Transient crosslinking of soluble polymers for alkali-activated material and geopolymer slurries

Abstract

A geopolymer composition or slurry may include fluid loss additives (FLA), wherein the fluid loss additives comprise crosslinked carboxymethyl cellulose (CMC) powder or CMC composite particles. A method for pre-forming a crosslinking of carboxymethyl cellulose (CMC) for use as fluid loss additives (FLA) and / or geopolymer slurries comprising using crosslinked CMC powder or CMC composite particles as fluid loss additives (FLA) is also disclosed. Lastly, a method for slurry mixing is also disclosed comprising adding linear carboxymethyl cellulose (CMC) and crosslinking agents to a geopolymer composition or slurry and reacting the above compositions in situ to retard polymer hydration.

Description

Patent ApplicationAttorney Docket No. IS25.0186-WOTRANSIENT CROSSLINKING OF SOLUBLE POLYMERS FOR ALKALI-ACTIVATED MATERIAL AND GEOPOLYMER SLURRIESCROSS-REFERENCE TO RELATED APPLCIATIONS

[0001] This application for patent claims priority benefit of United States Provisional Patent Application Serial No. 63 / 760,444, filed February 19, 2025, which is entirely incorporated herein by reference.BACKGROUND

[0002] Economically managing the fluid loss performance of geopolymer and alkaline activated material (AAM) well construction slurries can be difficult. Many of the low and moderately priced fluid loss additives (FLA) developed for ordinary Portland cements (OPC) perform poorly or do not function at all in AAM slurries. Fortunately, carboxymethyl cellulose (CMC) (also known as polyanionic cellulose (PAC)) is a low-cost FLA that provides good fluid loss control in a range of AAM slurries at reasonable cost. However, CMC causes severe problems during the initial mixing of AAM blend with water. The inclusion of CMC into a dry AAM powder blend greatly increases the hydration time of the dry blend, and the residence time required for a high-shear mixer to prepare a well-conditioned uniform liquid slurry.

[0003] Mixing multi-phase blends of dry hydratable powders into water is ubiquitous both in industry (e.g. mixing cement) and in the home (e.g. mixing a store-bought cake mix). One usually don’t recognize it as a complicated dynamical physical chemical process. Even when the solid powder phase is composed of only one material - powdered guar for example - mixing kinetics requires precise control of powder addition rates and mechanical shear energy to avoid fisheyes, clumps, plugs, and gas entrainment. However, multi-phase granular solid-liquid mixing becomes an extremely complicated chemical process when an AAM dry blend powder - containing pozzolans, soluble activators, salts, surface active agents, soluble powders, etc. - is mixed into water. Multiple physical chemical processes occur simultaneously during the mixing, and many of these processes work antagonistically against each other.Patent ApplicationAttorney Docket No. IS25.0186-WO

[0004] The important physical / chemical processes that take place upon mixing a dry blend containing the many different components of an AAM include hydration of the different types of powders in the mixture, which occurs at different rates depending on their various hydrophilicities, densities, specific surface areas (SSA), and on how fast they mechanically disaggregate. Hydration, swelling and entanglement of soluble polymers occurs if dry polymers such as CMC are included in the blend. CMC is extremely hydrophilic and as such it can hydrate - at least partially - very quickly. It has a profound effective on the liquid phase viscosity, and can form gels, so its presence has a major impact on the mixing and hydration of the other particles in the dry blend. Early hydration of CMC is thought to be a major factor in slowing down the overall mixing rate. Gas can also escape from the dry powder as it enters the slurry, or alternatively be entrained into the liquid phase (if conditions are not right). Gas escape is suppressed if the fluid is viscosified or is “locally” viscosified as polymer (namely CMC) is instantaneously hydrated. Antifoam agents are often added to the liquid phase to facilitate gas escape from the mixing fluid. Mechanical disaggregation of powder aggregates into finer particles also occurs. Disaggregation is caused by mechanical shear and impact forces in the blender, and by capillary forces as the aggregates imbibe water. Viscosified water reduces the shear forces that the aggregates experience and impedes imbibition into the aggregates. Soluble salts included in an AAM dry blend also dissolve upon mixing with water, a process that can be exothermic or endothermic. Surfactants and other surfaceactive agents among the solid, liquid and gas phases in the developing mixture also redistribute and begin to coat solid particles, thus modifying their hydrophilicities, surface electrical charges, and tendencies to agglomerate. Finally, the chemical reactions that create solid polymer materials from the AAM initiate upon addition of water as a solvent.

[0005] Furthermore, within the mixing blender there is spatial variation in the local mechanical shear energy, the local slurry density, and in the local concentration of the various slurry components - so viscous fingering and “floatation” can suppress the overall rate of mixing. A “region” of the fluid that has a high local viscosity - caused by partial hydration of a polymer (e g. CMC), may suppress the flow of fresh water into the powder stream in its wake. Furthermore, air entrained in the powder poured into the vortex of a blender may cause the powder to temporarily float on top of the viscosified region of thePatent ApplicationAttorney Docket No. IS25.0186-WOliquid phase - thereby suppressing mixing. Minimizing the time required for mixing, dispersing and hydrating an AAM dry blend is important for wellbore cementing operations - faster mixing to a uniform cement slurry is almost always better.

[0006] Cement (or AAM or geopolymer) blending is a continuous process in many wellbore cementing operations. The dry blend cement is added via an eductor into centrifugal pump and a high shear mixing tank, before being pumped downhole. The laboratory process simulating field conditions uses a sized Waring blender cup operating at 4000 rpm according to a standardized API procedure. It has been found that blends that can be uniformly mixed within 30 seconds in the lab are usually mixable, and pumpable in the field. Unfortunately, many slurries formulated with CMC can take much longer 1 - 4 minutes for blend addition in the lab.DETAILED DESCRIPTION

[0007] As used herein, “geopolymer composition” means and includes a mixture (blend) of one or more dry materials to which water may be added to form a slurry (a fluid mixture of liquid and solid particles), referred to herein as a “geopolymer slurry.” During hardening (also referred to as “setting”), the geopolymer slurry undergoes polycondensation wherein the composition included in the slurry (e.g., aluminosilicate) polymerizes and forms a crosslinked network of aluminum, silicon, and oxygen atoms, which may be referred to herein as a “geopolymer,” a “set geopolymer,” or a “hardened geopolymer.” The hardened material generally contains the aluminum, silicon, oxygen atom network, which is sometimes referred to as a polysialate, along with other interstitial or included materials. The term “geopolymer” generally refers to the entire hardened mixture. A geopolymer slurry is an alkaline activated material that hardens to form a geopolymer. Herein, the terms “aluminosilicate” and “aluminosilicate source” are used to refer to any alkaline reactive compound containing aluminum, silicon, and oxygen atoms bonded together, and may refer to materials that do not precisely conform to a chemical formula of a particular “aluminosilicate” compound. Thus, an aluminosilicate that can be used to perform the methods herein has chemically bonded aluminum, silicon, and oxygen atoms in amounts and ratios that vary. The aluminosilicates described herein are generally reactive in alkaline conditions to form geopolymers. Aluminum, silicon, andPatent ApplicationAttorney Docket No. IS25.0186-WOoxygen containing materials that are not reactive to form geopolymers are called “aluminosilicate precursors” herein.

