Radiation-activated well treatment agent

Abstract

A well treatment composition may include a capsule and a treatment agent solution within the capsule. The treatment agent solution may have a treatment agent. A system may include a radiation source: neutrons, gamma, X-rays, and / or ultraviolet rays. A method may include introducing a well treatment composition downhole in a wellbore circulating fluid, and introducing a radiation source into the wellbore and positioning the radiation source. The method may include activating a radiation source and emitting radiation mixed with a well treatment composition at a target location. The method may include maintaining a wellbore such that radiation emitted from an activated radiation source reacts with a well treatment composition to form a radiation activated well treatment composition. The method may include disintegrating or dissolving the radiation-activated well treatment composition, thereby breaking the encapsulation and releasing the treatment agent at the target location.

Description

Background Art

[0001] In oil and gas operations, fluid treatments are dispensed into the wellbore for a variety of purposes. Generally, well treatments ensure that hydrocarbons flow efficiently from the formation into the wellbore. The purposes of treatments include cleaning, breaking up accumulated sludge and scale, stimulating, and removing or opening blockages in formation passages.

[0002] Existing treatments may use excess fluids or active agents. These existing treatments may expose active agents to portions of the wellbore other than the target location, may require shutting in the well for an extended period of time, or may use additional equipment such as slickline or wireline tools. Summary of the invention

[0003] This Summary is provided to introduce a range of concepts that are further described in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0004] In one aspect, one or more embodiments disclosed relate to a system comprising a well treatment composition, which may include a capsule and a treatment agent solution in the capsule. The treatment agent solution may include a treatment agent, which includes one or more selected from the group consisting of the following: scale dissolving agent, scale inhibitor, hydrate inhibitor, halite inhibitor (halite inhibitor, or rock salt inhibitor), corrosion inhibitor, biocide, wax control material, asphaltene control material, demulsifier, degelling agent, drag reducer, deoxidizer, foaming agent, surfactant, acid treatment agent and well cleaning material. The system may include a radiation source, which includes one or more selected from the group consisting of a neutron source, a gamma source, an X-ray source and an ultraviolet source.

[0005] In another aspect, one or more embodiments disclosed relate to a method for treating a wellbore or hydrocarbon formation. The method may include introducing a well treatment composition comprising an encapsulated treatment agent downhole in a wellbore circulating fluid to a target location. The method may include introducing a radiation source into the wellbore and positioning the radiation source at the target location. The method may include activating the radiation source and emitting radiation intimately mixed with the well treatment composition at the target location. The method may also include maintaining the wellbore so that the radiation emitted from the activated radiation source reacts with the well treatment composition to form a radiation-activated well treatment agent. In addition, the method may include causing the radiation-activated well treatment agent to disintegrate or dissolve, thereby destroying the encapsulation and releasing the treatment agent at the target location.

[0006] Other aspects and advantages of the claimed subject matter will be apparent from the following detailed description and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A method of treating a wellbore or hydrocarbon formation according to one or more embodiments is shown. DETAILED DESCRIPTION

[0008] One or more embodiments of the present disclosure relate to systems and methods for targeted treatment of a wellbore.Targeted well treatment delivers an active agent to a target location in a wellbore.

[0009] Targeted well treatments can be performed for a variety of reasons. Precipitates can form scale on the wellbore walls, thereby impeding the flow of fluids from the formation, through the wellbore, or both. Targeted well treatments can remove scale (buildup or deposits) by breaking down the deposited material. Removing scale in a targeted manner increases process efficiency and reduces the overall amount of treatment agents used compared to non-targeted treatments.

[0010] Acid stimulation of a formation involves injecting a strong acid, such as hydrochloric acid (HCl) or hydrofluoric acid (HF), directly into the wellbore. Acid stimulation can dissolve secondary minerals or materials in the drilling mud, including but not limited to bentonite or polymers, and can mobilize these materials to release flow transport in the formation or wellbore. However, the reactivity of strong acids can cause the acid to be quickly consumed before it reaches the target treatment area. In addition, these acids are corrosive and may attack metal components of the well structure and downhole tools, causing collateral damage. These deficiencies can be overcome through targeted well treatments with acid stimulation.

[0011] In one or more embodiments, a radiation activated well treatment agent, also referred to as a radiation activated well treatment composition, is provided by the system and method. The system is used to deliver a well treatment agent (well treatment composition) downhole and activate the well treatment agent with a radiation source also downhole, thereby producing a radiation activated well treatment agent. The method includes a series of steps to introduce, target and activate the well treatment agent downhole.

[0012] For example, a well treatment agent can be triggered using radiation. Such a system can be used to precisely target the treatment agent when the well treatment agent and the radiation source are downhole in the wellbore near the target location. The well treatment agent can include a capsule having a shell that includes a polymer that degrades when exposed to radiation. The well treatment agent (which is degradable when irradiated) can release an active agent held within, for example, the capsule to achieve treatment.

[0013] system

[0014] In one or more embodiments, the system includes a well treatment agent and a radiation source, the well treatment agent including a delivery fluid, a capsule, and a treatment agent solution encapsulated in the capsule. The well treatment composition can be added to the wellbore circulating fluid. The treatment agent solution includes an active chemical component (to be described).

[0015] The delivery fluid can be water, or a mixture of water and a surfactant. Examples of delivery fluid surfactants include, but are not limited to, alkoxylated compounds; quaternary ammonium salts; organic sulfates; ethoxylates including sulfur atoms, such as sulfonated ethoxylated compounds; zwitterions; and combinations thereof.

[0016] The capsule may range in size from 1 to 10 millimeters (mm) in its widest dimension, whether length, width or height. When the capsule is 1 to 1,000 micrometers (μm), it may be referred to as a microcapsule.

