Non-condensible gas injection including alpha-olefin sulfonate surfactant additives

Claim 2

A non-condensible gas process of recovering hydrocarbons from a subterranean formation in the absence of steam, wherein said formation is penetrated by at least one injection well and at least one production well, said process sequentially comprising: (a) injecting a non-condensible gas at an injection well until non-condensible gas breakthrough occurs at a production well; (b) continuing to inject into said formation said non-condensible gas and, including therewith and under non-steam conditions, a sufficient amount of alpha-olefin sulfonate to form a non-condensible gas and alpha-olefin sulfonate foam to assist the movement of hydrocarbons toward said production well; and (c) recovering hydrocarbons from said production well.

Claim 3

The process according to claim 1 wherein the alpha-olefin sulfonate comprises from about 0.01% to about 10% of the liquid phase of the foam.

Claim 4

The process according to claim 2 wherein the non-condensible gas is from about 1% to about 99% of the gaseous phase of the foam.

Claim 5

The process according to claim 3 wherein the non-condensible gas is selected from the group consisting of nitrogen, carbon dioxide, CH 4 , air, carbon monoxide and flue gas.

Claim 6

The process according to claim 4 wherein the gas is nitrogen or CO 2 .

Claim 7

The process according to claim 5 wherein the alpha-olefin sulfonate includes alpha-olefin sulfonate having carbon chain lengths in the range of from about C 5 to about C 24 .

Claim 8

The process according to claim 6 wherein the alpha-olefin sulfonate has an alkyl carbon chain length in the range of from C 5 to C 24 .

Claim 9

The process according to claim 6 wherein the alpha-olefin sulfonate includes carbon chain lengths in the range of from about C 11 to about C 18 .

Claim 10

The process according to claim 8 wherein the gas is CO 2 and the alpha-olefin sulfonate has carbon chain lengths in the range of from C 11 to C 14 .

Claim 11

The process according to claim 2 wherein, said alpha-olefin sulfonate is injected with said non-condensible gas in step (a).

Claim 12

The process according to claim 2 which further comprises injecting non-condensible gas into the formation after the injection of said foam.

Claim 13

The process according to claim 11 wherein said non-condensible gas injection is tapered into said non-condensible gas and alpha-olefin sulfonate foam injection which is tapered into said non-condensible gas injection.

Claim 14

The process according to claim 12 wherein the alpha-olefin sulfonate are injected in their salt form or the acid form.

Claim 15

The process according to claim 13 wherein a non-condensible gas is from about 1% to about 99% of the foam.

Claim 16

The process according to claim 13 wherein the alpha-olefin sulfonate includes alkyl carbon chain lengths in the range of from about C 5 to about C 24 .

Claim 17

The process according to claim 15 wherein the alpha-olefin sulfonate includes carbon lengths in the range of from about C 11 to about C 18 .

Claim 18

The process according to claim 16 wherein the gas is CO 2 or nitrogen and the alpha-olefin sulfonate includes alkyl carbon chain lengths in the range of from C 11 to C 14 .

Claim 19

A process of recovering hydrocarbons from a subterranean formation in the absence of steam wherein the formation is penetrated by at least one injection well and at least one production well, said process comprising: injecting CO 2 or nitrogen gas into said formation at an injection well; continuing to inject CO 2 or nitrogen gas and a sufficient amount of alpha-olefin sulfonate to form a CO 2 or nitrogen and alpha-olefin sulfonate foam at an injection well under temperature and pressure conditions below the steam formation temperature and pressure at reservoir conditions, said alpha-olefin sulfonate includes alkyl carbon chain lengths in the range of C 11 to C 14 and wherein the alpha-olefin sulfonate is from about 0.01% to about 10% of the liquid phase of the foam and the gas is from about 1% to about 99% of the gaseous phase of the foam; displacing said gas-foam toward a production well; and recovering hydrocarbons from a production well.

Claim 20

A process of recovering hydrocarbons from a subterranean formation in the absence of steam wherein the formation is penetrated by at least one injection well and at least one production well, said process comprising: injecting CO 2 or nitrogen gas into said formation at an injection well; continuing to inject CO 2 or nitrogen gas and a sufficient amount of alpha-olefin sulfonate to form a CO 2 or nitrogen and alpha-olefin sulfonate foam at an injection well under temperature and pressure conditions below the steam formation temperature and pressure at reservoir conditions, said alpha-olefin sulfonate includes alkyl carbon chain lengths in the range of C 11 to C 14 and wherein the alpha-olefin sulfonate is from about 0.01% to about 10% of the liquid phase of the foam and the gas is from about 1% to about 99% of the gaseous phase of the foam; displacing said gas-foam toward a production well; and recovering hydrocarbons from a production well.

Claim 21

A CO 2 gas injection process of recovering hydrocarbons from a subterranean formation in the absence of steam, wherein the formation is penetrated by at least one injection well and at least one production well, said process sequentially comprising: (a) injecting CO 2 gas at an injection well until CO 2 gas breakthrough occurs at a production well; (b) continuing to inject into said formation said CO 2 gas and, including therewith and under non-steam conditions, a sufficient amount of an alpha-olefin sulfonate to form a CO 2 gas and alpha-olefin sulfonate foam to assist the movement of hydrocarbons toward said production well; and (c) recovering hydrocarbons from said production well.

Claim 22

A CO 2 gas injection process of recovering hydrocarbons from a subterranean formation in the absence of steam, wherein the formation is penetrated by at least one injection well and at least one production well, said process sequentially comprising: (a) injecting CO 2 gas at an injection well until CO 2 gas breakthrough occurs at a production well; (b) continuing to inject into said formation said CO 2 gas and, including therewith and under non-steam conditions, a sufficient amount of an alpha-olefin sulfonate to form a CO 2 gas and alpha-olefin sulfonate foam to assist the movement of hydrocarbons toward said production well; and (c) recovering hydrocarbons from said production well.

Claim 23

The process according to claim 19 wherein said alpha-olefin sulfonate includes carbon chain lengths in the range of about C 5 -C 24 .

Claim 24

The process according to claim 20 wherein said alpha-olefin sulfonate includes carbon chain lengths in the range of about C 15 -C 18 .

Claim 25

The process according to claim 21 wherein said CO 2 is injected in an amount of about 5,000,000 standard cubic feet per day and said alpha-olefin sulfonate is injected in an amount of about 2,500 barrels per day.

Claim 26

The process according to claim 20 wherein said alpha-olefin sulfonate has a carbon chain length in the range of from about C 5 to about C 24 .