Patent ID: 8316938

Claim:
A method of injecting water into a geological reservoir formation containing hydrocarbons in order to enhance the flow of hydrocarbons into one or more casings positioned in well bores in the reservoir, the method comprising: a. providing a casing with an upper and a lower isolation assembly to define a first portion of the well casing; b. admitting water into the first portion of the well casing from a first water-containing stratum in the reservoir; c. pumping pressurized water from the first portion of the casing through a vertically-mounted electric submersible pump (ESP) that is attached to one leg of a Y-tool; d. discharging the pressurized water from a second leg of the Y-tool into an injection conduit, the conduit passing through the lower isolation assembly of the first portion of the casing; e. discharging pressurized water from the injection conduit into a lower second portion of the well casing that is defined by a second isolation assembly; and f. injecting the water from the second portion of the well casing into a second stratum of the reservoir surrounding the well bore at a position proximate the hydrocarbons contained in the reservoir formation, whereby the water discharged into the second stratum enhances the flow of any hydrocarbons from the reservoir into the casing in the well bore.