N,N-Dimethylacrylamide copolymer injection water viscosifier for enhanced oil recovery

Claim 2

A high molecular weight water soluble polymer consisting essentially of chain linkages derived from a major amount of N,N-dimethylacrylamide and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate having a molecular weight above about 1,000,000 wherein said water soluble polymer has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 3

A water soluble polymer as specified in claim 1 wherein said water soluble polymer has between 0.1 and 5 percent by weight of its chain linkages being derived from N-methylolacrylamide.

Claim 4

A water soluble polymer as specified in claim 2 wherein said water soluble polymer has 1 to 3 percent by weight of its chain linkages being derived from N-methylolacrylamide.

Claim 5

A water soluble polymer as specified in claim 1 wherein said water soluble polymer has between 0.1 and 5 percent by weight of its chain linkages being derived from sodium styrene sulfonate.

Claim 6

A water soluble polymer as specified in claim 4 wherein said water soluble polymer has between 0.5 and 1.5 percent by weight of its chain linkages being derived from sodium styrene sulfonate.

Claim 7

A high molecular weight water soluble polymer consisting essentially of chain linkages derived from a major amount of N,N-dimethylacrylamide; at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate wherein said water soluble polymer has 40 to 50 percent by weight of its chain linkages being derived from N,N-dimethylacrylamide; 40 to 50 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate; and 0.1 to 10 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate and wherein said water soluble polymer has a molecular weight of above about 1,000,000.

Claim 8

A high molecular weight water soluble polymer consisting essentially of chain linkages derived from a major amount of N,N-dimethylacrylamide; at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate wherein said water soluble polymer has 40 to 50 percent by weight of its chain linkages being derived from N,N-dimethylacrylamide; 40 to 50 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate; and 0.1 to 10 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate and wherein said water soluble polymer has a molecular weight of above about 1,000,000.

Claim 9

A water soluble polymer as specified in claim 6 wherein the only member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is sodium 2-acrylamido-2-methylpropanesulfonate.

Claim 10

A water soluble polymer as specified in claim 1 or 15 wherein a sufficient amount of said water soluble polymer is dissolved in said water to increase the Brookfield viscosity of said water to between 2 cps and 30 cps.

Claim 11

An aqueous polymer solution comprising: water and a high molecular weight water soluble polymer consisting essentially of chain linkages derived from N,N-dimethylacrylamide and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate having a molecular weight above about 1,000,000 wherein said water soluble polymer has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 12

An aqueous polymer solution comprising: water and a high molecular weight water soluble polymer consisting essentially of chain linkages derived from N,N-dimethylacrylamide and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate having a molecular weight above about 1,000,000 wherein said water soluble polymer has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 13

An aqueous polymer solution as specified in claim 9 wherein said water soluble polymer has between 0.1 and 5 percent by weight of its chain linkages being derived from N-methylolacrylamide.

Claim 14

An aqueous polymer solution as specified in claim 10 wherein said water soluble polymer has 1 to 3 percent by weight of its chain linkages being derived from N-methylolacrylamide.

Claim 15

An aqueous polymer solution as specified in claim 9 wherein said water soluble polymer has between 0.1 and 5 percent by weight of its chain linkages being derived from sodium styrene sulfonate.

Claim 16

An aqueous polymer solution as specified in claim 12 wherein said water soluble polymer has between 0.5 and 1.5 percent by weight of its chain linkages being derived from sodium styrene sulfonate.

Claim 17

An aqueous polymer solution comprising: water and a high molecular weight water soluble polymer consisting essentially of chain linkages derived from a major amount of N,N-dimethylacrylamide; at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate wherein said water soluble polymer has a molecular weight above about 1,000,000 and wherein said water soluble polymer has 40 to 50 percent by weight of its chain linkages being derived from N,N-dimethylacrylamide; 40 to 50 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate and calcium 2-acrylamido-2-methylpropanesulfonate; and 0.1 to 10 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 18

An aqueous polymer solution comprising: water and a high molecular weight water soluble polymer consisting essentially of chain linkages derived from a major amount of N,N-dimethylacrylamide; at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate wherein said water soluble polymer has a molecular weight above about 1,000,000 and wherein said water soluble polymer has 40 to 50 percent by weight of its chain linkages being derived from N,N-dimethylacrylamide; 40 to 50 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate and calcium 2-acrylamido-2-methylpropanesulfonate; and 0.1 to 10 percent by weight of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 19

An aqueous polymer solution as specified in claim 14 wherein the only member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is sodium 2-acrylamido-2-methylpropanesulfonate.

