Method and composition for oil enhanced recovery
View Patent ↗A process for enhanced oil recovery includes the steps of providing an alkali metal borohydride; providing an alkali metal bisulfite; combining the alkali metal borohydride and the alkali metal bisulfite along with water to provide an oxygen-scavenger composition; combining the oxygen-scavenger composition and an aqueous composition to provide an oil recovery solution; and introducing the oil recovery solution into an earthen formation at a pressure to provide for enhanced oil recovery.
1. A process for oil recovery, the process comprising:
providing a stable aqueous solution comprising 12 percent sodium borohydride and 40 percent sodium hydroxide;
providing an alkali metal bisulfite;
combining the stable aqueous solution and the alkali metal bisulfite along with water to provide an oxygen-scavenger composition;
combining the oxygen-scavenger composition and an aqueous composition comprising a water soluble polymer to provide an oil recovery solution;
introducing the oil recovery solution into an earthen formation at a pressure to provide for oil recovery.
2. The process of claim 1 , wherein the water soluble polymer is selected from the group consisting of polyacrylates, polysaccharides, polyacrylamides and co-polymers of ethylenically unsaturated carboxylic acids.
3. The process of claim 1 , wherein the alkali metal bisulfite is sodium bisulfite.
4. The process of claim 1 , wherein the aqueous composition further comprises one or more surfactants.
5. The process of claim 4 , wherein the surfactant is selected from the group consisting of an aliphatic anionic surfactant, a synthetic polyisobutylene sulfonate, a sulfonate, an alcohol, a nonionic surfactant, or some combination thereof.
6. The process of claim 5 , wherein the surfactant is selected from the group consisting of an alpha-olefin sulfonate, an olefin sulfonated, an alkyl-aryl sulfonated, an alkyl-ether sulfonate.
7. The process of claim 1 , wherein the combining of the stable aqueous solution and the alkali metal bisulfite occurs outside the earthen formation.
8. The process of claim 1 , wherein the combining of the stable aqueous solution and the alkali metal bisulfite occurs within the earthen formation.
9. The process of claim 1 , wherein combining the oxygen-scavenger composition and the aqueous composition occurs outside the earthen formation.
10. The process of claim 1 , wherein combining the oxygen-scavenger composition and the aqueous composition occurs within the earthen formation.
11. The process of claim 1 , wherein the oil recovery solution has a pH ranging from 6 to about 8.
12. The process of claim 1 , further comprising introducing the oil recovery solution into an earthen formation at a pressure to provide for enhanced oil recovery.
13. The process of claim 1 , wherein the aqueous composition comprises seawater.
14. The process of claim 1 , wherein the aqueous composition comprises fresh water.
15. The process of claim 1 , wherein the process includes mixing a stream of the stable aqueous solution with a stream of the alkali metal bisulfite.
16. The process of claim 15 , wherein the mixing occurs via an in-line mixer upstream of a tank.
17. The process of claim 1 , wherein the oxygen-scavenger composition is added to a stream of water upstream of a tank.
18. The process of claim 1 , wherein the oxygen-scavenger composition and water are mixed in a tank without using a mixer.
19. The process of claim 1 , wherein the oil recovery solution provides an excess of about 50 ppm to about 100 ppm of sodium hydrosulfite equivalent after scavenging all the oxygen in the formation.