# Patent

## Title
Methods and compositions of treating subterranean formations with a novel resin system

## Abstract

Methods of treating a wellbore in a subterranean formation including providing an aqueous treatment fluid comprising a liquid resin agent, wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein the multifunctional electrophilic compound comprises least two electrophilic reactive groups; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and, curing the liquid resin agent.

## Background
BACKGROUND
The present invention relates to methods and compositions of treating subterranean formations with a novel resin system.
Subterranean wells are often stimulated by hydraulic fracturing treatments. In hydraulic fracturing treatments, a viscous treatment fluid is pumped into a portion of a subterranean formation at a rate and pressure such that the subterranean formation breaks down and one or more fractures are formed. While the treatment fluid used to initiate the fracture is generally solids-free, typically, particulate solids, such as graded sand, are introduced in a later portion of the treatment fluid and then deposited into the fracture. These particulate solids, (generally known as “proppant particulates” or, simply, “proppant”) serve to prop the fracture open (e.g., keep the fracture from fully closing) after the hydraulic pressure is removed. By keeping the fracture from fully closing, the proppants aid in forming conductive paths through which produced fluids, such as hydrocarbons, may flow.
Hydraulic fracturing of subterranean wells is often performed in formations that contain unconsolidated particulates. The unconsolidated particulates may migrate out of the subterranean formation and be produced with production fluids. The presence of unconsolidated particulates in a formation during production is undesirable because they may damage or abrade producing equipment or reduce well production. For example, unconsolidated particulates may migrate into wellbore casings, perforations, or the interstitial spaces between packed proppants within a fracture and clog or hinder well production. As used herein, the term “unconsolidated particulates” refers to any loose or loosely bonded particulates that may move through the formation with production fluids. Unconsolidated particulates may include, for example, sand, gravel, proppant particulates, and/or formation fines.
One method of controlling unconsolidated particulates in hydraulic fractured subterranean formations is to perform a gravel-packing treatment. In gravel-packing treatments, particulates are deposited into unconsolidated or weakly consolidated formation zones to create a physical barrier to the transport of unconsolidated particulates with the produced fluids. Typical gravel-packing treatments include placing a screen in a wellbore and packing the annulus between the screen and the wellbore with particulates of a certain size to prevent the transport of unconsolidated particulates with the produced fluids without compromising the conductivity of the well. Gravel-packing treatments, however, involve placement of additional unconsolidated particulates into the wellbore which may not be adequately maintained, for example, by a screen and which may, therefore, migrate along with the produced fluids, thus, contributing to the problem the gravel-packing treatment was attempting to solve.
Another method of controlling unconsolidated particulates is to treat the wellbore with a consolidating agent. In such treatments, a consolidating agent is placed into the wellbore in order to stabilize unconsolidated particulates, such as by providing a tacky substrate for unconsolidated particulates to adhere or by contacting unconsolidated particulates and curing into a hardened mass. As used herein, the term “tacky,” in all its forms, refers to a substance that is at least somewhat sticky to the touch. Typically, the consolidating agent may be used to lock unconsolidated particulates in place and form at least a partially immobilized substance, which may be accomplished by enhancing grain-to-grain or grain-to-formation contact of the unconsolidated particulates.
The present invention provides a novel system for treating unconsolidated particulates that is capable of hardening to lock the particulates into place and that may additionally possess non-hardening qualities such that it provides a partial tacky substrate for further control of the particulates.
SUMMARY OF THE INVENTION
The present invention relates to methods and compositions of treating subterranean formations with a novel resin system.
In some embodiments, the present invention provides a method of treating a wellbore in a subterranean formation comprising: providing an aqueous treatment fluid comprising a liquid resin agent, wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein the multifunctional electrophilic compound comprises at least two electrophilic reactive groups; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and, curing the liquid resin agent.
In other embodiments, the present invention provides a method of treating a wellbore in a subterranean formation comprising: providing an aqueous treatment fluid comprising proppant particulates coated with a liquid resin agent, wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein the multifunctional electrophilic compound comprises at least two electrophilic reactive groups; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and curing the liquid resin agent.
In still other embodiments, the present invention provides a method of treating a wellbore in a subterranean formation comprising: providing a first portion and a second portion of a liquid resin agent, wherein the first portion comprises a multifunctional electrophilic compound comprising at least two electrophilic reactive groups, wherein the second portion comprises a nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein a complete liquid resin agent is formed by a reaction of the first portion and the second portion; providing a pad fluid comprising either the first portion or the second portion of the liquid resin agent; providing an aqueous treatment fluid comprising proppant particulates and the portion of the liquid resin agent not in the pad fluid, wherein, when the first portion is in the pad fluid, the proppant particulates are coated with the second portion and when the second portion of the is in the pad fluid, the proppant particulates are coated with the first portion; introducing the pad fluid into the wellbore in the subterranean formation; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; reacting the first portion and the second portion of the liquid resin agent so as to form the complete liquid resin agent; and curing the liquid resin agent.
The features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the description of the preferred embodiments that follows.


