Abstract: The water-oil displacement process in hydraulic fractured horizontal wells (five-spot well pattern) is simulated by three models of dumbbell, nun and equal-length crack shapes, with their pictures of sweep regularity and records of oil and water production. The process can be divided into four stages, and each stage corresponds to different sweet area. Two dead oil areas are found in the end of the process. The experiment indicates that for water-free recovery, the nun model gives the highest, the dumbbell model gives the lowest; in water-bearing recovery stage, the nun model gives the lowest water cut and the highest oil recovery rate, while dumbbell model is in contrary for these values; however, the dumbbell model and equal-length model have relatively easy or stable stages in water cut and oil recovery rate, the nun mode has not; such three models are generally similar in the recovery, larger in injection pore volume, of which nun model is the biggest, dumbbell model is the smallest. According to the correlations of these models in water-free recovery, oil recovery rate and injection pore volume, water cut, the nun model has the best effect of water injection, the dumbbell model has the worst of it, while the equal-length crack model has the intermediate.

Key words: horizontal well, fracturing, plate model, five-spot well pattern, recovery, injection pore volume