초록 ▼

A gas flooding process for displacing oil within a reservoir is improved by injections of a surfactant having a composition and concentration correlated with those of the brine used to remain substantially within the water phase of the injected fluid at a concentration below the critical micelle con

A gas flooding process for displacing oil within a reservoir is improved by injections of a surfactant having a composition and concentration correlated with those of the brine used to remain substantially within the water phase of the injected fluid at a concentration below the critical micelle concentration of the surfactant.

대표청구항 ▼

A process for recovering oil from a reservoir, penetrated by at least one injection well and one production well, comprising: (a) formulating an aqueous surfactant solution such that the surfactant is present in the solution at a concentration less than its critical micelle concentration; (b) inject

A process for recovering oil from a reservoir, penetrated by at least one injection well and one production well, comprising: (a) formulating an aqueous surfactant solution such that the surfactant is present in the solution at a concentration less than its critical micelle concentration; (b) injecting the surfactant solution into the reservoir; and (c) injecting a gas to displace the surfactant solution through the reservoir to assist in the recovery of hydrocarbons at the production well. A process for recovering oil from a reservoir, penetrated by at least one injection well and one production well, comprising: (a) formulating two aqueous surfactant solutions wherein the first surfactant solution contains surfactant that is present in the solution at a concentration that is more than its critical micelle concentration and wherein the second surfactant solution contains surfactant that is present in the solution at a concentration that is less than its critical micelle concentration, and wherein the second surfactant is selected from the group consisting of: [Figure] Wherein: R=a 6 to 16 carbon linear or branched alkyl radical or blend of alkyl radicals R1=ethyl or i-propyl group R2=ethyl or i-propyl group R3=OH when R4=CH2, or H when R4 is absent R4=CH2 when R3=OH, or absent when R3=H M=sodium, potassium, or ammonium x=0-9 y=0-9 n=0-1 (b) injecting the surfactant mixture solution into the reservoir; (c) injecting carbon dioxide gas into the reservior; (d) injecting the second surfactant solution into the reservoir; (e) injecting the carbon dioxide gas into the reservoir; (f) repeating steps (d) and (e) at least once; and (g) displacing the carbon dioxide gas within the reservoir with a brine solution, wherein the volumetric ratio of second surfactant solution plus brine solution to carbon dioxide gas is from about 5:1 to about 20:1.