[0017] The capsule may include a shell that defines an open space within the shell (the interior of the capsule) that is configured to retain a treatment agent solution until activated. The interior of the capsule may be a volume of about 1 μL to about 1 mL. Therefore, the capsule is configured to retain a volume of about 1 μL to about 1 mL. The shell may include a polymer, referred to as a polymer shell. The polymer shell may be configured to degrade in the presence of radiation (to be described). The capsule may be a hardened capsule or a gel capsule (understood as a gel cap in the art). The thickness of the shell may be about 100 nm to about 100 μm.

[0018] The polymer shell of the capsule may include polymerization products of monomers including, but not limited to, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde resin, melamine-phenol-formaldehyde resin, furan-formaldehyde resin, epoxy resin, polysiloxane, polyacrylate, polyester, polyurethane, polyamide, polyether, polyimide, polyolefin, polypropylene-polyethylene copolymer, polystyrene, functionalized polystyrene derivative, gelatin, gelatin derivative, cellulose, cellulose derivative, starch, starch derivative, polyvinyl alcohol, ethylene-vinyl acetate copolymer, maleic anhydride-based copolymer, polyacrylamide, polyacrylamide-based copolymer, polyacrylic acid, polyacrylic acid-based copolymer, polyvinyl pyrrolidone, polyvinyl pyrrolidone-based copolymer, polyacrylate-based copolymer, propylene-acrylate copolymer, propylene-methacrylate copolymer, oxidized polypropylene, oxidized polyethylene, propylene-ethylene oxide copolymer, styrene-acrylate copolymer, acrylonitrile-butadiene-styrene copolymer, or a combination thereof.

[0019] The treatment agent solution within the capsule may include an emulsion, a suspension, or a polymer filler, wherein each type of treatment agent solution includes the treatment agent.

[0020] The term "emulsion" is used to describe a fine dispersion of droplets of a first liquid in a second liquid, wherein the droplets are not soluble or miscible. As used herein, the term emulsion may include microemulsion, mini-emulsion or macroemulsion.

[0021] The average diameter of the droplets in the dispersed phase of the microemulsion can be about 1 micron (1 μm, 10 -6 m) to about 1 mm (1 mm, 10 -3 The average diameter of the droplets in a macroemulsion (a "normal" emulsion) may be greater than 1 millimeter (1 mm, 10 -3 The average diameter of the droplets in the nanoemulsion can be less than 1 micrometer (1 μm, 10 -6 m).

[0022] The emulsion can be an oil-in-water emulsion (O / W) as a discontinuous internal oil phase in a continuous water phase, a water-in-oil emulsion (W / O) as a discontinuous internal water phase in a continuous oil phase, or an internal phase that is itself a dispersion such as a water-in-oil-in-water emulsion (W / O / W) or an oil-in-water-in-oil emulsion (O / W / O). The internal phase of the emulsion can include a treating agent. The emulsion can be added to the interior of the capsule. Therefore, the composition can include an encapsulated emulsion.

[0023] In one or more embodiments, the emulsion is a Pickering emulsion. Pickering emulsions are stabilized by solid particles (such as surface active nanoparticles). For example, solid particles in a Pickering emulsion can be adsorbed at the interface between two phases of the emulsion. Therefore, when an emulsion is included in a capsule, solid particles (such as nanoparticles) can be incorporated into the capsule. An example of a solid particle that can be incorporated is a stabilizer, such as nanosilica, nanoclay, modified nanosilica or nanoclay, or a combination thereof.

[0024] The suspension can include solid materials suspended in the liquid, such as treatment agents. The components of the suspension itself can be unaffected by the radiation source. The suspension can be added to the inside of the capsule. Therefore, the composition can include an encapsulated suspension comprising a treatment agent. Suitable examples of additional solid materials in the suspension can include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), tetrasodium glutamate diacetate (GLDA), sulfamic acid and combinations thereof. Suitable examples of liquid components in the suspension can include, but are not limited to, acetone, benzene, methanol, ether and combinations thereof.

[0025] The treating agent may be embedded in the polymer filler. The polymer filler may be encapsulated by a capsule surrounding the filler. The polymer filler may be an addition polymer of a vinyl monomer or a condensation polymer of a monomer, a condensation polymer of a prepolymer, or a combination thereof (to be described).

[0026] Suitable examples of vinyl monomers include, but are not limited to, acrylamide, acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, styrene, 4-vinylbenzyl chloride (also known as 4-chloromethylstyrene), divinylbenzene, methylenebisacrylamide, or combinations thereof.

[0027] Suitable examples of condensation polymers of monomers include, but are not limited to, melamine-formaldehyde resins, phenol-formaldehyde resins, urea-formaldehyde resins, epoxy resins, polyurethane resins, urea resins, polyurethane / urea resins, polyester resins, or combinations thereof. When urea-formaldehyde resins are included, the molar ratio of formaldehyde to urea may exceed 0.94:1.

[0028] Suitable examples of condensation polymers of prepolymers include, but are not limited to, methylene diphenyl diisocyanate (MDI) based prepolymers, toluene diisocyanate (TDI) based prepolymers, or combinations thereof (for isocyanate chemistry).

[0029] The system includes a treatment agent. The treatment agent can be a compound introduced into the wellbore to mitigate undesirable effects in the wellbore or reservoir. The undesirable effects can be caused by conditions including, but not limited to, scale formation, salt formation, paraffin deposition, emulsification (of undesirable emulsions), gas hydrate (gas hydrate, or natural gas hydrate) formation, corrosion, asphaltene precipitation, paraffin formation or a combination thereof. As used herein, an "undesirable emulsion" is an emulsion of oil components (such as cyclohexane acids and asphaltene acids) in a wellbore or reservoir, or an emulsion due to damage to the formation caused by a drilling mud component, and can be an oil-in-water or water-in-oil type emulsion.

[0030] When the treatment is encapsulated, for example, in a capsule, it may be referred to as an “encapsulated treatment.” The capsule may include an encapsulated treatment, or one or more of an encapsulated treatment, an emulsion, a suspension, and a polymer filler.

