Coated tools for use in oil well pipes

Use of coated tools in oil well pipes

Coated tools for use in oil well pipes

Full description

Background of the invention

REFERENCE TO APPLICATIONS This application seeks precedence under US Code Section 119 for the conditional application of US Patent No. 60/630,779 filed on November 24, 2004.

The invention relates to tools used in pipes that conduct oils, such as oil well pipes and oil pipelines, and to a more specific extent to cover the outer surface of these tools. Specifically, when used in oil pipes covered with these covers, the oil pipes that conduct large quantities of oil have primary attachments such as pipes. With a lower opening to deliver oil from underground deposits to the surface of the earth, and such as pipelines for long-distance transportation of oil across the surface of the earth. These pipes are typically made of carbon steel for economic reasons, but are particularly expensive due to metal alloys that are better at resisting corrosion in crude oil. Corrosion to a certain degree is dangerous in the hot environment located underground to deposit oil for these substances such as water, sulfur, sulfur dioxide, carbon dioxide, and hydrogen sulfide, which are typically present in oil, which makes it acidic. These 5 materials corrode oil pipes even at relatively low transportation temperatures. Long contact times with the inner surface of oil pipes create conditions for corrosion to occur.

Where nylon or polyphenylene sulfide is used. However, these materials do not possess the non-adhesive properties that are necessary to prevent the precipitation of asphaltenes and paraffin waxes. Therefore at that time there was no commercially attractive option for reducing clogging and corrosion on pipe tools. There are residues that need to be solved, corrosion and blockage problems occurring on the surfaces of tools used in oil pipes.

General description of the invention

The present invention solves these problems by covering the outer surface of the tools used in oil pipes after appropriately preparing this outer surface with a fluoropolymer.

Fluoropolymer which provides a non-stick surface on tools. The tool cover may have one or more layers of cover for a primer and one or more top covers. There is of course an economic advantage to providing thinner covers in applications determined to be less hazardous. In certain applications where the pipe in which this tool is used, use less than 1.5 ml, preferably less than 1 ml, and a single layer of cap may be used. However, highly thick coatings are preferred in conditions of serious damage or corrosion. In these circumstances the covers may be a multi-layer cover of a primer and one or more top covers.

According to the present invention, a tool cap used in an oil well with a cap including a fluoropolymer can reduce or eliminate the deposition of asphaltene, paraffin wax, or inorganic shell, reduce or eliminate deposition on the tool and therefore blockage in the oil pipes, and either reduce or eliminate corrosion of the outer surface of the tool. The decrease can be distinguished by being at least 40% and preferably at least 50% of one over

Less asphaltene, paraffin wax and inorganic veneers. Decreases can be perceived

This is especially expensive for metal alloys that are better at resisting corrosion factors in crude oil. Corrosion to a certain degree is dangerous in the hot underground environment of oil precipitation. These substances, such as water, sulfur, sulfur dioxide, carbon dioxide, and hydrogen sulfide, are typically present in the oil, which makes it acidic. These materials rust oil pipes even at relatively low transportation temperatures. Long contact times with the inner surface of oil pipes create the conditions for corrosion to occur.

An additional problem arises from the presence of organic materials dissolved in the oil at high oil precipitation temperatures. Such as asphalt and paraffin waxes, with dissolved inorganic matter, generally referred to as crust, and generally including calcite and/or barite, which are present in the oil or in the presence of salty water accompanying the delivery of oil from underground deposits. These substances become insoluble when the oil is cooled. It also occurs when the oil rises through the pipe through the lower opening to the surface of the ground. The resulting undissolved materials tend to paint outside the inner surface of the pipe. Reducing the flow of oil through it and permanently blocking the pipe. This blockage occurs during the long-distance delivery of oil through the piping network. This requires that the oil pipes be cleaned during the time of oil production or transportation, as this situation depends on.

Under these conditions, the tools used in oil well pipes are also susceptible to similar problems that clog the inner surface of the pipes, which means corrosion and coating outside the asphaltenes and paraffin waxes on their surfaces. Attempts have been made to cover the tools used in oil wells in order to treat resistance to corrosive damage. For example, US Patent No. 4,823,456 declares a method for covering a suction cup

At least 60%, 70%, 80%, and even at least 90%. It is preferable to use these dips for at least two material deposition and most preferably three of them. Therefore, according to the present invention there is a device provided for use in an oil pipe including a multi-layer cover including a primer layer adhered to its outer surface and an upper cover adhered to the previously mentioned primer layer.

