Numerical Simulation Study on Water Breakthrough Law of Horizontal Wells in Offshore Bottom Water Reservoir

Abstract The low height of oil columns, significant differences in fluid properties, high initial water content, and rapid increase in water content in offshore bottom water reservoirs lead to the rapid entry of the oil field into a high water content period during production, posing severe challenges to development efficiency and economic benefits. This article aims to study the water breakthrough law along the horizontal well in the bottom water reservoir of the X Oilfield. By analyzing the main controlling factors such as crude oil viscosity, permeability, bottom water energy, interlayer distribution, drainage policy, and oil column height, a two-stage bottom water reservoir horizontal well production model is established using numerical simulation software. By adjusting the model parameters, the study simulates the displacement mechanism and sweep law of bottom water reservoirs under different conditions, and evaluates the three-dimensional utilization effect of the reservoir. The results show that the increase in crude oil viscosity delays water breakthrough, and the energy of bottom water mainly affects the early water breakthrough time. The reasonable discharge volume affects the water breakthrough speed and the use of low-permeability sections. The interlayer delays the formation of water ridges and weakens the influence of permeability differences. The height of the oil column affects the water breakthrough difference and overall development effect. The research results provide theoretical guidance for tapping and adjusting the potential of offshore bottom water reservoirs.