[0031] The treatment agents may include, but are not limited to, scale dissolving agents, scale inhibitors, hydrate inhibitors, halite inhibitors, corrosion inhibitors, biocides, wax control substances, asphaltene control substances, demulsifiers (to be used with undesirable emulsions), gel breakers, drag reducers, oxygen scavengers, foaming agents, surfactants, acids, acid precursors and well cleaning substances (such as enzymes, organic molecules, acids, esters or aliphatic compounds) or combinations thereof.

[0032] As used herein, well cleaning substances are used to remove deposits formed during the production process, including scale buildup, paraffin, or other substances that may accumulate in a well or reservoir. Well cleaning substances may include, but are not limited to, acidic components such as for removing salts. However, acidic treatment agents may also be used to enhance oil production, and those of ordinary skill in the art will understand the differences between well cleaning substances and substances used for other purposes.

[0033] A scale dissolving agent is a chemical used to break up or dissolve scale, sludge or buildup. The scale dissolving agent may be an acid based scale dissolving agent, a chelating agent based scale dissolving agent or a combination thereof.

[0034] Acid-based scale dissolving agents may include, but are not limited to, hydrochloric acid, acetic acid, formic acid, citric acid, lactic acid, methanesulfonic acid (MSA), or combinations thereof.

[0035] The scale dissolving agent based on the chelating agent may include, but is not limited to, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), tetrasodium glutamate diacetate (GLDA), nitrilotriacetic acid (NTA), citrate, pyrophosphate (P2O7), tetrakis (hydroxymethyl) phosphonium sulfate (THPS), or a combination thereof. The scale dissolving agent based on the chelating agent may dissolve scale, for example, by trapping salts or other components in the scale (including, but not limited to, CaCO3, CaSO4, MgCO3, or a combination thereof).

[0036] A scale inhibitor is a chemical that inhibits or prevents the accumulation of scale and sludge. Scale inhibitors may include, but are not limited to, polyphosphates, 1-hydroxyethylidene diphosphonic acid (HDEP), ethane-1,2-diphosphonic acid (EDPA), diethylenetriamine penta(methylenephosphonic acid) (DETPMP), tris(phosphonomethyl)amine, nitrilotrimethylphosphonic acid, aminotri(methylphosphonic acid) (ATMP), bis(hexamethylenetriamine penta(methylenephosphonic acid)) (BHTMP), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), [[(2-hydroxyethyl)imino]bis(methylene)]bisphosphonic acid (MEA / HADMP), polyacrylic acid (PAA), polymaleic acid (PMA), polyphosphinocarboxylic acid ( acid, PPCA), polyvinyl sulfonate and polyacrylic acid copolymer (PVS), phosphonocarboxylic acid (POCA) and 2-phosphono-butane-1,2,4-tricarboxylic acid (PBTC), polyaminopolyethermethylenephosphonate (PAPEMP), polyaspartate or a combination thereof.

[0037] Hydrate inhibitors are chemicals that control the formation of hydrates in a wellbore. Hydrate inhibitors (such as gas hydrate inhibitors) may include, but are not limited to, methanol, ethylene glycol, glycopeptides, poly(N-vinylpyrrolidone) (PVP), tyrosine derivatives, terpolymers of N-vinylcaprolactam, N-vinylpyrrolidone and dimethylaminoethyl methacrylate, isobutylene succinate diester of monomethyl polyethylene glycol, hydroxyethyl cellulose (HEC), alkyl aryl sulfonic acid, ethoxylated sorbitan monolaurate, alkyl polyglycosides, tetraoxyethylene nonylphenyl ether, or combinations thereof.

[0038] Halite inhibitors may include, but are not limited to, nitrilotriacetic acid (NTA), potassium hexacyanoferrate (HCF), or a combination thereof. Halite inhibitors may mitigate, inhibit, or destroy halite formation. For example, halite (not limited to sodium chloride NaCl) may be present in a high temperature and high pressure well or reservoir. Changes in pressure and temperature may cause produced water to evaporate into a gas phase or a condensed phase, thereby placing the water flow in a supersaturated state. Supersaturation may cause halite to precipitate. Halite inhibitors may, for example, distort the nucleation and growth of halite, thereby resulting in dispersion and partial dissolution of already formed halite (in the form of crystals, scale, etc.). When a halite inhibitor is included, a reduced volume of fresh water may be included in the composition compared to when the halite inhibitor is not included.

[0039] A corrosion inhibitor is a chemical that reduces the corrosion rate of a material (such as a metal or alloy) in contact with a corrosive chemical. The corrosion inhibitor may include, but is not limited to, imidazolines, primary / secondary / tertiary / quaternary amines, n-dodecylamine, NN-dimethyldodecylamine, amides, amidoamines, amidoimidazolines, isoxazolidines, succinic acid, carboxylic acids, aldehydes, alkanolamines, imidazoline-imidazolidinyl compounds, α,β-ethylenically unsaturated aldehydes, polyalkylenepolyamines, diethylenetriamine, or combinations thereof.

[0040] A biocide is a chemical, microorganism, or mixture thereof that destroys, deters, renders harmless, or exerts a control effect on an organism. The organism may include, but is not limited to, sulfate-reducing bacteria, sulfate-reducing archaea, methanogens, or combinations thereof. One of ordinary skill in the art will appreciate that other organisms, harmful organisms, may be the target of a biocide.

[0041] Biocides may include, but are not limited to, glutaraldehyde, tetrakis(hydroxymethyl)phosphonium sulfate (THPS), alkyl dimethyl benzyl ammonium chloride (ADBAC), didecyl dimethyl ammonium chloride (DDAC), tributyl (tetradecyl) phosphonium chloride (TTPC), cocodiamine, 2,2-dibromo-3-nitrilopropionamide (DBNPA), 2-bromo-2-nitro-1,3-propanediol, tetrahydro-3,5-dimethyl 2H-1,3,5-thiadiazinethione, 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (CMIT / MIT), 4,4-dimethyloxazolidine (DMO), 1-(3-chloroallyl)-3,5,7-triaza-1-azoniadiamantane chloride (CTAC), tris(hydroxymethyl)nitromethane (THNM), sodium hypochlorite, ozone, chlorine dioxide, peracetic acid, and combinations thereof.

