RU2635413C2 - Cement setting activators for cement compositions and corresponding methods - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: cement compositions and methods of cement compositions application in subterranean formations are described. In one version of the invention, a method of cementing in a subterranean formation is provided, comprising: provision of a cement composition comprising water, pozzolan, slaked lime and a zeolite activator; and ensuring of the possibility of cement composition setting in an underground formation. The zeolite activator is located on the pozzolan surface. The invention is developed in subclaims.

EFFECT: accelerated build-up of cement composition compressive strength.

18 cl, 1 dwg, 6 tbl

Description

State of the art

[0001] Embodiments of the present invention relate to underground cementing operations and, in some embodiments, to delayed setting cement compositions and methods for using delayed setting cement compositions in underground formations.

[0002] Cement compositions can be used in various underground operations. For example, during the construction of an underground well, a string of pipes (for example, casing, liners, expandable pipe elements, etc.) can be lowered into the wellbore and cemented in place. The process of cementing a pipe string in place is commonly referred to as “primary cementing”. In a conventional primary cementing method, the cement composition may be pumped into an annular gap between the walls of the wellbore and the outer surface of the pipe string located therein. The cementitious composition can set in an annular gap to form an annular shell of hardened, substantially impermeable cement (i.e., cement shell), which can support and hold the pipe string in place in the wellbore, and can bond the outer surface of the pipe string to the subterranean layer. Among other things, the cement sheath surrounding the pipe string prevents the migration of fluids into the annular gap and protects the pipe string from corrosion. Cement compositions can also be used in repair cementing methods for sealing cracks or holes in pipe columns or cement shells, for sealing highly permeable zones or formation cracks, or for installing cement plugs or the like.

[0003] In underground cementing operations, many different cement compositions are used. In some cases, delayed setting cementitious compositions are used. Delayed setting cement compositions are characterized in that they remain in a fluid state suitable for pumping for at least about one day (e.g., about 7 days, about 2 weeks, about 2 years or more) at room temperature (e.g. , approximately 80 ° F (27 ° C)) when stored alone. If necessary, delayed setting cementitious compositions should be capable of activation with the subsequent development of the required compressive strength. For example, a cement setting activator may be added to the delayed setting cement composition to initiate setting of the composition into the hardened mass. Among other things, delayed setting cement compositions may be suitable for use in wellbore applications where it is necessary to obtain the cement composition in advance. This may allow storage of the cementitious composition prior to use. In addition, this may provide the possibility of obtaining a cement composition in a convenient place with subsequent transportation to the work site. Accordingly, capital costs can be reduced by reducing the need for bulk storage at the site and mixing equipment. This can be especially useful for offshore cementing operations where space on board for installing containers may be limited.

[0004] Despite the fact that cement compositions with delayed setting have been developed to date, there are problems with their successful application in underground cementing operations. For example, delayed setting cement compositions prepared using Portland cement may have undesirable gelation problems that may limit their use and effectiveness in cementing operations. Other delayed setting compositions, for example, compositions containing hydrated lime and quartz, may be effective for some operations, but may be of limited use at lower temperatures because they cannot develop sufficient compressive strength when used in underground formations having lower static temperatures at the bottom of the well. In addition, activating some delayed setting cementitious compositions while maintaining an acceptable thickening time and developing compressive strength can be problematic.

Brief Description of the Drawings

[0005] These drawings illustrate certain aspects of certain embodiments of the methods and compositions of the present invention, and should not be used to limit or define the scope of said methods or compositions.

[0006] FIG. 1 shows a system for producing and delivering a cement composition to a wellbore in accordance with some embodiments of the invention.

[0007] FIG. 2A depicts ground equipment that can be used to lay a cement composition in a wellbore in accordance with some embodiments of the invention.

[0008] FIG. 2B shows the placement of a cement composition in the annular space of a wellbore in accordance with some embodiments of the invention.

Description of preferred embodiments of the invention

[0009] Embodiments of the present invention relate to underground cementing operations and, in some embodiments, to delayed setting cement compositions and methods for using delayed setting cement compositions in underground formations. According to specific embodiments of the invention, improved cement setting activators are provided that are used to activate cement compositions containing pozzolanic materials that contain a cement set retarder, have a long setting time and / or have insufficient initial strength.

[0010] Embodiments of delayed setting cement compositions may typically comprise water, pozzolan, and hydrated lime. Optionally, the cement compositions may further comprise a dispersant and / or a cement setting retarder. Advantageously, embodiments of delayed setting cement compositions may be able to remain in a liquid state suitable for pumping by a pump for an extended period of time. For example, delayed setting cement compositions can be maintained in a liquid state suitable for pumping for at least about 1 day or longer. Advantageously, delayed setting cementitious compositions can develop the required compressive strength after activation at relatively low temperatures. While delayed setting cement compositions may be suitable for many underground cementing operations, they may be particularly suitable for use in underground formations with relatively low static temperatures at the bottom of the well, for example, temperatures lower than about 200 ° F (93 ° C) or ranging from about 100 ° F (38 ° C) to about 200 ° F (93 ° C). In alternative embodiments of the invention, delayed setting cement compositions can be used in subterranean formations with static bottomhole temperatures of up to 450 ° F (232 ° C) or higher.

[0011] The water used in various embodiments may be from any source, provided that it does not contain an excess of compounds that can adversely affect other components of delayed setting cement compositions. For example, the cement composition may contain fresh water or salt water. Salt water, as a rule, may contain one or more salts dissolved in it, and may be saturated or unsaturated, as required for a particular application. Seawater or brines may be suitable for use in various embodiments. In addition, water may be present in an amount sufficient to obtain a solution suitable for pumping. In some embodiments, water may be present in delayed setting cement compositions in an amount in the range of about 33% to about 200% based on the weight of pozzolan. In some embodiments, water may be present in delayed setting cement compositions in an amount in the range of from about 35% to about 70% based on the weight of pozzolan. Specialists in the art using the present description can determine the appropriate amount of water for the selected application.

[0012] Embodiments of delayed setting cement compositions may include pozzolan. For use in various embodiments, any pozzolan is suitable. Illustrative embodiments containing pozzolan may contain fly ash, silica dust, metakaolin, natural pozzolan (e.g., pumice), or combinations thereof.