[0008] This disclosure generally relates to devices, systems, and methods for geopolymer compositions, geopolymer slurries, and geopolymers including at least one aluminosilicate material, a fluid loss control material, and a salt (e.g., an inorganic salt) formulated and configured to inhibit (e.g., reduce and / or prevent) gelling of the geopolymer composition, such as of the fluid loss control material. In some embodiments, the geopolymer compositions, geopolymer slurries, and geopolymers further include an additional fluid loss control material that exhibits synergistic effects with the fluid loss control material, wherein the fluid loss control material comprises a crosslinked anionic polymer, such as a crosslinked modified polysaccharide with anionic functional groups.

[0009] The geopolymer composition may include from about 0.1 weight percent to about 15.0 weight percent of the fluid loss control material based on the weight of the at least one aluminosilicate material. In other words, for every about 100 parts by weight of the at least one aluminosilicate material, the geopolymer composition may include from about 0.1 weight percent to about 15.0 weight percent of the fluid loss control material.

[0010] The at least one aluminosilicate source may be in the form of a solid or an aqueous solution. The at least one aluminosilicate source may include, but is not limited to, fly ashes such as ASTM type C fly ash, ASTM type F fly ash, and fly ashes not classified by ASTM, volcanic ash, volcanic glass, slag, ferrous slag, ferroalloy slag, non-ferrous slag (e.g., copper slag, nickel slag, tin slag, zinc slag), blast furnace slag, basic oxygen furnace slag, electric arc furnace slag, ground granulated blast furnace slag (GGBFS), (or ground granulated blast slag, GGBS), diatomaceous earths, pumice, calcined or partially calcined clays (such as metakaolin), aluminum-containing silica fume, natural aluminosilicate, feldspars (which may be dehydrated), alumina and silica sols, synthetic aluminosilicate glass powder, zeolite, scoria, allophone, bentonite, red mud, which may be calcined, and pumice. Such materials may include a significant proportion of an amorphous aluminosilicate phase, which reacts in strong alkaline solutions. Generally, an aluminosilicate or an aluminosilicate precursor can be subjected to thermal processing to make an alkaline reactive aluminosilicate, which usually involves creating an amorphous morphology in the material. For example, the bentonite or metakaolin mayPatent ApplicationAttorney Docket No. IS25.0186-WObe calcined to convert the material from a crystalline to an amorphous morphology. Such thermal processing can convert an aluminosilicate precursor into an aluminosilicate that has any suitable degree of crystallinity. Such thermal processing can also reduce the crystallinity of an aluminosilicate material, in some cases rendering the aluminosilicate material amorphous. Amorphous aluminosilicate materials are generally more reactive in forming geopolymers than aluminosilicate materials having high crystallinity, although crystalline aluminosilicates can be used in geopolymer slurries in some cases, particularly where other alkaline activated materials are also used.

[0011] In some embodiments, the at least one aluminosilicate source includes at least one of fly ash, metakaolin, or blast furnace slag. In some embodiments, the at least one aluminosilicate source includes fly ash, such as ASTM type C fly ash. In some embodiments, the at least one aluminosilicate source includes a mixture of two or more aluminosilicate sources. In addition, alumina and silica sources may be added separately, for example, as a blend of bauxite and silica fume or as separate ingredients. Other amorphous silica sources can also be used in a geopolymer slurry. For example, sodalime glass dust, borosilicate glass dust, microsilica, fumed silica, precipitated silica, nanosilica, rice husk ash, or a combination thereof, can be used. It should be noted that some of the aluminosilicate sources mentioned above, such as GGBS and ASTM Class C fly ash, also contain calcium oxide, so these materials can also be considered activator sources. Suitable aluminosilicate sources for purposes herein can have at least 2%, at least 7%, at least 12%, at least 18%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% by weight calcium oxide. These aluminosilicate sources become reactive when placed in strongly alkaline environments, typically at pH greater than 11. The aluminosilicate sources described above react under such conditions to form geopolymers and other materials derived from alkali active materials.

[0012] In most cases, a geopolymer slurry (reactive precursor to a hardened geopolymer) is made by preparing a dry blend and then mixing the dry blend (herein called a “geopolymer composition,” as stated above) with an aqueous solution or water. The aqueous solution can be water or brine, and can be an alkaline solution configured to activate polymerization of the geopolymer slurry. The at least one aluminosilicate source may be present in the geopolymer composition at a weight percent within a range of fromPatent ApplicationAttorney Docket No. IS25.0186-WOabout 50 weight percent to about 99 weight percent, such as from about 50 weight percent to about 60 weight percent, from about 60 weight percent to about 70 weight percent, from about 70 weight percent to about 80 weight percent, from about 80 weight percent to about 90 weight percent, from about 90 weight percent to about 95 weight percent, from about 95 weight percent to about 97 weight percent, or from about 97 weight percent to about 99 weight percent, based on the weight of the dry blend (BWOB). However, the disclosure is not so limited, and the weight percent of the at least one aluminosilicate source in the geopolymer composition may be different than that described.

[0013] A fluid loss control material may be formulated and configured, and added to a geopolymer slurry, to reduce fluid loss from the geopolymer slurry. The fluid loss control material may be completely soluble in the water, brine, or aqueous solution of the geopolymer slurry. For example, the fluid loss material may be a soluble hydrophilic polymer. The fluid loss control materials described herein are generally added as a solid material, for example as a powder. Such materials can be added, as a powder, to the dry geopolymer composition, to a fluid portion, such as water, brine, or other aqueous solution that may contain dissolved activator, to be mixed with the dry geopolymer composition, or to a geopolymer slurry. Such materials can be added to, and dispersed into, the fluid portion as a coarse powder, a fine powder, or a volume of grains or pellets, and may be allowed to hydrate to an extent before mixing the fluid portion with the geopolymer composition. How the fluid loss control materials described herein are added can depend on the initial reaction rates and kinetics of the geopolymer slurry, which in turn depends on the composition of the slurry. It is generally desired to promote mixing of the slurry before significant hydration of the fluid loss control materials and before significant thickening of the geopolymer slurry to minimize mixing time. The method of adding the fluid loss control materials described herein is therefore selected to minimize mixing time of the geopolymer slurry.