[0042] Wax control substances are chemicals that are paraffin inhibitors (inhibit the aggregation of paraffin or waxy substances). Wax control substances can reduce the pour point temperature and viscosity of the mixture.

[0043] Wax control materials may include, but are not limited to, poly(ethylene-co-vinyl acetate) (EVA), ethylene / acrylonitrile copolymers, poly(ethylene-b-propylene), poly(ethylene butylene) polymers, (meth)acrylic acid and maleic anhydride copolymers, polyesters, amine ethoxylates, alkyl sulfonates, alkyl aryl sulfonates, fatty amine ethoxylates, or combinations thereof.

[0044] Asphaltene control substances are chemicals that inhibit the aggregation of asphaltene (such as tar, asphalt or bitumen). Asphaltene control substances can reduce the pour point temperature and viscosity of the mixture.

[0045] Asphaltene control substances may include, but are not limited to, xylene, n-butylisoquinolinium chloride ionic liquid, amphiphilic P (n-dodecyl) benzene sulfonic acid, vegetable oil, coconut essential oil, sweet almond oil, andiroba oil and sandalwood oil, boscan resin, cerro negro resin, 1-allyl-3-hexadecyl imidazolium bromide, dodecylbenzene sulfonic acid (DBSA), dodecyltrimethylammonium bromide (DTAB), light cycle oil (LCO), TiO2 nanoparticles, surfactant (SDJ), Al2O3 nanofluid, propoxylated polydodecyl, phenol formaldehyde, octylphenol, dodecylphenol, 2-hydroxybenzoic acid C6H4(OH)COOH salicylic acid or a combination thereof.

[0046] Demulsifier is a chemical that destroys emulsion. That is, demulsifier separates two or more mixed phases of emulsion. Demulsifier can include but is not limited to urea, polyethylene glycol, diethylene glycol, propylene glycol, fatty alcohol ethoxylate, monoethylene glycol, triethanolamine, 2-ethylhexyl acrylate, methacrylic acid, sodium lauryl sulfate, butyl acrylate, anhydrous acrylic acid, methyl methacrylate, naphthalene, methyl trioctyl ammonium chloride (TOMAC), dioctylamine or its combination.

[0047] A breaker is a chemical that breaks up a gel (or gel mixture) over a period of time. A breaker can reduce the viscosity of the composition compared to when the composition does not include a breaker. A breaker can include, but is not limited to, enzymes, polyacrylamide, guar gum, sodium hypochlorite, ammonium peroxide, hydrogen peroxide, or a combination thereof.

[0048] Drag reducers are chemicals that reduce turbulence (drag) in a well, pipeline or reservoir. Drag reducers may include, but are not limited to, polyethylene, copolymers of linear alpha-olefins with crosslinking agents, polyacrylamide, polyalkylene oxide, fluorocarbons, polyalkyl methacrylates, terpolymers of styrene, alkyl acrylates, acrylic acid or methacrylic acid, or combinations thereof.

[0049] Oxidizers are chemicals that capture dissolved oxygen in a chemical reaction, making it unavailable for corrosion reactions. Oxidizers may include, but are not limited to, sulfite (SO3 -2 ) and bisulfite (HSO3 - ) ions, diethylhydroxylamine (DEHA) or a combination thereof.

[0050] Foaming agent is a chemical that promotes the formation of foam, such as surfactant or foaming agent. Foaming agent can reduce the surface tension of liquid and produce uniform and stable foam. Foaming agent can include but is not limited to azodicarbonamide (azodicarbonamide), inorganic bicarbonate (sodium bicarbonate, potassium bicarbonate, aluminum bicarbonate, ferric bicarbonate), sodium lauryl sulfate, azodicarbonamide (azodicarbonamide), benzenesulfonylhydrazide, dinitrosopentamethylenetetramine, toluenesulfonylhydrazide, azobisisobutyronitrile, barium azodicarboxylate or its combination.

[0051] Surfactants are chemicals that adsorb at the interface between two fluids, thereby reducing the surface tension or interfacial tension between the fluids or between a fluid and a solid. Surfactants may include, but are not limited to, sodium dodecyl sulfate, tris(hydroxymethyl)aminoethane dodecyl sulfate, sodium dodecyl sulfonate, sodium cholate, sodium taurocholate, sodium deoxycholate, sodium taurodeoxycholate, sodium N-dodecanoyl-N-methyl taurate, lithium perfluorooctane sulfonate, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, carboxy betaine (-NR2CH2COO-), sulfobetaine (-N(CH3)2C3H6SO3 - ) and quaternary ammonium salts (-R4N + ), alcohol ethoxylates, alkylphenol ethoxylates, fatty acid ethoxylates, monoalkaolamide ethoxylates, sorbitan ester ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide copolymers, glycol esters, glycerol and polyglycerol esters, glucosides and polyglucosides, sucrose esters or combinations thereof.

[0052] The treatment agent may include an acid treatment agent (or an acid system). The acid treatment agent may be a mineral acid, a powdered acid, a mixed acid, a retarded acid (or a retarded acid), an acid precursor or a combination thereof.

[0053] The mineral acid may include hydrochloric acid, hydrofluoric acid, or a combination thereof.

[0054] The organic acid may include formic acid, acetic acid or a mixture thereof. The powdered acid may include a powdered solid acid such as sulfamic acid, chloroacetic acid or a combination thereof.

[0055] The mixed acid may include, for example, an acetic acid-hydrochloric acid mixture or a formic acid-hydrochloric acid mixture.

[0056] The passivating acid may include a gelled acid, a chemically passivating acid, an emulsified acid, or a combination thereof. When a concentrated mineral acid or organic acid is used in a capsule, it may be chemically passivated. A mixed acid is a mixture of acids, such as a mixture of any of the aforementioned acids.

