The Research and Application of Carbon Fiber Rods in Deep Oil Wells of Xinjiang Oilfield, China

Abstract

Abstract As development of deep oil reservoir, more and more deep and ultra-deep wells, of which the chief lifting method is sucker-rod pumping system, are drilled. There often exist problems for systems above such as high load and low pumping efficiency. Because of low density and high intensity of carbon fiber rod, polished rod load can be decreased by using carbon fiber rod to increase safety factor. Meanwhile, since elastic modulus of carbon fiber rod is low, stroke loss will be increased by unreasonable lifting parameters. Test of carbon fiber rod was conducted in Xinjiang oil field in order to verify the feasibility of carbon fiber rod in deep oil wells and evaluate load shedding and energy saving effect. To lighten field test workload, a 3D rod mechanical model was built to simulate conditions of different production parameters. From the results of field test and simulation, it is indicated that carbon fiber rod owns better load shedding capacity and higher strength intensity; under the condition of deep wells, more stroke loss may be caused by carbon fiber composite rod. For some conditions, pumping efficiency is low, even worse, rod lock problems like gaslock may appear; reasonable combination of rod string and production parameters can improve the feasibility of carbon fiber rod.