Synthetic silica glass in non-Portland cement.

Abstract

The cement composition may include water and a blended cement. The cement composition may not include Portland cement. The blended cement may include a cement and an auxiliary cementitious material. The cement may be a calcium aluminate cement or a calcium aluminophosphate cement. Fly ash is a common auxiliary cementitious material that contains silica. However, the fly ash may vary widely depending on the source of the fly ash. Instead of fly ash, the auxiliary cementitious material may be a synthetic glass powder, such as soda-lime glass, which has consistent properties regardless of source.

Description

[Technical field]

[0001] Cement compositions containing Portland cement may not be used in certain wells. Instead of Portland cement, a mixed cement composition containing calcium aluminate or calcium aluminophosphate cement and a supplementary cementitious material consisting of synthetic silica glass powder can be used.

[0002] The features and advantages of particular embodiments will be more readily understood when considered in conjunction with the accompanying drawings, which should not be construed as limiting any of the preferred embodiments. [Brief description of the drawings]

[0003] [Figure 1] FIG. 1 illustrates a system for preparing and delivering a cement composition to a well bore according to certain embodiments. [Figure 2A] FIG. 1 illustrates a surface device that may be used to place the cement composition in a well bore. [Figure 2B] FIG. 1 illustrates placement of a cement composition within the annulus of a well bore. [Diagram 3] 1 is a graph depicting pressure, consistency, temperature, and shear stress versus time for non-Portland cement compositions containing fly ash as a silica source. [Figure 4] 1 is a graph depicting pressure, consistency, temperature, and shear stress versus time for non-Portland cement compositions that include silica glass powder as a silica source. [Diagram 5] 1 is a graph depicting pressure, consistency, temperature, and shear stress versus time in field testing for non-Portland cement compositions containing glass powder as a silica source. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0004] Petroleum hydrocarbons and hydrocarbon gases occur naturally in some subterranean formations. In the oil and gas industry, a subterranean formation containing oil and / or gas is referred to as a reservoir. Reservoirs may be located onshore or offshore. Reservoirs are typically located at depths ranging from a few hundred feet (shallow reservoirs) to tens of thousands of feet (ultra-deep reservoirs). To produce the oil or gas, well boreholes are drilled into or near the reservoir. The oil, gas, or water produced from the reservoir is referred to as the reservoir fluid.

[0005] As used herein, a "fluid" is a material that has a continuous phase that is capable of flowing and conforming to the contours of its container when the material is tested at a temperature of 71 degrees Fahrenheit (22°C) and a pressure of 1 atmosphere "atm" (0.1 megapascals "MPa"). A fluid can be a liquid or a gas. A heterogeneous fluid has multiple distinct phases, whereas a homogeneous fluid has only one phase. A colloid is an example of a heterogeneous fluid. A heterogeneous fluid can be a slurry with a continuous liquid phase and undissolved solid particles as the dispersed phase, an emulsion with a continuous liquid phase and at least one dispersed phase consisting of immiscible droplets, a foam with a continuous liquid phase and a gas as the dispersed phase, or a mist with a continuous gas phase and liquid droplets as the dispersed phase. As used herein, the term "base fluid" refers to the solvent of a solution or the continuous phase of a heterogeneous fluid, which is the liquid that is the largest volume percentage of the processing fluid.

[0006] A well may include, but is not limited to, an oil, gas, or water production well, an injection well, or a geothermal well. As used herein, a "well" includes at least one well bore. A well bore may include vertical, inclined, and horizontal portions and may be straight, curved, or branched. As used herein, the term "well bore" includes any casing and any uncased open portion of a well bore. The proximal well bore region is the subterranean material and rock of the subterranean formation surrounding the well bore. As used herein, a "well" also includes the proximal well bore region. The proximal well bore region is generally considered to be the region within about a 100 foot radius of the well bore. As used herein, "into a well" means and includes "into any portion of the well," including "into the well bore," "through the well bore into the proximal well bore region," or "through the well bore into the subterranean formation."

[0007] A portion of a wellbore may be an open bore or a cased bore. In an open wellbore section, a tube string may be placed within the wellbore. The tube string allows fluids to be introduced into or removed from the wellbore. In a cased wellbore section, a casing, which may also include a tube string, is placed within the wellbore. The wellbore may include an annulus. Examples of an annulus include, but are not limited to, the space between the wellbore and the outside of the tube string in an open wellbore, the space between the wellbore and the outside of the casing in a cased wellbore, and the space between the inside of the casing and the outside of the tube string in a cased wellbore.

[0008] Generally, a cement composition is introduced into the annulus of a wellbore during well completion. For example, in a cased wellbore, to stabilize and fix the casing within the wellbore, the cement composition can be placed and set in the annulus between the wellbore and the casing. By cementing the casing within the wellbore, the influx of fluid into the annulus is prevented. As a result, oil or gas can be produced in a controlled manner by guiding the flow of oil or gas through the casing into the wellhead. The cement composition can also be used in primary or secondary cementing operations, well plugging operations, or squeeze cementing.

[0009] As used herein, "cement composition" is at least a mixture of cement and water. The cement composition can include additives such as pozzolan. The term "cement" as used herein means a substance that is initially dry and develops compressive strength or sets in the presence of water. Some examples of cement include, but are not limited to, Portland cement, gypsum cement, high alumina cement, slag cement, high magnesia cement, Sorel cement, and combinations thereof. The cement composition is a heterogeneous fluid that includes water as the continuous phase of the base fluid and slurry, and cement (and any other insoluble particles) as the dispersed phase. The continuous phase of the cement composition can include dissolved substances.