[0057] As used, "thickening acid" is a type of passivating acid having a gel structure and comprising an acid and a gelling agent. The gelling agent may include, but is not limited to, xanthan polymer (XP), guar gum (GG), hydroxyethyl cellulose (HEC), carboxymethyl-hydroxyethyl cellulose (CMHEC), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), acrylamide / sodium 2-acrylamido-2-methylpropane sulfonate copolymer (PAM / AMPS), or a combination thereof.

[0058] The capsule may include a thickening acid such as obtained by core-shell hot melt extrusion or other methods known in the art such as machine or manual tablet loading, gel cap formation, etc. Core-shell hot melt extrusion may be used to form microcapsules. The capsule may be a shell forming material including, but not limited to, polyethylene, polypropylene, poly(1-butene), poly(methyl methacrylate), polyvinyl chloride, or a combination thereof.

[0059] The acid precursor may be a non-aqueous (not water soluble) ester compound that dissociates into its associated acid and alcohol in a deesterification with water. The acid precursor is hydrolyzed into the associated acid (and alcohol) in the presence of water at elevated temperatures. Elevated temperatures include a temperature range of about 60° C. to about 150° C. The associated acid and alcohol from the deesterification may be water soluble.

[0060] Suitable acid precursors include, but are not limited to, lactic acid derivatives such as methyl lactate, ethyl lactate, propyl lactate or butyl lactate; water-soluble or partially water-soluble esters or formates such as ethylene glycol monoformate, methyl formate, ethyl formate, methyl chloroformate, triethyl orthoformate, trimethyl orthoformate, ethylene glycol diformate, diethylene glycol diformate, glycerol monoformate, glycerol diformate, glycerol triformate or triethylene glycol diformate; formic acid esters of pentaerythritol; esters or polyesters of glycerol such as tripropionin (triester of propionic acid and glycerol) or triacetin. esters of acetic acid and glycerol, such as monoacetin, diacetin or triacetin; esters of glycolic acid, such as ethyl glycolate, methyl glycolate, propyl glycolate or butyl glycolate; esters of glycolic acid with polyols, such as glycerol and glycols; esters of oxalic acid; polymers or copolymers of any of the above or the following, such as aliphatic polyesters, poly(lactide), poly(glycolide), poly(c-caprolactone), poly(hydroxybutyrate); poly(anhydrides), aliphatic polycarbonates, poly(amino acids); polyphosphazenes, poly(ortho esters), ortho esters (which may also be referred to as "poly ortho ethers" or "ortho ethers"), esters of propionic acid, esters of butyric acid; esters of monochloroacetic acid, esters of dichloroacetic acid, esters of trichloroacetic acid; derivatives thereof or combinations thereof. Other suitable acid precursors include halide esters and esters of acids such as esters of nitric acid, sulfuric acid, sulfonic acid, sulfinic acid, phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid, sulfamic acid, or combinations thereof.

[0061] The system includes one or more radiation sources placed at or near the treatment location. The radiation source can be activated to selectively emit radiation. The radiation source can be a "natural radiation source", meaning a radioactive material that emits radiation, such as a chemical. The radiation can be an "artificial radiation source", meaning a device that emits radiation, including but not limited to a pulsed radiation generator (such as a pulsed neutron generator). The emitted radiation can activate the well treatment agent at a desired location downhole.

[0062] The radiation source may include a source for emitting gamma rays. Gamma radiation can provide a greater amount of energy into the fluid stream than radiation other than gamma rays, with sufficient penetration depth. For example, the energy range of gamma radiation (a photon) is 10 5 electron volt (eV) or greater, while the energy of X-ray radiation (a photon) ranges from 10 2 Up to 10 5 eV, the energy range of ultraviolet radiation (a photon) is 10 0 Up to 10 2 eV, and the energy range of neutron radiation (a particle) is 10 4 Up to 10 7 eV. Multiple radiation sources can be combined to provide 100 eV or more, 10 2 eV or greater, or 10 4 Energy range of eV or greater. Gamma radiation may provide sufficient penetration depth, such as up to 10 to 15 cm or 100 cm or less, depending on the energy and material type.

[0063] Other radiation sources may also be used in combination with gamma rays or separately from gamma rays. The radiation source emits radiation, such as neutrons, gamma rays, X-rays, or ultraviolet (UV). For example, the source may be a neutron source (such as neutrons emitted from a pulsed neutron generator), a gamma source, an X-ray source, an ultraviolet source (UV source), or a combination thereof. The parameters of the radiation source, such as the energy of the neutrons, gamma rays, X-rays, or UV rays, are selected in a manner to provide radiation emission for shell destruction.

[0064] The frequency range of the emitted radiation may vary depending on the type of radiation, the situation, the application, etc. For example, gamma rays are radio waves with a frequency typically greater than 10 19 -10 20 Hz electromagnetic waves; X-rays have a frequency of about 10 17 -10 19 Hz range; ultraviolet (UV) rays have a frequency of about 7.5*10 14 -10 16 Electromagnetic waves in the Hz range; neutrons, alpha and beta radiation are particles (not electromagnetic radiation) within the energy spectrum.

[0065] Electromagnetic radiation with a frequency of 50 to 1500 kHz is below the range of visible light (4*10 14 -8*10 14 Hz). Within this range, effective degradation is observed for 100-300 kHz electromagnetic (EM) frequencies (where EM frequencies are applicable, e.g., not neutron, alpha, and beta radiation), depending on the capsule used, but the effect is also present at other frequencies.

[0066] The emitted radiation has a penetration depth that can vary based on the type of medium, the type of radiation, and the intensity of the emitted radiation. For example, the neutron flux is reduced by about an order of magnitude or about 10 centimeters (cm) in ordinary water. Therefore, the neutron source can be placed within tens of centimeters, such as 100 cm or less, 50 cm or less, 40 cm or less, 30 cm or less, 20 cm or less, or 10 cm or less from the treatment location and is sufficient to treat the annulus.

