JP6266788B2 - Mud treatment fluid containing pumice and related methods - Google Patents

Description

  The cement composition can be used for various underground operations. For example, in underground well construction, pipe strings (eg, casings, liners, expandable tubing, etc.) can be withdrawn into the well and cemented into place. The method of cementing a pipe string in place is commonly referred to as “primary cementing”. In a typical primary cementing process, the cement composition is pumped into the annulus between the well wall and the outer surface of the pipe string descended into the well. The cement composition sets in an annular space, thereby forming a hard, substantially impervious cement annular sheath (ie, cement sheath) that supports and positions the pipe string within the well. Bond the outer surface of the puddle and pipe string to the underground composition. Among other things, the cement sheath surrounding the pipe string functions to prevent fluid migration within the annulus and to protect the pipe string from corrosion. Cement compositions can also be used in remedial cementing methods, for example, sealing cracks or holes in pipe strings or cement sheaths, sealing highly permeable formations and cracks, and placing cement plugs, etc. Can also be used.

  A wide range of cement compositions have been used in underground cementing operations. In some cases, retarded cement compositions have been used. The retarding cement composition is characterized by maintaining a fluid state that can be pumped for an extended period of time (eg, at least about 1 day to about 2 weeks or more). The set retarding cement composition can be activated when desired to use, thereby developing a reasonable compressive strength. For example, a cement setting activator may be added to the set retarding cement composition, thereby causing the composition to set into a hardened mass. Set retarding cement compositions are particularly suitable for use in well applications, eg where it is desirable to prepare the cement composition in advance. Thereby, for example, the cement composition can be stored prior to use. In addition, this allows, for example, the cement composition to be prepared at hand and then transported to the work site. Accordingly, capital expenditure can be reduced by reducing the need for on-site bulk storage and mixing equipment. This is particularly useful for offshore cementing operations where space on board may be limited.

  Drilling requires the use of drilling fluid (also known as drilling mud). One challenge associated with drilling is the undesirable loss of drilling fluid into the formation. This lost fluid flows, for example, into cracks induced by excessive mud pressure, existing cracks, or large openings with structural strength in the formation. This problem is sometimes referred to as “mud loss”, and the formation in which the lost drilling fluid flows is sometimes referred to as the “mud loss zone”. Mud problems are also found in drilling fluids, as well as other treatment fluids, such as spacer fluids, finishing fluids (eg, finishing brine), fracturing fluids, and cement compositions introduced into wells There is a case.

  Loss of treatment fluid to the formation is undesirable due to, among other things, the expense associated with treatment fluid lost to the formation, loss of time, and in extreme situations, abandoned mines. Replenishment of treatment fluids not only results in work interruptions, but also requires extra fluid storage, human resources, and equipment. Fluid replenishment, in addition to increased work costs, can cause additional work site problems such as higher environmental loads and reuse of fluids and materials after work is complete .

  These drawings illustrate some specific aspects of embodiments of the invention and should not be used to limit or define the invention.

FIG. 1 illustrates a system that uses a mud treatment fluid when a drilling rig is present in a well according to certain embodiments.

FIG. 2 illustrates ground equipment that can be used to deliver a mud treatment fluid to a mud zone in a well according to a particular embodiment.

FIG. 3 illustrates the feeding of a mud treatment fluid into a mud zone in a well according to a particular embodiment.

  Embodiments of the present invention relate to underground operations, and more particularly, in certain embodiments, to set retarding cement compositions and methods of using set retarded cement compositions in underground formations. A mud fluid comprising a set retarding cement composition can be used to prevent loss of various treatment fluids. One of the many potential benefits of these methods and compositions is to immediately plug the mud zone by developing sufficient static gel strength to be effective in mud control. There may be in unplugging or bridging. Other advantages are that they condense to form a hardened mass with sufficient compressive strength to support the structure, they isolate the underground zone, or they are thixotropic (e.g. shear thinning or Shearing sensitivity), so that the fluid remains pumpable for a long enough time to be delivered, but may once again develop gel strength once stopped.

  Embodiments of the retarding cement composition can generally include water, pumice, slaked lime, and a setting inhibitor. Optionally, the retarding cement composition can further comprise a dispersant. Advantageously, embodiments of the retarding cement composition can remain in a fluid state that can be pumped for extended periods of time. For example, the retarding cement composition may remain in a fluid state that can be pumped for at least about one day or more. Advantageously, the retarding cement composition can develop suitable compressive strength after activation. The retarding cement composition is suitable for many subsurface cementing operations, including in formations having a bottom static temperature in the range of about 100 ° F. to about 450 ° F. or higher. In some embodiments, the retarding cement composition can be used in formations that have a relatively low bottom temperature (eg, less than about 200 ° F.).

  The water used in the set retarding cement composition embodiment is derived from any source if it does not contain an excess of a compound that may undesirably adversely affect other components of the set retarding cement composition. It may have been For example, the set retarding cement composition may include fresh water or salt water. Brine is broad and may contain one or more dissolved salts and may be saturated or unsaturated as desired in a particular application. Sea water or salt water is suitable for use in certain embodiments. The water may further be included in an amount sufficient to form a pumpable slurry. In certain embodiments, water may be present in the retarding cement composition in the range of about 33 to about 200% by weight of pumice. In certain embodiments, water may be present in the set retarding cement composition in the range of about 35 to about 70% by weight of pumice. Those skilled in the art having the benefit of this disclosure will know the appropriate amount of water for the selected application.

  Embodiments of the retarding cement composition can include pumice. In general, pumice is a volcanic rock that can exhibit cementitious properties in that it can condense and harden in the presence of slaked lime and water. The pumice may also be ground, for example. In general, the pumice may have any particle size distribution as desired in a particular application. In certain embodiments, the pumice stone can have a d50 particle size distribution ranging from about 1 micron to about 200 microns. The d50 particle size distribution corresponds to the d50 value measured, for example, with a particle size analyzer made by Malvern Instruments (Worcestershire, United Kingdom). In certain embodiments, the pumice can have a d50 particle size distribution ranging 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, the pumice may have a d50 particle size distribution of about 15 microns or less. Examples of suitable pumice having a d50 particle size distribution of about 15 microns or less are available as DS-325 lightweight aggregates, Hess Volume Products, Inc. (Malad, Idaho). It should be understood that if the particle size is too small, there may be mixing problems, and if the particle size is too large, it may not be effectively dispersed in the composition. Those skilled in the art having the benefit of this disclosure must be able to select a pumice particle size suitable for use in the selected application.

  Embodiments of the retarding cement composition can include slaked lime. As used herein, the term “slaked lime” is understood to mean calcium hydroxide. Slaked lime may be included in the set retarding cement composition embodiment, for example, to make a hydraulic composition with pumice. For example, slaked lime may be included in a weight ratio of pumice to slaked lime from about 10: 1 to about 1: 1, or from about 3: 1 to about 5: 1. When present, slaked lime can be included in the delayed-setting cement composition, for example, in the range of about 10 to about 100% by weight of the pumice. In some embodiments, the slaked lime is in a range between an amount of about 10%, about 20%, about 40%, about 60%, about 80% or about 100% by weight of the pumice. And / or any amount of these. In some embodiments, the cementitious component present in the retarded cement composition can consist essentially of pumice and slaked lime. For example, the cementitious component can consist primarily of pumice and slaked lime without any additional components (eg, Portland cement, fly ash, slag cement), which set in water in the presence of water. Those skilled in the art having the benefit of this disclosure will know the appropriate amount of slaked lime to include for the selected application.