DETAILED DESCRIPTION
The present invention relates to methods and compositions of treating subterranean formations with a novel resin system.
In some embodiments, the present invention provides methods of treating a wellbore in a subterranean formation with an aqueous treatment fluid comprising a liquid resin agent. The liquid resin agent is comprised of the reaction product of a multifunctional electrophilic compound having at least two electrophilic reactive groups and at least one nucleophilic compound selected from the group consisting of a dimmer acid; a dimmer amine; and any combination thereof. The aqueous treatment fluid is then introduced into the wellbore and the liquid resin agent is cured. In some embodiments, the aqueous treatment fluid may further comprise proppant particulates that, in some embodiments, may be coated with the liquid resin agent.
In those embodiments in which proppant particulates are coated with the liquid resin agent of the present invention, the methods disclosed herein provide the advantage of permitting either dry-coating or wet-coating of the liquid resin agent onto the proppant particulates. The proppant particulates may be wet-coated directly in a blender tub or via the suction side of a discharge pump. In other embodiments, the liquid resin agent may be dry coated onto the proppant particulates via a sand screw. A combination of dry-coating and wet-coating may also be employed. For example, in some embodiments, the multifunctional electrophilic compound may be dry-coated onto the proppant particulates using a sand screw and the nucleophilic compound may be wet-coated thereupon using via the suction side of a discharge pump. Additionally, the methods of the present invention may be used to coat the proppant particulates with the liquid resin agent of the present invention on-the-fly at the wellbore site. As used herein, the term “on-the-fly” refers to performing an operation during a subterranean treatment that does not require stopping normal operations.
The methods of the present invention may be used in any subterranean formation operation that may benefit from the use of a resin system. Such operations may include, but are not limited to, well completions (e.g., hydraulic fracturing, gravel packing, and frac-packing operations); remedial proppant or gravel treatments; near-wellbore formation sand consolidation treatments; consolidation-while-drilling target interval operations; plug-and-abandonment operations, and the like. One of ordinary skill in the art, with the benefit of this disclosure, will recognize whether the liquid resin agent of the present invention will be suitable in a particular subterranean operation.
As used herein, the term “multifunctional” refers to a molecule or compound carrying at least two different reactive groups. As used herein, the term “multifunctional electrophilic compound” refers to a molecule or compound carrying at least two different reactive electrophilic groups capable of reacting with at least one nucleophilic group or compound. As used herein, the term “electrophilic group” or “electrophilic compound” refers to chemical species (e.g., atoms, molecules, ions, etc.) that behave as electron acceptors. As used herein the term, “nucleophilic group” or “nucleophilic compound” refers to chemical species (e.g., atoms, molecules, ions, etc.) that behave as electron donors.
An advantage of the use of multifunctional electrophilic compounds in the methods of the present invention is that they are capable of reacting with the nucleophilic compounds of the present invention to provide a resin system. Additionally, because the multifunctional electrophilic compounds have at least two electrophilic groups, the amount of nucleophilic compound required to react with the multifunctional electrophilic compounds of the present invention may be greatly reduced in the methods disclosed herein. Moreover, because of their multiple electrophilic reaction sites, the likelihood that a reaction will occur between the multifunctional electrophilic compounds and the nucleophilic compounds of the present invention is greatly enhanced.
The multifunctional electrophilic compounds of the present invention serve as substrate-anchoring agents. That is, the multifunctional electrophilic agent is capable of adhering to a substrate such as, for example, on the surface of a fracture face in a subterranean formation or on proppant particulates. The ability of the multifunctional electrophilic compounds of the present invention to anchor onto a substrate permits effective wet-coating of the liquid resin agents of the present invention onto the formation or proppant particulates. Additionally, the multifunctional electrophilic compounds of the present invention serve to impart a hardening consolidating agent qualities to the liquid resin agents of the present invention. Suitable multifunctional electrophilic compounds for use in the present invention may include, but are not limited to, a polyepoxide; an epoxy containing alkoxysilane; and any combination thereof. Suitable polyepoxides for use as the multifunctional electrophilic compounds of the present invention may include, but are not limited to, a bisphenol A diglycidyl ether; a bisphenol A-epichlorohydrin; a bisphenol F; novolak; a tetrabromobisphenol A; an aliphatic diepoxide (e.g., 1,4-di(oxiran-2-yl)butane); and any combination thereof. A suitable commercially available polyepoxide for use as the multifunctional electrophilic compounds of the present invention includes, but is not limited to, Expedite® 225, Part A available from Halliburton Energy Services, Inc. in Houston, Tex.
Suitable alkoxysilanes for use as the multifunctional compounds of the present invention are preferably epoxy containing and may be derived from the formula: RnR′mSiX(4−n−m), where R′ is a nonhydrolyzable organic group functionalized with an epoxy end group, R is a nonhydrolyzable organic group, X is a hydrolyzable group, and n and m are integers typically between about 1 to about 4. The nonhydrolyzable organic group R may include, but is not limited to, an alkyl moiety; an ethyl moiety; a methyl moiety; a propyl moiety; a butyl moiety; a hexyl moiety; an octyl moiety; a benzyl moiety; a cyclohexyl moiety; and any combination thereof. The hydrolyzable group X may include, but is not limited to, an alkoxy moiety; a methoxy moiety; an ethoxy moiety; an acyloxy moiety; an amine moiety; a hydroxyl moiety; a halo moiety; an acetoxy moiety; a propoxy moiety; a butoxy moiety; a phenoxy moiety; a chloride moiety; a bromide moiety; an iodide moiety; a pentoxy moiety; and any combination thereof.
Suitable examples of an epoxy containing alkoxysilane multifunctional electrophilic compound that may be used in the methods of the present invention include, but are not limited to, glycidoxysilanes (e.g, (3-glycidoxypropyl)triethoxysilane).
The nonhydrolyzable group R′, which is preferably functionalized with an epoxy end group, of the alkoxysilane for use as the multifunctional compound reacts with the nucleophilic compounds of the present invention to form the liquid resin agents disclosed herein. Suitable nucleophilic compounds for use in the present invention include, but are not limited to, a dimer acid (also referred to as a dimerized fatty acid); a dimer amine; any derivative thereof; and any combination thereof. The dimer amines suitable for use in the present invention may include, but are not limited to, dimer amines; dimer diamines; and dimer triamines. The term “derivative” is defined herein any compound that is made from one of the listed compounds, for example, by replacing one atom in one of the listed compounds with another atom or group of atoms, ionizing one of the listed compounds, or creating a salt of one of the listed compounds.
The multiple reactive sites on the multifunctional electrophilic compounds of the present invention may permit interaction with more than one nucleophilic compound. Similarly, the nucleophilic compounds of the present invention may react with more than one multifunctional electrophilic compound. For example, in some embodiments the liquid resin agent of the present invention may be formed by the reaction product of a multifunctional electrophilic compound, (3-glycidoxypropyl)triethoxysilane, and a nucleophilic compound, dimer acid. The resulting compound comprises a free carboxy acid group that may react with a second multifunctional electrophilic compound, followed by a condensation polymerization reaction to make a crosslinked product forming the liquid resin agent of the present invention. In another example, in some embodiments the liquid resin agent of the present invention may be formed by the reaction product of a multifunctional electrophilic compound, (3-glycidoxypropyl)triethoxysilane, and a nucleophilic compound, dimer diamine. The resulting compound comprises a free amine group that may react with a second multifunctional electrophilic compound, followed by a condensation polymerization reaction to make a crosslinked product forming the liquid resin agent of the present invention.