[0067] Gamma radiation has a smaller penetration depth than neutron radiation. The gamma source can be placed within tens of centimeters, such as 100 cm or less, 90 cm or less, 50 cm or less, 40 cm or less, 30 cm or less, 20 cm or less, 10 cm or less, or 8 cm or less, from the treatment location and is sufficient to treat the annulus.

[0068] X-ray radiation has a smaller penetration depth than gamma radiation. The X-ray source can be placed within a few centimeters, such as 10 cm or less, 9 cm or less, 8 cm or less, 7 cm or less, 6 cm or less, 5 cm or less, 4 cm or less, 3 cm or less, 2 cm or less, or 1 cm or less from the treatment location and sufficient to treat the annulus.

[0069] Compared to X-ray radiation, ultraviolet radiation has a smaller penetration depth. The UV source can be placed within a few millimeters, such as 10 mm (1 cm) or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, or 1 mm or less from the treatment location and is sufficient to treat the annular space.

[0070] The emitted radiation reacts with the capsule, resulting in a chemical reaction that causes the shell of the capsule to disintegrate or dissolve (or otherwise break down). Upon shell disintegration, the contents of the capsule (including the treatment agent) may be released into the surrounding environment.

[0071] method

[0072] The method may include preparing the well treatment composition prior to introducing the system downhole.

[0073] In one or more embodiments, the method includes introducing a system downhole. The system includes a well treatment composition including a treatment agent and a radiation source to a target location.

[0074] Figure 1 A method of treating a wellbore or hydrocarbon formation 100 is shown and includes introducing a well treatment composition into the wellbore 102 and introducing a radiation source into the wellbore 104. The method may include activating the radiation source and emitting radiation at a target location 106. The method may include maintaining the wellbore to allow the emitted radiation to react with the well treatment composition 108. The method may include disintegrating or dissolving a radiation activated well treatment agent, thereby releasing the treatment agent from the well treatment composition at the target location 110.

[0075] The well treatment composition (including the treatment agent) can be introduced downhole using a wellbore circulating fluid such as mud (drilling fluid). The well treatment composition including the treatment agent is positioned together with the wellbore fluid to reach the target location.

[0076] The radiation source may be introduced into the wellbore after the well treatment composition. The radiation source is introduced and positioned to the target location (treatment area). Alternatively, the radiation source may be introduced into the wellbore and positioned prior to the introduction of the well treatment composition. The radiation source may be introduced into the wellbore using a tool (e.g., using a winch or other suitable tool that can be introduced downhole).

[0077] Activating the radiation source is followed by a step of emitting radiation, which is closely mixed with the well treatment composition at the target location. The step of activating the radiation source depends on the type of radiation source. For example, when using a natural radiation source (radioactive material, chemical), activating the radiation source includes introducing the radiation source into the well (to be described) while the radioactive material is emitting radiation sufficient to provide sufficient penetration depth. When using an artificial radiation source (such as a device that emits radiation), activating the radiation source includes powering the source, such as using a wired cable to power the device. Other power sources that will be understood by a person of ordinary skill in the art can be used. After activating the radiation source, radiation is emitted, such as neutrons, gamma, X-rays, ultraviolet (UV) radiation, or a combination thereof. The emitted radiation is configured to react with the well treatment composition, thereby causing the release of the treatment agent. For example, the emitted radiation can react with the capsule, thereby causing the shell to disintegrate or dissolve, and causing the release of the encapsulated treatment agent.

[0078] A single type of radiation source can provide more effective activation of a particular amount of a well treatment composition than an array of radiation sources.For example, a single radiation source can be matched to a particular well treatment composition to provide a response.

[0079] An array of radiation sources (multiple sources of one or more types of radiation sources) can provide a greater affected volume and amount of released agent over an area compared to a single type of radiation source. When an array of radiation sources is included, the array can be activated simultaneously or sequentially. In addition, individual radiation sources in a combination of radiation sources can be activated simultaneously or sequentially (e.g., with a time delay).

[0080] The method may include activating a well treatment composition at a target location using a radiation source to produce a radiation-activated well treatment agent. The target location may be a treatment zone downhole, such as a drilling zone, a formation zone, or a combination thereof. Once the well treatment composition approaches the target location, the wellbore is maintained so that the radiation emitted from the activated radiation source reacts with the well treatment composition. Maintaining the wellbore may include avoiding closing the well so that a tool including a radiation source can be operated. Therefore, the method includes exposing the target location to (emitted) radiation. After a period of time, the emitted radiation reacts with the well treatment agent including the treatment agent and decomposes it. The method includes releasing the treatment agent from the radiation-activated well treatment agent. After the radiation-activated well treatment agent decomposes (disintegrates or dissolves), the treatment agent is released to the target location.

[0081] For example, activating the well treatment composition at the target location using a radiation source may include, but is not limited to, ultraviolet (UV) radiation, which causes, for example, photo-oxidative degradation of polymer chains in the well treatment composition, for example, in the capsule. Degradation may result in the breakage of polymer chains, a decrease in the molecular weight of polymer chains, degradation of the mechanical properties of polymers, and rupture of capsule shells. Examples of such polymers that may be degraded include polystyrene (PS), polyvinyl chloride (PVC), and polyolefins such as polypropylene (PP) and polyethylene (PE), etc. The type of reaction may include, but is not limited to, UV radiation that causes damage and breakage of polystyrene chains; gamma radiation that causes degradation of polyvinyl chloride chains; neutron radiation that causes degradation of isobutylene-isoprene rubber, polymethyl methacrylate (PMMA), and polystyrene (PS). The chemical mechanism of degradation may be different and may include, but is not limited to, for example, chain scission or oxidation.

