Calculation of waterflood front in fractured low-permeability sandstone reservoirs

For fractured low-permeability waterflooding sandstone reservoirs, due to the strong heterogeneity, start-up pressure gradient and anisotropy etc., there is a huge difference in the amount of water absorbed in the direction of wells around the injection well, and the effects are not uniform between injection and production wells, and the direction of water flooding is not clear. How to determine the location of the front edge, so as to analyze the range of water flooding as well as the flow priority direction, is the technical challenge faced by this type of reservoirs. In this paper, the governing and the waterflood front equation suitable for fractured low-permeability reservoirs considering the three characteristic features of startup pressure gradient, pressure sensitivity, and anisotropy at the same time are derived. In addition, the effects of these three features on the waterflood front were comparatively analyzed by an example, so as to provide a reference for the development of fractured low-permeability reservoirs.