Low-viscosity drag reducer
View Patent ↗Low-viscosity drag reducers, systems for delivering low-viscosity drag reducers, and methods of making low-viscosity drag reducers are disclosed. The low-viscosity drag reducers have a viscosity less than 350 cP at a shear rate of 250 sec −1 and a temperature of 60° P. This low-viscosity allows the drag reducers to be delivered through a long and relatively small diameter conduit of a subsea umbilical line without an unacceptable level of pressure drop or plugging of the conduit. The low-viscosity drag reducers can be delivered to a subsea flowline carrying fluids produced from a subterranean formation to 10 thereby provide significant drag reduction in the flow line.
1. A polymer solution drag reducer having a viscosity less than about 350 cP at a shear rate of 250 sec −1 and a temperature of 60° F., wherein said polymer solution drag reducer is purified to obtain a solid particulate content of NAS 1638 Class 12 or less.
2. The drag reducer of claim 1 , said drag reducer having a viscosity less than about 250 cP at a shear rate of 250 sec −1 and a temperature of 60° F.
3. The drag reducer of claim 1 , said drag reducer comprising a non-crystalline drag reducing polymer having a weight average molecular weight of at least 1×10 6 , said drag reducer comprising about 3 weight percent or less of said drag reducing polymer.
4. The drag reducer of claim 1 , said drag reducer having a viscosity less than 150 cP at a shear rate of 250 sec −1 and a temperature of 60° F.,
said drag reducer having a solid particulate content of NAS 1638 Class 10 or less,
said drag reducer comprising a non-crystalline drag reducing polymer having a weight average molecular weight of at least 2.5×10 6 ,
said drag reducer comprising about 0.1 to about 2 weight percent of said drag reducing polymer.
5. The drag reducer of claim 1 , said drag reducer comprising a non-crystalline drag reducing polymer having a weight average molecular weight of at least 5×10 6 .
6. The drag reducer of claim 5 , said drag reducing polymer being water soluble.
7. The drag reducer of claim 5 , said drag reducing polymer being hydrocarbon soluble.
8. The drag reducer of claim 5 , said drag reducer comprising a hydrocarbon solvent, said drag reducing polymer being substantially dissolved in the hydrocarbon solvent.
9. The drag reducer of claim 8 , said drag reducer being a product of solution polymerization carried out in the hydrocarbon solvent.
10. A drag reducer comprising: a solvent; and
a non-crystalline polymer substantially dissolved in the solvent, said polymer having a weight average molecular weight of at least 1×10 6 , wherein said drag reducer is purified to obtain a solid particulate content of NAS 1638 Class 12 or less.
11. The drag reducer of claim 10 , said drag reducer having a viscosity less than about 350 cP at a shear rate of 250 sec −1 and a temperature of 60° F.
12. The drag reducer of claim 10 , said drag reducer comprising about 3 weight percent or less of the polymer.
13. The drag reducer of claim 10 , said drag reducer being a product of solution polymerization carried out in the solvent.
14. The drag reducer of claim 10 ,
said drag reducer having a viscosity less than 250 cP at a shear rate of 250 sec −1 and a temperature of 60° F.,
said drag reducer having a solid particulate content of NAS 1638 Class 10 or less,
said drag reducer comprising a non-crystalline drag reducing polymer having a weight average molecular weight of at least 2.5×10 6 ,
said drag reducer comprising about 0.1 to about 2 weight percent of said drag reducing polymer.
15. A drag reducer comprising:
a solvent; and
a non-crystalline high molecular weight polymer substantially dissolved in the solvent,
said drag reducer comprising about 3 weight percent or less of said polymer,
wherein said drag reducer is purified to obtain a solid particulate content of NAS 1638 Class 12 or less.
16. The drag reducer of claim 15 , said drag reducer having a viscosity less than about 350 cP at a shear rate of 250 sec −1 and a temperature of 60° F.
17. The drag reducer of claim 16 , said polymer having a weight average molecular weight of at least 2.5×10 6 , said polymer being water soluble.
18. The drag reducer of claim 17 , said polymer having a weight average molecular weight of at least 2.5×10 6 , said polymer being hydrocarbon soluble.
19. The drag reducer of claim 17 , said drag reducer comprising about 0.1 to about 2 weight percent of said polymer.
20. The drag reducer of claim 17 , said drag reducer comprising 0.2 to 1 weight percent of said polymer.