COMPOSITIONS AND METHODS FOR WELL CEMENTING
A method for well cementing may include supplying a settable composition including a cement composition and water into a well bore, and allowing the settable composition to set to form hardened concrete. The cement composition may include a hydraulic cement and natural glass, and the hardened concrete may have a strength activity index of at least 125%. A method for making well cement may include combining hydraulic cement and natural glass to form a cement composition, and adding water to form a settable composition. The method may further include allowing the settable composition to set to form hardened concrete, wherein the hardened concrete may have a strength activity index of at least 125%. A cement composition for use in well cementing may include hydraulic cement and natural glass having a median particle size (d 50 ) of less than 12 microns and a top particle size (d m ) of less than 30 microns.
1 . A method for well cementing, the method comprising:
supplying a settable composition comprising a cement composition and water into a well bore; and
allowing the settable composition to set to form hardened concrete,
wherein the cement composition comprises a hydraulic cement and natural glass, and
wherein the hardened concrete has a strength activity index of at least 125%.
2 . The method of claim 1 , wherein the natural glass comprises at least one of perlite, pumice, pumicite, shirasu, obsidian, pitchstone, and volcanic ash.
3 . The method of claim 1 , wherein the natural glass comprises unexpanded perlite.
4 . The method of claim 3 , wherein the unexpanded perlite has a median particle size (d 50 ) of less than 15 microns.
5 . (canceled)
6 . (canceled)
7 . The method of claim 3 , wherein the unexpanded perlite has a top particle size (d 90 ) of less than 40 microns.
8 . (canceled)
9 . (canceled)
10 . The method of claim 3 , wherein the unexpanded perlite has a BET surface area of at least 1 m 2 /gram.
11 . (canceled)
12 . (canceled)
13 . The method of claim 3 , wherein the unexpanded perlite has a bulk density of at least 25 lbs/ft 3 .
14 . (canceled)
15 . (canceled)
16 . The method of claim 3 , wherein the unexpanded perlite comprises crude unexpanded perlite fines.
17 . The method of claim 1 , wherein the hardened concrete has a strength activity index of at least 150%.
18 . (canceled)
19 . (canceled)
20 . (canceled)
21 . The method of claim 1 , wherein the settable composition has a slurry density of at least 10 lb/gal.
22 . (canceled)
23 . (canceled)
24 . The method of claim 1 , wherein the cement composition comprises at least 15% by weight natural glass.
25 . (canceled)
26 . (canceled)
27 . (canceled)
28 . The method of claim 1 , wherein the cement composition comprises at least 25% by weight fly ash.
29 . The method of claim 1 , wherein the settable composition comprises at least one of accelerators to reduce setting time, extenders to reduce density and/or hydraulic cement, weighting agents to increase density, fluid loss control agents to control water loss of the settable composition in the well bore, lost circulation control agents, dispersants, anti-foaming agents, and fibers.
30 . The method of claim 1 , wherein the natural glass serves as at least one of a strength enhancer and a substitute for fly ash.
31 - 45 . (canceled)
46 . A cement composition for use in well cementing, the cement composition comprising:
hydraulic cement; and
natural glass,
wherein the natural glass has a median particle size (d 50 ) of less than 12 microns and a top particle size (d 90 ) of less than 30 microns.
47 . The cement composition of claim 46 , wherein the natural glass comprises at least one of perlite, pumice, pumicite, shirasu, obsidian, pitchstone, and volcanic ash.
48 . A settable composition for use in well cementing, the settable composition comprising:
the cement composition of claim 46 ; and
water,
wherein the settable composition is configured to set to form hardened concrete.
wherein the hardened concrete has a strength activity index of at least 125%.
49 . The settable composition of claim 48 , wherein the hardened concrete has a strength activity index of at least 150%.
50 . A hardened concrete for use in well cementing, the hardened concrete comprising:
the cement composition of claim 46 ,
wherein the hardened concrete has a strength activity index of 125%.
51 . The hardened concrete of claim 50 , wherein the hardened concrete has a strength activity index of at least 150%.