Claim 20

An aqueous polymer solution as specified in claim 9 or 14 wherein a sufficient amount of said water soluble polymer is dissolved in said water to increase the Brookfield viscosity of said water to between 2 cps and 30 cps.

Claim 21

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfate, and sodium dithionite to an aqueous reaction solution consisting essentially of water; N,N-dimethylacrylamide; and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate, in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein the polymer produced has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 22

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfate, and sodium dithionite to an aqueous reaction solution consisting essentially of water; N,N-dimethylacrylamide; and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate, in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein the polymer produced has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 23

A process as specified in claim 17 wherein the total concentration in said reaction solution of said N,N-dimethylacrylamide and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is from 2 weight percent to 50 weight percent.

Claim 24

A process as specified in claim 18 wherein the total concentration in said reaction solution of said N,N-dimethylacrylamide and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is from 10 weight percent to 20 weight percent.

Claim 25

A process as specified in claim 17 wherein the level of said sodium styrene sulfonate is 0.1 to 5 weight percent based upon total monomers.

Claim 26

A process as specified in claim 20 wherein the level of said sodium styrene sulfonate is 0.5 to 1.5 weight percent based upon total monomers.

Claim 27

A process as specified in claim 17 wherein the only member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is sodium styrene sulfonate.

Claim 28

A process as specified in claim 17 wherein the level of said N-methylolacrylamide is 0.1 to 5 weight percent base upon total monomers.

Claim 29

A process as specified in claim 23 wherein the level of said N-methylolacrylamide is 1 to 3 weight percent.

Claim 30

A process as specified in claim 17 wherein the only member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is N-methylolacrylamide.

Claim 31

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfate, and sodium dithionite to an aqueous reaction solution consisting essentially of water, N,N-dimethylacrylamide, at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate; in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein the polymer produced has from about 30 to 95 weight percent of its chain linkages being derived from N,N-dimethylacrylamide.

Claim 32

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfate, and sodium dithionite to an aqueous reaction solution consisting essentially of water, N,N-dimethylacrylamide, at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate; in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein the polymer produced has from about 30 to 95 weight percent of its chain linkages being derived from N,N-dimethylacrylamide.

Claim 33

A process as specified in claim 26 wherein the total concentration in said reaction solution of said N,N-dimethylacrylamide, at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate, and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is from 2 weight percent to 50 weight percent.

Claim 34

A process as specified in claim 27 wherein the total concentration in said reaction solution of said N,N-dimethylacrylamide, at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate, and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is from 10 weight percent to 20 weight percent.

Claim 35

A process as specified in claim 26 wherein the level of N,N-dimethylacrylamide is from 40 to 50 weight percent based upon total monomers; the total level of at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is 0.1 to 10 weight percent based upon total monomers and the total level of at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is 40 to 50 weight percent based upon total monomers.

Claim 36

A process as specified in claim 26 wherein the only member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is N-methylolacrylamide.

Claim 37

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfate, and sodium dithionite to a reaction solution consisting essentially of water, an oil, a dispersing agent, N,N-dimethylacrylamide, and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein said high molecular weight polymer has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 38

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfate, and sodium dithionite to a reaction solution consisting essentially of water, an oil, a dispersing agent, N,N-dimethylacrylamide, and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein said high molecular weight polymer has from 0.1 to 5 weight percent of its chain linkages being derived from at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate.

Claim 39

A process as specified in claim 31 wherein said reaction solution is comprised of about 50 percent by weight water; about 25 percent by weight N,N-dimethylacrylamide and at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and about 25 percent by weight of said oil which contains 2 to 20 percent by weight of said dispersing agent.

Claim 40

A process as specified in claim 31 wherein the level of said sodium styrene sulfonate is 0.1 to 5 weight percent based upon total monomers.

Claim 41

A process as specified in claim 33 wherein the level of said sodium styrene sulfonate is 0.5 to 1.5 weight percent based upon total monomers.

Claim 42

A process as specified in claim 31 wherein the only member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is sodium styrene sulfonate.

Claim 43

A process as specified in claim 31 wherein the level of said N-methylolacrylamide is 0.1 to 5 weight percent based upon total monomers.

Claim 44

A process as specified in claim 36 wherein the level of said N-methylolacrylamide is 1 to 3 weight percent based upon total monomers.