[0010] Portland cement may be restricted for use in certain wells. Portland cement can be classified into Class A, C, H, and G cements according to the Specification for Materials and Testing for Well Cements (API Specification 10, 5th Edition, July 1, 1990) of the American Petroleum Institute (API). Portland cement can also be classified as Type I, Type II, Type III, Type IV, or Type V cement according to the American National Standards Institute. For example, in high-temperature wells (i.e., wells with bottom-hole temperatures exceeding 230°F (110°C)), Portland cement may compromise its structural integrity by decomposing due to high temperatures. Additives can be added to Portland cement to enhance its thermal stability. For example, by adding silica additives, the thermal stability of Portland cement can be increased to approximately 600°F (315.6°C). As another example, wells such as geothermal wells may contain reactive substances such as carbon dioxide, hydrogen sulfide, or acid. These substances can react corrosively, decompose Portland cement, and compromise its structural integrity. However, there are still certain types of wells where Portland cement cannot be used even with additives.

[0011] Non-Portland cement compositions can be used in these types of wells. In these cement compositions, some or all of the Portland cement can be replaced with other types of cement. An example of another type of cement that can replace Portland cement is calcium aluminate cement (CAC). The phases of calcium aluminate cement are C 3 A, C 12 A 7 、CA、CA 2 、and CA 6 are. In contrast, the phases of Portland cement are C 3S, C 2 S, C 3 A and C 4 AF. Another example of another type of cement that can replace Portland cement is calcium aluminophosphate cement (CAP). Calcium aluminate phosphate cement may be characterized by a hydration product that includes phases resulting from calcium phosphate, calcium oxyapatite, and hydroxyapatite, in addition to the aforementioned phases resulting from calcium aluminate cement hydrate. These other types of cements may have their own properties, for example, the thermal stability of CAC and CAP is higher than that of Portland cement, and the chemical stability of CAP is higher than that of CAC and Portland cement.

[0012] Supplementary cementitious materials (SCMs), such as pozzolans, lime, fly ash, kiln dust, or other materials, can be added to cement to form blended cements. Supplementary cementitious materials can not only help reduce the cost of cement, but can also improve the properties of the set cement through hydraulic or pozzolanic activity, or both. As used herein, a "pozzolan" is a siliceous or siliceous and aluminous auxiliary cementitious material that has little or no cementitious value in itself, but which, in finely divided form and in the presence of water, reacts chemically at activation temperatures, e.g., with a calcium, lime, sodium, or potassium source, to form a compound with cementitious properties. As used herein, the phrase "cementitious properties" refers to the ability to bind materials together, to exert compressive strength, and to set. It should be understood that the term "pozzolan" does not necessarily refer to the exact chemical composition of a material, but rather its ability to react with a source of calcium and water to form a compound with cementitious properties. Pozzolans generally contain silicate phases. When a pozzolan is mixed with water and a calcium source, the silicate phase of the pozzolan can undergo a hydration reaction to form calcium silicate hydrates (often abbreviated as CSH) and sometimes calcium aluminate hydrate hydration products at the activation temperature of the particular pozzolan.

[0013] An example of an auxiliary cementitious material is fly ash. Fly ash is a by-product of coal combustion. The characteristics and concentration of silica in fly ash can vary widely depending on the coal source. For example, the silica content can vary from 30% to 80% by weight depending on the source. In addition, calcium aluminophosphate cements are pH sensitive. They may require a pH in the range of, for example, 8 to 10 to initiate setting. The pH of fly ash can vary from 3 to 12 depending on the source. Thus, depending on the pH of the fly ash, the pH of the blended cement composition can change significantly, and the pH of the cement composition may not initiate setting.

[0014] Furthermore, the wide variation in the properties and concentration of silica in fly ash can result in undesirable properties of the blended cement composition, such as inability to pump for a desired period of time, having a faster initial setting time than desired, and inability to extend pumpability or initial setting times. Pumpability times may range from 1 hour to 10 hours depending on the source of fly ash used. As a result of these widely varying properties and compositions, most fly ash sources may be unsuitable for use in cementing operations due to the inability to control the pumpability or initial setting times of the blended cement composition. Thus, new alternatives to fly ash are needed for blended cement compositions that do not contain non-Portland cement, and there is continuing wide interest throughout the industry.

[0015] It has been unexpectedly discovered that synthetic silica glass powders can be used as a silica source for auxiliary cementitious materials in non-Portland blended cement compositions. Glass is generally manufactured according to standardized procedures, including the materials used to manufacture the glass, regardless of where it is manufactured, and what contaminants, if any, are permitted to be included. Thus, glass powders can consistently provide desirable properties to cement compositions, regardless of the source of the glass. As used herein, the term "synthetic glass" refers to a non-crystalline, amorphous inorganic solid that contains silica, which is not naturally occurring and is manufactured. Examples of naturally occurring glasses include, but are not limited to, obsidian or volcanic glass, fluorite formed by lightning strikes, tektites found on land, and microtektites found on the ocean floor. Examples of manufactured synthetic glasses include, but are not limited to, soda-lime glass, borosilicate glass, lead glass, and aluminosilicate glass.

[0016] Some of the desirable properties of a cement composition include viscosity, pumpability, thickening time, initial setting time, water demand, and compressive strength. Viscosity is a measure of the resistance of a fluid to flow and is defined as the ratio of shear stress to shear rate. Viscosity can be expressed in units of (force x time) / area. For example, viscosity can be expressed in dynes*s / cm 2 It can be expressed in units of poise (commonly called poise (P)) or in units of pascals per second (Pa / s). However, since a material with a viscosity of 1P is a relatively viscous material, viscosity is more commonly expressed in units of centipoise (cP), which is 1 / 100 of a P. The viscosity and flowability of a material are inversely proportional. A material with a high viscosity is more difficult to flow. Conversely, a material with a low viscosity can flow more easily.

