Nonionic inversion agents for water-in-oil latices and methods of use
Water-in-oil latices of water soluble or dispersible polymers and methods of using the same are presented. The latices include nonionic inversion agents that provide rapid and complete inversion of the latices under conditions wherein the water source used to invert the latex is provided at high temperature, or includes a high level of total dissolved solids, or is both high temperature and high total dissolved solids.
1. A water-in-oil latex comprising
about 15 wt % to 70 wt % of a water soluble or dispersible polymer comprising 1 mol % to about 100 mol % acrylamide monomers;
about 0.1 wt % to 20.0 wt % of an inversion surfactant characterized as having a hydrophilic/lipophilic balance of 10 or greater; and
about 0.1 wt % to 20.0 wt % of a nonionic inversion agent having a structure corresponding to
wherein each m, n, o, p, q, and r is independently any integer, R and R′ are (CH 2 ) n′ , n′ is independently 0 or 1, and the sum of m, n, o, p, q, and r is from 10 to 135.
2. The latex of claim 1 comprising about 1.0 wt % to 20.0 wt % of the nonionic inversion agent and inversion surfactant combined.
3. The latex of claim 1 comprising about 0.1 wt % to 5.0 wt % of the nonionic inversion agent.
4. The latex of claim 1 comprising
about 3 wt % to 50 wt % water;
about 10 wt % to 40 wt % of a compound or blend thereof that is less than 0.1 wt % soluble in water at 25° C. and is substantially a liquid over the range of 20° C. to 90° C. and comprising linear, branched, or cyclic hydrocarbon moieties;
about 20 wt % or less of a latex surfactant characterized as having a hydrophilic/lipophilic balance of between 2 and 10; and
about 0.1 wt % to 5.0 wt % of the nonionic inversion agent.
5. The latex of claim 1 , wherein the latex is shelf stable.
6. A method of forming an invertible latex, the method comprising
(a) forming a water-in-oil latex comprising
about 15 wt % to 70 wt % of a water soluble or dispersible polymer;
about 3 wt % to 50 wt % water;
about 10 wt % to 40 wt % of a compound or blend thereof that is less than 0.1 wt % soluble in water at 25° C. and is substantially a liquid over the range of 20° C. to 90° C. and comprising linear, branched, or cyclic hydrocarbon moieties; and
about 20 wt % or less of a latex surfactant characterized as having a hydrophilic/lipophilic balance of between 2 and 10; and
(b) adding to the latex about 0.1 wt % to 20.0 wt % of an inversion surfactant characterized as having a hydrophilic/lipophilic balance of 10 or greater and about 0.1 wt % to 5.0 wt % of a nonionic inversion agent,
to form the invertible latex, wherein the nonionic inversion agent has a structure corresponding to
wherein each m, n, o, p, q, and r is independently any integer, R and R′ are (CH 2 ) n′ , n′ is independently 0 or 1, and the sum of m, n, o, p, q, and r is from 10 to 135.
7. The method of claim 6 , wherein the invertible latex is shelf stable.
8. A method of recovering hydrocarbon compounds from a subterranean reservoir, the method comprising
(a) forming an invertible latex according to the method of claim 6 ,
(b) adding a water source to the invertible latex in a single addition to form a polymer flooding solution comprising about 100 ppm to 10,000 ppm of the water soluble or dispersible polymer,
(c) injecting the polymer flooding solution into the subterranean reservoir, and
(d) recovering the hydrocarbon compounds.
9. The method of claim 8 , wherein the water source is about 30° C. to 100° C.
10. The method of claim 8 , wherein the water source includes about 0.1 to 30 wt % total dissolved solids.
11. The method of claim 8 , wherein the water source is about 30° C. to 100° C. and includes about 0.1 to 30 wt % total dissolved solids.