Soluble fibers for use in resin coated proppant
View Patent ↗Coated particle substrates having a coating of resin and/or water soluble polymers and soluble, fibrous material are provided for use in subterranean formations. The coated particle substrate particles are typically proppants used to prop open subterranean hydrocarbon formations during recovery processes, such as after a hydraulic fracture, and provide both improved settling characteristics and improved hydrocarbon flow characteristics due to the conductive channels formed by the soluble fibers downhole. Methods of making the coated particles are also described.
1. A proppant particle comprising:
a particulate substrate having an outer surface;
a coating comprising resin or polymer; and
a soluble, fibrous material;
wherein the coating substantially covers the outer surface of the particulate substrate,
wherein the soluble fibrous material is embedded in the coating on the outer surface of the particulate substrate, and
wherein the soluble fibrous material is soluble in a subterranean environment.
2. The proppant particle of claim 1 , further comprising a soluble resin or polymer coating that substantially encapsulates the particulate substrate.
3. The proppant particle of claim 1 , further comprising a water soluble polymer coating that substantially encapsulates the particulate substrate.
4. The proppant particle of claim 1 , wherein the particulate substrate is selected from the group consisting of natural materials, silica proppants, ceramic proppants, metallic proppants, synthetic organic proppants, and mixtures thereof.
5. The proppant particle of claim 1 , wherein the particulate substrate has a particle size in the range from about 4 mesh to about 200 mesh.
6. The proppant particle of claim 1 , wherein the soluble, fibrous material is selected from the group consisting of polyethylene oxides, polypropylene oxides, polymeric lactones, water-soluble acrylic fibers, latex fibers, polyester fibers, polyactide fibers, collagen fibers, natural fibers, synthetic fibers, and mixtures thereof.
7. The proppant particle of claim 1 , wherein the soluble, fibrous material has a softening point of from about 70° C. to about 100° C.
8. The proppant particle of claim 1 , wherein the soluble fibrous material has a length to diameter ratio of at least about 2:1.
9. The proppant particle of claim 1 , wherein the soluble fibrous material includes soluble particles having a length to diameter ratio of less than about 2.
10. The proppant particle of claim 1 , wherein the resin coating comprises novolac polymers, resole polymers, and mixtures thereof.
11. The proppant particle of claim 1 , wherein the resin coating comprises a member of the group consisting of a furan resin, a phenolic-furan resin, and mixtures thereof.
12. The proppant particle of claim 1 , wherein the resin comprises a curable resin.
13. The proppant particle of claim 1 , wherein the soluble fibrous material is dispersed within the resin.
14. The proppant particle of claim 1 , wherein the soluble fibrous material is embedded in the resin.
15. The proppant particle of claim 1 , further comprising at least one additional resin or polymer coating surrounding the soluble fibrous material embedded in the resin coat.
16. A method of making a proppant particle of claim 1 comprising the steps of:
a) providing a particulate substrate material;
b) contacting the particulate substrate material with a resin or polymer to coat the particulate substrate with a coating of resin or polymer;
c) providing a soluble fibrous material; and
d) combining the particulate substrate material of step (b) with the soluble fibrous material such that the soluble fibrous material is at least partially embedded in the resin or polymer coat, wherein the soluble fibrous material is soluble in a subterranean environment.
17. The proppant particle prepared according to the method of claim 16 .
18. A method of making a proppant particle of claim 1 , the method comprising the steps of:
providing a particulate substrate, a resin or polymer, and a soluble fibrous material, wherein the soluble fibrous material is soluble in a subterranean environment;
combining the particulate substrate, the resin or polymer, and the soluble fibrous material in a manner wherein the resin or polymer coats the particulate substrate with a coating of resin or polymer and soluble fibrous material; and
solidifying the mixture.
19. The method of claim 18 , wherein the resin or polymer is coated onto the particulate substrate and then the soluble fibrous material is added to the resin or polymer coated particulate substrate.
20. The method of claim 18 , further comprising heating the resin or polymer to a temperature sufficient to melt the resin or polymer,
forming a mixture and coating the particulate substrate,
adding a soluble fibrous material to the resin or polymer coated particulate substrate, and then
adding a crosslinking agent to the mixture.
21. A proppant particle comprising:
a particulate substrate having an outer surface;
a first coating comprising resin or polymer;
a soluble, fibrous material; and
a soluble polymer outer coating,
wherein the first coating substantially covers the outer surface of the particulate substrate,
the soluble fibrous material is embedded in the coating on the outer surface of the particulate substrate,
the soluble fibrous material is soluble in a subterranean environment, and
the soluble polymer outer coating substantially encapsulates the particulate substrate.