[0017] "Viscosity" of a material as used herein is measured in accordance with API RP 10B-2 / ISO10426-2 as follows: A test material, e.g., an aqueous solution or suspension, is prepared. The material is placed in the test cell of a rotational viscometer, such as a FANN® Model 35 viscometer equipped with a FANN® Yield Stress Adapter (FYSA). The material is tested at ambient temperature and pressure, about 71°F (22°C) and about 1 atm (0.1 MPa). Viscosity may be calculated using the following formula, expressed in units of centipoise:

number

[0018] In cementing operations, it is desirable for the cement composition to remain pumpable from the time it is introduced into the well bore until it is located in the cemented portion of the well bore. After it reaches the cemented portion of the well bore, the cement composition may eventually set. If the cement composition thickens prematurely during pumping, it may damage pumping equipment or clog tubing or pipes, and if the cement composition sets too slowly, time and money may be wasted waiting for the composition to set.

[0019] If any test (e.g., thickening time or compressive strength) requires a mixing step, the cement composition is "mixed" according to the following procedure: Water is added to the mixing vessel, and then the vessel is placed on the mixer base. The motor of the base is then started and maintained at 4,000 revolutions per minute (rpm). The cement and any other ingredients are added to the vessel at a uniform rate within 15 seconds (s). After all the cement and any other ingredients have been added to the water in the vessel, a cover is placed on the vessel and the cement composition is mixed at 12,000 rpm (±500 rpm) for 35 seconds (±1 s). It should be understood that the cement composition is mixed at ambient temperature and pressure (approximately 71 degrees Fahrenheit (22°C) and approximately 1 atm (0.1 MPa)).

[0020] When any test (e.g., thickening time or compressive strength) is specified to be performed at a particular temperature and optionally at a particular pressure, it should also be understood that after mixing the cement composition at ambient temperature and pressure, the temperature and pressure of the cement composition are raised to the particular temperature and pressure. For example, the cement composition can be mixed at 71 degrees Fahrenheit (22°C) and 1 atm (0.1 MPa) and then placed in a testing apparatus and the temperature of the cement composition is raised to the particular temperature. Heating rates used herein range from about 3°F / min to about 5°F / min (about 1.5°C / min to about 3°C / min). After the cement composition is raised to the particular temperature and optionally at a particular pressure, the cement composition is maintained at that temperature and pressure for the duration of the test.

[0021] As used herein, "thickening time" is the time it takes for a cement composition to become unpumpable at a particular temperature and pressure. The pumpability of a cement composition is related to the consistency of the composition. The consistency of a cement composition is measured in Bearden consistency units (Bc), which are dimensionless units that have no direct conversion factor to more common units of viscosity. As used herein, a cement composition is considered "unpumpable" if its consistency reaches 70 Bc. As used herein, the consistency of a cement composition is measured as follows: The cement composition is mixed. The cement composition is then placed in the test cell of a high temperature and high pressure (HTHP) consistency meter, such as the FANN® Model 290 or Chandler Model 8240. Consistency measurements are continuously taken until the consistency of the cement composition exceeds 70 Bc.

[0022] The cement composition can exhibit compressive strength. The compressive strength of the cement composition can vary from 0 psi to over 10,000 psi (0 to over 69 MPa). The compressive strength is generally measured at a specific time after the composition is mixed, at a specific temperature and pressure. The compressive strength can be measured, for example, at 24 hours. According to ANSI / API Recommendation 10B-2, the compressive strength can be measured by either destructive or non-destructive methods.

[0023] The destructive method mechanically tests the compressive strength of a cement composition sample by breaking a cement composition sample taken at a specific time after mixing in a compression testing apparatus such as a Super L Universal testing machine model 602 from Tinius Olsen (Horsham, PA, USA). According to the destructive method, the compressive strength is calculated as the force required to break the sample divided by the minimum cross-sectional area in contact with the load-bearing plate of the compression testing apparatus. Compressive strength is reported in units of pressure such as pounds per square inch (psi) or megapascals (MPa).

[0024] The non-destructive method utilizes a non-destructive sonic device, such as the Ultrasonic Cement Analyzer (UCA) available from FANN® Instruments (Houston, Texas, USA), to continuously measure the relative compressive strength of a cement composition sample throughout the test period. As used herein, the "compressive strength" of a cement composition is measured using a non-destructive method at a specific time, temperature, and pressure as follows: The cement composition is mixed. The cement composition is then placed in the Ultrasonic Cement Analyzer and tested at a specific temperature and pressure. The UCA continuously measures the propagation time of an acoustic signal through the sample. The UCA device includes a pre-set algorithm that relates propagation time to compressive strength. The UCA reports the compressive strength of the cement composition in units of pressure, such as psi or MPa.

[0025] The compressive strength of a cement composition can be used to indicate whether the cement composition is initially set or set. As used herein, a cement composition is considered to be "initially set" if it exhibits a compressive strength of 50 psi (0.3 MPa) using a non-destructive compressive strength method at a specified temperature and a pressure of 3,000 psi (20 MPa). As used herein, "initial setting time" is the time difference between when the cement and any other ingredients are added to the water and when the composition has initially set.

[0026] As used herein, the term "setting" and all grammatical variations thereof are intended to mean the process of becoming hard or solid by hardening. As used herein, "setting time" is the time difference between when the cement and any other ingredients are added to water and when the composition sets at a particular temperature. A cement composition may take 48 hours or more to set. Some cement compositions can continue to exert compressive strength for several days. The compressive strength of a cement composition may exceed 10,000 psi (69 MPa).