[0014] In some cases, an FLA herein may be added to a carrier fluid to form a pre-mix which is then subsequently added to the fluid portion to be used to make the geopolymer slurry, or to the geopolymer slurry itself. The FLA is dissolved and / or dispersed in the carrier fluid to form the pre-mix, which may be mixed for a time prior to adding the pre-mix to the geopolymer slurry, or to any other component of the geopolymer slurry. The carrierPatent ApplicationAttorney Docket No. IS25.0186-WOfluid may be a mutual solvent that is miscible with the fluid portion of the geopolymer slurry, such as an alcohol, ether, or combination thereof. For example, the carrier fluid may be, or main contain, a lower alcohol such as methanol, ethanol, propanol, isopropanol, butanol, butyl glycol, or combination thereof. Alternately or additionally, the carrier fluid can be, or can contain, an alcohol-ether such as ethyleneglycolmonobutyl ether or butanol-dibutylglycol ether. These materials can also be combined with water or another aqueous fluid to form a partially aqueous solvent for the FLA pre-mix. Alternately, or additionally, the carrier fluid may be, or may contain, a brine such as a high concentration brine. In some cases, the carrier fluid can be, or can contain, a high concentration brine combined with another water-miscible solvent, with which the high concentration brine is immiscible, to form the FLA pre-mix in a “water-in-water emulsion.” In other cases, the carrier fluid may be, or may contain, a water immiscible oil, such as Isopar M, Isopar L, isohexadecane, 101618, Saraline 185V, diesel, and the like. These can be hydrocarbon materials or materials containing hydrocarbon portions and nonhydrocarbon portions, and can be used in mixtures like the other materials mentioned above. Any of these materials, and combinations thereof, can be used as a carrier fluid to deliver crosslinked polymer to a geopolymer slurry as an FLA.

[0015] It is believed that the fluid loss materials described herein function by increasing the viscosity of the geopolymer slurry interstitial fluid, after thorough mixing of the geopolymer slurry. For example, in use and operation, such as during pumping of the geopolymer slurry into an annulus between a subterranean borehole and a casing, it is believed that the geopolymer slurry may form a filtercake including the fluid loss control material. The fluid loss control materials described herein are believed to increase resistance to flow within and through the pore network of the filtercake, or by precipitating out as a film in the pores of the filtercake or adjacent rock. The fluid loss control material in the filtercake may reduce and / or prevent loss of fluid from the geopolymer slurry or components thereof into the earth formation. Without being bound by any particular theory, in some embodiments, the fluid loss control material may swell (e.g., in the filtercake) to yield a filtercake that is substantially impermeable to fluids (e.g., the water present in the geopolymer slurry) to reduce and / or prevent losses of fluid from the geopolymer slurry through the filtercake to the earth formation.Patent ApplicationAttorney Docket No. IS25.0186-WO

[0016] The fluid loss control material may be added to the geopolymer composition prior to forming a geopolymer slurry. The fluid loss control material may be present in the geopolymer composition at a weight percent within a range of from about 0.1 weight percent to about 15.0 weight percent by weight of the aluminosilicate in the geopolymer composition. For example, for every 100 parts by weight of the aluminosilicate, the geopolymer composition may include from about 0.10 parts to about 15.0 parts by weight of the fluid loss control material. The fluid loss control material may be present in the geopolymer composition at a weight percent within a range of from about 0.1 weight percent to about 0.2 weight percent, from about 0.2 weight percent to about 0.5 weight percent, from about 0.5 weight percent to about 1.0 weight percent, from about 1.0 weight percent to about 1.5 weight percent, from about 1.5 weight percent to about 2.0 weight percent, from about 2.0 weight percent to about 2.5 weight percent, from about 2.5 weight percent to about 3.0 weight percent, from about 3.0 weight percent to about 3.5 weight percent, from about 3.5 weight percent to about 4.0 weight percent, from about 4.0 weight percent to about 4.5 weight percent, from about 4.5 weight percent to about 5.0 weight, from about 5.0 weight percent to about 5.5 weight percent, from about 5.5 weight percent to about 6.5 weight percent, from about 6.5 weight percent to about 7.5 weight percent, from about 7.5 weight percent to about 8.5 weight percent, from about 8.5 weight percent to about 9.5 weight percent, from about 9.5 weight percent to about 10.5 weight percent, from about 10.5 weight percent to about 11.5 weight percent, from about 11.5. weight percent to about 12.5 weight percent, from about 12.5 weight percent to about 13.5 weight percent, from about 13.5 weight percent to about 14.5 weight percent, from about 14.5 weight percent to about 15 weight percent by weight of the aluminosilicate.

[0017] Processes are described herein to control hydration kinetics of the anionic polymeric FLA in an AAM dry mixture, to facilitate fast blend addition and mixing of a dry AAM blend into water or aqueous solution without compromising the subsequent fluid loss performance of the geopolymer slurry upon placement in the formation.

[0018] Carboxy-alkylated polysaccharides (CAPS) are a group of synthetically modified polysaccharides which have been reacted with alkyl-carboxylic acid reactants, and / or alkyl-carboxylic acid salt reactants such as chloroalkyl-carboxylic acids or chloroalkyl-carboxylic acid salts to provide the nonionic structure of the polysaccharidePatent ApplicationAttorney Docket No. IS25.0186-WOwith additional anionic functional groups to enhance their solubility and other properties, where the alkyl group can have, typically, from 1 to 21 carbon atoms. A chloroalkylcarboxylic acid that has an alkyl group with one single carbon atom is chloromethylcarboxylic acid (i.e. chloroacetic acid). The sodium salt of chloromethyl-carboxylic acid is sodium chloromethyl-carboxylate (i.e. sodium chloroacetate). Nonionic polysaccharides modified with such materials, including halogenated materials and non-halogenated materials, are called Carboxymethylated polysaccharides. (CMPS), of which Carboxymethyl Cellulose, CMC is one of several commercial products. Other suitable anionic polysaccharides may include, but are not limited to, polycarboxylates, alginates, hyaluronates, pectins, carrageenans, fucoidan, xanthan gums, diutan gum, chondroitin sulfate, sulfated dextrans, and cellulose derivatives, such as carboxyalkyl celluloses, and oxidized celluloses.

[0019] The processes described herein use metal ions (aluminum, iron, titanium, zirconium, transition metals, etc.) and complexes to temporarily crosslink CAPS, CMPS, and or CMC early in the mixing process. During mixing of a geopolymer composition that includes such materials with water or aqueous solution, the crosslinking restricts and retards the complete hydration of the CAPS, CMPS, and or CMC polymer and slows the development of viscosity in the fluid being mixed with the geopolymer composition. This crosslinking is temporary, and only needs to last for the duration of the mixing process, which depends on the composition of the geopolymer slurry and the mixing method and can be selected based on such parameters. Subsequently, the high concentration of hydroxyl, carbonate, or silicate anions in the geopolymer slurry competitively bind the crosslinking cations, destroying the crosslink, and releasing the polymer to perform its function.