[0013] An example of a suitable pozzolan may include fly ash. Various types of fly ash may be suitable, including the fly ash classified by the American Petroleum Institute as Class C and Class F fly ash, API Specification for Materials and Testing for Well Cements, API Specification 10, fifth edition, July 1, 1990 Class C fly ash contains silicon dioxide and lime at the same time, so when mixed with water it can set and produce a hardened mass. Class F fly ash, as a rule, does not contain enough lime to initiate the cementation reaction, therefore an additional source of calcium ions is required for a delayed setting cement composition containing fly ash class F. In some embodiments of the invention, lime may be mixed with class F fly ash in an amount in the range of about 0.1% to about 100% based on the weight of fly ash. In some cases, the lime may be slaked lime. Suitable examples of fly ash include, but are not limited to, cement additive POZMIX ^® A, manufactured by Halliburton Energy Services, Inc., Houston, Texas.

[0014] An example of a suitable pozzolan may include metakaolin. Typically, metakaolin is a white pozzolan, which can be obtained by heating kaolin clay, to temperatures in the range from about 600 ° C to about 800 ° C.

[0015] An example of a suitable pozzolan may include natural pozzolan. Natural pozzolans are usually found on the surface of the earth and set and harden in the presence of hydrated lime and water. Embodiments containing natural pozzolan may include pumice, diatomaceous earth, volcanic ash, opaline shale, tuff, and combinations thereof. Natural pozzolans can be shredded or unshredded. Typically, natural pozzolans can have any particle size distribution appropriate for the particular application. In some embodiments of the invention, natural pozzolans may have an average particle size in the range of from about 1 micron to about 200 microns. The average particle size corresponds to d50 values measured using particle size analyzers, such as analyzers manufactured by Malvern Instruments, Worcestershire, UK. In particular embodiments, natural pozzolans may have an average particle size in the range of from about 1 micron to about 200 microns, from about 5 microns to about 100 microns, or from about 10 microns to about 50 microns. In one particular embodiment, natural pozzolans may have an average particle size of less than about 15 microns. An example of a suitable industrial natural pozzolan is pumice made by Hess Pumice Products, Inc., Malad, Idaho, sold as a lightweight aggregate DS-325 that has a particle size of less than about 15 microns. It should be understood that too small a particle size can cause mixing problems, while too large a particle size can cause insufficiently effective suspension in the compositions and weaker reactivity due to a lower specific surface area. Specialists in the art using the present description can choose the particle size of natural pozzolans, suitable for use in the selected application.

[0016] Embodiments of delayed setting cement compositions may include slaked lime. In the context of the present invention, the term "slaked lime" should be understood as calcium hydroxide. In some embodiments of the invention, slaked lime may be in the form of quicklime (calcium oxide), which is hydrated when mixed with water to produce slaked lime. Slaked lime can be involved in various embodiments, for example, to obtain a hydraulic composition with pozzolan. For example, slaked lime can be added in a weight ratio of pozzolan to slaked lime of about 10: 1 to about 1: 1, or in a ratio of from about 3: 1 to about 5: 1. If present, slaked lime can be incorporated into cement compositions with delayed setting in an amount, for example, in the range of from about 10% to about 100%, relative to the weight of pozzolan. In some embodiments, slaked lime may be present in an amount in the range between any of the following values: about 10%, about 20%, about 40%, about 60%, about 80%, or about 100% based on the weight of pozzolan, and / or including values. In some embodiments, cementitious components present in a delayed setting cement composition may consist essentially of pozzolan and slaked lime. For example, cementitious components may contain mainly pozzolan and slaked lime without any additional cementitious components (e.g. Portland cement) that hydraulically set in the presence of water. Specialists in the art using the present description can determine the appropriate amount of slaked lime for introduction into the selected application.

[0017] Embodiments of the delayed setting cement compositions may include a setting retarder. A wide range of setting retarders is suitable for use in delayed setting cement compositions. For example, the setting retarder may contain phosphonic acids such as ethylenediamine-tetra- (methylenephosphonic acid), diethylene triamine-penta- (methylenephosphonic acid), etc .; lignosulfonates such as sodium lignosulfonate, calcium lignosulfonate, etc .; salts such as stannous sulfate, lead acetate, monocalcium phosphate, organic acids such as citric acid, tartaric acid, etc .; cellulose derivatives such as hydroxyethyl cellulose (HEC) and carboxymethyl hydroxyethyl cellulose (CMHEC); synthetic co- or terpolymers containing sulfonate groups or carboxyl groups, such as copolymers of acrylamide and acrylic acid containing sulfonate functional groups; borate compounds such as alkali borate compounds, sodium metaborate, sodium tetraborate, potassium pentaborate; derivatives of these compounds or mixtures of these compounds. Examples of suitable setting retarders include, but are not limited to, phosphonic acid derivatives. One example of a suitable retarder is the Micro Matrix ^® retarder from Halliburton Energy Services, Inc. In general, a setting retarder may be present in cementitious compositions with delayed setting in an amount sufficient to delay the hardening by the desired time. In some embodiments, a cement setting retarder may be present in delayed setting cement compositions in an amount in the range of about 0.01% to about 10% based on the weight of pozzolan. In specific embodiments of the invention, the cement set retarder may be present in an amount in the range between any of the following values: about 0.01%, about 0.1%, about 1%, about 2%, about 4%, about 6%, about 8% or about 10% based on the weight of pozzolan, and / or including the indicated values. Specialists in the art using the present description are able to determine the appropriate amount of retarder for introduction to the selected application.