The liquid resin agent of the present invention exhibits enhanced compressive strength, as well as elasticity, when compared to conventional resin systems. Moreover, the liquid resin agent of the present invention may exhibit the qualities of a non-hardening consolidating agent; a hardening consolidating agent; or a combination thereof. As used herein, the term “non-hardening consolidating agent” refers to a substance that is somewhat tacky (or may be activated to become so). As used herein, the term “hardening consolidating agent” refers to a substance that is not tacky after curing. The tacky nature of the non-hardening consolidating agent may enhance grain-to-grain or grain-to-formation contact of the unconsolidated particulates. Hardening consolidating agents may form a cohesive, flexible, and potentially permeable mass that immobilizes unconsolidated particulates. The multifunctional electrophilic compound of the liquid resin agent of the present invention may impart hardening consolidating agent qualities to the liquid resin agent and the nucleophilic compound may impart non-hardening consolidating agent qualities to the liquid resin agent. Therefore, by adjusting the ratio of multifunctional electrophilic compound to nucleophilic compound to form the liquid resin agent of the present invention, the prominence of either of consolidating qualities or tackifying qualities may be manipulated.
In some embodiments, the ratio of the multifunctional electrophilic compound to the nucleophilic compound forming the liquid resin agent is about 1 to greater than about 6 ( ̃1:≧ ̃6), such that the liquid resin agent is capable of acting primarily as a non-hardening consolidating agent. In some embodiments, the ratio of the multifunctional electrophilic compound to the nucleophilic compound forming the liquid resin agent is greater than about 3 to about 1 (≧ ̃3: ̃1), such that the liquid resin agent is capable of acting primarily as a hardening consolidating agent. In other embodiments, ratios therebetween, in the range of between less than about 2 to about 1 to less than about 2 to less than about 10 (≦ ̃2:1 to ≦ ̃2:10), allow the liquid resin agent to behave as both a hardening consolidating agent and a non-hardening consolidating agent. One with ordinary skill in the art, with the benefit of this disclosure, will understand whether the liquid resin agent should possess predominantly hardening or non-hardening consolidating agent qualities or a combination thereof depending on the particulate application.
In some embodiments, the multifunctional electrophilic compounds of the present invention may be reacted with the nucleophilic compounds of the present invention in situ in the wellbore. In those embodiments, the present invention provides a method of treating a wellbore in a subterranean formation comprising providing a first portion and a second portion of a liquid resin agent. The first portion comprises a multifunctional electrophilic compound comprising at least the electrophilic reactive groups and the second portion comprises a nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof. A complete liquid resin agent is formed by reacting the first portion and the second portion. A pad fluid is provided comprising the either the first or second portion of the liquid, and an aqueous treatment fluid is provided comprising proppant particulates and the portion of the liquid resin agent not in the pad fluid. When the first portion is in the pad fluid, the proppant particulates are coated with the second portion and when the second portion is in the pad fluid, the proppant particulates are coated with the first portion. In any order, the pad fluid is introduced into the wellbore and the aqueous treatment fluid is introduced into the subterranean formation. In preferred embodiments, the pad fluid is introduced into the subterranean formation prior to introducing the aqueous treatment fluid, such as to, for example, fracture the subterranean formation. The two portions of the liquid resin agent come into contact with one another in situ and react to form the complete liquid resin agent, which is thereafter cured. In some embodiments, the first portion of the liquid resin agent is the pad fluid and the second portion of the liquid resin agent is in the aqueous treatment fluid. In other embodiments, the first portion of the liquid resin agent is in the aqueous treatment fluid and the second portion of the liquid resin agent is in the pad fluid.
In some embodiments, the liquid resin agent of the present invention may further comprise an accelerator; silane coupling agent; a surfactant; a solvent; a hydrolyzable ester; and any combination thereof. The accelerator may increase the cure kinetic of the liquid resin agent, particularly in low temperature environments. Suitable accelerators for use in the methods of the present invention may include, but are not limited to, an organic amine; an inorganic base; and any combination thereof. Suitable organic amines for use as an accelerator in the methods of the present invention may include, but are not limited to, a pyridine; an isoquinoline; a quinoline; a N,N-dimethylcyclohexylamine; a tributylamine; a tripropylamine; a N-ethylmorpholine; a dimethylaniline; a triethylamine; and any combination thereof. Suitable inorganic bases for use as an accelerator in the methods of the present invention may include, but are not limited to, potassium hydroxide; sodium hydroxide; ammonium hydroxide; and any combination thereof. In some embodiments, the accelerator may be present in the liquid resin agent in an amount from about 0.1% to about 5% by weight of the combined multifunctional electrophilic compound and nucleophilic compound, and preferably in an amount from about 1% to about 3% by weight of the combined multifunctional electrophilic compound and nucleophilic compound.
A curing agent may be included in the liquid resin agent of the present invention in order to facilitate curing of the liquid resin agent (i.e., by decreasing curing time). Suitable curing agents may include polyacids including, but not limited to, C36 dibasic acids; dimer acids; trimer acids; synthetic acids produced from fatty acids; maleic anydrides; acrylic acids; and any combination thereof. In some embodiments of the present invention, the curing agent used is included in the liquid resin agent in the range of about 0.1% to about 95% by weight of the combined multifunctional electrophilic compound and nucleophilic compound. In other embodiments, the curing agent used may be included in the liquid resin agent in an amount of about 15% to about 85% by weight of the combined multifunctional electrophilic compound and nucleophilic compound. In still other embodiments, the curing agent used may be included in the liquid resin agent in an amount of about 15% to about 55% by weight of the combined multifunctional electrophilic compound and nucleophilic compound.
In some embodiments, the curing agent of the present invention may be coated onto proppant particulates and then introduced to the liquid resin agent. This may facilitate curing of the liquid resin agent onto the proppant particulates. In other embodiments, the curing agent of the present invention may be coated onto the proppant particulates and then further encapsulated with a degradable coating (e.g., a degradable polymer that degrades downhole) that delays the interaction of the liquid resin agent and the curing agent until a desired time or place within the wellbore.
The optional silane-coupling agent for use in the liquid resin agent of the present invention may be used, among other things, to act as a mediator to help bond the liquid resin agent to a substrate, such as the surface of a wellbore in a subterranean formation or proppant particulates. Suitable silane coupling agents for use in the methods of the present invention include, but are not limited to, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane; 3-glycidoxypropyltrimethoxysolane; n-beta-(aminoethyl)-gamma-aminopropyl trimethoxysilane; and any combination thereof. The silane coupling agent may be included in the liquid resin agent of the present invention according to the chemistry of the particular group as determined by one skilled in the art with the benefit of this disclosure. In some embodiments of the present invention, the silane-coupling agent used is included in the liquid resin agent in the range of about 0.1% to about 3% by weight of the combined multifunctional electrophilic compound and nucleophilic compound.
A surfactant may further be used in the liquid resin agent of the present invention to facilitate coating of the liquid resin agent onto a suitable substrate. Any surfactant compatible with the multifunctional electrophilic compound and the nucleophilic compound of the present invention may be used. Suitable surfactants include, but are not limited to an alkyl phosphonate surfactant (e.g., a C12-C22 alkyl phosphonate surfactant); an ethoxylated nonyl phenol phosphate ester; one or more cationic surfactants; and one or more nonionic surfactants; and any combination thereof. The surfactant or surfactants that may be used in the liquid resin agent may be present in an amount in the range of about 1% to about 10% by weight of the combined multifunctional electrophilic compound and nucleophilic compound.
In some embodiments, a silane coupling agent and a surfactant of the present invention may be used to facilitate coating of the liquid resin agent onto a suitable substrate. In other embodiments, only one of the silane coupling agent or the surfactant are included in the liquid resin agent. One of ordinary skill in the art, with the benefit of this disclosure, will understand whether one or both of the silane coupling agent and surfactant will be of use in a particular application.