[0027] Any component of the cement can be analyzed to determine their water demand by any method. Water demand can be broadly defined as the amount of mixing water that needs to be added to the powdered solid material to form a slurry of a particular consistency. One example of a technique for determining water demand is to keep the consistency and amount of water constant while varying the amount of solid material. However, techniques that vary the amount of water, consistency, and / or amount of solid material in any combination can also be applied. As used herein, the "water demand" of the supplemental cementitious material is measured as follows: Prepare a blender (e.g., Waring RTM blender) with a particular amount of water (e.g., about 100 grams to about 500 grams) and agitate the water at a particular blender rpm (e.g., 4,000 to 15,000 rpm). With the blender motor running, begin adding the powdered supplemental cementitious material to be tested to the water and evaluate the consistency of the slurry. Continue adding the powdered supplemental cementitious material until the particular consistency is obtained. The water demand is then calculated based on the ratio of water to solids required to achieve the desired consistency. The specified consistency is that when the supplemental cementitious materials are considered to be thoroughly wetted and mixed, forming a vortex of approximately 0.7 inches (17.9 mm) at the surface of the mixture in the blender.

[0028] The cement composition can include water and a blended cement, the blended cement including a cement and an auxiliary cementitious material, where 0% by weight of the cement is Portland cement, and the auxiliary cementitious material is a synthetic glass powder.

[0029] A method of cementing in a wellbore can include introducing a cement composition into a well and allowing the cement composition to set.

[0030] It is understood that the description of any embodiment with respect to the cement composition or any component therein is intended to apply to all method and composition embodiments and need not repeat individual embodiments throughout. All references to the unit "gallons" refer to U.S. gallons.

[0031] The cement composition includes water as a base fluid. The water may be selected from the group consisting of fresh water, brackish water, and salt water, in any combination and in any proportion. The cement composition may further include a hydrocarbon liquid. The cement composition may also include a water-soluble salt. According to any embodiment, the salt may be selected from sodium chloride, calcium chloride, calcium bromide, potassium chloride, potassium bromide, magnesium chloride, and any combination thereof in any proportion. The concentration of the salt may range from about 0.1% to about 40% by weight of the water.

[0032] The cement composition includes a blended cement. The blended cement can be a hydraulic cement. The blended cement includes a cement. According to certain embodiments, the cement is a non-Portland cement (i.e., 0 w / w% of the total amount of cement is Portland cement).

[0033] The cement of the blended cement may be a calcium aluminate cement (CAC). The cement may also be a calcium aluminophosphate (CAP) cement. The exact composition of the CAC or CAP cement may vary. The phase of the cement may also vary. By way of example, CAC cements contain from greater than 35% to greater than 70% alumina (Al 2 O 3 ). The concentration of calcium aluminate cement may range from 20% to 80% by weight of the blended cement. For CAP cement, the concentration of phosphate may range from 1% to 10% by weight of the blended cement.

[0034] The blended cement also includes an auxiliary cementitious material. The auxiliary cementitious material may be a pozzolan. The pozzolan includes a silicate. The auxiliary cementitious material may be a synthetic glass powder. The synthetic glass powder may include silica. The synthetic glass powder may be selected from the group consisting of soda-lime glass, borosilicate glass, lead glass, aluminosilicate glass, germanosilicate glass (optical glass), phosphosilicate glass, silicate filter glass, and combinations thereof. Historically, silicate glass is the oldest type of glass produced by mankind and is still the most common glass today. Silicate glass is composed primarily of silicon dioxide (silica, SiO 2 ), but in contrast to pure silica glass (fused silica), silicate glasses contain several additional substances such as soda, alumina, phosphorus pentoxide, germania, and potassium carbonate. Depending on the composition, they lead to names such as aluminosilicate, germanosilicate, aluminogermanosilicate, borosilicate, phosphosilicate glasses, etc. According to an optional embodiment, the auxiliary cementitious material does not include fly ash.

[0035] The concentration of the synthetic glass powder can range from 20% to 80% by weight of the blended cement. The synthetic glass powder can be recycled glass. One advantage is that by replacing the combustion of coal, where fly ash is a by-product, with glass, and by using recycled glass, the compounds in the blended cement are more environmentally friendly compared to pozzolans that contain fly ash.

[0036] The particle size of the auxiliary cementitious material may be selected such that when mixed with water, the mixture has cementitious properties. As discussed above, when the auxiliary cementitious material is in finely divided form, it can chemically react with water to exhibit cementitious properties. According to any embodiment, the mesh size of the cement and auxiliary cementitious material is 20 mesh or less (0.8 millimeters (mm) or less). The mesh size of the cement and auxiliary cementitious material may range from 500 mesh to 20 mesh (0.025 to 0.8 mm).

[0037] The synthetic glass powder may be colorless, also known as clear glass. All or part of the synthetic glass powder may also be selected from colored glass. The color of the glass may vary, for example, including red, blue, green, yellow, and combinations thereof. Different colored glasses may affect the properties of the glass. According to any embodiment, if colored glass is used, the exact color (e.g., red or green) may be selected so that the silica glass powder has the desired properties. The glass may be colored by adding dopants during the manufacturing process. The manufacturing of colored glass is generally very standardized, so there should not be a significant difference between two glasses of the same color from different sources. Thus, in contrast to fly ash, there should not be a significant difference in the properties of the silica glass powder regardless of the source of the glass.

[0038] The thickening time of the cement composition may be at least 1 hour at a temperature of 200°F (93.3°C) and a pressure of 9,500 psi (65 MPa). In another embodiment, the thickening time of the cement composition may range from about 4 to about 15 hours at a temperature of 200°F (93.3°C) and a pressure of 9,500 psi (65 MPa). Some of the variables that may affect the thickening time of the cement composition include the concentration of any set retarder included in the cement composition, the concentration of any salts present in the cement composition, and the bottom hole temperature of the subterranean formation. As used herein, the term "bottom hole" refers to the portion of the well that is cemented. In another embodiment, the thickening time of the cement composition is at least 3 hours at the pressure and bottom hole temperature of the well. The consistency of the cement composition may be less than 5 Bc for at least 1 hour at a temperature of 200°F (93.3°C) and a pressure of 9,500 psi (65 MPa).