[0020] The geopolymer composition may further include an additional fluid loss control material with the FLA described above. The additional fluid loss control material provides additional fluid loss functionality that may be independent of, or interdependent with, or synergistic with, the function of the FLA described above. The additional fluid loss control material may include one or more of a polymeric latex material, an alkali-swellable latex, an acrylic polymer, a styrene butadiene latex material, a carbonate powder, bentonite, attapulgite, fuller’s earth, carbon black, silica, fumed silica, nanosilica dispersions,Patent ApplicationAttorney Docket No. IS25.0186-WOalumina, nano-alumina dispersions, asphaltenes, thermoplastic resins, crosslinked polyvinyl alcohol (PVA), hydroxy ethyl cellulose (HEC), a cellulose polymer containing anionic carboxymethyl and nonionic hydroxyethyl groups added by ether linkages to hydroxyl groups on the cellulose backbone (CMHEC), hydroxypropyl cellulose (HPC), a galactomannan, polyvinylpyrrolidone (PVP), a mixture of polyvinylpyrrolidone and maleic anhydride-N-vinylpyrrolidone copolymer, poly(aryl-vinylbenzyl) ammonium chloride, a copolymer of N-vinylpyrrolidone and styrene sulfonate (SS), or another fluid loss control material. In some embodiments, the additional fluid loss control material includes a styrene butadiene latex material. In some embodiments, the additional fluid loss control material includes an alkali-swellable latex. The additional fluid loss control material, which when delivered in liquid form its concentration would be typically quantified as a volume of additive per unit volume of slurry, may be present in the geopolymer slurry at a concentration between 0.02 L / L and 0.3 L / L (1 gal / bbl and 15 gal / bbl), or between 0.05 L / L and 0.15 L / L.

[0021] The additional fluid loss control material may be present in the geopolymer composition at a weight percent within a range of from about 1.0 weight percent to about 5.0 weight percent by weight of the aluminosilicate in the geopolymer composition, such as from about 1.0 weight percent to about 1.5 weight percent, from about 1.5 weight percent to about 2.0 weight percent, from about 2.0 weight percent to about 2.5 weight percent, from about 2.5 weight percent to about 3.0 weight percent, from about 3.0 weight percent to about 3.5 weight percent, from about 3.5 weight percent to about 4.0 weight percent, from about 4.0 weight percent to about 4.5 weight percent, or from about 4.5 weight percent to about 5.0 weight percent by weight of the aluminosilicate. In some embodiments, the additional fluid loss control material is present in the geopolymer composition at a weight percent within a range of from about 1.4 weight percent to about 2.0 weight percent by weight of the aluminosilicate. In some cases when the additional fluid loss control material is delivered in liquid form, its concentration can also be quantified as a weight of the additional fluid loss control material per unit volume of the geopolymer slurry.

[0022] The geopolymer composition may include a greater weight percent of the FLA than of the additional fluid loss control material. In other embodiments, the geopolymerPatent ApplicationAttorney Docket No. IS25.0186-WOcomposition includes a greater weight percent of the additional fluid loss control material than of the FLA. In some embodiments, a weight percent of the FLA may be about the same as the weight percent of the additional fluid loss control material in the geopolymer composition or the geopolymer slurry, or both.

[0023] As described above, the geopolymer composition may include one or more additives. The one or more additives may include one or more of an activator, a retarder, an accelerator, a binder, a density modifier including a high specific gravity inorganic solid, a low density polymeric solid, a low specific gravity inorganic solid, glass bubbles, cenospheres a gas or an immiscible liquid, a viscosifier, a fluid loss agent, an extender, a dispersant, an antifoam agent, a defoamer, a surfactant, a foaming agent silica, an expanding agent, an anti-settling additive, a coagulant, or combinations thereof.

[0024] The activator may include an alkali activator or an alkali activator precursor. The alkali activator may be an alkali metal hydroxide, an alkaline-earth metal hydroxide, an alkaline earth metal oxide, an alkaline earth metal peroxide, at least one alkali salt, or combinations thereof. Alkali metal hydroxides may include lithium hydroxide, sodium hydroxide, or potassium hydroxide. Alkaline earth metal hydroxides may include calcium hydroxide, magnesium hydroxide, strontium hydroxide, or barium hydroxide. The alkaline earth metal oxides may be calcium oxide (e.g., lime), magnesium oxide, strontium oxide, barium oxide, or combinations thereof. The alkaline earth metal peroxide may be calcium peroxide or magnesium peroxide. The at least one alkali salt may be a metal carbonate (e.g., M2CO3, such as sodium carbonate), a metal sulfate (e.g., M2SO4), a metal sulfite (e.g., M2SO3), a metal phosphate (e.g., M3PO4), a metal oxalate (e.g., M2C2O4), a metal silicate (e.g., M2xSiyO(2y+x), wherein x is 1 , 2, or 3, and y is 1 or 2), a metal fluoride (e.g., MF), a metal hexafluoride (e.g., M2SiFe), a metal iodate (e.g., MIO3), a metal molybdate (e.g., M2MOO4), wherein M is a metal such as lithium, sodium, potassium, rubidium, and / or cesium in each of the above examples. The alkali activator may be added as a solid, an aqueous mixture, or an encapsulated liquid or solid material. In an encapsulated embodiment, the solid or liquid activator can be trapped in a capsule that will break when subjected to, for example, mechanical stress on the capsule, or coating degradation from temperature, radiation, and / or chemical exposure. The capsule can also naturally degrade if made from a biodegradable or self-destructive material. Furthermore, the alkali activatorPatent ApplicationAttorney Docket No. IS25.0186-WOwhen in liquid state may be adsorbed into a porous material and may be released after a certain time or due to a predefined event. The alkali activator may be added to the geopolymer slurry at a concentration within a range of from about 1M to about 10M, such as from about 3M to about 6M.

[0025] In some embodiments, the activator includes a metal silicate, such as an alkali metal silicate, such as sodium silicate, sodium metasilicate (Na2SiO3), potassium silicate (e.g., potassium metasilicate (foSiOs)), calcium silicate (Ca2SiO4), calcium metasilicate (CaSiOs), sodium carbonate (Na2CO3), or combinations thereof. The activator may include silicates of lithium, sodium, potassium, rubidium, cesium, or com binations thereof.

[0026] In some embodiments, the activator includes a first activator and a second activator. For example, the activator may include a metal hydroxide (e.g., sodium hydroxide) and a metal silicate (e.g., sodium silicate).