An optional solvent may be included in the liquid resin agent to reduce the viscosity of the liquid resin agent (i.e., to enhance the pumpability of the liquid resin agent through subterranean formation operational equipment). Suitable solvents include, but are not limited to, butyl lactate; butylglycidyl ether; dipropylene glycol methyl ether; dipropylene glycol dimethyl ether; dimethyl formamide; diethylene glycol methyl ether; ethyleneglycol butyl ether; diethylene glycol butyl ether; propylene carbonate; methanol; butyl alcohol; d'limonene; fatty acid methyl esters; isopropanol; 2-butyoxy ethanol; an ether of a C2 to C6 dihydric alkanol containing at least one C1 to C6 alkyl group; a monoether of dihydric alkanol; methoxypropanol; butoxyethanol; hexoxyethanol; any isomer thereof; and any combination thereof. In some embodiments, those solvents having high flash points of above about 125° F. are preferred. It is within the ability of one skilled in the art, with the benefit of this disclosure, to determine if and how much solvent is needed to achieve a suitable viscosity. In some embodiments, the amount of the solvent used in the liquid resin agent may be in the range of about 0.1% to about 30% by weight of the combined multifunctional electrophilic compound and nucleophilic compound.
A hydrolyzable ester may be included in the present invention to further reduce the viscosity of the liquid resin agent. Suitable examples of hydrolyzable esters that may be used in the liquid resin agent of the present invention include, but are not limited to, dimethylglutarate; dimethyladipate; dimethylsuccinate; sorbitol; catechol; dimethylthiolate; methyl salicylate; dimethyl salicylate; dimethylsuccinate; ter-butylhydroperoxide; butyl lactate; and any combination thereof. When used, a hydrolyzable ester is included in the liquid resin agent in an amount in the range of about 0.1% to about 3% by weight of the combined multifunctional electrophilic compound and nucleophilic compound. In some embodiments, a hydrolyzable ester is included in the liquid hardening agent component in an amount in the range of about 1% to about 2.5% by weight of the combined multifunctional electrophilic compound and nucleophilic compound.
In some embodiments, a solvent and a hydrolyzable ester of the present invention may be used to control the viscosity of the liquid resin agent of the present invention. In other embodiments, only one of the solvent or the hydrolyzable ester are included in the liquid resin agent. One of ordinary skill in the art, with the benefit of this disclosure, will understand whether one or both of the solvent or the hydrolyzable ester will be of use in a particular application. Optionally, the liquid resin agent may be heated to reduce its viscosity, in place of, or in addition to, using a solvent and/or a hydrolyzable ester.
The aqueous treatment fluid and pad fluid of the present invention (collectively referred to herein as “fluids”) may be comprised on an aqueous base fluid; an aqueous-miscible base fluid; and any combination thereof. Suitable aqueous base fluids for use in the fluids of the present invention may include, but are not limited to, fresh water; saltwater (e.g., water containing one or more salts dissolved therein); brine (e.g., saturated salt water); seawater; and any combination thereof. Generally, the water may be from any source, provided that it does not contain components that might adversely affect the stability and/or performance of the fluids of the present invention. Suitable aqueous-miscible base fluids for use in the fluids of the present invention may include, but are not limited to, aqueous base fluids suitable for use in conjunction with the fluids described herein may include, but are not limited to, aqueous fluid, aqueous-miscible fluids, and any combination thereof. Aqueous fluids may, in some embodiments, include, but are not limited to, fresh water, saltwater (e.g., water containing one or more salts dissolved therein), brine (e.g., saturated salt water), seawater, and any combination thereof. Suitable aqueous-miscible fluids may, in some embodiments, include, but not be limited to, alcohols (e.g., methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, and t-butanol); glycerins; glycols (e.g., polyglycols, propylene glycol, and ethylene glycol); polyglycol amines; polyols; any in combination with salts (e.g., sodium chloride, calcium chloride, calcium bromide, zinc bromide, potassium carbonate, sodium formate, potassium formate, cesium formate, sodium acetate, potassium acetate, calcium acetate, ammonium acetate, ammonium chloride, ammonium bromide, sodium nitrate, potassium nitrate, ammonium nitrate, ammonium sulfate, calcium nitrate, sodium carbonate, and potassium carbonate); any in combination with an aqueous fluid described above; any derivative thereof; and any combination thereof.
In certain embodiments, the viscosity of the aqueous base fluid or aqueous-miscible base fluid can be adjusted, among other purposes, to change the viscosity of the fluid (e.g., to provide additional proppant particulate transport and suspension in the fluids used in the methods of the present invention). In these embodiments, the pH may be adjusted to a specific level, which may depend on, among other factors, the types of gelling agents, acids, and other additives included in the fluid. One of ordinary skill in the art, with the benefit of this disclosure, will recognize when such pH adjustments are appropriate. In some embodiments, the pH range may preferably be from about 4 to about 11.
In some embodiments, the fluids of the present invention may be gelled with a gelling agent, to increase the viscosity of the fluid to aid in, among other things, transporting proppant particulates or other additives in the fluids. Suitable gelling agents may comprise any substance (e.g., a polymeric material) capable of increasing the viscosity of the fluids disclosed herein. In certain embodiments, the gelling agent may comprise one or more polymers that have at least two molecules that are capable of forming a crosslink in a crosslinking reaction in the presence of a crosslinking agent, and/or polymers that have at least two molecules that are so crosslinked (i.e., a crosslinked gelling agent). The gelling agents may be naturally occurring gelling agents; synthetic gelling agents; or a combination thereof. The gelling agents also may be cationic gelling agents; anionic gelling agents; or a combination thereof. Suitable gelling agents include, but are not limited to, polysaccharides; biopolymers; and/or derivatives thereof that contain one or more of these monosaccharide units: galactose, mannose, glucoside, glucose, xylose, arabinose, fructose, glucuronic acid, or pyranosyl sulfate. Examples of suitable polysaccharides include, but are not limited to, guar gums (e.g., hydroxyethyl guar, hydroxypropyl guar, carboxymethyl guar, carboxymethylhydroxyethyl guar, and carboxymethylhydroxypropyl guar (“CMHPG”)); cellulose derivatives (e.g., hydroxyethyl cellulose, carboxyethylcellulose, carboxymethylcellulose, and carboxymethylhydroxyethylcellulose); xanthan; scleroglucan; succinoglycan; diutan; and combinations thereof. In certain embodiments, the gelling agents comprise an organic carboxylated polymer, such as CMHPG. An example of a suitable commercially available gelling agent is WG-35TM Gelling Agent, available from Halliburton Energy Services, Inc. in Houston, Tex.
Suitable synthetic polymer gelling agents include, but are not limited to, 2,2′-azobis(2,4-dimethyl valeronitrile); 2,2′-azobis(2,4-dimethyl-4-methoxy valeronitrile); polymers and copolymers of acrylamide ethyltrimethyl ammonium chloride, acrylamide, acrylamido-and methacrylamido-alkyl trialkyl ammonium salts, acrylamidomethylpropane sulfonic acid, acrylamidopropyl trimethyl ammonium chloride; acrylic acid; dimethylaminoethyl methacrylamide; dimethylaminoethyl methacrylate; dimethylaminopropyl methacrylamide; dimethyldiallylammonium chloride; dimethylethyl acrylate; fumaramide; methacrylamide; methacrylamidopropyl trimethyl ammonium chloride; methacrylamidopropyldimethyl-n-dodecylammonium chloride; methacrylamidopropyldimethyl-n-octylammonium chloride; methacrylamidopropyltrimethylammonium chloride; methacryloylalkyl trialkyl ammonium salts; methacryloylethyl trimethyl ammonium chloride; methacrylylamidopropyldimethylcetylammonium chloride; N-(3-sulfopropyl)-N-methacrylamidopropyl-N,N-dimethyl ammonium betaine; N,N-dimethylacrylamide; N-methylacrylamide; nonylphenoxypoly(ethyleneoxy)ethylmethacrylate; partially hydrolyzed polyacrylamide; poly 2-amino-2-methyl propane sulfonic acid; polyvinyl alcohol; sodium 2-acrylamido-2-methylpropane sulfonate; quaternized dimethylaminoethylacrylate; quaternized dimethylaminoethylmethacrylate; any derivatives thereof; and any combinations thereof. In certain embodiments, the gelling agent comprises an acrylannide/2-(methacryloyloxy)ethyltrimethylammonium methyl sulfate copolymer. In certain embodiments, the gelling agent may comprise an acrylannide/2-(methacryloyloxy)ethyltrimethylammonium chloride copolymer. In certain embodiments, the gelling agent may comprise a derivatized cellulose that comprises cellulose grafted with an allyl or a vinyl monomer, such as those disclosed in U.S. Pat. Nos. 4,982,793, 5,067,565, and 5,122,549, the entire disclosures of which are incorporated herein by reference. Additionally, polymers and copolymers that comprise one or more functional groups (e.g., hydroxyl, cis-hydroxyl, carboxylic acids, derivatives of carboxylic acids, sulfate, sulfonate, phosphate, phosphonate, amino, or amide groups) may be used as gelling agents.
