Analysis of Seepage Law of Precipitation in Horizontal Wells with Low Permeability Formation

Abstract

Based on the euler model of multiphase flow in FLUENT and standard k-epsilon model, considering the influence of negative pressure inlet position (pump position) and nitial water head height (water head thickness), a 3d Pipe flow-seepage coupling pumping model for horizontal wells is built and calculated iteratively. On this basis, a detailed study is carried out on how to improve the fluid collection efficiency of horizontal wells. The results show that: (1) the fluid velocity at the negative pressure inlet increases as the pressure inlet location decreases from the top of the horizontal well to the heel, in the process of the depth change from heel to toe in the horizontal section, the fluid velocity at the negative pressure inlet increases first and then decreases; (2) the pressure increases in a certain proportion with the increase of the initial water head (that is, the thickness of water layer), and then the efficiency of horizontal well is improved; (3) Combined with numerical simulation analysis, in the model experiment, fluid flow causes uneven distribution of sand around the horizontal well, leading to a certain degree of pore annihilation, which causes pressure fluctuation along the horizontal well and reduces the production efficiency.