  An embodiment of the set retarding cement composition can include a set inhibitor. A wide variety of set inhibitors may be suitable for use in the set retarding cement composition embodiment. For example, the setting inhibitor may be phosphonic acid, phosphonic acid derivatives, lignosulfonic acid, salts, organic acids, carboxymethylated hydroxyethyl cellulose, sulfonic acid groups and carboxylic acid groups, boric acid compounds, derivatives thereof or mixtures thereof Synthetic copolymers or terpolymers may be included. Suitable setting inhibitor embodiments include, among others, phosphonic acid derivatives available as Micro Matrix® cement inhibitors from Halliburton Energy Services (Houston, TX). Generally, the set inhibitor may be included in the set retarding cement composition in an amount sufficient to delay set for a desired time. In some embodiments, the set inhibitor may be included in the set retarding cement composition in the range of about 0.01% to about 10% by weight of pumice. In certain embodiments, the anti-caking agent is about 0.01%, about 0.1%, about 1%, about 2%, about 4%, about 6%, about 8% by weight of pumice. % Or any amount within the range between about 10% by weight and / or any of these. Those skilled in the art having the benefit of this disclosure will know the appropriate amount of anti-caking agent to include for the chosen application.

As mentioned above, embodiments of the retarding cement composition may optionally include a dispersant. Suitable dispersant embodiments include, but are not limited to, sulfonated formaldehyde-based dispersants, and polycarboxyl ether dispersants. An example of a suitable sulfonated formaldehyde-based dispersant is a sulfonated acetone-formaldehyde condensate available as a CFR ^™ -3 dispersant from Halliburton Energy Services (Houston, TX). An example of a suitable polycarboxyl ether-based dispersant is a Liquid® 514L dispersant available from BASF (Houston, Texas) containing 36% by weight polycarboxyl ether in water. While certain dispersants can be used according to certain embodiments, in some embodiments, the use of polycarboxyl ether dispersants may be particularly suitable. Without being limited by theory, it is believed that the polycarboxyl ether dispersant may interact synergistically with other components of the set retarding cement composition. For example, a polycarboxyl ether dispersant may react with a specific setting inhibitor (for example, a phosphonic acid derivative) to form a gel that disperses pumice and slaked lime in the composition for a long time. .

  In some embodiments, a dispersant can be included in the retarding cement in the range of about 0.01% to about 5% by weight of pumice. In certain embodiments, the dispersant is about 0.01%, about 0.1%, 0.5%, about 1%, about 2%, about 3%, about 4% by weight of pumice. Or it can be present in an amount in the range between any amount of about 5% by weight and / or any of these. Those skilled in the art having the benefit of this disclosure will know the appropriate amount of dispersant to include for the chosen application.

  The set retarding cement composition embodiment may also include other additives suitable for use in underground cementing operations. Examples of this type of additive include fillers, lightweight additives, gas generating additives, mechanical property enhancing additives, mud materials, filtration control additives, fluid loss control additives, antifoaming agents, foaming agents, Including but not limited to thixotropic additives, and combinations thereof. In an embodiment, one or more of these additives can be added to the set retarding cement composition after storage but before delivery to the underground layer. Those skilled in the art having the benefit of this disclosure will readily be able to determine the types and amounts of additives useful for a particular application and desired result.

Optionally, foaming additives may be included in the set retarding cement composition, for example, to facilitate foaming and / or to stabilize the resulting foam formed therewith. In particular, the cement composition may be foamed by a foaming additive and a gas. The foaming additive can include a surfactant or combination of surfactants that reduce the surface tension of water. For example, the foaming agent can consist of anionic, nonionic, amphoteric (including zwitterionic surfactants), cationic surfactants or mixtures thereof. Examples of suitable foaming additives include but are not limited to: betaine, anionic surfactants such as hydrolyzed keratin, amine oxides such as alkyl or alkene dimethylamine oxide, cocoamidopropyl Quaternary surfactants such as dimethylamine oxide, sulfonic acid methyl esters, alkyl or alkenyl amide betaines such as cocoamidopropyl betaine, α-olefin sulfonates, trimethylethylammonium chloride, and trimethylcocoammonium chloride, C8 to C22 alkyl ethoxy Rate sulfate, and combinations thereof. Specific examples of suitable foaming additives include, but are not limited to, ammonium salts of alkyl ether sulfates, cocoamidopropyl betaine surfactants, cocoamidopropyldimethylamine oxide surfactants. , Sodium chloride, and water mixtures; ammonium salts of alkyl ether sulfate surfactants, cocoamide propylene hydroxyline surfactants, cocoamidopropyldimethylamine oxide surfactants, sodium chloride, and water mixtures; hydrolyzed keratins; alcohol ethoxys A mixture of a rate sulfate surfactant, an alkyl or alkene amide betaine surfactant, and an alkyl or alkene dimethylamine oxide surfactant; an α-olefin sulfonate surfactant; Aqueous solution of the fine betaine surfactant; and combinations thereof. An example of a suitable foaming additive is Halliburton Energy Services Inc. ZONESEALANT ^™ 2000 agent available from

  Optionally, a strength retrograde additive is included in the retarded cement composition to prevent strength retrograde when, for example, the cement composition is exposed to high temperatures after the cement composition has developed compressive strength. It's okay. These additives allow the cement composition to form as intended and prevent cracking and premature failure of the cementitious composition. Examples of suitable strength retrograde additives include, but are not limited to, amorphous silica, coarse crystalline silica, fine crystalline silica, or combinations thereof.

  Optionally, lightweight additives may be included in the retarded cement composition, for example, to reduce the density of the cement composition. Examples of suitable lightweight additives include bentonite, coal, diatomaceous earth, expanded perlite, fly ash, gilsonite, hollow microspheres, low density rubber beads, nitrogen, pozzolanic-bentonite, sodium silicate, combinations thereof, or other well known Including but not limited to lightweight additives.

  Optionally, a gas generating additive may be included in the set retarding cement composition to release the gas at a predetermined time, which creates a gas transfer from the formation into the cement composition prior to setting. May be useful to prevent The generated gas can be combined with the formation gas or can inhibit the penetration of the cement composition by the formation gas. Examples of suitable gas generating additives include, but are not limited to, metal particles (eg, aluminum powder) that react with an alkaline solution to produce a gas.

  Optionally, mechanical property enhancing additives may be included in the retarded cement composition, for example, to ensure sufficient compressive strength and long-term structural integrity. These properties are affected by tension, stress, temperature, pressure, and impact effects from the underground environment. Examples of mechanical property enhancing additives include, but are not limited to, carbon fiber, glass fiber, metal fiber, mineral fiber, silica fiber, polymerized elastomer, latex, and combinations thereof.

  Optionally, a mudicide may be included in the set retarding cement composition to help prevent loss of fluid circulation to the formation, for example. Examples of mud removers include, but are not limited to, cedar bark, materials Finely chopped sugarcane stems, mineral fibers, mica flakes, cellophane, calcium carbonate, ground rubber, polymeric materials, plastics Including, but not limited to, pieces, ground marble, wood, nut shells, melamine laminates (eg, Formica® laminates), corn cobs, cotton shells, and combinations thereof It is not something.

