Cement compositions including volcanic ash
The present disclosure relates to cement compositions including Portland cement and volcanic ash. An exemplary cement composition includes about 10 wt % to about 85 wt % of Portland cement, and about 10% by weight of cement (BWOC) to about 70% BWOC of volcanic ash.
1 . A cement composition, comprising:
about 10 wt % to about 45 wt % of Portland cement;
about 30% by weight of cement (BWOC) to about 50% BWOC of volcanic ash, wherein the volcanic ash comprises about 75 wt % silicon dioxide (SiO 2 ); and
about 25 wt % to about 80 wt % of water;
wherein a weight ratio of water to a total amount of Portland cement and volcanic ash present in the cement composition is about 0.4:1 to about 2:1; and
the cement composition has no free fluid.
2 . The cement composition of claim 1 , wherein the volcanic ash comprises Saudi Arabian volcanic ash.
3 . The cement composition of claim 1 , wherein the Portland cement comprises an American Petroleum Institute (API) Class G cement.
4 . The cement composition of claim 1 , comprising about 30% BWOC to about 45% BWOC of volcanic ash.
5 . The cement composition of claim 1 , comprising about 40% BWOC of volcanic ash.
6 . The cement composition of claim 1 , comprising
about 15 wt % to about 45 wt % of Portland cement;
and about 30 wt % to about 65 wt % of water.
7 . The cement composition of claim 1 , further comprising an extender.
8 . The cement composition of claim 7 , comprising about 0.1% BWOC to about 20% BWOC of the extender.
9 . The cement composition of claim 1 , further comprising a defoamer.
10 . The cement composition of claim 9 , comprising about 0.01% BWOC to about 2% BWOC of the defoamer.
11 . The cement composition of claim 1 , further comprising a gelling agent.
12 . The cement composition of claim 11 , comprising about 0.1% BWOC to about 5% BWOC of the gelling agent.
13 . The cement composition of claim 1 , further comprising a retarder.
14 . The cement composition of claim 13 , comprising about 0.01% BWOC to about 3% BWOC of the retarder.
15 . The cement composition of claim 1 , having a density of about 80 pcf to about 120 pcf.
16 . The cement composition of claim 1 , having a density of about 80 pcf to about 105 pcf.
17 . The cement composition of claim 1 , having a thickening time of about 3 hours to about 8 hours at about 120° F. and about 2,700 psi.
18 . The cement composition of claim 1 , having a thickening time of about 4 hours to about 7 hours at about 120° F. and about 2,700 psi.
19 . The cement composition of claim 1 , having a compressive strength of about 50 psi to about 1,500 psi after curing for about 1 day at about 150° F.
20 . The cement composition of claim 1 , having a compressive strength of about 100 psi to about 2,000 psi after curing for about 3 days at about 150° F.
21 . A cement composition, comprising:
about 10 wt % to about 45 wt % of Portland cement;
about 30% BWOC to about 50% BWOC of volcanic ash, wherein the volcanic ash comprises about 75 wt % silicon dioxide (SiO 2 );
about 0.01% BWOC to about 2% BWOC of a defoamer;
about 0.1% BWOC to about 5% BWOC of a gelling agent;
about 0.1% BWOC to about 3% BWOC of a retarder; and
about 25 wt % to about 80 wt % of water;
wherein a weight ratio of water to a total amount of Portland cement and volcanic ash present in the cement composition is about 0.4:1 to about 2:1; and
the cement composition has no free fluid.
22 . The cement composition of claim 21 , further comprising about 0.1% BWOC to about 5% BWOC of an extender.
23 . The cement composition of claim 22 , wherein the extender comprises bentonite.
24 . A cement composition, comprising:
about 10 wt % to about 45 wt % of Portland cement;
about 30% BWOC to about 50% BWOC of volcanic ash, wherein the volcanic ash comprises about 75 wt % silicon dioxide (SiO 2 );
about 5% BWOC to about 20% BWOC of an extender;
about 0.01% BWOC to about 2% BWOC of a defoamer;
about 25 wt % to about 80 wt % of water;
wherein a weight ratio of water to a total amount of Portland cement and volcanic ash present in the cement composition is about 0.4:1 to about 2:1; and
the cement composition has no free fluid.
25 . The cement composition of claim 24 , wherein the extender comprises sodium silicate.
26 . A method of cementing a wellbore, comprising
providing the cement composition of claim 1 to the wellbore, and
curing the cement composition.
27 . The method of claim 26 , comprising pumping the cement composition into an annulus between the wellbore and a casing in the wellbore.