STEAM INJECTION METHOD WITH CONSTANT RATE OF HEAT

摘要

STEAM INJECTION METHOD WITH CONSTANT RATE OF HEAT (D#78,117-F) A method is disclosed for recovering hydrocarbons from underground formations by a series of sequenced steps, involving (1) injecting steam of a relatively high quality into the formation and (2) about the time of steam breakthrough, reducing the quality of the steam being injected to a quality between about 25% and about 50% while simultaneously increasing the rate of steam injection so as to maintain a constant rate of heat injection into the formation. Optionally, hot water having a temperature between about 120.degree. and 180.degree.F may be injected following the injection of about 0.5 pore volumes to about 2.5 pore volumes of reduced quality steam.