Patent Document ID: 4181176
Application ID: 05958312
Patent Flag: 1

Claim One:
1. In a method for the recovery of petroleum from a subterranean reservoir penetrated by at least one injection well and at least one production well, said wells being in fluid communication with each other through the reservoir,which comprises injecting an oil displacing fluid into the reservoir via the injection well to pass through the reservoir along a plurality of streamtubes, displacing the petroleum toward the production well and recovering petroleum from the production well, a technique for increasing the recovery efficiency of the method which comprises: a. determining the number of streamtubes which breakthrough at the production well within a preselected period of time for a plurality of fluid injection and production rates; b. identifying the fluid injection and production rates at which the number of streamtubes intersecting the production well is at least equal to a predetermined percentage of the total number of streamtubes; and c. injecting the oil displacing fluid and extracting the produced fluids at rates about equal to the rates determined in step b.