  Optionally, a fluid loss control additive may be included in the set retarding cement composition, for example, to reduce the amount of fluid lost to the formation. The properties of cement compositions are significantly affected by their water content. Fluid loss can expose the cement composition to degraded design properties or complete failure. Examples of suitable fluid loss control additives are specific polymers, such as hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, copolymers of 2-acrylamido-2-methylpropanesulfonic acid and acrylamide, or N, N-dimethylacrylamide. And a graft copolymer comprising a main chain of lignin or lignite and a pendant group comprising at least one selected from the group consisting of 2-acrylamido-2-methylpropanesulfonic acid, acrylonitrile, and N, N-dimethylacrylamide Including, but not limited to, polymers.

Optionally, antifoam additives may be included in the retarding cement, for example, to mitigate the tendency of the cement composition to foam during mixing and pumping. Examples of suitable antifoam additives include, but are not limited to, polyol silicone compounds. Examples of suitable antifoam additives are those from Halliburton Energy Services, Inc. To D-AIR ^™ defoaming agent.

  Optionally, a thixotropic additive may be included in the set retarding cement to provide a cement composition that can be pumped, for example, as a thin or low viscosity fluid, but exhibits a relatively high viscosity at rest. Among others, thixotropic additives control free water, cause rapid gelation as the slurry is set, counteract mud, prevent "retraction" in the annular column, and gas migration May be used to help minimize. Examples of suitable thixotropic additives include gypsum, water soluble carboxyalkyl, hydroxyalkyl, mixed carboxyalkyl-hydroxyalkylcellulose, polyvalent metal salts, zirconium oxychloride with hydroxyethylcellulose, or combinations thereof. Including, but not limited to.

  One skilled in the art will recognize that embodiments of the retarding cement composition generally must have a density suitable for a particular application. For example, the retarding cement composition can have a density ranging from about 4 pounds per gallon (“lb / gal”) to about 20 lb / gal. In certain embodiments, the retarding cement composition can have a density in the range of about 8 lb / gal to about 17 lb / gal. Embodiments of the retarding cement composition can be foamed or non-foamed, or provide other means for reducing density, such as hollow microspheres, low specific gravity rubber beads, or other known density reducing additives. May be included. In an embodiment, the density is reduced after storing the composition but before delivery to the formation. Those skilled in the art having the benefit of this disclosure will know the appropriate density for a particular application.

As described above, the set retarding cement composition embodiment can rapidly develop static gel strength. For example, the retarding cement composition can be characterized by a static gel strength of from about 50 to about 200 ° F. and at least about 100 lb / 100 ft ² to about 500 lb / 100 ft ² . As a further embodiment, set retarder cement composition, with from about 50 to about 200 ° F, it can be characterized by the static gel strength of about 350lb / 100ft ² from at least about 200 lb / 100 ft ^2.

  As described above, the retarding cement compositions may have a retarding setting property that they remain in a fluid state that can be pumped for an extended period of time. For example, the retarding cement composition may maintain a pumpable fluid state for a period of about 1 day to about 7 days or more, such as about 100 ° F. In some embodiments, the set retarding cement composition has a pumpable fluid state of at least about 1 day, about 7 days, about 10 days, about 20 days, about 30 days, about 40 days, about 50 days, May be held for about 60 days or longer, eg, about 100 ° F. The fluid is a high temperature high pressure consistency meter at room temperature (for example, 80 ° F.) according to the cement thickening time measurement method defined in API RP Practice 10B-2, Recommended Practiced for Testing Well Elements, First Edition, July 2005. If it has a Bearden unit consistency (“Bc”) of less than 70, it is considered to be in a fluid state that can be pumped.

  As required for use, embodiments of the retarded cement composition can be activated (eg, by mixing with a cement hardening activator) and thereby set into a setting mass. For example, an embodiment of a set retarding cement composition may be activated to set to a hardened mass within a time period ranging from about 2 hours to about 12 hours. For example, an embodiment of a set retarding cement composition may include a time within a range of any of about 2 hours, about 4 hours, about 6 hours, about 8 hours, about 10 hours, or about 12 hours, and / or It may be condensed to form a cured mass in any of these times. After activation, the retarding cement composition may develop a 24-hour compressive strength in the range of about 50 psi to about 5000 psi, alternatively about 100 psi to about 4500 psi, or about 500 psi to about 4000 psi. In some embodiments, the retarding cement composition may develop a 24 hour compressive strength of at least about 50 psi, at least about 100 psi, at least about 500 psi, or more. Compressive strength can be measured using UCA at 140 ° F. and 3000 psi according to API RP 10B-2, Recommended Practice for Testing Well Elements, First Edition, July 2005.

  Embodiments may include the addition of a cement hardening activator to the set retarded cement composition. Examples of suitable cement hardening activators are calcium chloride, triethanolamine, sodium silicate, zinc formate, calcium acetate, sodium hydroxide, monovalent salts, nanosilica (ie having a particle size of about 100 nanometers or less) Silica), polyphosphate esters, and combinations thereof, but are not limited to these. In some embodiments, a combination of polyphosphate ester and monovalent salt may be used for activation. The monovalent salt used can be any salt that dissociates to form a monovalent cation (eg, sodium and potassium salts). Examples of suitable monovalent salts include potassium sulfate, calcium chloride, and sodium sulfate. A variety of different polyphosphates, such as polymetaphosphates, phosphates, and combinations thereof, along with monovalent salts, can be used for activation of the retarded cement composition. Specific examples of polymetaphosphates that can be used include sodium hexametaphosphate, sodium trimetaphosphate, sodium tetrametaphosphate, sodium pentametaphosphate, sodium heptametaphosphate, sodium octametaphosphate, and combinations thereof. An example of a suitable cement hardening activator comprises a combination of sodium sulfate and sodium hexametaphosphate. In certain embodiments, the activator is provided as a liquid additive, eg, as a liquid additive consisting of a monovalent salt, a polyphosphate ester, and optionally a dispersant, and may be added to the set retarding cement composition. it can.

  The cement setting activator must be added to the set retarding cement composition embodiment in an amount sufficient to activate a wide range of curable compositions and set to a setting mass. In certain embodiments, the cement hardening activator may be added to the set retarding cement composition in the range of about 1% to about 20% by weight of pumice. In certain embodiments, the cement hardening activator is within a range between any amount of about 1%, about 5%, about 10%, about 15%, or about 20% by weight of pumice. May be present in amounts, and / or any of these amounts. Those skilled in the art having the benefit of this disclosure will know the appropriate amount of cement hardening activator to be included for the application.

  As is well known to those skilled in the art, the set retarding cement composition embodiments can be used in a variety of underground operations including drilling, fluid replacement, and primary and retrofit cementing. In addition, in this type of operation, a set retarding cement composition may be used as a “treatment fluid”. As used herein, the term “treatment” or “treating” fluid relates to a desired function and / or to any underground operation that uses the fluid for a desired effect. The term “treatment” or “treating” fluid does not imply any particular action by the fluid.

  In some embodiments, a set retarding cement composition may be provided that consists of water, pumice, slaked lime, a set inhibitor, and optionally a dispersant. The set retarding cement composition can be stored, for example, in a container or other suitable container. The set retarding cement composition may be able to remain stored for a desired period of time. For example, the retarding cement composition may remain stored for about a day or longer. For example, the retarding cement composition can be 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 It can remain stored for longer periods of time. In some embodiments, the set retarding cement composition may remain stored for a period ranging from about 1 day to about 7 days or more. The set retarding cement composition can then be activated, for example, by the addition of a cement hardening activator, delivered to an underground formation where it can set.