[0018] As mentioned above, embodiments of delayed setting cement compositions may optionally comprise a dispersant. Examples of suitable dispersants include, without limitation, dispersants based on sulfonated formaldehyde (e.g., the sulphonated condensation product of acetone, formaldehyde), examples of which may include a dispersant Daxad ^® 19 manufactured by Geo Specialty Chemicals, Ambler, Pennsylvania. Other suitable dispersants may be based dispersants polycarboxylate ether dispersants such as Liquiment ^® 5581F and Liquiment ^® 514L, manufactured by BASF Corporation Houston, Texas; or Ethacryl ^™ G Dispersant manufactured by Coatex, Genay, France. A further example of a suitable commercially available dispersant is the CFR ^™ -3 dispersant manufactured by Halliburton Energy Services, Inc. of Houston, Texas. Dispersant Liquiment ^® 514L may comprise 36% by weight of a polycarboxylate ether in water. Although various dispersants may be used in accordance with embodiments of the present invention, dispersants based on polycarboxylated ethers may be particularly suitable for use in some embodiments. Not limited to theory, it is believed that dispersants based on polycarboxylated ethers can synergistically interact with other components of a delayed setting cement composition. For example, it is believed that dispersants based on polycarboxylated ethers can interact with some cement set retarders (e.g., phosphonic acid derivatives), resulting in the formation of a gel that suspends pozzolan and slaked lime in the composition over an extended period of time.

[0019] In some embodiments, the dispersant may be included in delayed setting cement compositions in an amount in the range of from about 0.01% to about 5% based on the weight of pozzolan. In specific embodiments, the dispersant may be present in an amount in the range between any of the following values: about 0.01%, about 0.1%, about 0.5%, about 1%, about 2%, about 3%, about 4%, or about 5% by weight of pozzolan, and / or including the indicated values. Specialists in the art using the present description will be able to determine the appropriate amount of dispersant used for inclusion in the selected application.

[0020] Some embodiments of delayed setting cement compositions may contain silica sources other than pozzolan, for example crystalline silica and / or amorphous silica. Crystalline silicon dioxide is a powder that can be incorporated into various embodiments of delayed setting cement compositions, for example, to prevent a decrease in the compressive strength of cement. Amorphous silicon dioxide is a powder that can be included in various embodiments of delayed setting cement compositions as a lightweight filler and / or to increase the compressive strength of cement. Amorphous silicon dioxide is typically a by-product of the process of producing ferrosilicon, where amorphous silicon dioxide can be formed by oxidation and condensation of gaseous silicon dioxide, SiO, which is formed in the process as an intermediate. An example of a suitable source of amorphous silica is Silicalite ^™ cement additive manufactured by Halliburton Energy Services, Inc., Houston, Texas. In embodiments containing additional sources of silicon dioxide, an additional source of silicon dioxide can be used as necessary to improve compressive strength or setting time.

[0021] Other additives suitable for use in underground cementing operations may also be incorporated into delayed setting cement compositions. Examples of such additives include, but are not limited to: weighting agents, lightweight additives, blowing agents, additives to improve mechanical properties, materials to combat loss of circulation, additives to control filtration, additives to control water absorption, defoamers, foaming agents, thixotropic additives and combinations of these additives . In various embodiments, one or more of these additives can be added to the delayed setting cement compositions after storage, but before the delayed setting cement composition is laid in the subterranean formation. Specialists in the art using the present description can easily determine the type and amount of additive suitable for a particular application and the desired result.

[0022] Those skilled in the art will appreciate that embodiments of delayed setting cement compositions typically should have a density suitable for a particular application. For example, cementitious compositions may have a density in the range of from about 4 pounds per gallon (“f / gal.”) (480 kg / cubic meter) to about 20 f / gal. (2400 kg / cubic m). In some embodiments, cementitious compositions may have a density in the range of about 8 psig. (960 kg / cubic meter) to about 17 psig. (2040 kg / cubic m). Embodiments of delayed setting cement compositions may be foamed or non-foamed, or may contain other means for reducing density, such as hollow microspheres, low density elastic granules, or other density reducing additives known in the art. In various embodiments of the invention, the density may be reduced after storage, but before laying in an underground formation. In various embodiments, weighting additives can be used to increase the density of delayed setting cement compositions. Examples of suitable weighting agents may include barite, hematite, hausmanite, calcium carbonate, siderite, ilmenite, or combinations of these minerals. In specific embodiments, the weighting additives may have a specific gravity of 3 or more. Specialists in the art using the present description can determine the appropriate density for a particular application.

[0023] As previously indicated, delayed setting cement compositions may be in a setting delayed state in which they remain in a liquid state suitable for pumping for at least one day (eg, at least about 1 day, about 2 weeks, about 2 years or more) at room temperature (e.g., about 80 ° F (27 ° C)) when stored at rest. For example, delayed setting cement compositions may be maintained in a liquid state suitable for pumping for a period of from about 1 day to about 7 days or more. In some embodiments, delayed setting cement compositions can be maintained in a liquid state suitable for pumping for at least about 1 day, about 7 days, about 10 days, about 20 days, about 30 days, about 40 days, about 50 days, approximately 60 days or more. It is believed that the liquid is in a liquid state suitable for pumping if the liquid has a consistency of less than 70 Verdun consistency units (“Sun”), measured on a pressure consistency meter in accordance with the method of determining the thickening time of cement established in API RP Practice 10 B-2, Recommended Practice for Testing Well Cements, First Edition, July 2005.

[0024] If it is necessary to use embodiments of the invention of cementitious compositions with delayed setting, the composition can be activated (for example, by combination with an activator) to turn into a hardened mass. The term “cement setting activator” or “activator” as used herein refers to an additive that activates a cement composition with a delayed or too slow setting and can also accelerate the setting of a cement composition with a delayed, too slow or different setting. For example, embodiments of delayed setting cement compositions can be activated to produce a hardened mass over a period of time ranging from about 1 hour to about 12 hours. For example, embodiments of delayed setting cement compositions can set to form a hardened mass over a period of time in the range between any of the following values: about 1 day, about 2 days, about 4 days, about 6 days, about 8 days, about 10 days, or approximately 12 days, and / or including the indicated values.

[0025] In some embodiments, delayed setting cement compositions after activation can set and achieve the desired compressive strength. The compressive strength, as a rule, is the ability of a material or structure to withstand compressive forces applied in the direction along the axis. The compressive strength can be measured at a specific time after the delayed setting cement composition has been activated, and the resulting composition has been held at a specific temperature and pressure. The compressive strength can be measured by destructive or non-destructive methods. In the destructive method, the strength of the samples of the composition for treating the near-barrel zone is physically tested at various points in time by breaking the samples in a compression test machine. Compressive strength is calculated as the breaking load divided by the cross-sectional area that can withstand the specified load and is indicated in units of pound-force per square inch (psi). Non-destructive methods may include the use of an ultrasonic cement analyzer UCA ^™ manufactured by Fann Instrument Company, Houston, Texas. Compressive strength values can be determined in accordance with API RP 10 B-2, Recommended Practice for Testing Well Cements, First Edition, July 2005.