[0027] In some embodiments, the activator raises the pH of a geopolymer slurry formed from the geopolymer composition upon the addition of water or aqueous solution such that the aluminosilicates in the geopolymer composition dissolve and begin to react to form the geopolymer.

[0028] The activator may be present in the geopolymer composition at a concentration within a range of from about 4.0 weight percent to about 20.0 weight percent, such as from about 4.0 weight percent to about 6.0 weight percent, from about 6.0 weight percent to about 8.0 weight percent, from about 8.0 weight percent to about 10.0 weight percent, from about 10.0 weight percent to about 12.0 weight percent, from about 12.0 weight percent to about 14.0 weight percent, from about 14.0 weight percent to about 16.0 weight percent, from about 16.0 weight percent to about 18.0 weight percent, or from about 18.0 weight percent to about 20.0 weight percent by weight of aluminosilicate in the geopolymer composition. In some embodiments, the activator includes a first activator and a second activator. The weight percent of the second activator may be the same as the weight percent of the first activator in the geopolymer composition. In other embodiments, the weight percent of the first activator is different from the weight percent of the second activator in the geopolymer composition.Patent ApplicationAttorney Docket No. IS25.0186-WO

[0029] In embodiments including a metal silicate, the metal silicate may be present in the geopolymer slurry at a concentration between 0.01 kg / L and 0.2 kg / L, or between 0.05 kg / L and 0.1 kg / L. The SiO2 / Na2O molar ratio may be less than or equal to 3.2. The SiO2 / K2O molar ratio may be less than or equal to or less than 3.2. When mixed with the carrier fluid, the metal silicate may be present in the geopolymer slurry at a concentration between about 0.1 M and 5M, or between 0.5M and 2M. The metal silicates may be dry blended with the aluminosilicate source. Also, the metal silicate in another embodiment may be encapsulated.

[0030] The thickening time of geopolymer slurries formed from the geopolymer compositions described herein may be influenced by adding retarders and accelerators. The retarder may delay the setting and hardening of geopolymer slurries. The retarder may include one or more of ferric soluble salts, including but not limited to, ferric chloride FeCIs ferric sulfate (Fe2(SCU)3) or ferric nitrate Fe(NO3)3, sodium lignosulfonate (C2oH24Na20 S2), sodium pentaborate decahydrate, borax, boric acid, lignosulphonates, hydrocarboxylic acids and salts, sodium glucoheptonate, gluconic acid, tartaric acid, citric acid, sucrose, raffinose, or phosphorus containing compounds such as phosphoric acid, salts thereof, or mixtures thereof. In some embodiments, the retarder includes ferric sulfate. The amount of retardation of the polymerization reaction, and retarding of the setting of the geopolymer slurry, may depend on the type of raw materials used for the geopolymer slurry and the type and relative quantity of the retarder in the geopolymer slurry. A concentration of the retarder in the geopolymer composition may be within a range of from about 0.2 weight percent to about 3.0 weight percent, such as from about 0.2 weight percent to about 0.5 weight percent, from about 0.5 weight percent to about 1.0 weight percent, from about 1.0 weight percent to about 1.5 weight percent, from about 1.5 weight percent to about 2.0 weight percent, from about 2.0 weight percent to about 2.5 weight percent, or from about 2.5 weight percent to about 3.0 weight percent by weight of aluminosilicate in the geopolymer composition. In some embodiments, the retarder is present in the geopolymer composition at a concentration within a range of from about 1.1 weight percent to about 2.3 weight percent by weight of aluminosilicate in the geopolymer composition. It should be noted that at least some of the polysaccharides described herein as FLA materials can also retard polymerization. Thus, in some cases,Patent ApplicationAttorney Docket No. IS25.0186-WOan amount of retarder needed to achieve a certain thickening time can be reduced where the polysaccharide FLA materials described herein are used.

[0031] The density modifier may include density increasing particles and density reducing particles. Density reducing particles may be included in the geopolymer composition, or added to the geopolymer slurry, to achieve lower geopolymer slurry densities for a given amount of water added, or density increasing particles may be added to achieve higher geopolymer slurry densities. The density reducing particles may include surfactant stabilized gas bubbles, such as nitrogen or air gas bubbles in foams, or may include particles having a low specific gravity and having densities lower than 2 g / cm3, or lower than 1.3 g / cm3. Density reducing particles may include hollow glass or ceramic microspheres (cenospheres), plastic particles such as polypropylene beads, rubber particles, uintaite (sold as GILSONITE™), vitrified shale, petroleum coke or coal or combinations thereof. The density reducing particles may be present in the geopolymer slurry at concentrations between about 0.06 kg / L and 0.6 kg / L (20 Ib / bbl and 200 Ib / bbl). The particle size range of the density reducing particles may be between about 37 pm and 3350 pm (6 mesh and 400 mesh). The density increasing particles typically may have densities exceeding 2 g / cm3, or more than 3 g / cm3. Density increasing particles may include hematite, barite, ilmenite, silica (e.g., crystalline silica sand), crushed granite and also manganese tetroxide commercially available under the trade names of Micro Max™ and MicroMax FF™.

[0032] The viscosifier may include one or more of a polysaccharide (e.g., xanthan gum, diutan gum, welan gum), or another material. In some embodiments, the viscosifier includes diutan gum having a molecular weight higher than about 1 x 106g / mol. The viscosifier may be present in the geopolymer slurry at a concentration between 0.14 g / L and 1.4 g / L (0.05 Ib / bbl and 0.5 Ib / bbl). The molecular weight of the polysaccharides, which may be biopolymers, may be between 100,000 g / mol and 1,000,000 g / mol.

[0033] The antifoam agent may include one or more of a propylene glycol, such as polypropylene glycol, a polyglycol ether, a silicone, or another material. The antifoam agent may be present in the geopolymer composition at a weight percent from about 0.01 weight percent to about 0.05 weight percent by weight of aluminosilicate, such as from about 0.01 weight percent to about 0.02 weight percent, from about 0.02 weight percentPatent ApplicationAttorney Docket No. IS25.0186-WOto about 0.03 weight percent, from about 0.03 weight percent to about 0.04 weight percent, or from about 0.04 weight percent to about 0.05 weight percent by weight of aluminosilicate in the geopolymer composition. In some embodiments, the antifoam agent is present in the geopolymer composition at a weight percent of about 0.02 weight percent by weight of aluminosilicate in the geopolymer composition.