  The retarding cement composition may include properties that are useful as a mud treatment fluid. For example, a mud composition may develop a static gel strength in a short time, making the composition effective in controlling mud. In a further embodiment, the set retarding cement composition may set into a hardened mass having sufficient compressive strength to support the well structure. Further, the retarding cement composition may be thixotropic (eg, shear thinning or shear sensitivity) so that the fluid remains pumpable long enough to be pumped in, but once stopped. Sometimes quickly develops gel strength.

  Accordingly, embodiments provide a mud treatment fluid comprising a set retarding cement composition. The mud treatment fluid may be used during well drilling in the underground. The anti-mud treatment fluid may include a set retarding cement composition that may consist of water, pumice, slaked lime, a set inhibitor, and optionally a dispersant. The mud treatment fluid may further include a cement hardening activator. The sludge treatment fluid can be used to reduce the loss of drilling fluid to the underground sludge zone. In a further embodiment, the mud treatment fluid can be used at any time and during any well operation. Mud fluid can be used to reduce any treatment fluid loss to any geological terrain.

The mud treatment fluid may be a thixotropic shear thinning fluid. A thixotropic fluid is generally described as a fluid that becomes more viscous when it stops flowing. Thixotropic fluids often have a gel-like shape that requires sufficient shear stress to overcome this static gelling phenomenon in order to begin to flow. Once flow begins, a shear thinning or pseudoplastic fluid becomes a fluid whose apparent viscosity (defined as the ratio of shear stress to apparent viscosity shear rate) decreases as the shear rate increases. A dilatant (shear thickening) fluid is a fluid whose apparent viscosity increases as the shear rate increases. A Herschel-Bulkley (HB) fluid model can be used to classify fluids viscometrically as shear thinning (pseudoplastic fluid) or shear thickening (dilatant). The HB model is expressed as:
τ = μ _∞ γ ⁿ + τ ₀
Here, τ shear stress, μ _∞ is the fluid consistency coefficient, γ shear rate, n shear thinning index, and τ ₀ is yield stress. A shear thinning index less than 1 indicates that the fluid is shear thinning, while an n value greater than 1 indicates that the fluid is shear thickening. Thus, shear thinning fluids must have a shear thinning index of less than 1 when measured according to the Herschel-Bulkley model. Thus, a mud treatment fluid having the dual nature of thixotropic and shear thinning remains fluid when exposed to pumping agitation (or any other agitation), but the mud treatment As fluid flows into the mud zone and leaves the source of agitation, the fluid thickens and seals the mud zone, and any fluid flowing adjacent to the sealed mud zone Prevent fluid migration to the mud zone.

  In a mud treatment fluid embodiment, a mud treatment fluid comprising a set retarding cement composition may be used. For example, a mud treatment fluid embodiment comprises the disclosed setting retarded cement composition formulation described herein. In an embodiment, the mud treatment fluid may consist entirely of a retarded cement composition. Accordingly, in embodiments, the disclosed retarded cement composition is used to reduce the loss of treatment fluid in the underground layer, for example, by circulating the retarded cement composition when drilling a well. The mud treatment fluid can reduce the loss of drilling fluid to the underground mud zone. Embodiments can provide a method of drilling a well in an underground formation, the method comprising circulating a head treatment fluid comprising a set retarding cement composition through the well as the well is being drilled. The set retarding cement composition comprises pumice, slaked lime, a set inhibitor, and water. In a further embodiment, all or part of the set retarding cement composition can be set in the subsurface mud zone.

In any mud treatment fluid embodiment, aluminum sulfate (ie Al ₂ (SO ₄ ) ₃ ) may be used to improve the rheology of the mud treatment fluid. This improvement can be measured by the application of the Herschel-Bulkley model described above, where it induces a net decrease in the value of the aluminum sulfate added shear thinning index. The anti-mud treatment fluid may comprise about 0.1% to about 10% aluminum sulfate by weight of pumice. In certain embodiments, the aluminum sulfate is about 0.1%, about 0.5%, about 1%, about 2%, about 5%, about 7% or about 10% by weight of pumice. May be present in an amount in the range between and / or any of these amounts. Those skilled in the art having the benefit of this disclosure will know the appropriate amount of aluminum sulfate to include for the selected application. Aluminum sulfate induces the formation of ettrinite in the mud treatment fluid. Without being limited by theory, it is thought that the stringing properties form thixotropy because the stringing crystals form needle-like crystals that are aligned in the shear field and randomized in the stationary state. Thus, in embodiments, any other material that induces the formation of an stringite can be used in a manner similar to aluminum sulfate.

  As mentioned above, a mud zone is often encountered where drilling fluid may be lost. As a result, excavation operations usually have to be terminated, for example by performing repair procedures. According to an embodiment, the mud treatment fluid seals the mud zone so that an uncontrollable flow of treatment fluid into or out of the mud zone (eg, loss drilling fluid circulation, cross-flow) Can be used to prevent underground explosions, etc.). In certain embodiments, a mud treatment fluid comprising a set retarding cement composition may be prepared. After preparation, the mud treatment fluid may be delivered to the mud zone. In certain embodiments, the mud treatment fluid is pumped through one or more open ends of the drilling pipe string. For example, the mud treatment fluid may be pumped through a drill bit. Once placed in the mud treatment fluid, the mud treatment fluid must condense and form a hardened mass within the mud zone. This hardened mass must control the loss of the later pumped drilling fluid to seal the zone and allow drilling to continue. Embodiments of the mud treatment fluid can be placed in drilling fluids as well as other treatment fluids, such as spacer fluids, finishing fluids (eg, finishing brine), breaking fluids, and wells It may be used to control the sludge problem encountered by objects (setting delay etc.).

  There may be provided a method of sealing the mud zone. The method circulates a mud treatment fluid in a wellbore, wherein the mud treatment fluid comprises pumice, slaked lime, an agglomeration inhibitor, and water, and passes the mud treatment fluid to the mud zone. It can consist of condensing with and sealing the mud zone. The mud treatment fluid used in the method of sealing the mud can have various features of the embodiments of the mud treatment fluid described herein.

  A mud treatment fluid may be provided. The mud treatment fluid may consist of pumice, slaked lime, a setting inhibitor, and water. The mud treatment fluid can have various features of the mud treatment fluid embodiments described herein.

  A system may be provided to seal the mud zone in the underground formation. The system may consist of placing a mud treatment fluid in the mud zone. The mud treatment fluid may consist of pumice, slaked lime, and an anti-caking agent. The mud treatment fluid may further include mixing equipment that can mix the mud treatment fluid and pumping equipment that can pump the mud treatment fluid to the mud zone.

