Patent Application
20140144620
Not Applicable.
This invention relates generally to composites used in the oil and gas industry. More specifically, this invention relates to electrostatically coated composites used in the oil and gas industry and methods of making them.
Composites have been used in the oil and gas industry. For example, downhole composite tools have been found to boost durability and drillability. These tools are made with both thermoplastics and thermoset resins and they are used in a variety of applications.
The use of electrostatic powder coating techniques to paint electrically conductive substrates, such as metals, is well known and successfully employed. Using this method, a powder coating material is statically charged or ionized to a positive polarity or negative polarity, and then sprayed or blown onto a grounded, conductive article to which it adheres. The electrostatic attraction between the paint and the grounded article results in a more efficient painting process with less wasted material, and thicker, more consistent paint coverage, particularly on articles that have a complex shape. Once coated, the article is then baked. In electrostatic painting, a powder coating material is statically charged and applied using standard powder coating equipment. With electrically conductive substrates, a static electric potential is generated between the paint and the substrate to be painted resulting in an attraction of the paint to the object. When objects fabricated from metals are painted, the metal, which is inherently conductive, is easily grounded and efficiently painted.
However, the conventional electrostatic coating techniques are not as successful in coating composites due to their low electrical conductivity. If an object has low electrical conductivity, it cannot be efficiently electrostatically charged and cannot be efficiently electrostatically coated. Furthermore, on non-conductive surfaces, low humidity levels can have a negative impact on the quality of the bond between the powder coating and the surface. Even so, electrostatic painting techniques are still desirable for use due to benefits such as, less waste of paint, high quality coating, and better coverage.
There is continuing interest in developing powder coated composites with superior performance and methods of making such for applications in the oil and gas industry.
Herein disclosed is a method of electrostatically coating a composite object comprising: a) Pretreating a surface of the composite object with a composition to induce conductivity; b) Applying a charge to the object after surface pretreatment; and c) Electrostatically applying a coating material to the object.
In an embodiment, the method comprises cleaning the surface of the composite object prior to pretreating. In an embodiment, the method comprises utilizing acetone or denatured alcohol to clean the surface.
In an embodiment, step (b) takes place immediately after step (a) or after the composition dries or at any state in between.
In an embodiment, the method comprises curing the object after coating. In an embodiment, curing takes place at a temperature of from about 250° F. to about 450° F. In an embodiment, curing takes place for less than 1 hour.
In an embodiment, the composition comprises at least one iodophor of a member selected from the group consisting of nonionic surfactants, glycol ether, polyvinylpyrrolidone and combinations thereof. In an embodiment, the composition comprises at least one iodophor of polyethoxylated nonylphenol, at least one iodophor of polyethoxylated fatty alcohol and combinations thereof. In an embodiment, the composition comprises from about 0.001 wt-% to about 100 wt-% of the at least one iodophor of a nonionic surfactant, glycol ether, polyvinylpyrrolidone and combinations thereof. In an embodiment, the composition comprises from about 0.5 wt-% to about 1.5 wt-% titratable iodine.
In an embodiment, the composition comprises at least one member selected from the group consisting of water, alcohol, ether toluene, p-xylene, benzene, carbon disulfide, chloroform, carbon tetrachloride, glycerol, alkaline iodide solution, and combinations thereof. In an embodiment, the composition comprises at least one iodophor of a nonionic surfactant selected from the group consisting of primary and secondary aliphatic alcohol ethoxylates, alkylphenol ethoxylates and ethylene oxide/propylene oxide condensates on primary alkanols, condensates of ethylene oxide with sorbitan fatty acid esters, condensates of ethylene oxide and aliphatic ethers or glycols and combinations thereof.
In an embodiment, composition comprises at least one ethylene oxide/propylene oxide condensates which comprises about 50% to about 70% ethylene oxide and at least one of nonylphenoxypoly (ethyleneoxy) ethanol or octylphenoxypoly (ethyleneoxy) ethanol.
In an embodiment, the composition comprises at least one of water, ethanol, methanol, isopropanol or combinations thereof. In an embodiment, the composition comprises at least one halophor of a nonionic surfactant, glycol ether, polyvinylpyrrolidone and combinations thereof.
