubing is reduced in turn.Under the three working conditions,the grit content in the crude oil has a greatest influence on the residual internal pressure strength of the tubing.Secondly,the degree of tubing wear under two crude oils is compared and analyzed.It is found that the weight loss,thickness reduction and wear rate of the tubing under high viscosity crude oil are higher than those of low viscosity crude oil;The of the tubing in the high viscosity crude oil is about ~10 times that of the low viscosity crude oil;the residual internal pressure strength of the high viscosity crude oil is also reduced more than the low viscosity crude oil.Finally,the low-viscosity crude oil has a significantly better lubricating effect than the high-viscosity crude oil,and the cable wear in the low-viscosity crude oil is much lower than that in the high-viscosity crude oil.