[0026] For example, delayed setting cement compositions can develop 24-hour compressive strength in the range of from about 50 psi (345 kPa) to about 5000 psi (34.5 MPa), in alternative embodiments, from about 100 psi (690 kPa) up to about 4,500 psi (31.0 MPa), or alternatively from about 50 psi to about 4,000 psi (27.6 MPa). In some embodiments, delayed setting cementitious compositions can develop a 24-hour compressive strength of at least about 50 psi, at least about 100 psi, at least about 500 psi (3.4 MPa) or more. In some embodiments of the invention, the values of compression strength can be determined using destructive or non-destructive methods in the temperature range from 100 ° F (38 ° C) to 200 ° F (93 ° C).

[0027] In some embodiments of the invention, delayed setting cement compositions may have the desired thickening time after activation. Thickening time generally refers to the time during which a fluid, such as a delayed setting cement composition, remains in a liquid state suitable for pumping. Numerous laboratory techniques can be used to measure thickening time. A pressure consistent consistometer operated in accordance with the method described in the API RP Practice 10 B-2 above can be used to determine if a fluid is in a liquid state suitable for pumping. The thickening time may be the time during which the fluid for processing the trunk zone reaches a value of 70 Vs, and may be indicated as the time to reach 70 Vs. In some embodiments of the invention, cementitious compositions may have a thickening time of more than about 1 hour, alternatively, more than about 2 hours, alternatively, more than about 5 hours at 3000 psi (20.7 MPa) and temperatures in the range of about 50 ° F (10 ° C) to about 400 ° F (204 ° C), alternatively, in the range of about 80 ° F (27 ° C) to about 250 ° F (121 ° C) and alternatively, at a temperature of about 140 ° F (60 ° C).

[0028] Embodiments may include introducing a cement setting agent into delayed setting cement compositions. Examples of suitable cement setting agents include, but are not limited to: zeolites, amines such as triethanolamine, diethanolamine; silicates such as sodium silicate; zinc formate; calcium acetate; hydroxides of the elements of group IA and group IIA, such as sodium hydroxide, magnesium hydroxide and calcium hydroxide; monovalent salts, such as sodium chloride; divalent salts such as calcium chloride; silicon nanodioxide (i.e., silicon dioxide having a particle size of less than or about 100 nanometers); polyphosphates; and combinations of these additives. In some embodiments of the invention, a combination of a polyphosphate and a monovalent salt may be used for activation. The monovalent salt may be any salt that dissociates to form a monovalent cation, such as sodium and potassium salts. Specific examples of suitable monovalent salts include potassium sulfate and sodium sulfate. In combination with monovalent salts, various polyphosphates, including polymer metaphosphate salts, phosphate salts and combinations of these salts, can be used to activate delayed setting cement compositions. Specific examples of polymer metaphosphate salts that can be used include sodium hexametaphosphate, sodium trimetaphosphate, sodium tetramethaphosphate, sodium pentametaphosphate, sodium heptametaphosphate, sodium octametaphosphate, and combinations of these layers. A specific example of a suitable cement setting agent comprises a combination of sodium sulfate and sodium hexametaphosphate. In specific embodiments of the invention, the activator can be provided and incorporated into the delayed setting cementitious composition in the form of a liquid additive, for example, a liquid additive containing a monovalent salt, polyphosphate and, optionally, a dispersant.

[0029] As discussed above, zeolites can also be included as activators in embodiments of delayed setting cement compositions. Zeolites are usually porous aluminosilicate minerals that can be natural or synthetic. Synthetic zeolites are based on the same type of structural cell as natural zeolites and may contain hydrates of aluminosilicates. In this context, the term "zeolite" refers to all natural and synthetic forms of zeolites. An example of a suitable source of zeolite is Valfor-100 ^® Zeolite or Advera ^® 401 Zeolite manufactured by PQ Corporation, Malvern, PA.

[0030] Embodiments of delayed setting cement compositions may include a cement setting activator comprising a zeolite, a combination of zeolites, a combination of zeolite and an activator not related to zeolites, a combination of zeolites and an activator not related to zeolites, a combination of zeolites and a combination of activators not related to zeolites, or a combination of these options. Embodiments containing zeolite may contain any zeolite. Examples of zeolites include mordenite, zsm-5, zeolite x, zeolite y, zeolite a, etc. In addition, embodiments containing zeolite may contain zeolite in combination with a cation such as Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , etc. Zeolites containing cations, such as sodium, can also, as the zeolites dissolve, provide additional cation sources for the delayed setting cement composition. An example of a zeolite containing a cation (e.g., Na ^+), is the aforementioned zeolite Valfor ^® 100. Without being limited by theory, it is believed that the increased surface area zeolites pozzolan, without increasing the size of the pozzolan particles. The increased specific surface of pozzolan can provide a high dissolution rate of silicon dioxide, free silicon dioxide is able to interact with calcium compounds, for example, from slaked lime, with the formation of gels of calcium silicate hydrate. The increase in specific surface area without changing the particle size provides an advantage, since it allows to obtain greater reactivity without affecting other properties, such as viscosity or pumpability. Sodium zeolites can also participate in the exchange of sodium for calcium in solution, as a result of this reaction, the pH of the liquid cement increases and, therefore, the rate of dissolution of silicon dioxide increases.

[0031] Zeolites can be added to delayed setting cement compositions using a number of methods. One embodiment includes a method according to which zeolites are added directly to cement compositions with delayed setting in an amount sufficient to activate or accelerate setting of the cement composition. An alternative implementation option involves initiating the growth of zeolite crystals directly on pozzolan. Pozzolan can serve as a source of nutrients for zeolite crystals, and when pozzolan particles are placed in the conditions of zeolite synthesis, it is possible to initiate the growth of zeolite crystals in the form of a film or as an integral part of the particle. To obtain various zeolites (e.g. zsm-5, zeolite x, etc.) on pozzolan, various nucleation methods can be applied, such as pulsed laser deposition, secondary growth, vacuum deposition, etc. The synthesized zeolites can form crystals, films and / or be incorporated directly into pozzolan. Pozzolan with zeolite deposited on it can be provided and used for the preparation of a cement composition with a delayed setting.