In an embodiment, the composition comprises at least one member selected from the group consisting of halophors of nonionic surfactants; halophors of amphoteric surfactants; iodophors, chlorophors and bromophors of anionic surfactants; halophors of glycol ether or polyvinylpyrrolidone; hypohalites; hypohalates; perhalates; iodine, chlorine, bromine, fluorine; and combinations thereof.
In an embodiment, the composition comprises a halogen complex which is an iodophor of a surfactant. In an embodiment, the composition comprises an iodophor of polyethoxylated nonylphenol, an iodophor of polyethoxylated fatty alcohol or a combination thereof.
In an embodiment, the composition comprises at least one member selected from the group consisting of halophors of nonionic surfactants; halophors of amphoteric surfactants; iodophors, chlorophors, and bromophors of anionic surfactants; halophors of glycol ether or polyvinylpyrrolidone; hypohalites; hypohalates; perhalates; iodine, chlorine, bromine, fluorine; and combinations thereof. In an embodiment, the halogen salt is an alkali metal or alkaline earth metal halide salt, hypohalite, hypohalate, or perhalate.
In an embodiment, the composition is a hypohalite. In an embodiment, the hypohalite is sodium hypochlorite.
In an embodiment, the composition comprises at least one member selected from the group consisting of iodophors nonionic surfactants, iodophors of amphoteric surfactants; iodophors of cationic surfactants; iodophors of anionic surfactants; iodophors of glycol ether, iodophors of polyvinylpyrrolidone, and combinations thereof.
Further described is a composite object made according to the method of this disclosure, wherein the object is used in the oil and gas industry. In an embodiment, the object comprises bridge or frac plug mandrels, wedges, sleeves, noses, cones, mule shoes, extrusion limiters, slips, baffles, landing seats, frac balls, wireline tools, housings for measurement-while-drilling, housings for logging-while-drilling, or tubular parts.
Disclosed herein is a composite object pretreated with a surface treatment composition comprising at least one halogen complex which is an iodophor and electrostatically coated. In an embodiment, the iodophor is an iodophor of polyethoxylated nonylphenol, an iodophor of polyethoxylated fatty alcohol or combination thereof.
Also disclosed herein is a composite object used in the oil and gas industry wherein the object is pretreated with a surface pretreatment composition comprising at least one halogen, a halogen salt, a halogen complex or combination thereof, wherein the halogen is iodine and electrostatically coated.
Further described is a composite object used in the oil and gas industry wherein the object is pretreated with a surface pretreatment composition comprising at least one member selected from the group consisting of halophors of nonionic surfactants; halophors of amphoteric surfactants; iodophors, chlorophors and bromopbors of anionic surfactants; halophors of glycol ether or polyvinylpyrrolidone; hypohalites; hypohalates; perhalates; iodine, chlorine, bromine, fluorine; and combinations thereof and electrostatically coated.
Still further disclosed is a method of manufacturing a composite downhole tool comprising: a) pretreating a surface of the composite object with a composition to induce conductivity; b) applying a charge to the object after surface pretreatment; and c) electrostatically applying a coating material to the object; wherein the composite downhole tool comprises bridge or frac plug mandrels, wedges, sleeves, noses, cones, mule shoes, extrusion limiters, slips, baffles, landing seats, frac balls, wireline tools, housings for measurement-while-drilling, housings for logging-while-drilling, or tubular parts.
In an embodiment, the method further comprises cleaning the surface of the composite object prior to pretreating. In an embodiment, the method comprises utilizing acetone or denatured alcohol to clean the surface.
Herein disclosed is a composite downhole tool pretreated with a surface treatment composition comprising at least one halogen complex which is an iodophor and electrostatically coated. In an embodiment, the iodophor is an iodophor of polyethoxylated nonylphenol, an iodophor of polyethoxylated fatty alcohol or combination thereof.
Herein described is a composite downhole tool pretreated with a surface pretreatment composition comprising at least one halogen, a halogen salt, a halogen complex or combination thereof, wherein the halogen is iodine and electrostatically coated.