The gelling agent may be present in the fluids useful in the methods of the present invention in an amount sufficient to provide the desired viscosity. In some embodiments, the gelling agents may be present in an amount in the range of from about 0.1% to about 10% by weight of the fluid. In other embodiments, the gelling agents may be present in an amount in the range of from about 0.15% to about 2.5% by weight of the fluid.
In those embodiments of the present invention where it is desirable to crosslink the gelling agent, the fluid may further comprise one or more crosslinking agents. The crosslinking agents may comprise a borate ion; a metal ion; or similar component that is capable of crosslinking at least two molecules of the gelling agent. Examples of suitable crosslinking agents include, but are not limited to, borate ions; magnesium ions; zirconium IV ions; titanium IV ions; aluminum ions; antimony ions; chromium ions; iron ions; copper ions; magnesium ions; and zinc ions. These ions may be provided by providing any compound that is capable of producing one or more of these ions. Examples of such compounds include, but are not limited to, ferric chloride; boric acid; disodium octaborate tetrahydrate; sodium diborate; pentaborates; ulexite; colemanite; magnesium oxide; zirconium lactate; zirconium triethanol amine; zirconium lactate triethanolamine; zirconium carbonate; zirconium acetylacetonate; zirconium malate; zirconium citrate; zirconium diisopropylamine lactate; zirconium glycolate; zirconium triethanol amine glycolate; zirconium lactate glycolate; titanium lactate; titanium malate; titanium citrate; titanium ammonium lactate; titanium triethanolamine; titanium acetylacetonate; aluminum lactate; aluminum citrate; antimony compounds; chromium compounds; iron compounds; copper compounds; zinc compounds; and any combinations thereof. In certain embodiments of the present invention, the crosslinking agent may be formulated to remain inactive until it is “activated” by, among other things, certain conditions in the fluid (e.g., pH, temperature, etc.) and/or interaction with some other substance. In some embodiments, the activation of the crosslinking agent may be delayed by encapsulation with a coating (e.g., a porous coating through which the crosslinking agent may diffuse slowly, or a degradable coating that degrades downhole) that delays the release of the crosslinking agent until a desired time or place. The choice of a particular crosslinking agent will be governed by several considerations that will be recognized by one skilled in the art, including but not limited to the type of gelling agent(s) included, the molecular weight of the gelling agent(s), the conditions in the subterranean formation being treated, the safety handling requirements, the pH of the fluid, temperature, and/or the desired delay for the crosslinking agent to crosslink the gelling agent molecules.
When included, suitable crosslinking agents may be present in the fluids useful in the methods of the present invention in an amount sufficient to provide the desired degree of crosslinking between molecules of the gelling agent(s). In certain embodiments, the crosslinking agent may be present in the fluids of the present invention in an amount in the range of from about 0.005% to about 1% by weight of the fluid. In certain embodiments, the crosslinking agent may be present in the fluids of the present invention in an amount in the range of from about 0.05% to about 1% by weight of the fluid. One of ordinary skill in the art, with the benefit of this disclosure, will recognize the appropriate amount of crosslinking agent to include in a fluid of the present invention.
In some embodiments, the fluids of the present invention (e.g., the treatment fluid and/or pad fluid) may further comprise a weighting agent. The weighting agent may aid in generating hydrostatic pressure needed to circulate fluids to the wellbore head. Suitable weighing agents may include, but are not limited to, hollow mineral glass spheres; hollow glass microspheres; cenospheres; ceramic microspheres; polymeric microspheres; plastic microspheres; silica; ilmenite; hematite; barite; cementitious material; manganese tetraoxide; and any combination thereof. In certain embodiments, the weighting agent may be present in the fluids of the present invention in an amount up to about 70% by volume of the fluid (v %) (e.g., about 5%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, etc.). In certain embodiments, the weighting agent may be present in the drilling fluid in an amount of 10 v % to about 40 v %.
Suitable proppant particulates for use in the present invention may comprise any material suitable for use in a subterranean operation and include, but are not limited to, sand; bauxite; ceramic materials; glass materials; polymer materials; polytetrafluoroethylene materials; nut shell pieces; cured resinous particulates comprising nut shell pieces; seed shell pieces; cured resinous particulates comprising seed shell pieces; fruit pit pieces; cured resinous particulates comprising fruit pit pieces; wood; composite particulates; and any combination thereof. Suitable composite particulates may comprise a binder and a filler material wherein suitable filler materials include, but is not limited to, silica; alumina; fumed carbon; carbon black; graphite; mica; titanium dioxide; meta-silicate; calcium silicate; kaolin; talc; zirconia; boron; fly ash; hollow glass microspheres; solid glass; and any combination thereof. The mean size of the proppant particulates for use in the present invention generally may range from about 2 mesh to about 400 mesh on the U.S. Sieve Series; however, in certain circumstances, other mean sizes may be desired and will be entirely suitable for practice of the present invention. In particular embodiments, the preferred mean size distribution of the proppant particulates ranges are one or more of 6/12, 8/16, 12/20, 16/30, 20/40, 30/50, 40/60, 40/70, or 50/70 mesh. It should be understood that the term “proppant particulate” or “particulate,” as used in this disclosure, includes all known shapes of materials, including substantially spherical materials; fibrous materials; polygonal materials (e.g., cubic materials); and any combination thereof. Moreover, fibrous materials may be included in certain embodiments of the present invention. In certain embodiments, the proppant particulates may be present in the treatment fluids of the present invention in an amount in the range of from about 0.5 pounds per gallon (“ppg”) to about 30 ppg by volume of the treatment fluid.
To facilitate a better understanding of the present invention, the following examples of preferred or representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the invention.
EXAMPLE 1
In this example, 0.33 g of bisphenol A diepoxy (multifunctional electrophilic compound), 2.67 g of dimer acid (nucleophilic compound), 0.1 g triethylamine (accelerator), 0.1 g SILQUEST® A-1120 (silane coupling agent), 50 g of 3% KCl (aqueous treatment fluid), and 100 g of 20/40-mesh Brady sand (proppant particulates) were added to a glass vial. The mixture was rotated continuously in the glass vial in a rolling oven for 24 hours at 93.3° C. (200° F.). Thereafter, the mixture was washed with 100 g of tap water 3 times. Next, 100 g of kerosene was added to the mixture in the glass vial, followed by vigorous shaking for approximately 3 minutes. After shaking the mixture, the kerosene was decanted and again rinsed with tap water to remove all visibly present kerosene. After removal of the kerosene, 0.5 g of coal fines were added to the mixture and the mixture was vigorously shaken for 1-2 min.
Based on visual inspection, the bisphenol A diepoxy and dimer acid were capable of reacting in the presence of a brine solution to form a liquid resin agent, which was capable of being wet-coated onto the proppant particulates within 24 hours at 93.3° C. (200° F.) and was not removed by the presence of the hydrocarbon kerosene. The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 8 multifunctional electrophilic compound to nucleophilic compound, demonstrated strong non-hardening consolidating agent qualities, as indicated by adherence of the coal fines to the coated proppant particulates rather than their accumulation in the brine aqueous treatment fluid lacking the coated proppant particulates.
EXAMPLE 2
In this example, 0.33 g of bisphenol A diepoxy (multifunctional electrophilic compound), 2.67 g of dimer acid (nucleophilic compound), 0.1 g triethylamine (accelerator), 0.1 g SILQUEST® A-1120 (silane coupling agent), 100 g of 25 lbs/Mgal WG-36TM in aqueous-based polysaccharide fluid (gelled aqueous treatment fluid), and 100 g of 20/40-mesh Brady sand (proppant particulates) were added to a glass vial. The mixture was vigorously shaken for approximately 1 minute at ambient temperature. Thereafter, the liquid component of the mixture (i.e., the gelled aqueous treatment fluid) was decanted and the remaining solid component was washed with 100 g of tap water 3 times. Next, 100 g of kerosene was added to the mixture in the glass vial, followed by vigorous shaking for approximately 3 minutes. After shaking the mixture, the kerosene was decanted and again rinsed with tap water to remove all visibly present kerosene. After removal of the kerosene, 0.5 g of coal fines were added to the mixture and the mixture was vigorously shaken for 1-2 min.