[0032] A cement setting activator should be added to various delayed setting cementitious embodiments in an amount sufficient to initiate setting setting delayed setting in a hardened mass. In some embodiments of the invention, the cement setting agent can be added to the cement composition in an amount in the range of from about 0.1% to about 20% based on the weight of pozzolan. In specific embodiments, the cement set activator may be present in an amount in the range between any of the following values: about 0.1%, about 1%, about 5%, about 10%, about 15%, or about 20%, relative to the weight of pozzolan, and / or including the indicated values. Specialists in the art using the present description can determine the appropriate amount of used cement setting agent for the selected application.

[0033] Although the above describes the use of zeolites as activators of a delayed setting cement composition, it is understood that zeolites can be used in other cement systems containing pozzolan to accelerate the setting time of the cement composition and to improve the development of early compressive strength. In some embodiments, the zeolite can be used in a cement composition containing pozzolan and water. In other embodiments, the cement composition may further comprise hydrated lime and other optional additives described above. The description of the use of zeolite in this application is not limited to delayed setting pozzolanic cement compositions, but can be used for any pozzolanic cement composition, regardless of whether said cement composition can be considered as a “delayed setting” composition.

[0034] Those skilled in the art will appreciate that embodiments of delayed setting cement compositions can be used in a variety of underground operations, including primary and repair cementing. In some embodiments, a delayed setting cement composition may be provided that comprises water, pozzolan, slaked lime, a cement setting retarder, and optionally a dispersant. Delayed setting cementitious composition can be introduced into the subterranean formation and left to set. In the context of this document, the introduction of a delayed setting cement composition into the subterranean formation includes the introduction into any part of the subterranean formation, including, without limitation, into the wellbore drilled in the subterranean formation, into the bottomhole zone surrounding the wellbore, or both. Embodiments of the invention may further include delayed setting cement composition activation. Activation of a delayed setting cement composition may include, for example, introducing a cement setting activator into a delayed setting cement composition.

[0035] In some embodiments, a delayed setting cement composition may be provided that comprises water, pozzolan, slaked lime, a cement setting retarder, and optionally a dispersant. Delayed setting cementitious composition can be stored, for example, in a container or other suitable reservoir. Delayed setting cementitious composition can be left in storage for the desired period of time. For example, a delayed setting cement composition can be left in storage for a period of about 1 day or longer. For example, a delayed setting cement composition can be left in storage for about 1 day, about 2 days, about 5 days, about 7 days, about 10 days, about 20 days, about 30 days, about 40 days, about 50 days, about 60 days or longer. In some embodiments of the invention, the delayed setting cement composition may be left in storage for a period of time ranging from about 1 day to about 7 days or longer. After this, a delayed setting cement composition can be activated, for example, by introducing a cement setting activator, injected into the subterranean formation and allowed to solidify there.

[0036] In primary cementing embodiments, for example, delayed setting cement embodiments can be introduced into the annular space between the pipe located in the wellbore and the walls of the wellbore (and / or larger diameter pipes in the wellbore), where the wellbore passes through an underground layer. Delayed setting cementitious composition may be left to set in the annular space to form an annular casing of hardened cement. Delayed setting cementitious composition may form a barrier that prevents the migration of fluids in the wellbore. Delayed setting cementitious composition may also, for example, support the pipe in the wellbore.

[0037] In embodiments of repair cementing, a delayed setting cement composition may be used, for example, in cementing operations or when installing cement plugs. For example, a delayed setting composition may be introduced into the wellbore to plug holes (e.g., voids or cracks) in the formation, in gravel packing, in the pipe, in the cement sheath and / or between the cement sheath and the pipe (for example, in an annular micro-gap) .

[0038] In one embodiment of the invention, there is provided a method of cementing in a subterranean formation, comprising: providing a cement composition comprising water, pozzolan, hydrated lime and a zeolite activator; and providing the possibility of setting the cement composition in the subterranean formation, the zeolite activator accelerating the development of compressive strength of the cement composition.

[0039] An embodiment of the invention includes a delayed setting activated cement composition, which comprises: water, pozzolan, slaked lime, setting retarder and zeolite activator.

[0040] One embodiment of the invention includes a cementing system that comprises: a delayed setting cement composition comprising water, pozzolan, slaked lime, and a setting retarder; zeolite activator for activation of cement composition with delayed setting; mixing equipment for mixing a delayed setting cement composition and a zeolite activator to create an activated cement composition; and pumping equipment for delivering the activated cement composition to the wellbore.

[0041] Now, consider FIG. 1, which shows the preparation of a cement composition (which may be a delayed setting composition or another type of composition) in accordance with illustrative embodiments of the invention. In FIG. 1 shows a system 2 for preparing a cement composition and delivering it to a wellbore in accordance with certain embodiments of the invention. As shown, the delayed setting cement composition can be mixed in mixing equipment 4, such as, for example, a jet mixer, recirculation mixer or batch mixer, and then pumped into the wellbore using pumping equipment 6. In some embodiments of the invention, the mixing equipment 4 and pumping equipment 6 can be located on one or more cement trucks, as is clear to specialists in this field of technology. In some embodiments of the invention, a jet mixer may be used, for example, to continuously mix lime / setting material with water as it is pumped into the wellbore. In delayed setting embodiments, a recirculation mixer and / or batch mixer can be used to mix the delayed setting cement composition and the activator can be added to the mixer in powder form before pumping the cement composition into the well.

[0042] An exemplary method of laying cementitious compositions with delayed setting in a subterranean formation is described below with reference to FIG. 2A and 2B. In FIG. 2A shows ground equipment 10 that can be used for laying a cement composition in accordance with some embodiments of the invention. It should be noted that although in FIG. 2A shows a general ground operation, it will be understood by those skilled in the art that the principles described herein are equally applicable to underwater operations in which floating or offshore platforms and drilling rigs can be used without departing from the scope of the present description. As shown in FIG. 2A, ground equipment 10 may include a cementing unit 12, which may include one or more cement trucks. Cementing unit 12 may include mixing equipment 4 and pumping equipment 6 (for example, Fig. 1), as is clear to specialists in this field of technology. Cementing unit 12 can pump the cement composition 14 through the feed pipe 16 and into the cementing head 18, which delivers the cement composition 14 to the well.