Herein described is a composite downhole tool pretreated with a surface pretreatment composition comprising at least one member selected from the group consisting of halophors of nonionic surfactants; halophors of amphoteric surfactants; iodophors, chlorophors and bromopbors of anionic surfactants; halophors of glycol ether or polyvinylpyrrolidone; hypohalites; hypohalates; perhalates; iodine, chlorine, bromine, fluorine; and combinations thereof and electrostatically coated. In an embodiment, the composite downhole tool comprises bridge or frac plug mandrels, wedges, sleeves, noses, cones, mule shoes, extrusion limiters, slips, baffles, landing seats, frac balls, wireline tools, housings for measurement-while-drilling, housings for logging-while-drilling, or tubular parts.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
Certain terms are used throughout the following description and claims to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function.
In this disclosure, “halophors” including bromophors, chlorophors, iodophors, fluorophors. As used herein, the term “halophor” is used to refer to complexes of halogens with solubilizers or carriers which are typically polymers such as polyvinyl pyrrolidone or polyethylene glycol, or certain types of surface active agents including those that have detergent properties. Complexes of halogens are known to one skilled in the art.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”.
Overview.
In an embodiment, an object made of a composite is pretreated on its surface with a composition; an electrical charge is then applied to the object; and a coating material is deposited on the object electrostatically. In various embodiments, the composite objects include bridge or frac plug mandrels, wedges, sleeves, noses, cones, mule shoes, extrusion limiters, slips, baffles, landing seats, frac balls, wireline tools, housings for MWD (measurement-while-drilling) and LWD (logging-while-drilling), or any tubular parts. As one skilled in the art would recognize, these parts are not differentiated by name but only by function. In an embodiment, the surface pretreatment composition includes a halogen, halogen complex, or hypohalite. In some embodiments, the surface pretreatment composition includes iodine or iodine complex. In other embodiments, the surface pretreatment composition includes sodium hypochlorite, or bleach. Details of powder coated composites and methods of their making are described herein below.
Surface Pretreatment.
The surface of the composite is pretreated so that it is clean and free of oils, dirt, debris, or other foreign impurities that may inhibit a secure bond. Acetone, denatured alcohol, or any other agent/method as known to ones skilled in the art may be used to clean the surface of the composites. In an embodiment, a liquid surface pretreatment composition is applied to a composite object. Such an object may be sprayed with the composition or dipped in a bath of the composition. The composition may also be brushed on the object. Any suitable method of applying the composition to an object is contemplated and is thus within the scope of this disclosure.
Surface Pretreatment Composition.
In an embodiment, the surface pretreatment composition comprises at least one halogen, halogen complex, a halide salt, hypohalite, hypohalate, perhalate, and so forth, or combination thereof, and a liquid carrier or solvent. Examples of suitable carriers include, but are not limited to, water, alcohol (such as ethanol, isopropanol and methanol), acetone, ethers (such as diethyl ether), toluene, p-xylene, benzene, carbon disulfide, chloroform, carbon tetrachloride, glycerol, alkaline iodide solutions, and so forth, and combinations thereof. Some carriers are more suitable due to the varying levels of toxicity or environmental concerns. In an embodiment, water is the solvent. In another embodiment, water mixed with another carrier (such as an alcohol) is used as the solvent.
In various embodiments, halogen includes iodine, bromine, chlorine, and fluorine. In an embodiment, the halogen used is iodine or chlorine. In a further embodiment, the halogen used is iodine.
In various embodiments, hypohalites of this disclosure include hypochlorite, hypoiodite, hypobromite, hypofluorite, hypoastatite, and combinations thereof. In some embodiments, hypochlorite is utilized because it is readily available and economical. The corresponding cation may be an alkali or an alkaline earth metal, such as sodium and potassium. In another embodiment, other metal salts are used including metal halides, perhalates, hypohalates, and so forth. In some cases, certain salts may produce graininess in the resulting powder coating, which is a lower quality coating.
In order to increase halogen solubility in solvents, complexes of halogens may be utilized. These halogen containing complexes are referred to as “halophors” in this disclosure and include bromophors, chlorophors, fluorophors and iodophors. In some embodiments, the complexes are prepared either with surfactants including nonionic, anionic, cationic, and amphoteric surfactants, or with polymers. The polymers or surface active agents (surfactants) may act to solubilize the halogen. In some cases, iodophors or chlorophors are utilized. In other cases, iodophors are utilized for the surface pretreatment composition.
Surfactants useful in forming halophors are known to one skilled in the art. Some examples are discussed herein below. Anionic surface-active agents are less popular in forming halogen complexes because they may not have the stability required for many applications. It may therefore be desirable to use them in combination with another surfactant. A suitable class of cationic surfactants useful in forming halophors is quaternary ammonium compounds.