[0082] Without wishing to be bound by theory, a gamma source may be advantageously introduced compared to another radiation source due to the ability to emit a greater amount of energy and sufficient penetration depth and capsule shell rupture capability. For example, a gamma source may penetrate to a depth of 90, 80, 70, 60, 50, 40, 30, 20, or 10 cm or less. A gamma source may provide 10 5 The neutron source may have an energy of electron volt (eV) or more and may have the ability to rupture the capsule shell because it is the highest in energy and penetration depth among electromagnetic radiation sources (including UV, X-rays and gamma). Neutron sources may have comparable energy and similar or greater penetration depth than gamma sources. The degradation effects of gamma radiation are comparable to those of neutrons. The choice between the radiation sources used may be determined by the sensitivity of the components of the composition to be irradiated.

[0083] The method can be used for targeted descaling of a wellbore, such as in a wellbore having scale. The scale can include barite scale and is understood by those of ordinary skill in the art. The descaling method includes a well treatment composition including a descaling agent. When applied to descaling, the method can include releasing a treatment agent including a descaling agent to destroy scale deposits in a target location.

[0084] A method for targeted descaling of a wellbore may include introducing a ball device with a radiation source (ball activated radiation source) into the well and positioning the ball device at a target location. One of ordinary skill in the art will understand the operation of a ball device (such as a ball activated fracturing tool completion device). The ball device may be a compact autonomous device that falls into the well at the wellhead and travels inside the well. The ball device may be connected to a cable, such as a shielded wired cable. The ball device may also be recyclable. The positioning of the ball device may be self-positioning or controlled by an operator. The ball device may include a fluid pressure pulse link to convey a signal through fluid pulse telemetry. For example, a fluid pressure pulse (a step change in pressure) may be applied to the fluid in the borehole at the wellhead. The fluid pressure pulse is propagated through the fluid and may be used as a signal.

[0085] Once the ball device and the radiation source are in the proper position at the target location, the well treatment composition is introduced into the wellbore. The ball device can be instructed to activate the radiation source. Two ball devices can be used, for example, the first ball device can be used to introduce the radiation source, and the second ball device can be used to introduce the well treatment composition. The well treatment composition can also be introduced by pumping from the top of the wellhead or by releasing from a container carried by a tool (such as a tool lowered on a cable in the well). When the well treatment composition arrives at the treatment location, the radiation source is activated, and the emitted radiation reacts with the well treatment composition to form the resulting radiation-activated well treatment agent. The treatment agent (descaler) is released after the radiation-activated well treatment agent breaks down. The signal for activating the radiation source can be received at the ball device via fluid pulse telemetry. The released descaler decomposes the scale at the target location.

[0086] The method may be used for acidizing a target location, such as using an acid stimulation treatment. One of ordinary skill in the art understands that acidizing can restore or enhance the productivity of a well or formation compared to not performing the acidizing. The acidizing method includes a well treatment composition comprising a treatment agent including an acidizing agent. When applied to acidizing, the method may include releasing an acid or an acid precursor (as an acidizing agent) at the target location.

[0087] A method of targeted acidizing of a wellbore may include introducing a ball device with a radiation source downhole and positioning the ball device at a target location. The positioning of the ball device may be self-positioning or controlled by an operator. The ball device may include a fluid pressure pulse link to communicate signals via fluid pulse telemetry.

[0088] Once the ball device is in position at the target location, the well treatment composition is introduced into the wellbore. When the well treatment composition reaches the treatment location by flow, the radiation source is activated. The ball device can be instructed to activate the radiation source. The emitted radiation is closely mixed with the well treatment composition to react with the well treatment composition and form the resulting radiation-activated well treatment agent. The treatment agent (acidifier) ​​is released after the radiation-activated well treatment agent is broken. The signal for activating the radiation source can be received at the ball device via fluid pulse telemetry. The released acidifier stimulates the wellbore and formation at the target location.

[0089] The ball device and the radiation source can be configured to allow the emitted radiation to penetrate to a target location in the formation. Thus, the acidizing agent can be released inside the formation as compared to both inside the wellbore and inside the formation. Without wishing to be bound by theory, releasing the acidizing agent inside the formation can increase the penetration depth of the agent or ensure that the agent is located at a desired distance from the wellbore (at the target location). The desired distance from the wellbore can be 1 cm to 100 cm, such as 2 cm to 80 cm, 5 cm to 50 cm, 5 cm to 25 cm, 5 cm to 15 cm, or 1 cm to 10 cm.

[0090] When the system of one or more embodiments is applied, a smaller amount of well treatment composition can be used compared to a non-targeted system or method. This means that the system and method of one or more embodiments can avoid the loss of well treatment composition to areas or locations other than the target location.

[0091] In one or more embodiments, a combined treatment may be used. For example, a descaling treatment and an acidizing treatment may be combined into a single wellbore treatment composition and method.

[0092] The system of one or more embodiments also provides control over the activation of targeted well treatment compositions, such as the ability to control well depth activation and penetration depth activation into the formation. In this way, the system and method of one or more embodiments allows for targeted activation control at two-axis or three-axis penetration spaces.

[0093] Additionally, the system of one or more embodiments prevents premature activation of the treatment downhole by controlling the ability to activate the well treatment composition via a radiation source.

[0094] Finally, the system of one or more embodiments may advantageously be operated without shutting in the well.

[0095] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0096] As used herein and in the appended claims, the terms "comprising," "having," and "including" and all grammatical variations thereof are intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

[0097] "Optionally" means that the subsequently described event or circumstance may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0098] When the word "about" or "approximately" is used, the term may mean that the value may vary by up to ±10%, up to 5%, up to 2%, up to 1%, up to 0.5%, up to 0.1%, or up to 0.01%.

[0099] When used, the term "substantially" means a majority or majority, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99% or at least about 99.999% or more.

[0100] Ranges can be expressed as about one particular value to about another particular value (including endpoints). When such a range is expressed, it should be understood that another embodiment is from one particular value to another particular value, and all the particular values ​​and combinations thereof within the range.