[0043] Consider FIG. 2B, where it is shown that cement composition 14, which is a delayed setting composition or other pozzolanic cement composition, can be laid in subterranean formation 20 in accordance with illustrative embodiments of the invention. As shown, the wellbore 22 may be drilled in the subterranean formation 20. Although the wellbore 22 is shown as being directed generally vertically into the subterranean formation 20, the principles described herein also apply to wellbores directed through the subterranean formation 20 at an angle. such as horizontal and deviated wellbores. As shown, the wellbore 22 comprises walls 24. In the illustrated embodiment, a conductor string 26 is inserted into the wellbore 22. The conductor string 26 may be cemented to the walls 24 of the wellbore 22 by a cement sheath 28. In the illustrated embodiment, in the wellbore 22 one or more additional pipes (eg, intermediate string, production string, shanks, etc.) shown herein as column 30 may also be located. As shown however, the annular space 32 of the wellbore is formed between the column 30 and the walls 24 of the wellbore 22 and / or the conductor string 26. One or more centralizers 34 may be attached to the string 30, for example, to center the string 30 in the wellbore 22 before and during cementing operations.

[0044] Continuing to consider FIG. 2B, where it can be seen that the cement composition 14 can be pumped into the inside of the casing 30. The cement composition 14 can be allowed to flow down inside the casing 30 through the shoe of the casing 42 at the bottom of the casing 30 and rise upward around the casing 30 into the annular space 32 of the wellbore. The cement composition 14 may be left to set in the annular space 32 of the wellbore, for example, to form a cement sheath that supports and holds in place the string 30 in the wellbore 22. Although not shown, other techniques may also be used to introduce the pozzolanic cement composition 14. For example, you can use the reverse circulation method, which includes the introduction of the cement composition 14 into the subterranean formation 20 not through the casing 30, but through the annular space 32 of the wellbore.

[0045] After administration, the cement composition 14 may displace other fluids 36, such as drilling fluids and / or displacement fluids, which may be present in the interior of the casing 30 and / or in the annular space 32 of the wellbore. At least a portion of the displaced fluids 36 may escape from the annular space 32 of the wellbore through the drain pipe 38 and may be placed, for example, in one or more drain tanks 40 (e.g., a mud reservoir), as shown in FIG. 2A. We continue to consider FIG. 2B, it is shown that a lower cement 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 located inside the casing 30 prior to cementing. After the bottom plug 44 has reached the column suspension sleeve 46, the membrane or other suitable device must be destroyed to allow the pozzolanic cement composition 14 to pass through the bottom plug 44. In FIG. 2B, the bottom plug 44 is shown on a sleeve 46 for suspending the column. In the illustrated embodiment, the upper plug 48 can be inserted into the wellbore 22 after the cement composition 14. The upper plug 48 can separate the cement composition 14 from the displacement fluid 50, as well as push the cement composition 14 through the lower cement plug 44.

[0046] The exemplary cement compositions described herein may directly or indirectly affect one or more components or parts of equipment associated with the receipt, delivery, return, disposal, reuse, and / or disposal of the described cement compositions. For example, the described cement compositions can directly or indirectly affect one or more mixers, associated mixing equipment, mud tanks, storage facilities or blocks, composition separators, heat exchangers, sensors, measuring instruments, pumps, compressors, and the like. equipment that is used for the generation, storage, monitoring, regulation and / or restoration of the previous properties of the exemplary cement compositions. The described cement compositions can also directly or indirectly affect any transport or delivery equipment that is used to transport cement compositions to the well site or to deliver them to the well, such as, for example, any transportation containers, pipes, pipelines, trucks, pipe systems and / or pipes used for the composite movement of cement compositions from one place to another, any pumps, compressors or motors (for example, on upper structures or in a well) that are used for driving cement compositions, any valves or similar compounds that are used to control the pressure or flow rate of cement compositions and any sensors (i.e., pressure and temperature), measuring instruments and / or combinations thereof, etc. The described cement compositions can also directly or indirectly affect various equipment within the well and tools that can come into contact with the cement compositions, such as, without limitation, the wellbore casing, the wellbore liner, the completion string, insertion cores, the drillstring, coiled tubing string, wire rope, cable, drill pipe, weighted drill pipes, hydraulic downhole motors, downhole motors and / or pumps, cement pumps mounted on top motors and / or pumps, centralizers, turbulators, scrapers, check valves (e.g. shoes, couplings, valves, etc.), logging tools and related telemetry equipment, drive elements (e.g. electromechanical devices, hydromechanical devices and etc.), sliding couplings, service couplings, plugs, sieves, filters, flow control devices (e.g. inflow regulators, autonomous inflow regulators, outflow regulators, etc.), connections (e.g. wet electro-hydraulic connection type, dry type connection, inductive coupler, etc.), control lines (e.g. electric, fiber optic, hydraulic, etc.), monitoring lines, drill bits and reamers, sensors or distributed sensors, downhole heat exchangers, valves and associated drive devices, tool seals, packers, cement plugs, bridge plugs and other devices for isolating the wellbore, or components of said equipment, etc.

[0047] To facilitate understanding of the present embodiments of the invention, the following examples of certain aspects of certain embodiments of the invention are provided. The following examples should not be taken as limiting or defining the scope of the present invention.