The halogens, and in particular iodine may form complexes with nonionic surfactants. Useful synthetic nonionic surfactants are often the condensation products of an organic aliphatic or alkyl aromatic hydrophobic compound and hydrophilic ethylene oxide groups. Practically any hydrophobic compound having a carboxy, hydroxy, amido, or amino group with a free hydrogen attached to the nitrogen can be condensed with ethylene oxide or with the polyhydration product thereof, polyethylene glycol, to form a water-soluble nonionic surfactant.
Examples of nonionic surfactants useful in forming halophors include, but are not limited to, primary and secondary aliphatic alcohol ethoxylates, alkylphenol ethoxylates and ethylene oxide/propylene oxide condensates on primary alkanols, condensates of ethylene oxide with sorbitan fatty acid esters, condensates of ethylene oxide and aliphatic ethers or glycols, and so forth.
Examples of ethylene oxide/propylene oxide condensates useful herein include those having about 50% to about 70% ethylene oxide and nonylphenoxypoly (ethyleneoxy) ethanol and octylphenoxypoly (ethyleneoxy) ethanol.
Nonionic surfactants useful in forming halophors, in particular iodophors, are discussed in U.S. Pat. No. 5,707,955, incorporated by reference herein in its entirety. Bromophors and iodophors are discussed in U.S. Pat. No. 4,894,241, incorporated by reference herein in its entirety. Nonionic surfactants, anionic and cationic surfactants for use in halophor formation are described in U.S. Pat. No. 4,206,204, incorporated by reference herein in its entirety.
In an embodiment, a nonionic surfactant is used to form the halophor, including glycol ether, and polyvinylpyrrolidone (1-ethenyl-2-pyrrolidone homopolymer compound). While these are commonly used complexes of halogens, other compounds as described above may be used in the formation of the complexes as well. The titratable halogen, such as the titratable iodine, in such complexes is typically between about 0.5 and 1.5% halogen. It is surmised that a certain amount of halide may also be present in the composition.
Specific examples of useful iodophors of nonionic surfactants include, but are not limited to polyethoxylated nonylphenol iodine complex and polyethoxylated fatty alcohol iodine complex. In one embodiment, a blend of these two iodophors is utilized.
Other suitable surfactants are discussed in McCutcheon's Detergents and Emulsifiers, 1999, North American Edition, MC Publishing Co., incorporated by reference herein in its entirety. Other halophors may be readily substituted for use as known to one skilled in the art without departing from the scope of the present disclosure.
Varying the concentration of the halogen or halogen complex in the liquid carrier will result in different conductivities as well. In various embodiments, the concentration of halide or halide containing compound is in the range of from about 0.001% to about 100%. In an embodiment, the surface pretreatment composition comprises from about 0.01% to about 20% halogen or halogen complex, or alternatively from about 0.1 to about 10% halogen or halogen complex, or alternatively from about 0.1% to about 5% halogen or halogen complex.
In an embodiment, a mixture of an iodine complex in a solvent is used as the surface pretreatment composition. A solution of about 12.5% iodine complex is further diluted with water at a volume ratio of about 13:1, providing a solution of about 1% iodine complex. The titratable iodine is about 1% before dilution and the titratable iodine is less than about 0.1% after dilution. In some cases, denatured alcohol is the solvent/carrier. In some other cases, water is the solvent/carrier.
In various embodiments, the concentration of iodine is in the range of from 0.001% iodine or iodine complex to about 100% iodine or iodine complex, or alternatively from about 0.1% to about 10%, or alternatively from about 0.1% to about 5% iodine or iodine complex. In one particular embodiment, a solution of 12% iodine in water is employed.
Electrostatic Coating.
In embodiments, an electrostatic charge is applied to the surface of the composite object after the surface pretreatment using any powder coating equipment known in the art, such as one made by Nordsen or by Wagner (including a Nordsen 2001 powder coating system, a Wagner EPG 2007 powder coating system).
In an embodiment, a charge is applied to the pretreated surface of the composite object and an opposite charge is applied to the coating material used in the electrostatic coating process. In an embodiment, a negative charge is applied to the pretreated surface of the composite object and an opposite charge is applied to the coating material.