The tools used in the present invention will depend on the environment in which the tools are used. These tools may be insulation pads, absorbent rods, and the like. The exemplary tools used in the present invention are commercially available manufactured and sold by Halliburton under the registered trademarks Hydrostatic-Set Versa-Trieve® Packers and Hydraulic Set Perma-Series® Packers. In particular, the present invention can be applied to tools and, to a specific extent, oil pipes used, where both deposition and corrosion are concerned. Oil pipes mean that they are at the bottom of the hole, i.e. oil well pipes or above-ground piping network systems, i.e. oil delivery pipes.

Oil pipes are used in large tools. The inner diameters are 2 inches

(5.08 cm) 23/8 inches (6.03 cm) and 3 inches (7.6 cm) and larger and longer at least 20 feet (6.1 m) are quite common. While the relative dimensions of the oil pipe are large, the thickness of the cover on the outer surface of the tool is very small. The cover includes the primer layer and the top cover, and the primer layer needs to be thin enough to adhere to the top cover layer itself and thus to the outer surface of the tool. Typically the indentation layer is about 0.5 mil and the top coat tool thickness is about 1.0 mil. If the pipette in which the device used holds less than 1.5 ml then only may

The indentation layer is used. The primer layer needs to be thin enough to adhere to the top layer itself and thus to the outside of the instrument.

In the other embodiment the top cover includes a multi-layer cover of the first user's cover on the starting layer so that the layer below the top cover is of a perfluoropolymer composition containing a small amount of mica distributed there. Attached to the following cover is the fluoropolymer/mica layer below the fluoropolymer layer above the mica-free one. Both of these layers can be used by powder coating. For additional details about the perfluoropolymer/mica composition described in US Patent No. 5,972,494, where mica compositions of 2-15% by weight of the composition and 0.5-1.5% by weight of the talc present for these purposes of the present invention are described, these percentages refer to the combined weight of Perfluoropolymer, mica, and talc, if available. The presence of this lower layer also improves the permeability efficiency of the casing when particularly corrosive conditions in oil wells require enhanced protection of the oil tool and pipe. Current fluoropolymer. In this representation the coating of the present invention consists of specifically a perfluoropolymer. In perfluoropolymer carbon atoms make a polymer chain. If it is not replaced with oxygen, it is replaced with fluorine atoms. The end groups of the perfluoropolymer may also be completely fluorine-substituted, but other relatively stable end groups such as CF2H and CONH2 are found specifically in the fluoropolymer present in the starting layer. The perfluoropolymer used in the present invention is meltable and flowable at baking temperatures which will generally be in the range of 300-400 degrees.

percentage . Polytetrafluoroethylene which has a melt viscosity of at least 10 8 bar/s at 372°C and will be able to flow in a melted form. The perfluoropolymers used in the primer and topcoat are fluoropolymers

Capable of melting flow. Examples of these include melt-flowable fluoropolymers, copolymers, tetrafluoroethylene copolymers, and a covalently polymerizable monomer consisting of at least one fluoro (covalent monomer) present in the polymer in sufficient quantity to significantly reduce the melting point of the copolymer below that tetrafluoroethylene copolymer. And polytetrafluoroethylene (PTFE), such that the melting point is not greater than 315 degrees Celsius. Preferred covalent monomers with tetrafluoroethylene include perfluorinated monomers

Monomer such as perfluoro olefins with 3-6 carbon atoms and perfluoroalkyl vinyl ethers (PAVE), where the alkyl group contains 1-8 carbon atoms, with a specific degree of 1-3 carbon atoms. To a specific degree, the preferred covalent monomers include hexafluoropropylene (HFP), perfluoro(ethyl vinyl ether) (PAVE), perfluoro(propyl vinyl ether) (PPVE), perfluoro(methyl vinyl ether PMVE) (ether), and covalent polymers. Tetrafluoroethylene (TFE) Preferred FEP covalent polymers include tetrafluoroethylene (TFE), (HFP), and (PFA) covalent polymers PAVE/TFE and PAVE/HFP/TFE, where PAVE is PEVE and/or PPVE. And TFE) MFA / PMVE / PAVE where the alkyl group of PAVE has

