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US-20260125317-A1 - METHOD TO ENHANCE POZZOLAN REACTIVITY

US20260125317A1US 20260125317 A1US20260125317 A1US 20260125317A1US-20260125317-A1

Abstract

A method of preparing an enhanced reactivity pozzolan may include: contacting a starting pozzolan with a catalyst material to form a mixture of the starting pozzolan and the catalyst material; reacting the mixture of starting pozzolan and catalyst material during an induction period to form reaction products; and recovering the enhanced reactivity pozzolan.

Inventors

  • Thomas Jason Pisklak
  • Claudia Carmen Osegueda
  • Samuel LEWIS

Assignees

  • HALLIBURTON ENERGY SERVICES, INC.

Dates

Publication Date
20260507
Application Date
20241217

Claims (20)

  1. 1 . A method of preparing an enhanced reactivity pozzolan comprising: contacting a starting pozzolan with a catalyst material to form a mixture of the starting pozzolan and the catalyst material; reacting the mixture of starting pozzolan and catalyst material during an induction period to form reaction products; and recovering the enhanced reactivity pozzolan.
  2. 2 . The method of claim 1 wherein the starting pozzolan comprises at least one pozzolan selected from the group consisting of fly ash, volcanic ash, tuft, pumicites, fumed silica, precipitated silica, high surface area silica, silica fume, slag, lime ash, perlite, silicate glass, soda-lime glass, soda-silica glass, borosilicate glass, aluminosilicate glass, volcanic rock, calcined clays, as metakaolin, partially calcined clays, mine tailings, recycled glass, bottom ash, cenospheres, bioashes, agricultural waste ash, silica flour, crystalline silica, cement kiln dust, glass bubbles, diatomaceous earth, zeolite, shale, vitrified shale, ground vitrified pipe, and combinations thereof.
  3. 3 . The method of claim 1 wherein the catalyst material comprises a Group I hydroxide selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), and potassium hydroxide (KOH), and combinations thereof.
  4. 4 . The method of claim 1 wherein the catalyst material comprises a catalyst solution comprising a Group I hydroxide dissolved in a solvent.
  5. 5 . The method of claim 4 wherein the catalyst solution comprises the Group I hydroxide in an amount of at least about 1 mole per liter of catalyst solution up to saturation.
  6. 6 . The method of claim 4 wherein the starting pozzolan is contacted with the catalyst solution in an amount of about 0.01 grams to about 1.0 grams of catalyst solution per gram of starting pozzolan.
  7. 7 . The method of claim 4 wherein the catalyst solution is sprayed onto the starting pozzolan.
  8. 8 . The method of claim 7 wherein the catalyst solution and starting pozzolan are mixed using a mixer while contacting the starting pozzolan with the catalyst solution.
  9. 9 . The method of claim 1 wherein the catalyst material comprises particles of a Group I hydroxide comprising hygroscopic water, wherein the particles of the Group I hydroxide are mixed using a mixer while contacting the starting pozzolan, and wherein the starting pozzolan is contacted with the particles of the Group I hydroxide in an amount of about 0.01 grams to about 0.5 grams of Group I hydroxide particles per gram of starting pozzolan.
  10. 10 . The method of claim 1 wherein the induction period is in a range of from about 1 hour to about 3 months.
  11. 11 . The method of claim 1 wherein the catalyst material further comprises a divalent hydroxide, a trivalent hydroxide, or a combination of divalent hydroxide and trivalent hydroxide.
  12. 12 . The method of claim 1 wherein the catalyst material further comprises at least one material selected from the group consisting of ethylene glycol, propylene glycol, Portland cement, calcium aluminate cement, triethanolamine, nano calcium-silicate-hydrate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, sodium borate, magnesium oxide, lithium nitrate, calcium nitrate, potassium nitrate, calcium bromide, calcium chloride, calcium formate, sodium bromide, sodium chloride, sodium formate, sodium nitrate, potassium chloride, potassium bromide, potassium formate, and combinations thereof.
  13. 13 . A method comprising: preparing a slurry comprising an enhanced reactivity pozzolan and water; and allowing the slurry to set to form a hardened composition.
  14. 14 . The method of claim 13 wherein the slurry further comprises a hydraulic cement selected from the group consisting of Portland cement, pozzolana cement, gypsum cement, alumina cement, silica cement, and any combination thereof.
  15. 15 . The method of claim 13 wherein the enhanced reactivity pozzolan is produced by a process comprising: contacting a starting pozzolan with a catalyst material to form a mixture of the starting pozzolan and a catalyst material; reacting the mixture of starting pozzolan and catalyst material during an induction period to form reaction products; and recovering the enhanced reactivity pozzolan.
  16. 16 . The method of claim 15 wherein the catalyst material comprises a catalyst solution comprising a Group I hydroxide dissolved in a solvent, wherein the catalyst solution comprises a Group I hydroxide in an amount of at least about 1 moles per liter of the catalyst solution up to saturation, and wherein the starting pozzolan is contacted with the catalyst solution in an amount of about 0.01 grams to about 0.5 grams of the catalyst solution per gram of the starting pozzolan.
  17. 17 . The method of claim 15 wherein the catalyst material comprises particles of a Group I hydroxide comprising hygroscopic water and wherein the starting pozzolan is contacted with the particles of the Group I hydroxide in an amount of about 0.01 grams to about 0.5 grams of Group I hydroxide particles per gram of starting pozzolan.
  18. 18 . The method of claim 15 wherein the catalyst material further comprises at least one material selected from the group consisting of a divalent hydroxide, ethylene glycol, propylene glycol, portland cement, calcium aluminate cement, triethanolamine, nano calcium-silicate-hydrate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, sodium borate, magnesium oxide, lithium nitrate, calcium nitrate, potassium nitrate, calcium bromide, calcium chloride, calcium formate, sodium bromide, sodium chloride, sodium formate, sodium nitrate, potassium chloride, potassium bromide, potassium formate, and combinations thereof.