  FIG. 1 illustrates an example technique for delivering a mud treatment fluid 122 containing a set retarding cement composition disclosed herein to the mud zone 125 when drilling equipment is present in the well 116. . This type of embodiment may be used, for example, when it is desirable to reduce drilling fluid loss to the mud zone 125. Accordingly, an exemplary sludge treatment fluid comprising a set retarding cement composition disclosed herein directly, or indirectly, prepares, transports, recovers, recycles, reuses the disclosed set retarded cement composition. And / or may affect one or more parts or parts of equipment associated with disposal. For example, and referring to FIG. 1, according to one or more embodiments, the mud treatment fluid 122 is directly or indirectly one of the equipment associated with the exemplary well drilling assembly 100 or It may affect further parts or parts. Although FIG. 1 generally depicts a ground drilling assembly, the principles described herein are equivalent to subsea drilling operations using floating or offshore platforms and rigs without departing from the spirit of the disclosure. It should be noted that those skilled in the art will readily recognize that this is applicable.

  As shown, the drilling assembly 100 may include a drilling platform 102 that supports a derrick 104 that has a traveling block 106 for raising and lowering a drill string 108. As is well known to those skilled in the art, drill string 108 includes, but is not limited to, drill pipes and helical pipes. Kelly 110 supports drill string 108 as it is lowered through rotary table 112. Bit 114 is attached to the distal end of drill string 108 and is driven by a downhole motor and / or by rotating drill string 108 from the well surface. As the bit 114 rotates, it creates wells 116 that penetrate the various underground layers 118.

  A pump 120 (e.g., mud pump) circulates the mud treatment fluid 122 through the supply tube 124 and to the kelly 110, and Kelly takes the mud treatment fluid 122 downhole, inside the drill string 108, and the drill bit Convey through one or more openings in 114. The mud treatment fluid 122 may be delivered to the well prior to, in parallel with, or after delivery of drilling fluid or other treatment fluid (not shown). The mud treatment fluid 122 can then contact the mud zone 125. The mud treatment fluid 122 that contacts the mud zone 125 is no longer exposed to sufficient shear forces to remain fluid, and once static, the mud treatment fluid 122 thickens. The mud zone 125 can be sealed and eventually set to form a hardened mass. The mud treatment fluid 122 that does not contact the mud zone 125 is then an annulus 126 defined between the drill string 108 and the well 116 wall regardless of the presence or absence of other fluids (eg, drilling fluid). You can circulate back to the ground through. On the ground, the recirculated or spent fluid treatment fluid 122 can exit the annulus 126 and be transported through the interconnected flow line 130 to one or more fluid treatment units 128. After passing through the fluid treatment unit 128, the “cleaned” mud treatment fluid 122 may be deposited in an adjacent storage pit 132 (ie, a mud pit). Although illustrated as being located at the outlet of the well 116 through the annulus 126, the fluid treatment unit 128 is drilled to facilitate its proper function without departing from the scope of the disclosure. Those skilled in the art will readily recognize that the assembly 100 can be placed in any other location.

  In an embodiment, the mud treatment fluid 122 comprising the set retarding cement composition disclosed herein is coupled to the storage pit 132 in a transmittable manner or added to a mixing hopper 134 that is in fluid communication. There is a case. The mixing hopper 134 may include, but is not limited to, a mixer and related mixing equipment known to those skilled in the art. However, in other embodiments, the mud treatment fluid 122 may not be added to the mixing hopper. For example, in at least one embodiment, there may be one or more storage pits 132 (eg, a plurality of storage pits 132 in series). In addition, the storage pit 132 may be one or more that may store, regenerate, and / or condition the disclosed retarded cement composition therein, for example, until use as a mud treatment fluid 122 is desired. It may be a representative example of the above fluid storage equipment and / or unit.

  As noted above, the disclosed mud treatment fluid 122 comprising the set retarding cement composition disclosed herein may directly or indirectly affect the components and equipment of the drilling assembly 100. For example, disclosed mud treatment fluids 122 can be shakers (eg, shale shakers), centrifuges, hydrocyclones, separators (including magnetic and electrical separators), desilters, desanders, separators, filters (eg, , Diatomaceous earth filters), heat exchangers, and any fluid regenerator, which may directly or indirectly affect one or more fluid treatment units 128. The fluid treatment unit 128 further includes one or more sensors, gauges, pumps, compressors used to store, monitor, regulate, and / or regenerate the exemplary sludge treatment fluid 122. There is.

  The mud treatment fluid 122 is used to drive any conduit, pipeline, truck, tubular and / or pipe, mud treatment fluid 122 that fluidically transports the mud treatment fluid 122 into the downhole. Any pump, compressor, or motor used (eg, topside or downhole), any valve or associated connection used to regulate the pressure or flow rate of the mud treatment fluid 122, and any sensor (ie, pressure) , Temperature, flow rate, etc.), gauges, and / or combinations thereof, etc., may be directly or indirectly affected. Also, the disclosed mud treatment fluid 122 may directly or indirectly affect the mixing hopper 134 and storage pit 132, and various variations thereof.

  The disclosed mud treatment fluid 122 may also directly or indirectly affect various downhole equipment and tools that may come into contact with the mud treatment fluid 122. Such equipment and tools include, but are not limited to, the following: drill string 108, any float, drill collar, mud motor, downhole motor, and / or drill string 108. Any MWD / LWD tool and associated telemetry device, sensor or distributed sensor associated with the drill string 108 and the pump associated with the drill string 108. The disclosed mud treatment fluid 122 may also be used in heat exchangers, valves, and corresponding actuators, tool seals, packaging equipment, and other well isolation devices or parts in any downhole associated with the well 116. May directly or indirectly affect. The disclosed set retarding cement composition also includes a drill bit 114 directly or directly including, but not limited to, a roller cone bit, PDC bit, natural diamond bit, any digger, reamer, core bit, etc. Indirect effects may occur.

  Although not specifically illustrated herein, the disclosed mud treatment fluid 122 also allows any transport or delivery device used to transport it to the drilling assembly 100, such as the mud treatment fluid 122 from one location. Any transport container, conduit, pipeline, truck, tubular, and / or pipe used to move fluidically to the other position, any pump used to move the mud treatment fluid 122; Compressor, or motor, any valve or associated connection used to regulate the pressure or flow rate of the sludge treatment fluid 122, and any sensor (ie, pressure, temperature, flow rate, etc.), gauge, and / or May also have a direct or indirect effect on .

  2 and 3, a mud treatment fluid 214 comprising a set retarding cement composition as disclosed herein is placed in the mud zone 225 with cementing equipment and casing present in the well 222. A technical example is shown. Such an embodiment may be used, for example, when it is desirable to reduce the loss of replacement fluid to the mud zone 225. FIG. 2 illustrates a surface device 210 that may be used to place the sludge treatment fluid 214, according to certain embodiments. Although FIG. 2 generally depicts a ground drilling assembly, the principles described herein are equivalent to subsea drilling operations using floating or offshore platforms and rigs without departing from the spirit of the disclosure. It should be noted that those skilled in the art will readily recognize that this is applicable. In addition, the mud treatment fluid 214 may be supplied to the well 222 in parallel with or prior to delivery of any other treatment fluid (eg, displacement fluid, finishing fluid, etc.) to the well 222. It should be noted that it may be sent to. As shown in FIG. 2, the surface device 210 may include a cementing unit 212 that may include one or more cement trucks. The cementing unit 212 may include mixing equipment 204 and pumping equipment 206 as will be apparent to those skilled in the art. The cementing unit 212 can pump the mud treatment fluid 214 through the supply tube 216 to the cementing head 218, which conveys the mud treatment fluid 214 into the downhole.