[0039] The initial setting time of the cement composition may be less than 24 hours at a temperature of 200° F. (93.3° C.) and a pressure of 9,500 psi (65 MPa), or at the well pressure and bottom hole temperature.

[0040] The setting time of the cement composition may be less than 48 hours at a temperature of 200° F. (93.3° C.) and a pressure of 9,500 psi (65 MPa). The setting time of the cement composition may be less than 24 hours at a temperature of 200° F. (93.3° C.) and a pressure of 9,500 psi (65 MPa). According to any embodiment, the setting time of the cement composition ranges from 3 to 24 hours at a temperature of 200° F. (93.3° C.) and a pressure of 9,500 psi (65 MPa) or at the well pressure and bottom hole temperature.

[0041] The cement composition may have a compressive strength of at least 500 psi (3.5 MPa) when tested at a temperature of 125° F. (51° C.) and a pressure of 3,000 psi (21 MPa) for 24 hours. The cement composition may have a compressive strength in the range of 500 to 10,000 psi (about 3.5 to about 69 MPa) when tested at a temperature of 125° F. (51° C.) and a pressure of 3,000 psi (21 MPa) for 24 hours.

[0042] The cement composition may further include additional additives. Examples of additional additives include, but are not limited to, high density additives, fillers, strength retardation inhibitors, set accelerators, set retarders, friction reducers, mechanical property enhancers, lost circulation inhibitors, filtration control agents, antifoaming agents, thixotropic additives, nanoparticles, and combinations thereof. The cement composition may also include a second auxiliary cementitious material. The second auxiliary cementitious material may include lime or kiln dust.

[0043] The density of the cement composition may be at least 4 pounds per gallon (ppg) (0.48 kilograms per liter (kg / l)). The density of the cement composition may range from 4 to 20 ppg (about 0.48 to about 2.4 kg / l). It has been unexpectedly discovered that the water demand of a cement composition containing synthetic glass powder is higher than that of a similar cement composition containing fly ash as a silica source. It has also been unexpectedly discovered that the viscosity of the cement composition is lower than would be expected based on the higher water demand. Thus, water can be extracted from the cement composition to create a denser cement slurry without affecting pumpability (i.e., thickening time), or without affecting viscosity, or requiring the addition of dispersants. This means that thickening times can be extended even for denser cement slurries.

[0044] The method may include mixing water and calcium aluminate, phosphate, and synthetic glass powder. The method includes introducing a cement composition into the well. The method also includes setting the cement composition. The setting may occur after the step of introducing the cement composition into the well. The method may further include an additional step of drilling, fracturing, or acidifying after the setting step.

[0045] The well may be an offshore well or a land well. The well may be a geothermal well. The well may be a corrosive well, for example, a carbon dioxide-containing well, an acid well, or a hydrogen sulfide-containing well. A notable advantage of the blended cement is that it is corrosion-resistant and can be used in high temperature wells without compromising structural integrity. The loss of structural integrity can be a decrease in compressive strength over time. The cement composition may have a desired thermal stability. Thermal stability is the highest temperature at which the cement composition retains structural integrity for a desired period of time. According to any embodiment, the cement of the blended cement is a calcium aluminate cement, and the cement composition has a thermal stability of up to 2,552°F (1,400°C). According to any embodiment, the cement of the blended cement is a calcium aluminophosphate cement, and the cement composition has a thermal stability of up to 2,552°F (1,400°C). As mentioned above, the CAP cement may have a higher corrosion resistance compared to CAC. According to any embodiment, the well contains a substance that may have a corrosive effect on the cement composition. According to this embodiment, the cement can be a CAP cement. According to any embodiment, the cement composition does not lose compressive strength after placement in the well and after setting for at least 1 to 7 days.

[0046] One embodiment of the present disclosure is a cement composition comprising water and a blended cement, the blended cement comprising (i) a cement, wherein less than 30% by weight of the cement is Portland cement, and (ii) an auxiliary cementitious material, which is a synthetic glass powder. Optionally, the cement composition further comprises the water being selected from the group consisting of fresh water, brackish water, salt water, and any combination thereof. Optionally, the cement composition further comprises the cement concentration is in the range of 20% to 80% by weight of the blended cement. Optionally, the cement composition further comprises the cement is a calcium aluminate cement. Optionally, the cement composition further comprises the cement is a calcium aluminophosphate cement, and the phosphate concentration is in the range of 1% to 10% by weight of the cement. Optionally, the cement composition further comprises the synthetic glass powder is selected from the group consisting of soda-lime glass, borosilicate glass, lead glass, aluminosilicate glass, germanosilicate glass, phosphosilicate glass, silicate filter glass, and combinations thereof. Optionally, the cement composition further comprises a concentration of the synthetic glass powder in the range of 20% to 80% by weight of the blended cement. Optionally, the cement composition further comprises the synthetic glass powder being recycled glass. Optionally, the cement composition further comprises a particle size of the cement and auxiliary cementitious materials equal to or less than 0.8 millimeters. Optionally, the cement composition further comprises a particle size of the cement and auxiliary cementitious materials in the range of 0.025 to 0.8 millimeters. Optionally, the cement composition further comprises a thickening time of the cement composition in the range of 4 to 15 hours at a temperature of 93.3° C. and a pressure of 65 millipascals. Optionally, the cement composition further comprises a compressive strength of the cement composition in the range of 500 to 10,000 psi when tested for 24 hours at a temperature of 125° F. and a pressure of 3,000 psi. Optionally, the cement composition further comprises a water demand of the blended cement that is at least 20% greater than a blended cement containing fly ash as an auxiliary cementitious material.Optionally, the cement composition further includes that the cement composition further includes a second supplementary cementitious material, and that the second supplementary cementitious material is selected from lime or kiln dust. Optionally, the cement composition further includes that the thermal stability of the cement composition is at a temperature of 1,400 °C or lower.