Based on visual inspection, the bisphenol A diepoxy and dimer acid were capable of reacting in the presence of a gelled aqueous treatment fluid to form a liquid resin agent, which was capable of being wet-coated onto the proppant particulates within 1 min during vigorous shaking at ambient temperature and was not removed by the presence of the hydrocarbon kerosene. The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 8 multifunctional electrophilic compound to nucleophilic compound, demonstrated strong non-hardening consolidating agent qualities, as indicated by adherence of the coal fines to the coated proppant particulates rather than their accumulation in the gelled aqueous treatment fluid lacking the coated proppant particulates.
EXAMPLE 3
In this example, 3 g of bisphenol A diepoxy (multifunctional electrophilic compound), 10 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator), 50 g of 3% KCl (aqueous treatment fluid), and 100 g of 20/40-mesh Brady sand (proppant particulates) were added to a glass vial. The mixture was rotated continuously in the glass vial in a rolling oven for 24 hours at 93.3° C. (200° F.). Thereafter, the mixture was washed with 100 g of tap water 3 times. Next, 100 g of kerosene was added to the mixture in the glass vial, followed by vigorous shaking for approximately 3 minutes. After shaking the mixture, the kerosene was decanted and again rinsed with tap water to remove all visibly present kerosene. After removal of the kerosene, 0.5 g of coal fines were added to the mixture and the mixture was vigorously shaken for 1-2 min.
Based on visual inspection, the bisphenol A diepoxy and dimer acid were capable of reacting in the presence of a brine solution to form a liquid resin agent, which was capable of being wet-coated onto the proppant particulates within 24 hours at 93.3° C. (200° F.) and was not removed by the presence of the hydrocarbon kerosene. The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 8 multifunctional electrophilic compound to nucleophilic compound, demonstrated strong non-hardening consolidating agent qualities, as indicated by adherence of the coal fines to the coated proppant particulates rather than their accumulation in the brine aqueous treatment fluid lacking the coated proppant particulates.
EXAMPLE 4
In this example, a liquid resin agent comprising 3 g of bisphenol A diepoxy (multifunctional electrophilic compound), 10 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator) was added to a glass vial. The mixture was static incubated in the glass vial for 48 hours at 107.2° C. (225° F.). After 48 hours, 3 g of the liquid resin agent was added to 100 g of 20/40-mesh Brady sand (proppant particulates) to dry-coat the liquid resin agent onto the sand at room temperature. After dry-coating, 100 g of 3% KCl (aqueous treatment fluid) and 0.5 g of coal fines was added and the contents were shaken vigorously for approximate 1-2 min.
Based on visual inspection, the bisphenol A diepoxy and dimer acid were capable of reacting to form the liquid resin agent of the present invention within 4 hours at 107.2° C. (225° F.), which was capable of being dry-coated onto the 20/40 sand. The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 3 multifunctional electrophilic compound to nucleophilic compound, demonstrated strong non-hardening consolidating agent qualities, as indicated by adherence of the coal fines to the coated proppant particulates rather than their accumulation in the brine treatment fluid lacking the coated proppant particulates.
EXAMPLE 5
In this example, a liquid resin agent comprising 3 g of bisphenol A diepoxy (multifunctional electrophilic compound), 10 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator) was added to a glass vial. The mixture was incubated static in the glass vial for 48 hours at 107.2° C. (225° F.). After 48 hours, approximately 100 g of kerosene was added to the mixture and immediately visually inspected. Upon visual inspection, the liquid resin component was insoluble in the kerosene.
EXAMPLE 6
In this example, a liquid resin agent comprising 3 g of bisphenol A diepoxy (multifunctional electrophilic compound), 10 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator) was added to a glass vial. The mixture was static incubated in the glass vial for 48 hours at 107.2° C. (225° F.). After 48 hours, 3 g of the liquid resin agent was added to 100 g of 20/40-mesh Brady sand (proppant particulates) to dry-coat the liquid resin agent onto the sand at room temperature. After dry-coating, 200 g of 3% KCl (aqueous treatment fluid) was added to the coated sand and mixed vigorously. After 1 minute, the 3% KCl was decanted and the coated sand was packed into a 12.7 cm (5 in) long column having an inner diameter of 2.54 cm (1 in). The column was capped and placed in an oven at 107.2° C. (225° F.) for 48 hours to form a hardened resinous mass. The hardened resinous mass was sliced into 2.54 cm×5.08 cm (1-inch×2-inch) samples and the slices were tested for unconfined compressive strength (“UCS”) measurements using an Instron 5550.
The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 3 multifunctional electrophilic compound to nucleophilic compound, demonstrated an average USC of 58 psi (399895.9 Pa). Additionally, the slices tested for USC measurements did not crumble but exhibited elasticity under the stress load.
EXAMPLE 7
In this example, 1 g of 1,4-di(oxiran-2-yl)butane (multifunctional electrophilic compound), 6 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator), 50 g of 3% KCl (aqueous treatment fluid), and 100 g of 20/40-mesh Brady sand (proppant particulates) were added to a glass vial. The mixture was rotated continuously in the glass vial in a rolling oven for 24 hours at 93.3° C. (200° F.). Thereafter, the mixture was washed with 100 g of tap water 3 times. Next, 100 g of kerosene was added to the mixture in the glass vial, followed by vigorous shaking for approximately 3 minutes. After shaking the mixture, the kerosene was decanted and again rinsed with tap water to remove all visibly present kerosene. After removal of the kerosene, 0.5 g of coal fines were added to the mixture and the mixture was vigorously shaken for 1-2 min.
Based on visual inspection, the 1,4-di(oxiran-2-yl)butane and dimer acid were capable of reacting in the presence of a brine solution to form a liquid resin agent, which was capable of being wet-coated onto the proppant particulates within 24 hours at 93.3° C. (200° F.) and was not removed by the presence of the hydrocarbon kerosene. The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 6 multifunctional electrophilic compound to nucleophilic compound, demonstrated strong non-hardening consolidating agent qualities, as indicated by adherence of the coal fines to the coated proppant particulates rather than their accumulation in the brine treatment fluid lacking the coated proppant particulates. A portion of the liquid resin agent was also observed as exhibiting hardening consolidating agent qualities.
EXAMPLE 8
In this example, a liquid resin agent comprising 1 g of 1,4-di(oxiran-2-yl)butane (multifunctional electrophilic compound), 6 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator) was added to a glass vial. The mixture was static incubated in the glass vial for 48 hours at 225° F. (107.2° C.). After 48 hours, 3 g of the liquid resin agent was added to 100 g of 20/40-mesh Brady dry sand (proppant particulates) to dry-coat the liquid resin agent onto the sand at room temperature. After dry-coating, 100 g of 3% KCl (aqueous treatment fluid) and 0.5 g of coal fines was added and the contents were shaken vigorously for approximately 1-2 min.
Based on visual inspection, the 1,4-di(oxiran-2-yl)butane and dimer acid were capable of reacting to form the liquid resin agent of the present invention within 4 hours at 107.2° C. (225° F.), which was capable of being dry-coated onto the 20/40-mesh Brady sand. The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 6 multifunctional electrophilic compound to nucleophilic compound, demonstrated strong non-hardening consolidating agent qualities, as indicated by adherence of the coal fines to the coated proppant particulates rather than their accumulation in the brine treatment fluid lacking the coated proppant particulates. A portion of the liquid resin agent also observed as exhibiting hardening consolidating agent qualities, having a compressive strength of 41 psi (282685.0 Pa).
EXAMPLE 9
In this example, a liquid resin agent comprising 1 g of 1,4-di(oxiran-2-yl)butane (multifunctional electrophilic compound), 6 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator) was added to a glass vial. The mixture was static incubated in the glass vial for 48 hours at 107.2° C. (225° F.). After 48 hours, approximately 100 g of kerosene was added to the mixture. Upon immediate visual inspection, the liquid resin component was insoluble in the kerosene.
EXAMPLE 10