  Referring to FIG. 3, a mud treatment fluid 214 comprising a set retarding cement composition disclosed herein can be placed in the underground formation 220 in accordance with an exemplary embodiment. As shown, the well 222 may be drilled into the underground layer 220. Although the well 222 is generally shown as extending vertically through the underground layer 220, the principles described herein are wells that extend obliquely through the underground layer 220 (eg, horizontal and It can also be applied to inclined wells. As shown, the well 222 comprises a wall 224 having a mud zone 225. In the illustrated embodiment, a surface casing 226 was fitted into the well 222. The surface casing 226 can be cemented to the wall 224 of the well 222 by a cement sheath 228. In the illustrated embodiment, one or more additional conduits (eg, intermediate casing, production casing, liner, etc.) illustrated as casing 230 may also be disposed in well 222. As shown, there is a well annulus 232 between the casing 230 and the wall 224 of the well 222 and / or the surface casing 226. One or more centralizers 234 may be attached to the casing 230, for example, to place the casing 230 in the center of the well 222 prior to and during the cementing operation.

  With continued reference to FIG. 3, the mud treatment fluid 214 can be pumped into the casing 230. The mud treatment fluid 214 may flow down in the casing 230, pass through the casing shoe 242 at the bottom of the casing 230, flow up around the casing 230, and flow into the well annulus 232. As the mud treatment fluid 214 flows upward through the well annulus 232, the mud treatment fluid 214 may contact the mud zone 225. As the mud treatment fluid 214 contacts the mud zone 225, the mud treatment fluid 214 may flow into the mud zone 225 and may become stationary if sufficiently pulled away from the shear force. When stationary, the mud treatment fluid 214 can rapidly develop gel strength. And once fully gelled, the mud treatment fluid 214 seals the mud zone 225 and can subsequently prevent the loss of any treatment fluid (not shown) that flows proximate to the mud zone 225. Over time, the mud treatment fluid 214 may harden in the mud zone 225, for example, to form a cement sheath that supports and positions the casing 230 in the well 222. Although not shown, other techniques can also be used to deliver the sludge treatment fluid 214. For example, a reverse circulation technique, that is, a technique in which the mud treatment fluid 214 is inserted into the mud zone 225 via the well annulus 232 instead of through the casing 230 may be used.

  As shown in FIG. 2, any of the mud treatment fluid 214 that does not contact the mud zone 225 flows out of the well annulus 232 through the flow line 238, eg, one or more storage pits 240 (eg, , Mud pits).

  As is well known to those skilled in the art, embodiments of delayed setting cement compositions may be used in a variety of cementing operations, including primary and retrofit cementing. In some embodiments, a set retarding cement composition may be provided that comprises water, pumice, slaked lime, a set inhibitor, and optionally a dispersant. The retarding cement composition can be delivered to an underground formation where it can set. In this specification, sending the set retarding cement composition to the underground layer refers to sending to a well drilled in the underground layer, to a nearby well region surrounding the well, or both. Including, but not limited to, any part of the underground layer. Embodiments may further include activation of the retarded cement composition. Activation of the set retarding cement composition may comprise, for example, adding a cement hardening activator to the set retarding cement composition.

  In a primary cementing embodiment, for example, an embodiment of a retarding cement composition includes a gap between a well wall and a conduit (eg, a branch line, liner) disposed in the well through the underground layer. May be sent to. The set retarding cement composition may set and form an annular sheath of set cement in the gap between the well wall and the conduit. In particular, the set cement composition can form a barrier and prevent migration of drilling fluid in the well. The set cement composition can also support the conduit, for example, in a well.

  In retrofit cementing embodiments, the retarding cement composition may be used, for example, in a squeeze cementing operation or in the placement of a cement plug. For example, the retarding composition may be placed in a well, in the formation, in the gravel pack, in the conduit, in the cement sheath, and / or in the microannulus between the cement sheath and conduit to close openings such as gaps or fissures. May be.

  In embodiments, the retarding cement composition can be used for different underground operations. In embodiments, the retarding cement composition can be used for one or more underground operations at a particular workplace. As noted above, the retarding cement composition may serve as a treatment fluid for these different underground operations. In embodiments, the retarding cement composition may be used as a mud treatment fluid, and when set as a cementing composition, the casing can be supported and positioned in the well. In embodiments, the retarding cement composition may be reused or recycled in the well for the same or different operations. The reusability of the set retarding cement composition allows reuse of the set retarding cement composition. Furthermore, this process reduces the amount of equipment and human resources required between operations related to transitioning between operations, fluid handling, and fluid storage.

  Exemplary set retarding cement compositions disclosed herein are directly or indirectly related to the preparation, transportation, recovery, recycling, reuse, and / or disposal of the disclosed set retarding cement compositions. May affect one or more parts or parts of the equipment. For example, the disclosed set retarding cement compositions can include one or more mixers, associated mixing, used to produce, store, monitor, condition, and / or regenerate exemplary set retarding cement compositions. May directly or indirectly affect equipment, mud pits, storage facilities or units, composition separators, heat exchangers, sensors, gauges, pumps, compressors, etc. The disclosed retarded cement composition is also compositional from any transport or delivery device used to transport it to a well or downhole, e.g., a retarded cement composition from one position to another. Any pump, compressor, or motor used to move any transport container, conduit, pipeline, truck, tubing, and / or pipe, setting retarded cement composition used to move compositionally (E.g., topside or downhole), any valve or associated connection used to regulate the pressure or flow rate of the set retarding cement composition, and any sensor (ie, pressure and temperature), gauge, and / or Directly or indirectly affect the combination of May affect. The disclosed retarded cement composition may also directly or indirectly affect various downhaul equipment and tools that may come into contact with the retarded cement composition. Such equipment and tools include, but are not limited to, well casings, well liners, finish strings, insert strings, drill strings, spiral tubes, and slipline. , Wireline, drill pipe, drill collar, mud motor, downhole motor and / or pump, cement pump, surface mount motor and / or pump, centralizer, turbolizer, scratcher, float (eg shoe, collar, valve etc. ), Recording tools and related telemetry devices, actuators (eg electromechanical devices, mechanical hydraulic devices, etc.), sliding sleeves, production sleeves, plugs, screens, Filters, flow control devices (eg, inflow control devices, autonomous inflow control devices, outflow control devices, etc.), couplers (eg, electrohydraulic wet connectors, dry connectors, inductive couplers), control lines (eg, electrical ), Monitoring lines, drill bits and reamers, sensors or distributed sensors, downhole heat exchangers, valves and corresponding actuators, tool seals, packaging equipment, cement plugs, bridge plugs, and others Well isolation device or parts, etc.

  In order to facilitate a better understanding of this embodiment, the following examples of certain aspects of some embodiments are provided. In any case, the following examples should not be read to limit or define the full scope of the embodiments.

