Lost-circulation materials of two different types of fibers

1. A treatment fluid comprising:

a base fluid;

a plurality of a first type of fiber, wherein the first type of fiber is degradable;

a plurality of a second type of fiber; and

a third lost-circulation material,

wherein the first and second type of fibers have a distribution such that at least 90% of the fibers have a length in the range of about 0.5 to about 3 millimeters,

wherein the first type of fibers, the second type of fibers, and the third lost-circulation material inhibit or prevent some or all of the treatment fluid from penetrating into a subterranean formation from a wellbore, wherein the wellbore penetrates the subterranean formation.

2. The treatment fluid according to claim 1 , wherein the base fluid comprises an aqueous liquid, an aqueous miscible liquid, or a hydrocarbon liquid.

3. The treatment fluid according to claim 1 , wherein the second type of fibers are degradable.

4. The treatment fluid according to claim 1 , wherein the first type of fibers are selected from, fibers composed of starch-g-poly (2-propenamide-co-2-propenoic acid) potassium salt, modified cellulose, chitosan, soya, modified chitosan, polycaprolactone, polylactic acid, poly(3-hydroxybutyrate), polyhydroxy-alkanoates, polyglycolic acid “PGA”, polylactic acid “PLA”, polyorthoesters, polycarbonates, polyaspartic acid, polyphosphoesters, soya, mineral fiber, or copolymers thereof.

5. The treatment fluid according to claim 1 , wherein the second type of fibers are selected from polymers or copolymers composed of polypropylene, polyaramid, polyester, polyacrylonitrile, polyvinyl alcohol, polycaprolactone, polylactic acid, poly(3-hydroxybutyrate), polyhydroxy-alkanoates, polyglycolic acid, polyorthoesters, polycarbonates, polyaspartic acid, polyphosphoesters, starch-g-poly (2-propenamide-co-2-propenoic acid) potassium salt, fibers composed of modified cellulose, chitosan, soya, modified chitosan, soya, viscose cellulosic fibers, oil coated cellulosic fibers, fibers derived from a plant product like paper fibers, carbon fibers, and melt-processed inorganic fibers including basalt fibers, wollastonite fibers, non-amorphous metallic fibers, ceramic fibers, and glass fibers.

6. The treatment fluid according to claim 1 , wherein the first type of fibers and the second type of fibers are each in a concentration in the range of about 0.1% to about 20% by weight of the base fluid.

7. The treatment fluid according to claim 1 , wherein the first and second type of fibers are in a combined total concentration in the range of about 1% to about 20% by weight of the base fluid.

8. The treatment fluid according to claim 1 , wherein the third lost-circulation material is ground oyster shells.

9. The treatment fluid according to claim 1 , wherein the third lost-circulation material is in a concentration in the range of about 10% to about 50% by weight of the base fluid.

10. The treatment fluid according to claim 1 , wherein the third lost-circulation material has a particle size such that at least 90% of the third lost-circulation material has a particle size in the range of about 2,000 to about 3,300 micrometers.

11. The treatment fluid according to claim 1 , wherein the treatment fluid further comprises one or more additional lost-circulation materials.

12. The treatment fluid according to claim 11 , wherein the additional lost-circulation materials are selected from: ground coal; petroleum coke; sized calcium carbonate; asphaltenes; perlite; cellophane; cellulose; ground tire material; vitrified shale; a plastic material; paper fiber; wood; cement; hardened foamed cement; glass; foamed glass; sand; bauxite; a ceramic material; a polymeric material (such as ethylene vinyl acetate or partially-hydrated polyacrylamide “PHPA”); a polytetrafluoroethylene material; a nut shell; a seed shell piece; a fruit pit piece; clay; silica; alumina; fumed carbon; carbon black; graphite; mica; titanium oxide; meta-silicate; calcium silicate; kaolin; talc; zirconia; boron; fly ash; a hollow glass microsphere; and any composite particle thereof.

13. The treatment fluid according to claim 11 , wherein the additional lost-circulation materials are in a concentration in the range of about 3% to about 30% by weight of the base fluid.

14. The treatment fluid according to claim 11 , wherein one or more types of the additional lost-circulation materials are degradable.

15. The treatment fluid according to claim 11 , wherein one or more types of the additional lost-circulation materials are water-swellable.

16. The treatment fluid according to claim 11 , wherein one or more types of the additional lost-circulation materials are degradable and water-swellable.

17. The treatment fluid according to claim 1 , wherein at least the first type of fibers, the second type of fibers, and the third lost-circulation material provide a fluid loss of less than 30 milliliters at a pressure of 1,000 pounds force per square inch.

18. The treatment fluid according to claim 1 , wherein at least the first type of fibers, the second type of fibers, and the third lost-circulation material provide a fluid loss of less than 30 milliliters at the bottomhole temperature and pressure of the subterranean formation.

19. The treatment fluid according to claim 1 , wherein the treatment fluid is a drilling fluid, spacer fluid, completion fluid, fracturing fluid, or acidizing fluid.

20. A method of treating a portion of wellbore comprising:

introducing a treatment fluid into the portion of the wellbore, wherein the treatment fluid comprises:

a base fluid;

a plurality of a first type of fiber, wherein the first type of fiber is degradable;

a plurality of a second type of fiber; and

a third lost-circulation material,

wherein the first and second type of fibers have a distribution such that at least 90% of the fibers have a length in the range of about 0.5 to about 3 millimeters,

wherein the first type of fibers, the second type of fibers, and the third lost-circulation material inhibit or prevent some or all of the treatment fluid from penetrating into a subterranean formation from a wellbore, wherein the wellbore penetrates the subterranean formation.

21. The method according to claim 20 , further comprising contacting at least a portion of the first type of fibers, the second type of fibers, and the third lost-circulation material with a degrading agent, wherein the step of contacting is performed after the step of introducing.

22. A system of treating a subterranean formation comprising:

a pump; and

a treatment fluid, wherein the treatment fluid comprises:

a base fluid;

a plurality of a first type of fiber, wherein the first type of fiber is degradable;

a plurality of a second type of fiber; and

a third lost-circulation material,

wherein the first and second type of fibers have a distribution such that at least 90% of the fibers have a length in the range of about 0.5 to about 3 millimeters,

wherein the first type of fibers, the second type of fibers, and the third lost-circulation material inhibit or prevent some or all of the treatment fluid from penetrating into a subterranean formation from a wellbore, wherein the wellbore penetrates the subterranean formation,

wherein the pump pumps the treatment fluid into the subterranean formation.

23. An additive comprising:

a plurality of a first type of fiber, wherein the first type of fiber is degradable;

a plurality of a second type of fiber; and

a third lost-circulation material,

wherein the first and second type of fibers have a distribution such that at least 90% of the fibers have a length in the range of about 0.5 to about 3 millimeters,

wherein the first type of fibers, the second type of fibers, and the third lost-circulation material inhibit or prevent some or all of a treatment fluid from penetrating into a subterranean formation from a wellbore, wherein the wellbore penetrates the subterranean formation.