In this example, a liquid resin agent comprising 1 g of 1,4-di(oxiran-2-yl)butane (multifunctional electrophilic compound), 6 g of dimer acid (nucleophilic compound), and 0.1 g triethylamine (accelerator) was added to a glass vial. The mixture was static incubated in the glass vial in a for 48 hours at 107.2° C. (225° F.). After 48 hours, 3 g of the liquid resin agent was added to 100 g of 20/40-mesh Brady sand (proppant particulates) to dry-coat the liquid resin agent onto the sand at room temperature. After dry-coating, 200 g of 3% KCl (aqueous treatment fluid) was added to the coated sand and mixed vigorously. After 1 minute, the 3% KCl was decanted and the coated sand was packed into a 12.7 cm (5 in) long column having an inner diameter of 2.54 cm (1 in). The column was capped and placed in an oven at 107.2° C. (225° F.) for 48 hours to form a hardened resinous mass. The hardened resinous mass was sliced into 2.54 cm×5.08 cm (1 in×2 in) samples and the slices were tested for unconfined compressive strength (“UCS”) measurements using an Instron 5550.
The liquid resin agent of this example, comprising a ratio of approximately 1 to approximately 6 multifunctional electrophilic compound to nucleophilic compound, demonstrated an average USC of 50 psi (344737.9 Pa). Additionally, the slices tested for USC measurements did not crumble but exhibited elasticity under the stress load.
EXAMPLE 11
In this example, a liquid resin agent mixture comprising 3 g of bisphenol A-epichlorohydrin (multifunctional electrophilic compound) and 1 g of dimer amine (nucleophilic compound) was prepared. After mixing the bisphenol A-epichlorohydrin and the dimer amine, 3 g of the liquid resin agent mixture was added to 100 g of 20/40-mesh Brady sand (proppant particulates) to dry-coat the liquid resin agent onto the sand at room temperature. After dry-coating, 200 g of 3% KCl (aqueous treatment fluid) was added to the coated sand and mixed vigorously. After 1 minute, the 3% KCl was decanted and the coated sand was packed into a 12.7 cm (5 in) long column having an inner diameter of 2.54 cm (1 in). The column was capped and placed in an oven at 107.2° C. (225° F.) for 24 hours to form a hardened resinous mass. The hardened resinous mass was sliced into 2.54 cm×5.08 cm (1 in×2 in) samples and tested for their unconfined compressive strength (“UCS”) measurements using an Instron 5550.
The liquid resin agent of this example, comprising a ratio of approximately 3 to approximately 1 multifunctional electrophilic compound to nucleophilic compound, demonstrated an average USC of 1530 psi (10.5 MPa) psi). Additionally, the slices tested for USC measurements did not crumble but exhibited elasticity under the stress load.
EXAMPLE 12
In this example, a liquid resin agent mixture comprising 6 g of bisphenol A-epichlorohydrin (multifunctional electrophilic compound) and 3 g of dimer amine (nucleophilic compound) was prepared. After mixing the bisphenol A-epichlorohydrin and the dimer amine, 3 g of the liquid resin agent mixture was added to 100 g of 20/40-mesh Brady sand (proppant particulates) to dry-coat the liquid resin agent onto the sand at room temperature. After dry-coating, 200 g of 3% KCl (aqueous treatment fluid) was added to the coated sand and mixed vigorously. After 1 minute, the 3% KCl was decanted and the coated sand was packed into a 12.7 cm (5 in) long column having an inner diameter of 2.54 cm (1 in). The column was capped and placed in an oven at 107.2° C. (225° F.) for 24 hours to form a hardened resinous mass. The hardened resinous mass was sliced into 2.54 cm×5.08 cm (1 in×2 in) samples and the slices were tested for unconfined compressive strength (“UCS”) measurements using an Instron 5550.
The liquid resin agent of this example, comprising a ratio of approximately 2 to approximately 1 multifunctional electrophilic compound to nucleophilic compound, demonstrated an average USC of 793 psi (5.5 MPa). Additionally, the slices tested for USC measurements did not crumble but exhibited elasticity under the stress load.
Embodiments disclosed herein include:
A. A method of treating a wellbore in a subterranean formation comprising: providing an aqueous treatment fluid comprising a liquid resin agent, wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein the multifunctional electrophilic compound comprises at least two electrophilic reactive groups; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and, curing the liquid resin agent.
B. A method of treating a wellbore in a subterranean formation comprising: providing an aqueous treatment fluid comprising proppant particulates coated with a liquid resin agent, wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein the multifunctional electrophilic compound comprises at least two electrophilic reactive groups; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and curing the liquid resin agent.
C. A method of treating a wellbore in a subterranean formation comprising: providing a first portion and a second portion of a liquid resin agent, wherein the first portion comprises a multifunctional electrophilic compound comprising at least two electrophilic reactive groups, wherein the second portion comprises a nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and wherein a complete liquid resin agent is formed by a reaction of the first portion and the second portion; providing a pad fluid comprising either the first portion or the second portion of the liquid resin agent; providing an aqueous treatment fluid comprising proppant particulates and the portion of the liquid resin agent not in the pad fluid, wherein, when the first portion is in the pad fluid, the proppant particulates are coated with the second portion and when the second portion of the is in the pad fluid, the proppant particulates are coated with the first portion; introducing the pad fluid into the wellbore in the subterranean formation; introducing the aqueous treatment fluid into the wellbore in the subterranean formation; reacting the first portion and the second portion of the liquid resin agent so as to form the complete liquid resin agent; and curing the liquid resin agent.
Each of embodiments A, B, and C may have one or more of the following additional elements in any combination:
Element 1: The multifunctional electrophilic compound is selected from the group consisting of a polyepoxide; an epoxy containing alkoxysilane; and any combination thereof.
Element 2: The multifunctional electrophilic compound is a polyepoxide selected from the group consisting of a bisphenol A diglycidyl ether; a bisphenol A-epichlorohydrin; a bisphenol F; novolak; a tetrabromobisphenol A; an aliphatic diepoxide; and any combination thereof.
Element 3: The multifunctional electrophilic compound is an epoxy containing alkoxysilane comprising the formula: RnR′mSiX(4−n−m), where R′ is a nonhydrolyzable organic group functionalized with an epoxy end group, R is a nonhydrolyzable organic group, X is a hydrolyzable group, and n and m are integers.
Element 4: The multifunctional electrophilic compound is an epoxy containing alkoxysilane comprising the formula: RnR′mSiX(4−n−m), where R′ is a nonhydrolyzable organic group functionalized with an epoxy end group, R is a nonhydrolyzable organic group, X is a hydrolyzable group, and n and m are integers, wherein the nonhydrolyzable organic group R is selected from the group consisting of an alkyl moiety; an ethyl moiety; a methyl moiety; a propyl moiety; a butyl moiety; a hexyl moiety; an octyl moiety; a benzyl moiety; a cyclohexyl moiety; and any combination thereof, and wherein the hydrolyzable organic group X is selected from the group consisting of an alkoxy moiety; a methoxy moiety; an ethoxy moiety; an acyloxy moiety; an amine moiety; a hydroxyl moiety; a halo moiety; an acetoxy moiety; a propoxy moiety; a butoxy moiety; a phenoxy moiety; a chloride moiety; a bromide moiety; an iodide moiety; a pentoxy moiety; and any combination thereof.
Element 5: The ratio of multifunctional electrophilic compound to the nucleophilic compound forming the liquid resin agent is about 1 to greater than about 6, such that the liquid resin agent is capable of acting as a non-hardening consolidating agent.
Element 6: The ratio of the multifunctional electrophilic compound to the nucleophilic compound forming the liquid resin agent is greater than about 3 to about 1, such that the liquid resin agent is capable of acting as a hardening consolidating agent.
Element 7: The ratio of the multifunctional electrophilic compound to the nucleophilic compound forming the liquid resin agent is in the range of between less than about 2 to about 1 to less than about 2 to less than about 10, such that a portion of the liquid resin agent is a non-hardening consolidating agent and a portion of the liquid resin agent is a hardening consolidating agent.
Element 8: The liquid resin agent further comprises at least one selected from the group consisting of an accelerator; silane coupling agent; a surfactant; a solvent; a hydrolyzable ester; and any combination thereof.
Element 9: When a first portion and a second portion of the liquid resin agent is introduced into the wellbore in a subterranean formation in separate fluids, the first portion of the liquid resin agent is in a pad fluid and the second portion is in an aqueous treatment fluid.
Element 9: When a first portion and a second portion of the liquid resin agent is introduced into the wellbore in a subterranean formation in separate fluids, the first portion of the liquid resin agent is in an aqueous treatment fluid and the second portion is in a pad fluid.
By way of non-limiting example, exemplary combinations applicable to A, B, C include: A with 8; A with 1, 2, and 7; B with 1, 3, 4, and 6; C with 1, 2, 5, and 9.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present invention. The invention illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