[0047] Another embodiment of the present disclosure is a method of cementing in a well, comprising introducing a cement composition into the well and setting the cement composition, the cement composition comprising water and a blended cement, the blended cement comprising (i) a cement in which less than 30% by weight of the cement is Portland cement, and (ii) a supplemental cementitious material that is a synthetic glass powder. Optionally, the method further comprises the water being selected from the group consisting of fresh water, brackish water, salt water, and any combination thereof. Optionally, the method further comprises the concentration of the cement being in the range of 20% to 80% by weight of the blended cement. Optionally, the method further comprises the cement being a calcium aluminate cement. Optionally, the method further comprises the cement being a calcium aluminophosphate cement, and the concentration of the phosphate being in the range of 1% to 10% by weight of the cement. Optionally, the method further comprises the synthetic glass powder being selected from the group consisting of soda-lime glass, borosilicate glass, lead glass, aluminosilicate glass, germanosilicate glass, phosphosilicate glass, silicate filter glass, and combinations thereof. Optionally, the method further comprises the concentration of the synthetic glass powder is in the range of 20% to 80% by weight of the blended cement. Optionally, the method further comprises the synthetic glass powder is recycled glass. Optionally, the method further comprises the cement and auxiliary cementitious materials have a particle size of 0.8 millimeters or less. Optionally, the method further comprises the cement and auxiliary cementitious materials have a particle size in the range of 0.025 to 0.8 millimeters. Optionally, the method further comprises the cement composition has a thickening time in the range of 4 to 15 hours at a temperature of 93.3° C. and a pressure of 65 millipascals. Optionally, the method further includes the cement composition having a compressive strength in the range of 500 to 10,000 psi when tested for 24 hours at a temperature of 125° F. and a pressure of 3,000 psi. Optionally, the method further includes the blended cement having a water demand at least 20% greater than a blended cement containing fly ash as an auxiliary cementitious material.Optionally, the method further includes the cement composition further comprising a second auxiliary cementitious material, and the second auxiliary cementitious material is selected from lime or kiln dust. Optionally, the method further includes the cement composition having a thermal stability at a temperature of 1,400° C. or less.

[0048] 1 illustrates a system that may be used to prepare and deliver a cement composition to a well bore according to any embodiment. As illustrated, the cement composition may be mixed in a mixing device 4, such as a jet mixer, a recirculation mixer, or a batch mixer, and then pumped to the well bore via a pumping device 6. The mixing device 4 and the pumping device 6 may be located on one or more cement trucks. The jet mixer may be used to continuously mix the cement composition, including water, as the cement composition is pumped down the well bore, for example.

[0049] Exemplary techniques and systems for introducing a cement composition into a subterranean formation are described with reference to Figures 2A and 2B. Figure 2A illustrates a surface equipment 10 that may be used to introduce the cement composition. It should be noted that while Figure 2A generally illustrates an onshore operation, the principles described herein are equally applicable to subsea operations employing floating or offshore platforms and rigs without departing from the scope of this disclosure. The surface equipment 10 may include a cementing unit 12 that may include one or more cement trucks, a mixing device 4, and a pumping device 6 (e.g., as shown in Figure 1). The cementing unit 12 may pump the cement composition 14 through a supply pipe 16 to a cementing head 18 that transports the cement composition 14 downhole.

[0050] The method may include introducing a cement composition into a well 22 through a well bore that penetrates a subterranean formation 20. Referring now to FIG. 2B, a cement composition 14 may be introduced into the well 22. The introducing step may include pumping the cement composition into the well using one or more pumps 6. The introducing step may be for at least one of the following: well completion, foam cementing, primary or secondary cementing operations, well plugging operations, squeeze cementing, and gravel packing. The cement composition may be in a pumpable state prior to and during introduction into the well 22. The well may be, but is not limited to, an oil, gas, or water production well, an injection well, a geothermal well, or a high temperature, high pressure (HTHP) well. The well bore 22 includes a wall 24. A surface casing 26 may be inserted into the well bore 22. The surface casing 26 may be cemented to the wall 24 via a cement sheath 28. One or more additional conduits (e.g., intermediate casing, production casing, liner, etc.), shown here as casing 30, may also be disposed within well bore 22. One or more centralizers 34 may be attached to casing 30, for example, to center casing 30 within well bore 22 prior to and during cementing operations. According to another embodiment, subterranean formation 20 is penetrated by well bore 22 and well includes annulus 32 and / or surface casing 26 formed between casing 30 and wall 24 of well bore 22. According to this other embodiment, the introducing step includes introducing the cement composition into a portion of annulus 32.

[0051] 2B, the cement composition 14 may be pumped downward through the interior of the casing 30. The cement composition 14 may flow down the interior of the casing 30, through a casing shoe 42 at the bottom of the casing 30, and up around the casing 30 into the annulus 32. Although not shown, other techniques for introducing the cement composition 14 may also be utilized. By way of example, a reverse circulation technique may be used that includes introducing the cement composition 14 into the subterranean formation 20 through the annulus 32 instead of through the casing 30.

[0052] As the cement composition 14 is introduced, it may displace other fluids 36, such as drilling fluid and / or spacer fluid, that may be present within the casing 30 and / or annulus 32. At least a portion of the displaced fluids 36 may be discharged from the annulus 32 via flow lines 38 and deposited, for example, in one or more retention pits 40 (e.g., mud pits), as shown in FIG. 2A. Referring again to FIG. 2B, a bottom plug 44 may be introduced into the wellbore 22 before the cement composition 14, for example, to separate the cement composition 14 from the fluids 36 that may be present within the casing 30 prior to cementing. After the bottom plug 44 reaches the landing collar 46, a diaphragm or other suitable device breaks, allowing the cement composition 14 to pass through the bottom plug 44. In FIG. 2B, the bottom plug 44 is shown on the landing collar 46. In the illustrated embodiment, a top plug 48 may be introduced into the wellbore 22 behind the cement composition 14. The top plug 48 can separate the cement composition 14 from the displacement fluid 50 and can force the cement composition 14 through the bottom plug 44 . EXAMPLES

[0053] In order to facilitate a better understanding of the various embodiments, the following examples are set forth.