[0034] The dispersant may include a sulfonate-based material, carboxylic acids including gluconic acid and soluble salts thereof, glucoheptonic acid and soluble salts thereof, tartaric acid and soluble salts thereof, citric acid and soluble salts thereof, glycolic acid and soluble salts thereof, lactic acid and soluble salts thereof, formic acid and soluble salts thereof, acetic acid and soluble salts thereof, propionic acid and soluble salts thereof, oxalic acid and soluble salts thereof, malonic acid and soluble salts thereof, succinic acid and soluble salts thereof, adipic acid and soluble salts thereof, malic acid and soluble salts thereof, nicotinic acid and soluble salts thereof, benzoic acid and soluble salts thereof, ethylenediamine tetraacetic acid (EDTA) and soluble salts thereof, phosphoric acid, or combinations thereof. By way of non-limiting example, the dispersant may include a sodium polynaphthalene (e.g., sodium polynaphthalene sulfonate), sodium lignosulfonate, calcium lignosulfonate, or combinations thereof. The dispersant may include a sodium polymelamine sulfonate salt, a polystyrene sulfonate salt, or a polycarboxylate salt.

[0035] The dispersant may be present in the geopolymer composition at a weight percent from about 0.05 weight percent to about 0.50 weight percent by weight of aluminosilicate in the geopolymer composition, such as from about 0.05 weight percent to about 0.10 weight percent, from about 0.10 weight percent to about 0.20 weight percent, from about 0.20 weight percent to about 0.30 weight percent, from about 0.30 weight percent to about 0.40 weight percent, or from about 0.40 weight percent to about 0.50 weight percent by weight of aluminosilicate in the geopolymer composition.

[0036] A density of the geopolymer slurry may be within a range of from about 800 kg / m3(about 6.69 pounds per gallon (Ib / gal) (ppg)) to about 2,900 kg / m3(about 24.2 ppg), such as from about 800 kg / m3(about 6.69 ppg) to about 1 ,000 kg / m3(about 8.35 ppg), from about 1,000 kg / m3(about 8.35 ppg) to about 1,200 kg / m3(about 10.0 ppg), from about 1,200 kg / m3(about 10.0 ppg) to about 1,400 kg / m3(about 11.7 ppg), from aboutPatent ApplicationAttorney Docket No. IS25.0186-WO1,400 kg / m3(about 11.7 ppg) to about 1,600 kg / m3(about 13.4 ppg), from about 1,600 kg / m3(about 13.4 ppg) to about 1,800 kg / m3(15.0 ppg), from about 1,800 kg / m3(about 15.0 ppg) to about 2,000 kg / m3(about 16.7 ppg), from about 2,000 kg / m3(about 16.7 ppg) to about 2,300 kg / m3(about 19.2 ppg), from about 2,300 kg / m3(about 19.2 ppg) to about 2,600 kg / m3(about 21.7 ppg), or from about 2,600 kg / m3(about 21.7 ppg) to about 2,900 kg / m3(about 24.2 ppg). In some embodiments, the density of the geopolymer slurry is about 1,800 kg / m3(about 15.0 ppg). However, the disclosure is not so limited, and the density of the geopolymer slurry may be different than those described. The density of the geopolymer slurry may be modified by incorporating one or more of the density reducing particles, density increasing particles, or by altering an amount of the aluminosilicate in the geopolymer composition.

[0037] A viscosity of the geopolymer slurry at about 20°C (about 68°F) may be less than about 400 centipoise (hereinafter “cP”), less than about 350 cP, or less than about 300 cP. A viscosity of the geopolymer slurry at about 48.9°C (about 120°F) may be less than about 200 cP, such as less than about 180 cP, less than about 160 cP, less than about 140 cP, less than about 120 cP, less than about 100 cP, or less than about 80 cP.

[0038] A solid volume fraction (SVF) of the geopolymer slurry (defined as the volumetric fraction of the geopolymer slurry comprised of solid particles) may be within a range of from about 25% to about 60%, such as from about 35% to about 55%., or from about 40% to about 50%. The carrier fluid (in which the solid materials of the geopolymer composition are either dissolved, or dispersed depending on their water solubility) may constitute from about 40% to about 75% by volume of the geopolymer slurry and may be referred to as a liquid volume fraction (LVF). The carrier fluid may be present in the geopolymer slurry at a volume percent within a range of from about 40.0 volume percent to about 75.0 volume percent, such as from about 40.0 volume percent to about 50.0 volume percent, from about 50.0 volume percent to about 60.0 volume percent, from about 60.0 volume percent to about 70.0 volume percent, or from about 70.0 volume percent to about 75.0 volume percent. However, the disclosure is not so limited, and the SVF and LVF of the geopolymer composition may be different than those described.

[0039] A pH of the geopolymer slurry may be greater than about 11.0, such as greater than about 11.5, greater than about 12.0, greater than about 12.5, or greater than aboutPatent ApplicationAttorney Docket No. IS25.0186-WO13.0. In some embodiments, the pH of the geopolymer slurry may be controlled by the alkali activator (e.g., the pH of the geopolymer slurry may be increased by increasing the amount of the alkali activator).

[0040] After setting, a density of the geopolymer formed from the geopolymer composition may be within a range of from about 800 kg / m3(about 6.68 ppg) to about 2.500 kg / m3(about 20.86 ppg), such as from about 800 kg / m3(about 6.68 ppg) to about 1.500 kg / m3(about 12.5 ppg), or from about 1,500 kg / m3(about 12.5 ppg) to about 2,500 kg / m3(about 20.86 ppg), however the disclosure is not so limited, and the density of the geopolymer may be different than those described.

[0041] The methods herein provide control over the hydration, crosslinking and subsequent de-crosslinking of fluid loss additives using competitive chemical kinetics of modified anionic polysaccharides, such as CAPS, CMPS, or CMC.

[0042] Without being bound to a particular theory the process of de-crosslinking may occur partially or completely by precipitation of the cross-linking metal ions as the pH of the AAM slurry increases after the initial mixing has been completed.

[0043] In one set of embodiments, the crosslinking of the CAPS, the CMPS, or in particular the CMC is pre-formed, so previously crosslinked CMC powder, for example, can be used as a FLA in AAM and geopolymer slurries. Such materials are commercially available as previously crosslinked, dried, and packaged powder or granular materials. Alternately or additionally, CMC composite particles (e.g. CMC-chitosan) may also be used as FLA for AAM and geopolymer slurries. Alternately or additionally, crosslinked CAPS polymers or crosslinked CMPS polymers may also be used as FLA for AAM and geopolymer slurries. The dry crosslinked CAPS polymer powder, CMPS polymer powder and CMC powder can be added to the geopolymer composition or directly to the geopolymer slurry. When adding crosslinked CMC directly to the geopolymer slurry, the crosslinked CMC can be dispersed or slurried into the fluid to be mixed with the geopolymer composition to make the geopolymer slurry.

