Erosion Law of Inner Drill Pipe in Reelwell Reverse Circulation Directional Drilling

Abstract

In the process of ReelWell reverse circulation directional drilling, the drilling fluid returns through the inner drill pipe, and the debris particles continuously eroded and wear the drill pipe in the inclined section, which easily causes the failure of the inner drill pipe erosion. Analysis, through the Fluent software to simulate the flow field in the inner drill pipe, to study the impact of different drilling fluid displacement, different mechanical drilling speed, different cuttings particle size on the drill pipe erosion. The results show that: (1) The larger the drilling fluid displacement, the higher the return velocity of the drilling fluid, the greater the number of cuttings, the larger the maximum erosion rate of the curved pipe section, and the larger the erosion area; (2) The higher the drilling rate High, the higher the concentration of cuttings particles, the higher the probability of particles hitting the pipe wall, the greater the maximum erosion rate of the curved pipe section, and the larger the erosion area. When the mechanical drilling rate is higher than 10m/h, the maximum erosion rate increases significantly; (3) the smaller the cuttings particle size, the larger the number of cuttings particles, and the greater the maximum erosion rate of the curved pipe section. It is recommended that the drilling fluid displacement and the mechanical drilling rate should not be too large during the reverse circulation drilling process. At the same time, the cuttings particle size should be controlled, the drilling tool management should be strengthened, and the reasonable use standard after the drill pipe erosion is established. The research results have a certain guiding significance for revealing the failure of the inner drill pipe erosion in ReelWell reverse circulation directional drilling and the scientific use of the wear drill pipe.