Claim 45

A process as specified in claim 31 wherein the only member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is N-methylolacrylamide.

Claim 46

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfite, and sodium dithionite to a reaction solution consisting essentially of: water, an oil, a dispersing agent, N,N-dimethylacrylamide, at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate, and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein the polymer produced has from about 30 to 95 weight percent of its chain linkages being derived from N,N-dimethylacrylamide.

Claim 47

A process for the synthesis of a high molecular weight polymer which comprises: the addition of a metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfite, and sodium dithionite to a reaction solution consisting essentially of: water, an oil, a dispersing agent, N,N-dimethylacrylamide, at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate, and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate in amounts and under conditions sufficient to initiate the polymerization wherein the polymer produced has a molecular weight above about 1,000,000 and wherein the polymer produced has from about 30 to 95 weight percent of its chain linkages being derived from N,N-dimethylacrylamide.

Claim 48

A process as specified in claim 39 wherein the level of N,N-dimethylacrylamide is from 40 to 50 weight percent based upon total monomers; the level of at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is 0.1 to 10 weight percent based upon total monomers; and the total level of at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is 40 to 50 weight percent based upon total monomers.

Claim 49

A process as specified in claim 39 wherein the only member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate is N-methylolacrylamide.

Claim 50

A process as specified in claim 26 or 39 wherein the only member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate is sodium 2-acrylamido-2-methylpropanesulfonate.

Claim 51

A process as specified in claim 31 or 39 wherein said oil is a member selected from the group consisting of kerosene, diesel fuel and hexane.

Claim 52

A process as specified in claim 31 or 39 wherein said dispersing agent is a nonionic surfactant that is insoluble in water and soluble in hydrocarbons.

Claim 53

A process as specified in claim 31 or 39 wherein said dispersing agent has the structural formula: ##STR12##

Claim 54

A process as specified in claims 17, 26, 31 or 39 wherein the level of said metal persulfate added is from 0.01 phm to 0.1 phm and the total level of at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfite and sodium dithionite added is from 0.01 phm to 0.1 phm.

Claim 55

A process as specified in claims 17, 26, 31 or 39 wherein the level of said metal persulfate added is about 0.0375 phm and the total level of at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfite and sodium dithionite added about 0.0375 phm.

Claim 56

A process as specified in claims 17, 26, 31 or 39 wherein said metal persulfate is ammonium persulfate.

Claim 57

A process as specified in claims 17, 26, 31 or 39 wherein the only member selected from the group consisting of sodium metabisulfite, sodium thiosulfite, and sodium dithionite is sodium metabisulfite.

Claim 58

A process as specified in claims 17, 26, 31 or 39 wherein the polymerization is run at a temperature from as low as 5° C. to as high as 50° C.

Claim 59

A process as specified in claim 50 wherein the polymerization is run at a temperature from 15° C. to 25° C.

Claim 60

A process as specified in claims 17, 26, 31 or 39 wherein the polymerization is run for a period of 6 to 18 hours.

Claim 61

A process as specified in claims 17, 26, 31 or 39, further comprising the removal of any dissolved oxygen in said reaction solution prior to the addition of said metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfite and sodium dithionite.

Claim 62

A process as specified in claims 17, 26, 31 or 39, further comprising sparging said aqueous solution with an inert gas prior to the addition of said metal persulfate and at least one member selected from the group consisting of sodium metabisulfite, sodium thiosulfite, and sodium dithionite to remove any dissolved oxygen from said aqueous solution.

Claim 63

A high molecular weight water soluble polymer comprised of chain linkages derived from N,N-dimethylacrylamide; at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate; wherein said water soluble polymer has from about 30 to 95 weight percent of its chain linkages being derived from N-N-dimethylacrylamide; and wherein said water soluble polymer has a molecular weight of above about 1,000,000.

Claim 64

A high molecular weight water soluble polymer comprised of chain linkages derived from N,N-dimethylacrylamide; at least one member selected from the group consisting of N-methylolacrylamide and sodium styrene sulfonate; and at least one member selected from the group consisting of sodium 2-acrylamido-2-methylpropanesulfonate, potassium 2-acrylamido-2-methylpropanesulfonate, ammonium 2-acrylamido-2-methylpropanesulfonate, and calcium 2-acrylamido-2-methylpropanesulfonate; wherein said water soluble polymer has from about 30 to 95 weight percent of its chain linkages being derived from N-N-dimethylacrylamide; and wherein said water soluble polymer has a molecular weight of above about 1,000,000.