[0044] In some cases, the crosslinking reactions take place in situ in the geopolymer slurry but are formulated to be faster than the more thermodynamic favorable subsequent complexing (and de-activation) of the metallic crosslinkers by the caustic species in thePatent ApplicationAttorney Docket No. IS25.0186-WOmixture. In such cases, CAPS, CMPS, or in particular CMC, which can be linear molecules or branched, or otherwise non-linear, molecules, and crosslinking agents are added separately to a geopolymer composition and have them react in situ during the slurry mixing process to retard polymer hydration. Alternatively, the crosslinking agent can be added to the fluid portion whilst the dry CMC powder is added to the geopolymer composition. Furthermore, the crosslinking agent can be added to the fluid portion whilst the dry CMC powder can be dispersed or slurried into the form of a separate liquid stream and added separately to the fluid portion.

[0045] The processes herein can be enhanced by using pH buffers, or pH-active agents, which can be added to the geopolymer composition and / or fluid portion to assist with the temporary crosslinking process.

[0046] Metal ions, such as aluminum, iron, titanium, boron, scandium, vanadium, chromium, zinc, gallium, yttrium, niobium, molybdenum, tin, antimony, lanthanum, hafnium, zirconium, and lanthanide metals, among others, are believed to provide crosslinking for polymers, such as polysaccharides, used as FLAs by chemically bonding to, or associating with, such polymer molecules to crosslink the polymer molecules. As described above, the crosslinking is reversible by removing the metal ions, which are eventually disassociated in the high pH environment that develops in a geopolymer slurry. The metal ion to use for crosslinking can be selected based on specific characteristics of the interaction between the metal ion and the polymers to be used as FLAs. Combinations of metal ions, for example two or more different metal ions, can also be used in a single fluid loss formulation to provide selected performance characteristics. A range of both inorganic salts, organic salts, complexes, hydrates, oxides or nanoparticles of these salts can be used. This includes aluminum chloride, aluminum chloride hexahydrate, polyaluminum chloride, zirconium, chloride, aluminum citrate, aluminum acetate, titanium lactate, zirconium chlorides, etc. Other metal complexes for iron, aluminum, zirconium, titanium with different ligands, including hydroxy acids, amino acids, alcohols, amines, polyamines, and chelating agents such as EDTA, HEDTA, and similar carboxymethylated amine chelating agents and carboxym ethylated polyamine chelating agents could be necessary to control the rate of crosslinking, and the rate of hydration. These materials containing metals can be added to water and mixed with any of the FLA materialsPatent ApplicationAttorney Docket No. IS25.0186-WOdescribed above to activate crosslinking of the polymer molecules. As noted above, precrosslinked FLA materials are also commercially available.

[0047] Even though the invention has been described in more detail using CMC (Carboxymethyl cellulose, CAS No.: 9000-11-7, EC / List no.: 618-326-2) as the polymer embodiment, a number of modified polysaccharides can potentially be used as FLA with controlled hydration kinetics. Such modified polysaccharides can include anionically modified polysaccharides such as several Carboxy-alkylated polysaccharides (CAPS), and several Carboxym ethylated polysaccharides. (CMPS) are examples of anionic polymers which can be crosslinked to exhibit transient crosslinking in the formulations and methods described herein. Some readily available and currently commercially accessible examples of such polymers, and or potentially commercially available examples of such polymers are listed below and are herein incorporated by reference: a) CMG (carboxymethyl Guar CAS No.: 39346-76-4, EC I List no.: 609-654-7); b) CMHPG (carboxymethyl Hydroxypropyl Guar, CAS No.:68130-15-4, EC / List no.: 614-287-0); c) CMS (Carboxymethyl Starch, or CAS No.: 9057-06-1, EC / List no.: 618-580-4); d) SSG (Sodium Starch Glycolate, CAS No.: 9063-38-1, EC / List no.: 618-597-7); e) CMTG (Carboxymethyl Tara Gum 68130-15-4); f) CMCG (Carboxymethyl Carob Gum or carboxymethyl locust bean gum, CAS No.:62046-80-4); g) CMHEC (Carboxymethyl Hydroxyethyl Cellulose, CAS No.: 9004-30-2, EC / List no.: 618-377-0); h) CPC, (Carboxypropyl Cellulose); i) CPS, (Carboxypropyl Starch); j) CEG, (Carboxyethyl Guar); j) CMKG, (Carboxymethyl Konjac Glucomanan).

[0048] Tables 1-4 below show data of mixtures made according to the methods described herein. Table 1 shows composition of the mixtures tested, and Tables 2-4 show mixing data of the mixtures. The mixtures are all geopolymer slurries made using FLA materials described herein. As shown in Table 1 , the geopolymer compositions all use an FLA material in a composition range of 0.5 % to 1.5 % by weight of the geopolymer composition. To make the slurries, water is added to each geopolymer composition to a slurry density of 13.2 pounds per gallon. Compositions in Table 1 are all %BW0B (% by weight of blend, meaning percent by weight of the dry blend geopolymer composition), with the exception of the defoamer composition, which is in units of gallons per sack.Patent ApplicationAttorney Docket No. IS25.0186-WO

[0049] Tables 2-4 below show mixing time, rheometer readings, gelling viscosity, thickening time, and API fluid loss of the tested geopolymer slurries, along with ultimate compression strength of the resulting geopolymers in Tables 2 and 3. Rheology data is provided at different rheometer rpm settings, with ascending and descending readings shown, using a Fann 35 rheometer in R1-B1-S1 configuration as per API 10B-2 section 11.

[0050] Table 1 shows the composition of tested blends, 13.2 ppg slurries.Table 1

[0051] Table 2 shows mixing results using CMC as the FLA. The blend tested to produce the results of Table 2 included 0.5 %BW0B of conventional CMC.Table 2Patent ApplicationAttorney Docket No. IS25.0186-WO

[0052] Table 3 shows mixing results using an aluminum pre-crosslinked CMC powder obtained from Nouryon of Radnor, PA, as the FLA. The blend tested contained 1.5 %BW0B of the crosslinked CMC powder.Table 3

[0053] Table 4 shows mixing results using crosslinked carboxym ethyl, hydroxyethyl cellulose powder, obtained from SE Tylose Gmbh & Co. KG, of Wiesbaden, Germany, as the FLA. The blend tested contained 1.5 %BW0B of the FLA powder.Table 4

[0054] The data of Tables 1-4 show that using crosslinked anionic polymers as fluid loss agents improves mixing and general usability of geopolymer slurries. The blends tested to create the data of Tables 3 and 4 exhibited much faster mixing time than the blend of Table 2, which used a conventional fluid loss agent. Rheology and fluid loss using thePatent ApplicationAttorney Docket No. IS25.0186-WOcrosslinked FLAs were similar to the blend using the conventional FLA. This data shows that crosslinked anionic polymers can be used to provide fluid loss functionality for geopolymer slurries while improving mixing time of the slurries.