^*ｂｗｏＰ＝対軽石重量比 A mud treatment fluid sample containing a set retarding cement composition was prepared. The sample consisted of pumice (DS-325 lightweight aggregate), slaked lime, Micro Matrix® cement inhibitor, and water. The composition structure of the sample is shown in Table 1 below:
Table 1
Composition structure of fluid treatment fluid Example 1

^* bwoP = Pumice weight ratio

^*軽石重量に対して０．１％の分散剤を添加 Samples were aged at room temperature, following the procedure described in API RP Practice 10B-2, Recommended Practice for Testing Well Comments, Fan Yield Stress Adapter (FYSA) and Rheological measurements were performed with a Model 35A Fan Viscometer equipped with one spring. Since aging was performed using the Herschel-Bulkley fluid model as described above, the measurements were used to calculate the shear thinning index (n) of the sample. The results of this test are shown in Table 2 below.
Table 2
Shear thinning index of fluid loss treatment fluid Example 1

^* 0.1% dispersant added to pumice weight

In addition, three separate samples were removed and each sample was subjected to additional test parameters, addition of cement hardening activator or increased temperature. These test results are shown in Table 3.
Table 3
Shear thinning index of fluid loss treatment fluid Example 1

  This result indicates that the mud treatment fluid sample exhibits a thinning behavior over 12 days. Furthermore, the samples remain shear thinning in the presence of cement hardening activators and even at high temperatures.

表５
逸泥処置流体実施例１の圧縮強度（ＣＳ）値（ｐｓｉ）

Three different cement hardening activators were tested to divide the original sample into three parts and measure compressive strength. The three different cement hardening activators were sodium hexametaphosphate-1 (SHMP-1), sodium hexametaphosphate-2 (SHMP-2), and a 10% calcium chloride solution. Table 4 below shows the formulation of the SHMP activator. The sample was then poured into a 2 inch × 4 inch plastic cylinder and cured in a 140 ° F. water bath for 24 hours. After the sample was cured, the sample was pulverized using a mechanical press, and the fracture compression strength was measured according to the procedure described in API RP Practice 10B-2, Recommended Practice for Testing Well Elements. The results are shown in Table 5 below.
Table 4
SHMP cement hardening activator formulation

Table 5
Compressive strength (CS) value (psi) of fluid loss treatment fluid Example 1

  This result may indicate that the mud treatment fluid sample exhibits good compressive strength values, especially with SHMP cement hardening activators, and thus may serve the purpose of supporting well structures in addition to stopping mud. Indicates.

^*ｂｗｏＰ＝対軽石重量比 A mud treatment fluid sample containing a set retarding cement composition was prepared. The sample consisted of pumice (DS-325 lightweight aggregate), slaked lime, Micro Matrix® cement inhibitor, and water. The composition structure of the sample is shown in Table 6 below:
Table 6
Composition structure of fluid loss treatment fluid Example 2

^* bwoP = Pumice weight ratio

Samples were aged at room temperature, following the procedure described in API RP Practice 10B-2, Recommended Practice for Testing Well Comments, Fan Yield Stress Adapter (FYSA) and Rheological measurements were performed with a Model 35A Fan Viscometer equipped with one spring. Since aging was performed using the Herschel-Bulkley fluid model as described above, the measurements were used to calculate the shear thinning index (n) of the sample. The results of this test are shown in Table 7 below.
Table 7
Shear thinning index of fluid loss treatment fluid example 2

In addition, three separate samples were removed and each sample was subjected to additional test parameters, addition of cement hardening activator or increased temperature. These test results are shown in Table 8.
Table 8
Shear thinning index of fluid loss treatment fluid example 2

  This result shows that the mud treatment fluid sample exhibits a thinning behavior over 21 days. Furthermore, the samples remain shear thinning in the presence of cement hardening activators and even at high temperatures.

^*ｂｗｏＰ＝対軽石重量比 Samples were then aged for 35 days and CaCl ₂ or SHMP / NaSO ₄ cement hardening activators were introduced. A portion of the sample was sampled periodically and their compressive strength was measured. The sample was then poured into a 2 inch × 4 inch brass cylinder and cured in a 134 ° F. water bath for 24 hours. After the sample was cured, the sample was pulverized using a mechanical press, and the fracture compression strength was measured according to the procedure described in API RP Practice 10B-2, Recommended Practice for Testing Well Elements. The results are shown in Table 9 below.
Table 9
Compressive strength value (psi) of fluid loss treatment fluid Example 2

^* bwoP = Pumice weight ratio

This result may serve the purpose of supporting a well structure in addition to stopping the mud, especially when the mud treatment fluid sample exhibits a good compressive strength value, especially with SHMP / NaSO ₄ cement hardening activator. Indicates that it cannot.

^*ｂｗｏＰ＝対軽石重量比、^**Ａｌ₂（ＳＯ₄）₃は、実験的サンプルのみに添加 Two types of sludge treatment fluid samples were prepared containing a retarded cement composition. The sample consisted of pumice (DS-325 lightweight aggregate), slaked lime, Micro Matrix® cement inhibitor, and water. For experimental samples, 33% aluminum sulfate solution was added. The control sample did not contain any aluminum sulfate solution. The composition structure of the sample is shown in Table 10 below:
Table 10
Composition structure of fluid loss treatment fluid Example 3

^* bwoP = weight ratio of pumice, ^** Al ₂ (SO ₄ ) ₃ added to experimental samples only

The sample was aged for 72 hours at room temperature. Rheology measurements were performed according to the procedures described in API RP Practice 10B-2, Recommended Practice for Testing Well Comments, Fann Yield Stress Adapter (FYSA) and Made with a Model 35A Fan Viscometer equipped with one spring. The results are shown in Table 11 below.
Table 11
Rheological measurement

Since the sample was aged using the Herschel-Bulkley fluid model, this measurement was used to calculate the shear thinning index (n) of the sample. The results of this test are shown in Table 12 below.
Table 12
Shear thinning index of Example 3

  These results indicate that the aluminate solution greatly increases the time period during which the fluid exhibits shear thinning behavior.

  Here, the compositions and methods are described in terms of various elements or steps “consisting”, “containing” or “including”, the compositions and methods also It should be understood that it may or may “consist of” various elements or steps. Furthermore, the indefinite article “a” or “an” as used in the claims is defined herein to mean one or more of the elements from which it is derived.

  For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit can be combined with any upper limit to enumerate ranges not explicitly listed, and ranges from any lower limit can be combined with any other lower limit to range not explicitly listed. Similarly, ranges from any upper limit can be combined with any other upper limit to enumerate ranges not explicitly listed. In addition, whenever a numerical range with a lower limit and an upper limit is disclosed, any number and range falling within the range is disclosed in detail. In particular, all ranges of numerical values disclosed herein (in the form “about a to about b”, or similarly, “approximately a to b”, or similarly “approximately from a to b”) are: It is understood that any number and range falling within the broader range of values is described, even if not explicitly detailed. Thus, every point or individual value may be used in combination with any other point or individual value, or any other lower or upper limit, and as its own lower or upper limit, and is not explicitly detailed. Is enumerated.