## Claims

1. A method of treating a wellbore in a subterranean formation consisting of:
providing an aqueous treatment fluid comprising a liquid resin agent,
wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof,
wherein the multifunctional electrophilic compound comprises at least two electrophilic reactive groups and is an aliphatic diepoxide of 1,4-di(oxiran-2-yl)butane, and
wherein (1) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is about 1 to greater than about 6, such that the liquid resin agent is capable of acting as a non-hardening consolidating agent, (2) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is greater than about 3 to about 1, such that the liquid resin agent is capable of acting as a hardening consolidating agent, or (3) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is less than about 2 to 1 to less than about 2 to 10, such that a portion of the liquid resin agent is a non-hardening consolidating agent and a portion of the liquid resin agent is a hardening consolidating agent;

introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and,
curing the liquid resin agent.

2. The method of claim 1, wherein the liquid resin agent further comprises at least one selected from the group consisting of an accelerator; silane coupling agent; a surfactant; a solvent; a hydrolyzable ester; and any combination thereof.

3. The method of claim 1, wherein the nucleophilic compound is a dimer acid.

4. The method of claim 1, wherein the nucleophilic compound is a dimer diamine.

5. A method of treating a wellbore in a subterranean formation consisting of:
providing an aqueous treatment fluid comprising proppant particulates coated with a liquid resin agent,
wherein the liquid resin agent comprises the reaction product of a multifunctional electrophilic compound and at least one nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof, and
wherein the multifunctional electrophilic compound comprises at least two electrophilic reactive groups and is an aliphatic diepoxide of 1,4-di(oxiran-2-yl)butane, and
wherein (1) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is about 1 to greater than about 6, such that the liquid resin agent is capable of acting as a non-hardening consolidating agent, (2) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is greater than about 3 to about 1, such that the liquid resin agent is capable of acting as a hardening consolidating agent, or (3) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is less than about 2 to 1 to less than about 2 to 10, such that a portion of the liquid resin agent is a non-hardening consolidating agent and a portion of the liquid resin agent is a hardening consolidating agent;

introducing the aqueous treatment fluid into the wellbore in the subterranean formation; and
curing the liquid resin agent.

6. The method of claim 5, wherein the liquid resin agent further comprises at least one selected from the group consisting of an accelerator; silane coupling agent; a surfactant; a solvent; a hydrolyzable ester; and any combination thereof.

7. The method of claim 5, wherein the nucleophilic compound is a dimer acid.

8. The method of claim 5, wherein the nucleophilic compound is a dimer diamine.

9. A method of treating a wellbore in a subterranean formation consisting of:
providing a first portion and a second portion of a liquid resin agent,
wherein the first portion comprises a multifunctional electrophilic compound comprising at least two electrophilic reactive groups and is an aliphatic diepoxide of 1,4-di(oxiran-2-yl)butane,
wherein the second portion comprises a nucleophilic compound selected from the group consisting of a dimer acid; a dimer amine; any derivative thereof; and any combination thereof,
wherein a complete liquid resin agent is formed by a reaction of the first portion and the second portion, and
wherein (1) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is about 1 to greater than about 6, such that the liquid resin agent is capable of acting as a non-hardening consolidating agent, (2) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is greater than about 3 to about 1, such that the liquid resin agent is capable of acting as a hardening consolidating agent, or (3) the ratio of the multifunctional electrophilic compound to the nucleophilic compound is less than about 2 to 1 to less than about 2 to 10, such that a portion of the liquid resin agent is a non-hardening consolidating agent and a portion of the liquid resin agent is a hardening consolidating agent;

providing a pad fluid comprising either the first portion or the second portion of the liquid resin agent;
providing an aqueous treatment fluid comprising proppant particulates and the portion of the liquid resin agent not in the pad fluid,
wherein, when the first portion is in the pad fluid, the proppant particulates are coated with the second portion and when the second portion of the is in the pad fluid, the proppant particulates are coated with the first portion;

introducing the pad fluid into the wellbore in the subterranean formation;
introducing the aqueous treatment fluid into the wellbore in the subterranean formation;
reacting the first portion and the second portion of the liquid resin agent so as to form the complete liquid resin agent; and
curing the liquid resin agent.

10. The method of claim 9, wherein the first portion of the liquid resin agent is in the pad fluid and the second portion of the liquid resin agent is in the aqueous treatment fluid.

11. The method of claim 9, wherein the first portion of the liquid resin agent is in the aqueous treatment fluid and the second portion of the liquid resin agent is in the pad fluid.

12. The method of claim 9, wherein the nucleophilic compound is a dimer acid.

13. The method of claim 9, wherein the nucleophilic compound is a dimer diamine.