At least two carbon atoms). Typically the melt viscosity will be in the range of 10 2 - 10 6 bar. Again, preferably from 310-10 bar. Seconds measured at 372°C. By modified ASTM D No. 1238 method as described in U.S. Pat

No. 4380618 Typically those covalent polymers have a dissolution flow rate of 1-100 g/10 min as described in ASTM D No. 1238 and ASTM tests that can be performed to identify covalent polymers (ASTM D No. 2116-91 or ASTM D No. 3307).

Melt-flowable polytetrafluoroethylene (PTFE), commonly referred to as a small powder, can be found in the indentation or top coat along with the melt-processable copolymers mentioned above and that small powder with a similar melt flow rate. Similarly, small proportions of insoluble manufacturable polytetrafluoroethylene can be found in either the primer layer, the top coat, or both. The primer layer helps the polytetrafluoroethylene saturate towards providing the pure perfluoropolymer in the primer at the primer/top coat interface.

The polytetrafluoroethylene (PTFE) in the top cover aids in the rigidity of the cover, but should not be used in proportions that reduce the overall permeability of the cover to corrosive fluids and to protect the outer surface of the tool supplied by the cover. In the case of the introductory layer and the upper cover, the polymer must be mixed with either polytetrafluoroethylene or a perfluoropolymer capable of flowing multiple melts, forming a Pers fluoropolymer.

In the primer/top cap representation the top cap includes a fluoropolymer. The fluoropolymer does not need to be a perfluoropolymer. In this representation the indent layer may also be included but is not necessarily a perfluoropolymer. In this case other materials may be used for this indent layer as long as it promotes adhesion to the top cover of the tool. The coating may be formed in a number of coating methods such as the use of a liquid coating formulation and/or the use of a powder coating. In representing the initiator/top cover may be used

Different covering methods for the primer layer and the top layer. Preferred covering methods include liquid based coatings for primer and top coat. Or covers consisting of liquid for the primer layer and a powder coating for the top cover. The cover is heated to form a coating on the surface of the tool. Optionally, the heating is sufficient to toast the lid. This roasting freezes the coating from the dried liquid or powder state into a thin, solid layer state. In the primer/top cover representation, the primer layer is baked and the thickness of the primer layer after baking is not greater than 25 micrometers (1 mil). In connection with this, the term roasting is used in the broad sense to accomplish the aforementioned state of freezing. Sometimes the term curing is used to describe the effect of film formation. The treatment includes the meaning of the term roasting. Typically, baking is accomplished by simply heating a coating sufficiently above the melting temperature of the covering material to cause the material to flow and melt to become a semi-thin film. This allows the top coat to adhere to the primer layer. In the primer/topper representation, this freezing will generally contribute to the baking of both the primer and topping either sequentially or simultaneously. The effect of freezing is modeled in this representation after baking and freezing the starting layer, and the thickness of the starting layer after baking is not greater.

From 25 micrometers (1 ml).

The upper cover is permeable to salt water in addition to the corrosive materials present in the oil and provides a non-sticky surface for the oil. In this way, the organic materials that are not dissolved in the oil are not adhered to the upper cover and reduce or avoid the restriction of oil flow and blockage. Due to its non-stick property, however, the top cover does not stick to the outer surface after removing impurities from the outer surface of the pipe. The separating primer provides adhesion to both the top cover and the outer surface of the pipe. Do not supply class

The primer itself has sufficient non-adhesion property and the ability to penetrate corrosive materials present in the oil in order to protect the outer surface of the tool from corrosion. In this preferred representation, where the thickness of the casing is relatively thick and the overall thickness (thickness of the primer layer plus the thickness of the top coat) of the coating is not greater than 8 mils (203 micrometers), the outer surface of the tool is provided with an adhesion coating that provides a non-stick surface for oil and provides High degree of protection from

Corrosion of the outer surface. In the other preferred representation, the overall cover thickness is relatively thick and the overall cover thickness (the thickness of the primer layer plus the thickness of the top coat in the primer/top cover representation) is at least 26 mils (660 µm).