Thus, the present invention is well suited to achieving the original and described objectives and benefits. Since the present invention can be modified and can be practiced in different but equivalent ways apparent to those skilled in the art sharing the advantages of the teachings herein, the embodiments disclosed above are The invention is merely illustrative. Although specific embodiments are contemplated, the present invention covers all combinations of all these embodiments. Further, the details of the configuration or the design shown here are not limited except those described in the claims. Also, unless explicitly and clearly defined by the patent owner, the terms of the claims have their clear ordinary meaning. It is therefore evident that the particular embodiments described above may be altered or modified and all such variations are considered within the scope and spirit of the invention. If there is any discrepancy in the usage of a word or term in this specification and in one or more patents or other documents incorporated herein by reference, the definition consistent with this specification is used. Should be adopted.
Preferred embodiments of the present invention are as follows.
[1] A method for sealing a mud zone, comprising the following steps:
Circulating a mud treatment fluid in the well, wherein the mud treatment fluid comprises pumice, slaked lime, a set inhibitor and water; and
A step of condensing the mud treatment fluid in the mud zone to seal the mud zone;
Said method.
[2] The method according to [1], wherein the shear mud treatment fluid has a shear thinning index calculated by a Herschel-Bulkley model of less than 1.
[3] The method according to [1], wherein the sludge treatment fluid further contains aluminum sulfate.
[4] The setting inhibitor is a phosphonic acid, a phosphonic acid derivative, a lignosulfonate, a salt, an organic acid, a carboxymethylated hydroxyethylated cellulose, a sulfonate and a synthetic copolymer or terpolymer containing a carboxylic acid group, boron The method according to [1] above, comprising at least one inhibitor selected from the group consisting of acid salt compounds and any mixtures thereof.
[5] The said mud treatment fluid further comprises a dispersant selected from the group consisting of a sulfonated formaldehyde-based dispersant, a polycarboxylated ether dispersant, and any combination thereof. the method of.
[6] The method according to [1], wherein the setting inhibitor includes a phosphonic acid derivative, and the setting retarded cement composition further includes a polycarboxylated ether dispersant.
[7] The method according to [1], further comprising the step of storing the fluid loss treatment fluid for at least about 7 days before the step of circulating the fluid loss treatment fluid.
[8] The fluid loss treatment fluid further includes a cement hardening activator, and the cement hardening activator is calcium chloride, triethanolamine, sodium silicate, zinc formate, calcium acetate, sodium hydroxide, sodium sulfate, nano silica. The method according to [1] above, comprising at least one cement hardening activator selected from the group consisting of sodium hexametaphosphate, and any combination thereof.
[9] The above-mentioned [1], wherein the mud treatment fluid is circulated in the well while at least one other treatment fluid comprising the drilling fluid, the replacement fluid, and the finishing fluid is present in the well. the method of.
[10] The method according to [1], wherein the sludge treatment fluid is circulated in the well while the drill string is disposed in the well.
[11] The said mud treatment fluid has a density in the range of about 0.96 g / cm ³ to about 2.04 g / cm ³ (about 8 lb / gal to about 17 lb / gal). Method.
[12] A mud treatment fluid containing pumice, slaked lime, a setting inhibitor and water.
[13] The fluid according to [12], wherein the shear mud treatment fluid has a shear thinning index calculated by a Herschel-Bulkley model of less than 1.
[14] The fluid according to [12], further including aluminum sulfate.
[15] The setting inhibitor includes a phosphonic acid, a phosphonic acid derivative, a lignosulfonate, a salt, an organic acid, a carboxymethylated hydroxyethylated cellulose, a sulfonate and a synthetic copolymer or terpolymer containing a carboxylic acid group, boron The fluid according to [12] above, comprising at least one inhibitor selected from the group consisting of acid salt compounds and any mixtures thereof.
[16] The fluid according to [12], further comprising a dispersant selected from the group consisting of a sulfonated formaldehyde-based dispersant, a polycarboxylated ether dispersant, and any combination thereof.
[17] The fluid according to [12], wherein the setting inhibitor includes a phosphonic acid derivative, and the setting retarded cement composition further includes a polycarboxylated ether dispersant.
[18] a cement hardening activator, wherein the cement hardening activator is calcium chloride, triethanolamine, sodium silicate, zinc formate, calcium acetate, sodium hydroxide, sodium sulfate, nanosilica, sodium hexametaphosphate, and The fluid according to [12] above, comprising at least one cement hardening activator selected from the group consisting of any combination of:
[19] A system for sealing a mud zone in an underground layer,
A mud treatment fluid for placement in the mud zone, including water, pumice, slaked lime, and a set inhibitor
A mixing device capable of mixing the fluid loss treatment fluid, and
A pumping device capable of pumping the mud treatment fluid into the mud zone;
Including the system.
[20] The system according to [19], further including a drill string disposed in a well that penetrates the underground layer.

Claims (17)

A method for sealing the mud zone, comprising the following steps:
Circulating a mud treatment fluid in a well, wherein the mud treatment fluid comprises pumice, slaked lime, a set inhibitor and water;
The step of sealing the lost circulation zone the lost circulation treatment fluid is condensed in lost circulation zone, and
Storing the fugitive treatment fluid for at least one day prior to circulating the mudging fluid;
Said method.   The method according to claim 1, wherein the sludge treatment fluid has a shear thinning index calculated by a Herschel-Bulkley model of less than one.   The method of claim 1, wherein the mud treatment fluid further comprises aluminum sulfate.   The coagulation inhibitor is a phosphonic acid, phosphonic acid derivative, lignosulfonate, salt, organic acid, carboxymethylated hydroxyethylated cellulose, sulfonate and carboxylic acid group-containing synthetic copolymer or terpolymer, borate compound And at least one inhibitor selected from the group consisting of any mixture thereof.   The method of claim 1, wherein the mud treatment fluid further comprises a dispersant selected from the group consisting of sulfonated formaldehyde-based dispersants, polycarboxylated ether dispersants, and any combination thereof.   The method of claim 1, wherein the setting inhibitor comprises a phosphonic acid derivative and the setting retarded cement composition further comprises a polycarboxylated ether dispersant. The method of claim 1, further comprising storing the sludge treatment fluid for at least 7 days prior to circulating the sludge treatment fluid.   The fluid treatment fluid further includes a cement hardening activator, and the cement hardening activator is calcium chloride, triethanolamine, sodium silicate, zinc formate, calcium acetate, sodium hydroxide, sodium sulfate, nano silica, hexametaphosphoric acid. The method of claim 1, comprising at least one cement hardening activator selected from the group consisting of sodium and any combination thereof.   The method of claim 1, wherein the sludge treatment fluid is circulated through the well while at least one other treatment fluid comprising a drilling fluid, a replacement fluid, and a finishing fluid is present in the well.   The method of claim 1, wherein the sludge treatment fluid is circulated through the well while a drill string is disposed in the well. The mud treatment fluid is: 0 . 96g / cm ³ ~ 2. Having a density in the range of ^{04g / cm 3 (8 lb /} gal~ 1 7lb / gal), The method of claim 1. A mud treatment fluid comprising an anti-caking agent comprising pumice, slaked lime, a phosphonic acid derivative , a polycarboxylated ether dispersant and water.   The fluid according to claim 12, wherein the shear mud treatment fluid has a shear thinning index calculated by a Herschel-Bulkley model of less than one.   The fluid of claim 12, further comprising aluminum sulfate.   A cement hardening activator, wherein the cement hardening activator is calcium chloride, triethanolamine, sodium silicate, zinc formate, calcium acetate, sodium hydroxide, sodium sulfate, nanosilica, sodium hexametaphosphate, and any of them The fluid of claim 12 comprising at least one cement hardening activator selected from the group consisting of combinations. A system for enclosing a mud zone in the underground layer,
A mud treatment fluid for placement in a mud zone comprising water, pumice, slaked lime , an anti-caking agent comprising a phosphonic acid derivative and a polycarboxylated ether dispersant ,
A mixing device capable of mixing the fluid loss treatment fluid, and a pumping device capable of pumping the fluid loss treatment fluid to the fluid loss zone,
Including the system. The system of claim 16 , further comprising a drill string disposed in a well bore through the underground layer.

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