Hydrate inhibited latex flow improver
View Patent ↗A process in which a mixture is agitated in a substantially oxygen-free environment to produce an agitated emulsion. The mixture comprises water, one or more surfactants, a hydrate inhibitor, and a monomer. The monomer is then polymerized in the emulsion using an initiator and a catalyst to form a hydrate inhibited latex drag reducer.
1. A process comprising:
a) agitating a mixture in a substantially oxygen-free environment to produce an agitated emulsion, wherein the mixture comprises:
i) water;
ii) one or more surfactants;
iii) a hydrate inhibitor; and
iv) a monomer,
b) polymerizing the monomer in the agitated emulsion using an initiator to generate free radicals and a catalyst, to form a hydrate inhibited latex drag reducer.
2. The process of claim 1 , wherein the surfactant comprises both a high HLB anionic surfactant and a high HLB nonionic surfactant.
3. The process of claim 1 , wherein the hydrate inhibitor is a polyhydric alcohol.
4. The process of claim 1 wherein the monomer is a methacrylate or acrylate monomer.
5. The process of claim 1 , wherein the mixture contains a buffer.
6. The process of claim 5 , wherein the buffer is used to maintain a pH in the emulsion from 6.5 to 10.
7. The process of claim 1 , wherein the initiator for generating free radicals is selected from the group consisting of: persulfate, peroxy persulfates and peroxides.
8. The process of claim 1 , wherein the amount of the hydrate inhibitor in the mixture is more than about 25 wt % of the continuous liquid phase of water and the hydrate inhibitor.
9. The process of claim 1 , wherein the hydrate inhibited latex drag reducer does not globularize after a freeze/thaw cycle.
10. The process of claim 1 , wherein the temperature for agitating the initiation solution occurs between the freezing point of the mixture to 50° C.
11. The process of claim 1 , wherein the catalyst comprises of a transition metal having at least two oxidation states.
12. A process comprising:
a) agitating a mixture in a substantially oxygen-free environment to produce an agitated emulsion, wherein the mixture comprises:
i) water;
ii) a surfactant comprising a high HLB anionic surfactant and a high HLB nonionic surfactant;
iii) at least about 25 wt % of a glycol in the carrier mixture of water and glycol;
iv) a methacrylate or acrylate monomer; and
v) an amount of buffer necessary to achieve a pH from 6.5 to 10 in the emulsion,
wherein the agitation does not cause any precipitation and occurs between the freezing point of the mixture to 60° C.,
b) polymerizing the monomer in the agitated emulsion using an initiator and a catalyst, to form a hydrate inhibited latex drag reducer, wherein the hydrate inhibited latex drag reducer does not globularize after five consecutive freeze/thaw cycles.