Enhanced oil recovery compositions and methods thereof

Patent metadata

Field	Value
Publication number	US-10337303-B2
Application number	US-201615511563-A
Country	US
Kind code	B2
Filing date	Sep 2, 2016
Priority date	Sep 2, 2015
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

Additional oil recovery is obtained from a reservoir with a composition comprising at least a coupling solvent typically employed in waterborne coating compositions. Embodiments include recovering hydrocarbons using at least one coupling solvent, such as an oxygenated coupling solvent. The coupling solvent increases the mutual solubility with water at the injection temperature to facilitate the mixing and injection, particularly with an optional co-solvent. The coupling solvent helps mitigate formation plugging and improve performance when injected into a formation, as the solvent mixture moves from being miscible in the injection field water to being miscible in the reservoir oil, mobilizing the reservoir oil to increase oil recovery.

First claim

The invention claimed is:

1. A method for selecting additive solvents for recovering hydrocarbons in a waterflooding operation, the method comprising:
obtaining characteristics of a reservoir, including the reservoir temperature;
obtaining characteristics of a brine from the reservoir including salinity, pH, and polar organic solvent contents;
identifying an oxygenated coupling solvent, wherein the oxygenated coupling solvent includes oxygen as a component thereof, and wherein the oxygenated coupling solvent is water miscible at injection temperature, and wherein the oxygenated coupling solvent is water immiscible at the reservoir temperature, and wherein the oxygenated coupling solvent comprises glycol ethers, glycol ether esters, or any combination thereof;
constructing a first phase equilibria diagram indicative of a boundary of miscibility of the identified oxygenated coupling solvent to confirm that the identified oxygenated coupling solvent is water miscible at the injection temperature and water immiscible at the reservoir temperature;
identifying a co-solvent for mixing into the aqueous mixture, wherein the co-solvent is water miscible at injection temperature, and wherein the co-solvent is water immiscible at the reservoir temperature;
constructing a second phase equilibria diagram indicative of a boundary of miscibility of the identified oxygenated coupling solvent and the identified co-solvent to confirm that the identified oxygenated coupling solvent and the identified co-solvent are water miscible at the injection temperature and water immiscible at the reservoir temperature;
forming an injection stream with the identified oxygenated coupling solvent and the identified co-solvent for injection into the reservoir at a desired concentration of oxygenated coupling solvent and co-solvent mixture; and
injecting the injection stream into the reservoir to displace hydrocarbons in the reservoir, wherein at least a portion of the identified oxygenated coupling solvent and the identified co-solvent are water immiscible at the reservoir temperature and therefore miscible with the hydrocarbons at the reservoir temperature for driving the hydrocarbons toward a production well.

2. The method of claim 1 , wherein the co-solvent comprises an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant, or any combination thereof.

3. The method of claim 1 , wherein the co-solvent is provided in a weight ratio of the oxygenated coupling solvent to the co-solvent ranging from 1:20 to 20:1.

4. The method of claim 1 , further comprising adding a sufficient amount of a polymer for mixing into the injection stream.

5. The method of claim 1 , wherein the reservoir temperature is in a range of 50° F. to 300° F.

6. The method of claim 1 , wherein the first phase equilibria diagram is constructed as a function of brine/oxygenated coupling solvent mixture ranging from 100-0% brine/oxygenated coupling solvent volume ratio to 0-100% brine/oxygenated coupling solvent volume ratio %, and as a function of temperature ranging from ambient to the reservoir temperature; and
wherein the second phase equilibria diagram is constructed as a function of brine/oxygenated coupling solvent/co-solvent mixture ranging from 100-0% brine/oxygenated coupling solvent/co-solvent volume ratio to 0-100% brine/oxygenated coupling solvent/co-solvent volume ratio %, and as a function of temperature ranging from ambient to the reservoir temperature.

7. The method of claim 1 , wherein the co-solvent comprises ketones, esters, ethers, glycol ethers, glycol ether esters, lactams, cyclic ureas, alcohols, aromatic hydrocarbons, aliphatic hydrocarbons, nitroalkanes, unsaturated hydrocarbons, halocarbons, or any combination thereof.

8. The method of claim 1 , wherein the co-solvent for mixing into the aqueous mixture comprises alkyl aryl sulfonates (AAS), a-olefin sulfonates (AOS), internal olefin sulfonates (IOS), alcohol ether sulfates derived from propoxylated Ci 2 -C 2 o alcohols, ethoxylated alcohols, mixtures of an alcohol and an ethoxylated alcohol, mixtures of anionic and cationic surfactants, disulfonated surfactants, aromatic ether polysulfonates, isomerized olefin sulfonates, alkyl aryl sulfonates, medium alcohol (C10 to C17) alkoxy sulfates, alcohol ether [alkoxy]carboxylates, alcohol ether [alkoxy]sulfates, primary amines, secondary amines, tertiary amines, quaternary ammonium cations, cationic surfactants that are linked to a terminal sulfonate or carboxylate group, alkyl aryl alkoxy alcohols, alkyl alkoxy alcohols, alkyl alkoxylated esters, alkyl polyglycosides, or any combination thereof.

9. The method of claim 1 , wherein the co-solvent for mixing into the aqueous mixture comprises alkoxy ethoxyethanol compounds.

Assignees

• Chevron Usa Inc

Inventors

• Dwarakanath Varadarajan
• Shong Robert G
• Winslow Gregory
• Malik Taimur
• Solano Marlon

Classifications

• C09K8/588

  characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} · CPC title

• C09K8/584

  characterised by the use of specific surfactants · CPC title

• C09K8/58 Primary

  Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids · CPC title

• C08L2201/54

  Aqueous solutions or dispersions · CPC title

• C08L81/08

  Polysulfonates · CPC title