[0054] All test cement compositions were mixed and tested according to the specific test procedures described in the Detailed Description section above.

[0055] Table 1 shows the components and concentrations in weight percent (wt%) of three different blended cement compositions. Compositions 1 and 2 were control cement slurries containing two fly ash types with different densities and temperatures as silica sources. Composition 3 contained soda lime glass powder with a particle size of 100 mesh as a silica source instead of fly ash. Composition 4 was a field test at an excavation site using soda lime glass powder. SECAR® 71 is a calcium aluminate hydraulic cement binder with an alumina content of about 70% sold by Kerneos Inc. (Chesapeake, Virginia, USA). [Table 1]

[0056] 3-5 are graphs showing pressure (psi), consistency (Bc), temperature (Fahrenheit), and shear stress (rpm) versus time (min:sec) for cement compositions. As can be seen from FIG. 3, fly ash (composition 1) showed a variation in consistency, with the consistency gradually increasing with a thickening time peak at about 4 hours 30 minutes. As can be seen from FIG. 4, glass powder (composition 3) showed a more consistent consistency, essentially a flat line around 4 Bc, with a very sharp rise to 120 Bc at 3 hours 50 minutes. It was unexpected that glass powder showed a thickening time very similar to fly ash. It was also unexpected that glass powder showed a much smoother consistency profile and a sharper consistency spike compared to fly ash. This indicates that glass powder is not only suitable as a replacement material for fly ash, but also that glass powder can impart superior properties such as improved pumpability and thickening time to cement compositions. As can be seen from Figure 5, the field test with glass powder (composition 4) not only showed a consistency profile very similar to that shown in Figure 4, but also allowed for extended thickening times as needed for each specific well (a thickening time of approximately 8 hours and 50 minutes was shown). This indicates that pozzolans can be used in a variety of wells and should show very similar properties regardless of the source of glass powder.

[0057] Table 2 shows the compressive strength of compositions 1-3, which contain the same ingredients and concentrations as shown in Table 1, except for different concentrations of supplementary cementitious material (SCM). [Table 2]

[0058] As can be seen from Table 2, for the blended cement compositions containing fly ash as the SCM, the compressive strength of Composition 1 at 200° F. was higher than that of Composition 2 at 150° F. Blended cement Composition 3 containing synthetic glass powder as the SCM had a higher compressive strength than Composition 2 containing fly ash as the SCM at the same temperature of 150° F. This indicates that the synthetic glass powder is not only a comparable substitute for fly ash, but also provides improved properties to the blended cement composition.

[0059] Table 3 shows the water demand ("WR") of two different dry blends of calcium aluminophosphate cement ("CAP") and cement containing either fly ash or synthetic glass powder. As can be seen from Table 3, it was unexpectedly discovered that the water demand of the synthetic glass powder and the dry blend containing synthetic glass powder is higher than the water demand of the fly ash and the dry blend containing fly ash. Determining the water demand is useful in that the water to solids ratio can be adjusted to provide a more stable slurry and reduce or eliminate the use of much more expensive additives such as suspension aids and dispersants. The synthetic glass powder material was unusual in that it required less water to achieve the same consistency than the corresponding water demand indicated. Those skilled in the art understand that if the water demand of the cement composition is higher, the consistency and viscosity will also be higher. For example, the water demand of a typical calcium aluminophosphate cement and fly ash blend is about 35, and the baseline consistency measurement that directly correlates to viscosity is about 5Bc at 200°F (see, for example, FIG. 3). Thus, traditionally, assuming a 1:1 replacement of fly ash with a different material, only the replacement material with a similar water demand of about 35 would exhibit a similar consistency measurement. In other words, if the replacement material has a water demand 35% greater than the fly ash, a 35% increase should also be observed in consistency. However, as shown, the synthetic glass powder had a water demand of 54, but exhibited a Bc measurement of about 5 at 200° F., the same as the fly ash. This unexpected discovery means that it is possible to extract water from the cement composition and increase the density of the cement slurry without adversely affecting the pumpability or viscosity of the cement slurry. [Table 3]

[0060] The exemplary fluids and additives disclosed herein may directly or indirectly affect one or more components or pieces of equipment associated with the preparation, delivery, recovery, recycling, reuse, and / or disposal of the disclosed fluids and additives. For example, the disclosed fluids and additives may directly or indirectly affect one or more mixers, associated mixing devices, mud pits, storage facilities or units, fluid separators, heat exchangers, sensors, gauges, pumps, compressors, etc., used to generate, store, monitor, regulate, and / or recondition the exemplary fluids and additives. The disclosed fluids and additives may also directly or indirectly affect any transportation or delivery equipment used to transport or supply the fluids and additives to a drilling site or downhole, such as any transport vessels, conduits, pipelines, trucks, tubing, and / or pipes used to fluidly move the fluids and additives from one location to another, any pumps, compressors, motors (e.g., topside or downhole) used to move the fluids and additives, any valves or associated joints used to regulate the pressure or flow rate of the fluids, any sensors (i.e., pressure and temperature), gauges, and / or combinations thereof, etc. The disclosed fluids and additives may also directly or indirectly affect various downhole equipment and tools that may come into contact with the fluids and additives, such as, but not limited to, drill strings, coiled tubing, drill pipe, drill collars, mud motors, downhole motors and / or pumps, floats, MWD / LWD tools and associated telemetry equipment, drill bits (including roller cones, PDCs, natural diamonds, hole openers, reamers, and core bits), sensors or distributed sensors, downhole heat exchangers, valves and corresponding actuators, tool seals, packers, and other wellbore isolation devices or components.