[0101] Although only a few exemplary embodiments have been described in detail, those skilled in the art will readily appreciate that many modifications are possible in these exemplary embodiments without substantially departing from the present disclosure. All modifications of one or more of the disclosed embodiments are intended to be included within the scope of the present disclosure as defined in the appended claims. In the claims, means-plus-function clauses are intended to cover structures previously described as performing the described function, not limited to structural equivalents, but also including equivalent structures. Applicant expressly disclaims any limitation of any of the claims by invoking 35 U.S.C. §112(f), except for those where the claims expressly use the term "means for..." together with the associated function.

[0102] Although one or more embodiments of the present disclosure have been described with respect to a limited number of embodiments, those skilled in the art having benefit of the present disclosure will appreciate that other embodiments can be conceived without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure shall be limited only by the appended claims.

Claims

1. A system comprising: A well treatment composition comprising a capsule and a treatment agent solution in the capsule, wherein the treating agent solution comprises a treating agent, the treating agent comprising one or more selected from the group consisting of: scale dissolving agents, scale inhibitors, hydrate inhibitors, rock salt inhibitors, corrosion inhibitors, biocides, wax control substances, asphaltene control substances, demulsifiers, gel breakers, drag reducers, deoxidizers, foaming agents, surfactants, acid treatment agents, and well cleaning substances; as well as A radiation source, wherein the radiation source comprises one or more selected from the group consisting of a neutron source, a gamma source, an X-ray source and an ultraviolet source.

2. The system of claim 1, wherein the well treatment composition further comprises a delivery fluid comprising water, a delivery fluid surfactant, or a mixture thereof.

3. The system of claim 1 , wherein the capsule has a polymer shell comprising one or more selected from the group consisting of melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde resin, melamine-phenol-formaldehyde resin, furan-formaldehyde resin, epoxy resin, polysiloxane, polyacrylate, polyester, polyurethane, polyamide, polyether, polyimide, polyolefin, polypropylene-polyethylene copolymer, polystyrene, functionalized polystyrene derivative, gelatin, gelatin derivative, cellulose, cellulose derivative, starch, starch derivative, polyvinyl alcohol, ethylene-vinyl acetate copolymer, maleic anhydride-based copolymer, polyacrylamide, polyacrylamide-based copolymer, polyacrylic acid, polyacrylic acid-based copolymer, polyvinyl pyrrolidone, polyvinyl pyrrolidone-based copolymer, polyacrylate-based copolymer, propylene-acrylate copolymer, propylene-methacrylate copolymer, oxidized polypropylene, oxidized polyethylene, propylene-ethylene oxide copolymer, styrene-acrylate copolymer, acrylonitrile-butadiene-styrene copolymer.

4. The system of claim 1, wherein the treating agent solution comprises one or more selected from the group consisting of an emulsion, a suspension, a polymer filler, and combinations thereof.

5. The system of claim 4, wherein the emulsion comprises one or more selected from the group consisting of an oil-in-water emulsion, a water-in-oil emulsion, a water-in-oil-in-water emulsion, and an oil-in-water-in-oil emulsion, and wherein the emulsion comprises an internal phase comprising the treating agent.

6. The system of claim 4, wherein the suspension comprises a solid material and a liquid component, wherein the solid material comprises the treating agent, and The liquid component is one or more selected from the group consisting of acetone, benzene, methanol, ether and combinations thereof.

7. The system of claim 6, wherein the solid material further comprises one or more selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), tetrasodium glutamate diacetate (GLDA), aminosulfonic acid, and combinations thereof.

8. The system of claim 4, wherein the treatment agent is embedded in the polymer filler, and The polymer filler comprises one or more selected from the group consisting of addition polymers of vinyl monomers, condensation polymers of monomers and condensation polymers of prepolymers.

9. The system of claim 8, wherein the addition polymer of vinyl monomers comprises one or more selected from the group consisting of acrylamide, acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, styrene, 4-vinylbenzyl chloride, divinylbenzene, and methylenebisacrylamide.

10. The system of claim 8, wherein the condensation polymer of monomers comprises one or more selected from the group consisting of melamine-formaldehyde resins, phenol-formaldehyde resins, urea-formaldehyde resins, epoxy resins, polyurethane resins, urea resins, polyurethane / urea resins, and polyester resins.

11. The system of claim 8, wherein the condensation polymer of the prepolymer comprises one or more selected from the group consisting of a methylene diphenyl diisocyanate (MDI) based prepolymer or a toluene diisocyanate (TDI) based prepolymer.

12. The system of claim 1, wherein the scale dissolving agent comprises one or more selected from the group consisting of an acid-based scale dissolving agent and a chelating agent-based scale dissolving agent.

13. The system of claim 1, wherein the acid treatment agent comprises one or more selected from the group consisting of a mineral acid, a powdered acid, a mixed acid, a passivating acid, and an acid precursor.

14. The system of claim 13, wherein the passivating acid is a thickening acid.

15. A method of treating a wellbore or hydrocarbon formation, comprising: introducing a well treatment composition comprising an encapsulated treatment agent downhole to a target location in a wellbore circulating fluid; introducing a radiation source into the wellbore and positioning the radiation source at the target location; activating the radiation source and emitting radiation intimately mixed with the well treatment composition at the target location; maintaining the wellbore to allow radiation emitted from an activated radiation source to react with the well treatment composition to form a radiation activated well treatment composition; as well as The radiation activated well treatment composition is caused to disintegrate or dissolve, thereby disrupting the encapsulation and releasing the treatment agent at the target site.

16. The method of claim 15, wherein the emitted radiation is one or more selected from the group consisting of neutrons, gamma, X-rays, ultraviolet (UV), and combinations thereof.

17. The method of claim 15, wherein the well treatment composition comprises a scale dissolving agent.

18. The method of claim 15, wherein the well treatment composition comprises an acid treatment agent.

19. The method of claim 15, wherein the emitted radiation has a penetration depth of 100 cm or less.

20. The method of claim 15, wherein the emitted radiation has a 0 Energy range of eV or larger.

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