Examples

Example 1

[0048] Four samples were prepared for testing the effectiveness of sodium zeolite A as an activator of calcareous-pozzolanic cement compositions. As the sodium zeolite A used in the experiment zeolite Valfor ^® 100, manufactured by PQ Corporation, Malvern, Pennsylvania. Zealite Valfor ^® 100 had an average particle size of 5 microns and a high specific surface area (i.e., 71.4 m ² / g). Two compositions of calcareous-pozzolanic cement with sodium zeolite A and without zeolite were prepared. The composition with sodium zeolite A had a density of 14.0 l / gal. (1680 kg / cu. M) and consisted of 304 grams of pumice (lightweight aggregate DS-325), 45 grams of hydrated lime, 25 grams of sodium zeolite A (Valfor ^® 100), 1.9 grams of a dispersant (dispersant Liquiment ^® 5581F) and 158.5 grams of water. The composition without sodium zeolite A had a density of 14.0 psi. and consisted of 304 grams of pumice (lightweight aggregate DS-325), 45 grams of hydrated lime, 1.9 grams dispersant (dispersant Liquiment ^® 5581F) and 145.5 grams of water. The strength development of the samples was monitored using a Fann ^® UCA ^™ ultrasonic cement analyzer at test temperatures of 80 ° F (27 ° C) and 100 ° F (38 ° C). The UCA ^™ device was used to determine the compressive strength of the samples after twenty-four hours, as well as the time during which the development of compressive strength of the samples was equal to 50 psi (345 kPa) and 500 psi (3.45 MPa). The UCA ^™ instrument determined the rate of development of compressive strength as a function of time. The rate of development of compressive strength was calculated as the angle of inclination of the initial linear part (starting from the occurrence of the development of strength) of the graph of the dependence of compressive strength on time. The test results are shown in Table 1 below.

Example 2

[0049] A pumice sample was treated with sodium hydroxide and sodium chloride to form a zeolite on the surface of the pumice. The zeolite was synthesized by mixing 300 grams of pumice (DS-325 lightweight aggregate) with 1.25 liters of a 30% NaCl solution containing 25 grams of NaOH. After mixing, the samples were placed in a sealed plastic container and heated at a temperature of 85 ° C for 17 hours. After processing, the solid phase was filtered off, washed several times with deionized water, and then dried. The solid phase was used to create a delayed setting calcareous-pozzolanic cement composition containing 250 grams of pumice treated with zeolite, 50 grams of slaked lime, 3.49 grams of dispersant (Liquiment ^® 514L dispersant), 3.13 grams of setting retarder (Micro Matrix cement setting retarder ^® ) and 207.4 grams of water. As a control sample, a delayed setting calcareous-pozzolanic cement composition was prepared that did not contain pumice treated with zeolite. A control formulation contained 250 grams of pumice (lightweight aggregate DS-325), 50 grams of hydrated lime and 3.49 grams of dispersant (dispersant Liquiment ^® 514L), 3,13 grams of retarder (retarder cement setting Micro Matrix ^®) and 154.9 grams water. The development of compressive strength of the samples was observed using UCA ^™ at a test temperature of 100 ° F. The UCA ^™ device was used to determine the compressive strength of the test sample and the control sample after seventy-two hours, as well as the time during which the development of the compressive strength of the test sample and control sample was equal to 50 psi and 100 psi (690 kPa). The UCA ^™ instrument determined the rate of development of compressive strength as a function of time. The rate of development of compressive strength was calculated as the angle of inclination of the initial linear part (starting from the occurrence of the development of strength) of the graph of the dependence of compressive strength on time. The test results are shown in Table 2 below.

Example 3

[0050] Several delayed setting cement compositions were obtained. The samples contained pumice (lightweight aggregate DS-325), 20% slaked lime, and 60% water. The density of each of the samples was 13.5 f / gal. (1620 kg / cubic meter). In addition to the basic composition in separate samples were administered various amounts of dispersant (dispersant Liquiment ^® 5581F), cement setting retarder (retarder Micro Matrix ^® cement setting) and setting of the activator (activator type varied depending on the sample). The selected activator types were sodium zeolite A (Valfor ^® 100 zeolite), hydrated sodium Zeolite A (Advera ^® 401 zeolite), divalent salt (CaCl ₂ ), and cement (API class A). The dispersant was administered as a percentage of pumice mass (bwoP). A cement setting retarder was introduced in units of a gallon per pumice bag weighing 46 pounds (gal / bag). The content of each setting activator was 10% of the samples, relative to the total mass of pumice and slaked lime (bwoP + HL). The development of compressive strength and initial setting times of the samples were monitored using UCA ^™ at a test temperature of 80 ° F. The UCA ^™ instrument was used to determine the compressive strength of the test sample and the control sample after twenty-four hours. The UCA ^™ instrument determined the rate of development of compressive strength as a function of time. The rate of development of compressive strength was calculated as the angle of inclination of the initial linear part (starting from the occurrence of the development of strength) of the graph of the dependence of compressive strength on time. The test results are shown in Table 3 below.

Example 4

[0051] Two samples of cementitious compositions with delayed setting were obtained. The samples contained pumice (lightweight aggregate DS-325), 20% hydrated lime, 65% water, 2% weighting agent (weighting Micromax ^®), 0,6% dispersant (dispersant Liquiment ^® 5581F) and 0.04 gpm. / Retarder bag cement (Micro Matrix ^® cement setting retarder). In addition, a prototype contained 10% bwoP + HL activator setting sodium zeolite A (zeolite Valfor ^® 100). The density of each of the samples was 13.5 f / gal. (1620 kg / cubic meter). The development of compressive strength of the samples was observed using UCA ^™ at a test temperature of 100 ° F. The UCA ^™ instrument was used to determine the development time of the compressive strength of 50 psi and the development time of the compressive strength of 500 psi for the prototype and control sample. The UCA ^™ instrument determined the rate of development of compressive strength as a function of time. The rate of development of compressive strength was calculated as the angle of inclination of the initial linear part (starting from the occurrence of the development of strength) of the graph of the dependence of compressive strength on time. The test results are shown in Table 4 below.

Example 5

[0052] Seven samples of delayed setting cement compositions were obtained. Samples contained 609 grams of fly ash (Magnablend class F fly ash, manufactured by Magnablend Inc., Waxahachi, Texas), 21 grams of silica dust, 3.5 grams of a friction reducing cement mortar (CFR cement friction reducing additive) -3 ^™ , manufactured by Halliburton Energy Services Inc., Houston, Texas), and 317 grams of water. In addition to the base composition, each test sample was administered various amounts of activator setting hydrated sodium zeolite A (zeolite Advera ^® 401). The development of compressive strength of the samples was observed using UCA ^™ at a test temperature of 150 ° F (66 ° C). The UCA ^™ instrument was used to determine the compressive strength of prototypes after twenty-four hours. The UCA ^™ instrument determined the rate of development of compressive strength as a function of time. The rate of development of compressive strength was calculated as the angle of inclination of the initial linear part (starting from the occurrence of the development of strength) of the graph of the dependence of compressive strength on time. The test results are shown in Table 5 below.