[0061] Thus, the compositions, methods, and systems of the present disclosure are well adapted to achieve the stated objectives and advantages, as well as those inherent therein. The specific embodiments disclosed above are merely illustrative, as the present disclosure may be modified and implemented in different but equivalent manners apparent to those skilled in the art having the teachings herein. Furthermore, no limitations are intended to the details of construction or design shown herein, except as set forth in the following claims. Thus, it is apparent that the specific exemplary embodiments disclosed above may be modified or altered, and all such variations are deemed to be within the scope and spirit of the present disclosure.

[0062] As used herein, the words "comprise," "have," "include," and all grammatical variations thereof are intended to each have an open, non-limiting meaning that does not exclude additional elements or steps. Although compositions, systems, and methods are described as "comprising," "containing," or "including" various components or steps, the compositions, systems, and methods can also "consist essentially of" or "consist of" various components and steps. It should be understood that "first," "second," and "third" as used herein are arbitrarily assigned and are intended only to distinguish between two or more fluids, etc., as the case may be, and do not indicate any order. Furthermore, it should be understood that the use of the word "first" alone does not require the presence of a "second," and the use of the word "second" alone does not require the presence of a "third."

[0063] When a numerical range is disclosed with a lower limit and an upper limit, any numerical value and any range falling within the range is specifically disclosed. In particular, all ranges of values ​​disclosed herein (expressed in the form of "from about a to about b," or equivalently "from about a to b," or equivalently "about a to b") should be understood to describe all numbers and ranges encompassed within the broader range of values. Moreover, the terms in the claims have their plain and ordinary meaning unless expressly and unambiguously defined by the patent owner. Moreover, the indefinite articles "a" or "an" used in the claims are defined herein to mean one or more of the element to which the indefinite article is attached. In the event of any inconsistency in the use of a word or term in this specification and one or more patents or other documents that may be incorporated herein by reference, the definition that is not inconsistent in this specification should be adopted.

Claims

1. Water, and 1. A cement composition comprising a blended cement, The mixed cement is (i) less than 30% by weight of the cement is Portland cement; and (ii) A cement composition comprising an auxiliary cementitious material which is a synthetic glass powder.

2. 10. The cement composition of claim 1, wherein the water is selected from the group consisting of fresh water, brackish water, salt water, and combinations thereof.

3. 3. The cement composition of claim 1 or 2, wherein the concentration of the cement ranges from 20% to 80% by weight of the blended cement.

4. The cement composition according to any one of claims 1 to 3, wherein the cement is a calcium aluminate cement.

5. 5. The cement composition according to claim 1, wherein the cement is a calcium aluminophosphate cement and the concentration of phosphate is in the range of 1% to 10% by weight of the cement.

6. 6. The cement composition of claim 1, wherein the synthetic glass powder is selected from the group consisting of soda-lime glass, borosilicate glass, lead glass, aluminosilicate glass, germanosilicate glass, phosphosilicate glass, silicate filter glass, and combinations thereof.

7. The cement composition according to any one of claims 1 to 6, wherein the concentration of said synthetic glass powder is in the range of 20% to 80% by weight of said blended cement.

8. The cement composition according to any one of claims 1 to 7, wherein the synthetic glass powder is recycled glass.

9. 9. The cement composition of claim 1, wherein the cement and the auxiliary cementitious materials have a particle size of 0.8 millimeters or less.

10. 10. The cement composition of any one of claims 1 to 9, wherein the particle size of the cement and the auxiliary cementitious materials is in the range of 0.025 to 0.8 millimeters.

11. 11. The cement composition of any one of claims 1 to 10, wherein the thickening time of the cement composition is in the range of 4 to 15 hours at a temperature of 93.3°C and a pressure of 65 millipascals.

12. 12. The cement composition of any one of claims 1 to 11, wherein the cement composition has a compressive strength in the range of 500 to 10,000 psi when tested at a temperature of 125°F and a pressure of 3,000 psi for 24 hours.

13. 13. The cement composition of any one of claims 1 to 12, wherein the water demand of the blended cement is at least 20% greater than a blended cement containing fly ash as an auxiliary cementitious material.

14. 14. The cementitious composition of any one of claims 1 to 13, further comprising a second auxiliary cementitious material, the second auxiliary cementitious material being selected from lime or kiln dust.

15. The cement composition according to any one of claims 1 to 14, wherein the thermal stability of the cement composition is at a temperature of 1,400°C or less.

16. 1. A method of cementing in a well, comprising the steps of: introducing a cement composition into the well; and allowing the cement composition to set; The cement composition comprises: Water, and Including blended cement, The mixed cement is (i) less than 30% by weight of the cement is Portland cement; and (ii) a supplemental cementitious material which is a synthetic glass powder.

17. 17. The method of claim 16, wherein the cement is a calcium aluminate cement or a calcium aluminophosphate cement, and the calcium aluminophosphate cement has a phosphate concentration in the range of 1% to 10% by weight of the cement.

18. 18. The method of claim 16 or 17, wherein the synthetic glass powder is selected from the group consisting of soda-lime glass, borosilicate glass, lead glass, aluminosilicate glass, germanosilicate glass, phosphosilicate glass, silicate filter glass, and combinations thereof.

19. The method according to any one of claims 16 to 18, wherein the concentration of said synthetic glass powder is in the range of 20% to 80% by weight of said mixed cement.

20. 20. The method according to any one of claims 16 to 19, wherein the thermal stability of the cement composition is at a temperature of 1,400°C or less.

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