Cementitious fracture fluid and methods of use thereof

Patent metadata

Field	Value
Publication number	US-9567841-B2
Application number	US-201514753427-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Jul 1, 2014
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

The present disclosure relates to cementitious fluids comprising additives configured to form a permeable cement matrix after curing of the cement. The cementitious fluids can comprise a cementitious medium (e.g., a cement slurry) with a plurality of fibers dispersed therein. The fibers can be hollow, can be porous, and can be degradable. The cementitious fluid particularly can be used in methods of stimulating hydrocarbon bearing formations. Specifically, the cementitious fluid can be injected into the formation to form or enlarge a fracture, and the fluid can be cured to form the permeable cement matrix, said permeability arising from a loosely assembled tubular network and/or passages remaining after degradation of the fibers.

First claim

The invention claimed is:

1. A method for stimulating a hydrocarbon bearing formation comprising:
injecting a first fluid of a first composition and a second fluid of a second, different composition into the hydrocarbon bearing formation at a pressure sufficient to create or enlarge a fracture therein, wherein the first fluid is a cementitious fracture fluid comprising fibers dispersed in a cementitious medium; and
curing the injected cementitious fracture fluid to form a permeable cement matrix comprising a continuous network of interconnected channels corresponding to the position of the dispersed fibers, the interconnected channels being configured for flow of the hydrocarbon therethrough;
wherein the second fluid is substantially degraded or dissolved during or after said curing of the cementitious fracture fluid so as to form a plurality of open sections alternating with a plurality of sections of the permeable cement matrix.

2. The method according to claim 1 , wherein the fibers are selected from the group consisting of hollow fibers, degradable fibers, and combinations thereof.

3. The method according to claim 1 , wherein the fibers comprise one or more of hollow glass fibers and polymeric fibers.

4. The method according to claim 1 , wherein the fibers comprise a degradable material selected from the group consisting of aliphatic polyesters, polyorthoesters, polyanhydrides, and combinations thereof.

5. The method according to claim 1 , wherein the fibers comprise a degradable material selected from the group consisting of polylactic acid (PLA), polyglycolic acid (PGA), copolymers of PLA and PGA (PLGA), polycaprolactone (PCL), thermoplastic starch (TPS), cellulose, polyhydroxyalkanoates (PHAs), blends of phosphate-based glasses and polypropylene, copolymers of glycolic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, copolymers of lactic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, and combinations thereof.

6. The method according to claim 1 , wherein the fibers comprise one or both of hydrolytic ally degradable fibers and enzymatically degradable fibers.

7. The method according to claim 1 , wherein the fibers have a melting temperature of about 80° C. to about 190° C.

8. The method according to claim 1 , wherein the fibers degrade after said injecting step over a time of about 6 hours to about 240 hours.

9. The method according to claim 1 , wherein the cementitious medium comprises a slurry of cement and water.

10. The method according to claim 1 , wherein the second fluid comprises a material selected from the group consisting of polylactic acid (PLA), polyglycolic acid (PGA), polyols, polyethylene terephthalate (PET), polysaccharides, waxes, salts, calcium carbonate, benzoic acid, naphthalene based materials, magnesium oxide, sodium bicarbonate, soluble resins, sodium chloride, ammonium sulfate, and combinations thereof.

11. The method according to claim 1 , wherein the fibers comprise about 2% to about 40% by volume of the cementitious fracture fluid.

12. The method according to claim 11 , wherein the cement comprises an expansive cement.

13. An artificially formed underground structure comprising:
a hydrocarbon bearing formation with a fracture therein;
a plurality of sections of an at least partially cured permeable cement matrix formed within the fracture, the cement matrix including a substantially continuous network of interconnected channels configured for flow of the hydrocarbon therethrough; and
a plurality of at least partially open sections alternating with the plurality of sections of the at least partially cured permeable cement matrix.

14. The artificially formed underground structure according to claim 13 , wherein the interconnected channels comprise fibers or remnants thereof.

15. The artificially formed underground structure according to claim 14 , wherein the fibers are selected from the group consisting of hollow fibers, degradable fibers, and combinations thereof.

16. The artificially formed underground structure according to claim 14 , wherein the fibers comprise one or both of hydrolytically degradable fibers and enzymatically degradable fibers.

Assignees

• Res Triangle Inst

Inventors

• Rothrock Ginger D
• Rao Vikram
• Gupta Vijay
• Johnson Leah

Classifications

• C09K2208/08

  Fiber-containing well treatment fluids · CPC title

• E21B43/267 Primary

  reinforcing fractures by propping · CPC title

• E21B43/26

  by forming crevices or fractures · CPC title

• C09K8/62

  Compositions for forming crevices or fractures · CPC title

• C09K8/467

  containing additives for specific purposes · CPC title