Cement compositions including epoxy resin systems for preventing fluid migration
A cement composition is disclosed that includes a cement slurry and an epoxy resin system that includes at least one epoxy resin and a curing agent. The cement slurry has a density in a range of from 65 pcf to 180 pcf and includes a cement precursor material, silica sand, silica flour, a weighting agent, and manganese tetraoxide. The epoxy resin system includes at least one of 2,3-epoxypropyl o-tolyl ether, alkyl glycidyl ethers having from 12 to 14 carbon atoms, bisphenol-A-epichlorohydrin epoxy resin, or a compound having formula (I): (OC 2 H 3 )—CH 2 —O—R 1 —O—CH 2 —(C 2 H 3 O) where R 1 is a linear or branched hydrocarbyl having from 4 to 24 carbon atoms; and a curing agent.
1. A cement composition comprising:
a cement slurry having a density in a range of from 130 pounds per cubic foot (pcf) to 180 pcf, the slurry comprising:
Portland Cement,
silica sand in an amount of from 10% to 20% by weight of cement,
silica flour in an amount of from 5% to 30% by weight of cement,
hematite in an amount of from 30% to 50% by weight of cement, and
manganese tetraoxide in an amount of from 30% to 50% by weight of cement; and
an epoxy resin system, the epoxy resin system comprising:
from 50 weight percent to 97 weight percent 2,3-epoxypropyl o-tolyl ether based on the weight of the epoxy resin system; and
from 2 weight percent to 30 weight percent of a curing agent based on the weight of the epoxy resin system.
2. The cement composition of claim 1 , where the epoxy resin system has a viscosity of from 1 millipascal seconds (mPa·s) to 50,000 mPa·s.
3. The cement composition of claim 1 , where the gel strength of the cement composition has a value greater than or equal to 1 when measured at room temperature and at a speed of 3 rotations per minute (rpm) using the method provided in the API Recommended Practice For Cementing (RP 10B).
4. The cement composition of claim 1 , where the cement composition has a gel strength greater than or equal to 1 using the method provided in the API Recommended Practice for Cementing.
5. The cement composition of claim 1 , where the cement composition has a density in a range of from 65 pcf to 180 pcf.
6. The cement composition of claim 1 , where the curing agent comprises an aliphatic amine curing agent.
7. The cement composition of claim 1 , where the curing agent comprises an aromatic amine curing agent.
8. The cement composition of claim 1 , further comprising an accelerator.
9. The cement composition of claim 1 , where the epoxy resin system further comprises a reactive diluent.
10. The cement composition of claim 1 , where the epoxy resin system further comprises multiple curing agents.
11. The cement composition of claim 1 , where the cement composition has a cure time of less than or equal to 48 hours.
12. The cement composition of claim 1 , comprising from 1 wt. % to 10 wt. % epoxy resin system based on the weight of the cement composition.
13. A method comprising
introducing a cement composition into a lost circulation zone or an annulus, the cement composition comprising:
a cement slurry having a density in a range of from 130 pounds per cubic foot (pcf) to 180 pcf, the cement slurry comprising:
Portland Cement,
silica sand in an amount of from 10% to 20% by weight of cement,
silica flour in an amount of from 5% to 30% by weight of cement,
hematite in an amount of from 30% to 50% by weight of cement, and
manganese tetraoxide in an amount of from 30% to 50% by weight of cement; and
an epoxy resin system comprising:
from 50 weight percent to 97 weight percent 2,3-epoxypropyl o-tolyl ether based on the weight of the epoxy resin system; and
from 2 weight percent to 30 weight percent of a curing agent based on the weight of the epoxy resin system; and
curing the cement composition to form a cured cement composition, where the cured cement composition seals the lost circulation zone or the annulus.
14. The method of claim 13 , where introducing the cement composition to the lost circulation zone comprises injecting the cement composition into the lost circulation zone.
15. The method of claim 13 , where the lost circulation zone is a narrow fracture gradient zone.
16. The method of claim 13 , further comprising drilling through the cured cement composition sealing the lost circulation zone to continue drilling the wellbore.
17. The method of claim 13 , where a spacer fluid, the cement composition, or both are introduced to the lost circulation zone through a drill string disposed within the wellbore.
18. The method of claim 13 , further comprising introducing a displacement fluid after the cement composition to displace the cement composition into lost circulation zone.
19. The method of claim 13 , where the cement composition has a cure time of less than or equal to 48 hours.