A New Method to Determine the Injection Allocation of Single Water Well in Low Permeability Reservoirs

摘要

The theory of non-Darcy flow is analyzed in low permeability reservoirs, and the reservoir average pressure equation is established, which considers the impact of threshold pressure gradient and injectionproduction ratio, according to material balance equation and injection-production ratio equation. A new method is advanced to determine the injectionproduction ratio and injection allocation flux in waterflooding reservoir. This method takes into account the impact of pressure gradient, while the amount injection allocation does not ensure oil well production, but also recover the formation of the average pressure. The computation process adopt the multilayer iteration method, consider the impact of the injection well and production well pressure in areal well pattern, the target liquid producing capacity, the average formation pressure and injection-production ratio. According to this method and combining with the real data of the Chinese daqing oilfield SI block, the water injection of single well is 8.26m3/d. The result is advisable and accurate, which provides theoretical guide for practical application.