[0055] The methods and compositions herein have been primarily described with reference to borehole and wellbore drilling operations; the geopolymer compositions, geopolymer slurries, and geopolymers described herein may be used in applications other than the drilling of a wellbore or borehole. In other embodiments, geopolymer compositions, geopolymer slurries, and geopolymers including the fluid loss control material and the salt according to the present disclosure may be used outside a wellbore, borehole, or other downhole environment used for the exploration or production of natural resources. Accordingly, the terms “wellbore,” “borehole,” and the like should not be interpreted to limit tools, systems, assemblies, or methods of the present disclosure to any particular industry, field, or environment. In addition, the drilling fluids may be used in cased completion wellbores and in open hole completion wellbores.

[0056] In some embodiments, the geopolymer compositions, geopolymer slurries, and geopolymers may be used during formation of a borehole and / or wellbore to be used for carbon capture, utilization, and storage (CClIS) and / or for recovery and use of geothermal energy. Geothermal energy is a promising source of renewable energy that captures energy from heat generated within the earth. For example, geothermal energy may be used to heat structures (e.g., buildings) and / or to generate electricity (e.g., by heating water to generate steam and drive a turbine with the steam). The geopolymer compositions, geopolymer slurries, and geopolymers described herein may be used to form boreholes and / or wellbores used to circulate a fluid that is heated within the earth formation through which the borehole and / or wellbore extends. The heated fluid may be circulated to the surface where the captured heat may be recovered to heat a structure and / or generate electricity, followed by recirculation of the fluid to the earth formation to continue the cycle.

[0057] CCUS facilitates the capture, use, and / or storage of carbon (e.g., carbon dioxide), which has a goal of achieving carbon neutrality and / or net zero carbon emissions (NZE). CCUS may facilitate the capture of carbon dioxide from large point sources (e.g., power plants, refineries, cement plants, other industrial processing plants, or other industrialPatent ApplicationAttorney Docket No. IS25.0186-WOfacilities that use fossil fuels, biomass fuels, or other fuels that generate carbon dioxide). The captured carbon dioxide may be converted into valuable products such as, for example, ethanol, sustainable aviation fuel, chemicals, and mineral aggregates. Alternatively, the carbon dioxide may be stored in geologic formations, such as in depleted hydrocarbon reservoirs. The carbon dioxide may be introduced into the earth formation through a borehole and / or wellbore constructed by using the alkali activated materials and geopolymer slurries described herein. In the earth formation, the carbon dioxide may be dispersed in an aqueous phase and stored as carbon dioxide, in mineral form (e.g., as a carbonate, such as calcium carbonate, magnesium carbonate, iron(ll) carbonate), or as another form of carbon. The geopolymer compositions, geopolymer slurries, and geopolymers described herein may be used in CCUS, such as in wellbores used for carbon storage.

[0058] One or more specific embodiments of the present disclosure are described herein. These described embodiments are examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, not all features of an actual embodiment may be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous embodiment-specific decisions will be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one embodiment to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0059] The articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements in the preceding descriptions. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. For example, any element described in relation to an embodiment herein may be combinable with any element of any other embodiment described herein.Patent ApplicationAttorney Docket No. IS25.0186-WONumbers, percentages, ratios, or other values stated herein are intended to include that value, and also other values that are “about” or “approximately” the stated value, as would be appreciated by one of ordinary skill in the art encompassed by embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable manufacturing or production process, and may include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value.

[0060] A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalent structures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is to be embraced by the claims.

[0061] The terms “approximately,” “about,” and “substantially” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” and “substantially” may refer to an amount that is within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of a stated amount. Further, it should be understood that any directions or reference frames in the preceding description are merely relative directions or movements. For example, any references to “up” and “down” or “above” or “below” are merely descriptive of the relative position or movement of the related elements.

[0062] The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are to be considered asPatent ApplicationAttorney Docket No. IS25.0186-WOillustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

Patent ApplicationAttorney Docket No. IS25.0186-WOCLAIMSWhat is claimed is:

1. A geopolymer composition comprising:an alkaline activated material (AAM); anda fluid loss additive (FLA) that comprises a crosslinked anionic polymer.

2. The geopolymer composition of claim 1, wherein the anionic polymer powder comprises a polysaccharide comprising anionic functional groups.

3. The geopolymer composition of claim 2, wherein the polysaccharide comprising anionic functional groups is selected from the group consisting of Carboxyalkyl polysaccharides (CAPS); Carboxymethyl polysaccharides (CMPS); Carboxymethyl Cellulose (CMC); CMC composite particles, and combinations thereof.

4. The geopolymer composition of claim 3, wherein the geopolymer composition is a dry material.

5. A geopolymer composition comprising a crosslinked anionic polymer powder.

6. The geopolymer composition of claim 5 wherein the anionic polymer comprises modified polysaccharide with anionic functional groups selected from Carboxyalkyl polysaccharides (CAPS); Carboxymethyl polysaccharides (CMPS); Carboxymethyl Cellulose (CMC); and CMC composite particles.

7. The geopolymer composition of claim 6, wherein the anionic polymer comprises CMC or CMC composite particles.

8. The geopolymer composition of claim 5 wherein the anionic polymer comprises a modified polysaccharide with anionic functional groups.Patent ApplicationAttorney Docket No. IS25.0186-WO9. The geopolymer composition of claim 6, wherein the CMC composite particles comprise CMC-Chitosan.

10. A method, comprising:forming a geopolymer slurry from the geopolymer composition of any of claims 5 to 9;mixing the geopolymer slurry;pumping the geopolymer slurry into a subterranean well; andallowing the geopolymer slurry to harden.

11. A method of treating a well, the method comprising:obtaining a geopolymer composition comprising an anionic polymer;adding water to the geopolymer composition to form a geopolymer slurry; mixing the geopolymer slurry;pumping the mixed slurry into a well; andallowing the mixed slurry to harden in the well, wherein the anionic polymer is crosslinked.

12. The method of claim 11 wherein the anionic polymer comprises CMC.

13. The method of claim 12, wherein the anionic polymer comprising CMC is a dry crosslinked CMC powder.

14. The method of claim 11, wherein the anionic polymer comprising CMC is a dry powder, a crosslinking agent is added to the water, and the anionic polymer comprising CMC is included in the geopolymer composition.

15. The method of claim 11, wherein pH buffers or pH-actives agents are included in the geopolymer composition, the water, or both.Patent ApplicationAttorney Docket No. IS25.0186-WO17. The method of claim 10 or 11, further comprising de-crosslinking the crosslinked anionic polymer after the mixing the geopolymer slurry.

18. The method of claim 17, wherein the de-crosslinking the crosslinked anionic polymer comprises partially or completely precipitating metal ions from the geopolymer slurry.

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