Self-healing durable cement
According to at least one embodiment of the present description, a cement slurry includes 1% to 90% BWOC of a cement precursor material based on the total weight of the cement slurry; and from 1% to 40% BWOC of a swelling additive based on the total weight of the cement slurry. The swelling additive comprises at least one micronized rubber, at least one distillate, and at least one solvent-refined heavy paraffinic.
1. A wellbore cementing system comprising:
a tubular positioned in a wellbore such that an annulus is formed between a geological formation and the tubular; and
a cement structure positioned in at least a portion of the annulus, where
the cement structure comprises:
from 1% to 90% by weight of the cement of a cement precursor material based on a total weight of the cement structure, and
from 1% to 40% by weight of the cement of a swelling additive based on the total weight of the cement structure, where the swelling additive comprises (a) at least one micronized rubber in an amount from 50.0% to 95.0% by weight of the cement, and (b) comprises a combination of at least one distillate and at least one solvent-refined heavy paraffinic in an amount from 5.0% to 15.0% by weight of the cement.
2. The wellbore cementing system of claim 1 , where the at least one micronized rubber comprises nitrile rubber, styrene butadiene, fluoro silicone, isobutylene maleic anhydride, acrylic acid-type polymers, polyethylene oxide polymers, bentonite, and mixtures of these components.
3. The wellbore cementing system of claim 1 , where the at least one micronized rubber has a density from 10.0 lb/gal to 20.5 lb/gal.
4. The wellbore cementing system of claim 1 , where the at least one micronized rubber has a specific gravity from 0.85 to 1.10.
5. The wellbore cementing system of claim 1 , where the at least one micronized rubber comprises a mixture of carbon black, zinc oxide, and an elastomer.
6. The wellbore cementing system of claim 5 , where the carbon black comprises from 10.0% to 40.0% by weight of the cement of the at least one micronized rubber, the zinc oxide comprises less than 3.0% by weight of the cement of the at least one micronized rubber, and the elastomer comprises from 60.0% to 80.0% by weight of the cement of the at least one micronized rubber.
7. The wellbore cementing system of claim 1 , where the at least one micronized rubber comprises a mixture of acrylonitrile rubber, zinc oxide, and styrene butadiene copolymer.
8. The wellbore cementing system of claim 7 , where the acrylonitrile rubber comprises from 25.0% to 50.0% by weight of the cement of the at least one micronized rubber, the zinc oxide comprises less than 2.5% by weight of the cement of the micronized rubber, and the styrene butadiene copolymer comprises from 50.0% to 70.0% by weight of the cement of the micronized rubber.
9. The wellbore cementing system of claim 1 , where the swelling additive has a density from 0.5 g/cm 3 to 2.0 g/cm 3 .
10. The wellbore cementing system of claim 1 , where the cement structure has a Young's modulus 10 days after curing from 7.50×10 5 psi to 7.95×10 5 psi.
11. The wellbore cementing system of claim 1 , where the cement structure has a Young's modulus 20 days after curing from 5.50×10 5 psi to 6.00×10 5 psi.
12. The wellbore cementing system of claim 1 , where the cement structure has a Young's modulus 30 days after curing from 7.00×10 5 psi to 7.50×10 5 psi.
13. The wellbore cementing system of claim 1 , where the cement structure has a Poisson's ratio 10 days after curing from 0.370 psi to 0.400 psi.
14. The wellbore cementing system of claim 1 , where the cement structure has a Poisson's ratio 20 days after curing from 0.330 psi to 0.360 psi.
15. The wellbore cementing system of claim 1 , where the cement structure has a Poisson's ratio 30 days after curing from 0.705 psi to 0.735 psi.
16. The wellbore cementing system of claim 1 , where the cement structure has a density from 100 pcf to 170 pcf.