[0053] In addition, for a sample containing 49 grams of zeolite, as shown in Table 5 above, strength development was further determined using a UCA ^™ instrument at test temperatures of 100 ° F (38 ° C) and 120 ° F (49 ° C) . The results obtained are shown in Table 6 below.

[0054] It should be understood that the compositions and methods are described herein in the context of "content", "containment" or "inclusion" of the various components or steps, and the compositions and methods may also "consist essentially of" or "consist of" various components and stages. Moreover, the singular forms used in the claims suggest the presence of one or more elements.

[0055] For brevity, only certain ranges are fully disclosed herein. However, ranges from any lower limit can be combined with any upper limit to describe a range not described in full, just as ranges from any lower limit can be combined with any other lower limit to describe a range not described in full. in the same way, ranges from any upper limit can be combined with any other upper limit to describe a range not fully described. In addition, in all cases where a numerical range with a lower limit and an upper limit is described, any number and any included range falling within the specified range are specifically described. In particular, each range of values (in the form of “from about a to about b” or, equivalently, “from about a to b” or, equivalently, “from about a-b”) described herein should be understood as describing each number and range included in a wider range of values, even if they are not explicitly stated. Thus, each point or individual value can act as its own lower or upper limit, combined with any other point or individual value, or with any other lower or upper limit, to describe a range that is not fully described.

[0056] Thus, the present embodiments of the invention are well suited to achieve the objectives and indicated advantages, as well as their inherent advantages. The specific embodiments of the invention disclosed above are merely illustrative, and can be modified and implemented in various, but equivalent ways, obvious to those skilled in the art who have the opportunity to familiarize themselves with the present description. Although only individual embodiments of the invention were discussed, this description covers any combination of all embodiments of the invention. In addition, the design or project details described herein are not limited except as described in the claims below. In addition, the terms in the claims have their simple, ordinary meaning, unless the patent holder expressly and clearly defines otherwise. Thus, it should be understood that the particular illustrative embodiments described above can be changed or modified, while all such changes are within the scope and essence of these embodiments of the invention. If there are contradictions in the use of a word or term in the present description and one or more patents (patents) or other documents that may be incorporated into this description by reference, the definitions corresponding to the present description should be adopted.

Claims (35)

1. A method of cementing in an underground formation, including: providing a cement composition containing water, pozzolan, slaked lime, setting retarder and zeolite activator; the introduction of a cement composition into an underground formation; and providing the possibility of setting the cement composition in the subterranean formation, where the zeolite activator contains zeolite located on the surface of the pozzolan, and the zeolite activator accelerates the development of compressive strength of the cement composition. 2. The method according to p. 1, further comprising the steps of: providing a delayed setting cement composition containing water, pozzolan, slaked lime and setting retarder; and introducing a zeolite activator into the cement composition with a delayed setting, to obtain a cement composition. 3. The method according to claim 2, further comprising storing the cement composition with delayed setting for at least about 7 days before the introduction of the zeolite activator. 4. The method according to any one of paragraphs. 1-3, characterized in that the pozzolan is selected from the group consisting of fly ash, silica dust, metakaolin, pumice and any combination of these materials. 5. The method according to p. 1, characterized in that the zeolite activator contains zeolite in combination with a cation. 6. The method according to p. 1, characterized in that the zeolite activator is present in an amount in the range from about 0.1% to about 20% relative to the weight of pozzolan. 7. The method according to p. 1, characterized in that the retarder contains at least one moderator selected from the group consisting of phosphonic acid, a derivative of phosphonic acid, a lignosulfonate, a salt, an organic acid, a derivative of cellulose, a synthetic co or terpolymer, containing sulfonate and carboxyl groups, borate compounds and any combination of these compounds. 8. The method according to p. 1, characterized in that the cement composition further comprises a dispersant. 9. The method according to p. 8, characterized in that the dispersant contains at least one dispersant selected from the group consisting of a dispersant based on sulfonated formaldehyde, a dispersant based on a polycarboxylated ether and a combination of these dispersants. 10. The method according to p. 1, characterized in that the cement composition further comprises a cement retarder based on a phosphonic acid derivative and a polycarboxylated ether dispersant. 11. The method according to p. 1, characterized in that the cement composition is injected into the subterranean formation using a method comprising pumping the cement composition with a delayed setting through the casing, through the shoe of the casing and into the annular space of the wellbore. 12. Activated delayed setting cement composition comprising: water pozzolan slaked lime setting retarder, and zeolite activator, where the zeolite activator contains zeolite located on the surface of pozzolan. 13. Activated cementitious composition with delayed setting according to claim 12, characterized by one or more features defined in any of paragraphs. 4-10. 14. A cementing system comprising: delayed setting cement composition containing water, pozzolan, slaked lime and setting retarder; zeolite activator for activation of cement composition with delayed setting; mixing equipment for mixing a delayed setting cement composition and a zeolite activator to obtain an activated cement composition; and pumping equipment for delivering the activated cement composition to the wellbore, where the zeolite activator contains zeolite located on the surface of pozzolan. 15. The system of claim 14, wherein the pozzolan is selected from the group consisting of fly ash, silica dust, metakaolin, pumice and any combination of these materials. 16. The system of claim 14, wherein the zeolite activator contains zeolite in combination with a cation. 17. The system of claim 14, wherein the setting retarder comprises a phosphonic acid derivative and the delayed setting cement composition further comprises a polycarboxylated ether dispersant. 18. The system of claim 14, wherein the set retarder comprises at least one moderator selected from the group consisting of phosphonic acid, a phosphonic acid derivative, a lignosulfonate, a salt, an organic acid, a cellulose derivative, a synthetic co or terpolymer, containing sulfonate and carboxyl groups, borate compounds and any combination of these compounds.

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