In various embodiments, the coating material includes any suitable composition that may be electrostatically applied, such as those used in electrostatic painting. In an embodiment, the coating material includes pigments or dyes.
In an embodiment, the coating process comprises (1) charging or ionizing a coating material and then spraying the coating material on a pretreated composite object as described above. The surface pretreatment step imparts sufficient conductivity to the surface of the composite object prior to electrostatic coating and thus enables sufficient electrostatic attraction between the coating material and the composite object.
Coating Material.
In embodiments, suitable coating material includes polyester resins, epoxy resins, epoxy-polyester resins, epoxy functional polyacrylate resins, and so forth. Such material is available, for example, from Spraylat Corp., BASF Corp. Examples of such coating material are described in U.S. Pat. No. 6,254,751 and U.S. Pat. No. 6,133,344, both of which are incorporated herein by reference in their entirety.
In an embodiment, the coating material also includes optional ingredients such as film formers, binders, crosslinking agents, flow aids, catalysts, devolatilization auxiliaries, dyes, and pigments.
In the case of paints, a dye or pigment is included if it is desirable to impart color to an object. The methods of this disclosure and objects made by such methods are not limited to any particular coating material employed in electrostatic coating or deposition.
In another embodiment, powder coating material is prepared by mixing the components in a high shear mixer or extruder at a temperature which is above the softening temperature of the film-forming polymer but below the crosslinking temperature and then bringing the resulting extrudate to a particle size of from about 40 to 70 microns by means of a milling process.
Post Treatment.
After electrostatic coating, the object may be placed in an oven at an appropriate temperature to cure. Typical temperatures for use with powder coating are in the range of from about 150° C. to 200° C. Other temperatures may be used depending on the type of coating material used. In an embodiment, the curing temperature is about 350° F. (about 175° C.). The amount of time to cure varies, but is typically less than 1 hour.
Composite Objects.
In various embodiments, the method of this disclosure is applied to a composite object used in the oil and gas industry as known to one skilled in the art. Such objects include bridge or frac plug mandrels, wedges, sleeves, noses, cones, mule shoes, extrusion limiters, slips, baffles, landing seats, frac balls, wireline tools, housings for MWD and LWD, or any tubular parts. As one killed in the art would recognize, these parts are not differentiated by name but only by function.
Advantages.
In various embodiments, the pretreated composite object may be electrostatically coated either “wet” or after drying or at any state in between. This allows electrostatic coating of the composite object to take place immediately after surface pretreatment. It has been surprisingly found that the method of this disclosure is not sensitive to the presence of moisture.
In various embodiments, the surface pretreatment composition may be used with any electrostatic coating or painting techniques known in the art. In various embodiments, electrostatic coating of both liquids and powders may be employed in the method of this disclosure. In the cases of a liquid coating, any suitable water-based (aqueous) and/or organic composition may be employed.
The method of this disclosure enables a more efficient coating process for non-conductive objects (such as composites). In certain embodiments, the coating process has less wasted material and produces thicker and more consistent coverage, which is difficult to achieve otherwise when the composite object has a complex shape.
In certain embodiments, a composite object used in the oil and gas industry coated by the method of this disclosure has 50% or more longevity than an object that is not coated. In certain embodiments, a composite object used in the oil and gas industry coated by the method of this disclosure has 40% or more longevity than an object that is not coated. In certain embodiments, a composite object used in the oil and gas industry coated by the method of this disclosure has 30% or more longevity than an object that is not coated. In certain embodiments, a composite object used in the oil and gas industry coated by the method of this disclosure has 20% or more longevity than an object that is not coated. In certain embodiments, a composite object used in the oil and gas industry coated by the method of this disclosure has 10% or more longevity than an object that is not coated.
While preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described herein are not comprehensive, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, and so forth). Use of the term “optionally” with respect to any element of a claim is intended to mean that the subject element is required, or alternatively, is not required. Both alternatives are intended to be within the scope of the claim. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, and the like.
Accordingly, the scope of protection is not limited by the description set out above but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated into the specification as an embodiment of the present invention. Thus, the claims are a further description and are an addition to the preferred embodiments of the present invention. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference, to the extent they provide some, procedural or other details supplementary to those set forth herein.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent application No. 61/730,941 filed Nov. 28, 2012, the disclosure of which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61730941 | Nov 2012 | US |