  19. 19 . An enhanced reactivity pozzolan produced by a process comprising: contacting a starting pozzolan with a catalyst material to form a mixture of the starting pozzolan and the catalyst material; reacting the mixture of starting pozzolan and catalyst material during an induction period to form reaction products; and recovering the enhanced reactivity pozzolan.
  20. 20 . The enhanced reactivity pozzolan produced by the process of claim 19 wherein the catalyst material comprises a catalyst solution comprising a Group I hydroxide dissolved in a solvent, wherein the catalyst solution comprises the Group I hydroxide in an amount of about 1 moles per liter of catalyst solution to a solubility limit of the Group I hydroxide, and wherein the starting pozzolan is contacted with the catalyst solution in an amount of about 0.01 grams to about 0.5 grams of catalyst solution per gram of starting pozzolan and wherein the catalyst solution is sprayed onto a surface of the starting pozzolan.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the priority of U.S. Provisional Patent Application No. 63/717,554, Filed Nov. 7, 2024, which is incorporated by reference in its entirety. BACKGROUND In well cementing, such as well construction and remedial cementing, cement slurries are commonly utilized. Cement slurries may be used in a variety of subterranean applications. For example, in subterranean well construction, a pipe string (e.g., casing, liners, expandable tubulars, etc.) may be run into a well bore and cemented in place. The process of cementing the pipe string in place is commonly referred to as “primary cementing.” In a typical primary cementing method, a cement slurry may be pumped into an annulus between the walls of the well bore and the exterior surface of the pipe string disposed therein. The cement slurry may set in the annular space, thereby forming an annular sheath of hardened, substantially impermeable cement (i.e., a cement sheath) that may support and position the pipe string in the well bore and may bond the exterior surface of the pipe string to the subterranean formation. Among other things, the cement sheath surrounding the pipe string functions to prevent the migration of fluids in the annulus, as well as protecting the pipe string from corrosion. Cement slurries also may be used in remedial cementing methods, for example, to seal cracks or holes in pipe strings or cement sheaths, to seal highly permeable formation zones or fractures, to place a cement plug, and the like. A particular challenge in wellbore and construction cementing may be to ensure that cements have consistent and predictable properties. Pozzolans are used in cement slurry designs for multiple purposes such as yield enhancement, carbon dioxide (CO2) footprint reduction, and increased mechanical properties, for example. However, pozzolans can vary greatly in their reactivity with some being highly reactive and others having very low reactivity, and some may be inert in typical oilwell conditions. The variation in pozzolan reactivity may lead to geographic variation in cement designs depending on what pozzolans are available. Locations with highly reactive pozzolan sources can design slurries which have a much higher proportion of pozzolan, while those with low reactivity pozzolans may be limited to low concentrations since these pozzolans do not contribute as much to strength development or other properties of cement. Cement slurries prepared with pozzolans with relatively lower reactivity may not have the desired properties for oil well cementing. Locations with relatively highly reactivity pozzolan sources may be able to formulate acceptable cement slurries with relatively lower cement content, such as Portland cement of less than 30 wt. %, including Portland-free cement slurries. Those locations with relatively lower reactivity pozzolans are generally limited to slurries with much higher Portland cement such as Portland content of >50 wt. % or even >70 wt. %. Furthermore, as the supplementary cementitious material (SCM) content, including pozzolans, of the cement slurry is increased, the temperature at which the cement slurry can effectively cure to form barriers with acceptable physical properties is also increased. When the SCM content reaches ˜50 wt. % or greater with relatively lower reactivity pozzolans, the lower temperature limit for these slurries to effectively cure is around 140° F. (60° C.). Reactivity of pozzolans, also known as pozzolanic activity, measures the extent to which a pozzolanic material can chemically interact with calcium hydroxide (lime) in water, creating compounds with cementitious properties. This reactivity is determined indirectly by creating a test mix where the pozzolan either replaces part of the cement or is added to the cement mixture or slurry. Following the preparation, the mix's compressive strength is tested after a designated curing period, adhering to standards such as those outlined in American Petroleum Institute (API) Recommended Practice (RP) 10B-2 Second Edition, Apr. 1, 2013), which provides guidelines for testing oil well cements. The observed increase in compressive strength over time serves as an indirect measure of the pozzolanic activity, indicating the formation of additional cementitious compounds from the pozzolanic reactions. A pozzolan exhibiting relatively higher reactivity leads to an improvement in compressive strength when compared to one with relatively lower reactivity when included in the same fraction in the test mix. The reactivity of pozzolans can be increased by several means. For example, a pozzolan can be interground with another relatively more reactive material to increase the overall activity of the blend, the pozzolan can be ground to a smaller particle size to increase surface area and reactivity, or the pozzolan can be calcined in a furnace to increase the reactivity. However, each of the aforementioned technique