In order to ensure that the upper cover does not have holes through the corrosion material that passes through to reach the outer surface of the tool in the end. It is preferable to perform the cover formation step using covers or multiple layers. One on top of the other. Where in the representation the cover includes the leading layer and the upper cover. The overall thickness of the top cover

It is still larger than 7 ml (175 micrometers) and preferably not larger than 6 ml (150 micrometers) if using either a liquid or powder cap toppers. Using the next cap of liquid or powder top cap installation will fill in any existing holes in the previous top cap.

In the primer/top cap configuration, the liquid base for the cap installation is preferably an organic solvent, which avoids the creation of rust on the clean, hardened outer surface of the tool. Rust will interfere with the adhesion of the primer to the outer surface of the tool, and heating the primer composition is sufficient to dry the composition to form the primer, and may be sufficient to bake the primer. Before forming the top cover. The liquid base for installing the top cover is best

Water to reduce the need for solvent recovery. In the case of the following liquid toppings, use them for the dried or roasted starting layer. The toppings are dried and then roasted at a sufficiently high temperature depending on the specific composition used. To melt the top cover to form a thin layer, and also to install the starting layer if it has not been baked previously. And the connection of the upper cover with the indentation layer. Liquid composition means that the composition of the coating is in liquid form, typically including the distribution of the perfluoropolymer molecules in the liquid, where the liquid is a continuous phase. The liquid base, i.e. the liquid medium, can be water or an organic solvent. In the case of forming the initiating layer, it is better for the liquid base to be an organic solvent, and in the case of the top cover, it is better for the liquid base to be water. The organic solvent may be present, for example, in the top cover liquid composition in a very small quantity, such that it does not exceed 25% of the total weight of the liquid, in order to improve the wettability of the top cover layer and thus improve the use of properties.

When using the primer composition as a liquid medium, the adhesion properties described will appear above themselves upon drying and baking the primer layer together with baking the next layer used to form a non-stick coating on the tool. When the primer composition is used as a dry powder, the adhesion property becomes apparent when the primer is baked. In the representation of the primer/top cover, the composition of the base layer and the top cover are the same or different, provided that when they are baked together, they stick to each other and the layer sticks to the tool. When the composition is similar, proper interlayer adhesion is obtained. In the preferred embodiment each of the primers and top coats each preferably independently includes perfluoropolymers in the primers and top coats selected from the group consisting of 1 - a covalent polymer of tetrafluoroethylene t with

Covalent polymer of perfluoroolefin. Perfluoroolefin, which contains 3 carbon atoms, is a covalent polymer of tetrafluoroethylene with one perfluoro on

Lesser (alkyl vinyl ether) and alkyl containing 1-8 carbon atoms. Additional covalent monomers may be present in covalent polymers to modify their properties. Adequate interfacial adhesion is also obtained when one of the perfluoropolymers is a copolymer (1) and the other is a copolymer (2). The melting temperature of a cover will vary depending on its composition. The melting temperature means the high absorption obtained in the DSC analysis of a cover. By representation, the covalent polymer of tetrafluoroethylene/perfluoro(propyl vinyl ether) (covalent polymer PPVE/TFE) melts at 305 degrees Celsius, while tetrafluoroethylene/hexafluoropropylene melts at 260 degrees Celsius. Covalent polymer HFP/TFE and tetrafluoroethylene/perfluoro(propyl vinyl ether) Covalent polymer (PPVE/PMVE/TFE) has a melting temperature in between those melting temperatures and so on. Thus in one embodiment of the present invention where the initiator layer includes the covalent polymer PPVE/PMVE/TFE and the perfluoropolymer in the top cover is the covalent polymer HFP/TFE and the top cover may not be baked at a high temperature. Enough to bake the base layer in the case of the base layer heated to the baking conditions before using the top cover of the base layer. Alternatively, the initiator layer may contain a low-dissolution perfluoropolymer that, in the case of top coat baking, will also bake the initiator layer. The preferred ingredient in the primer layer, whether the primer is composed of a liquid or dry powder, is a heat-resistant polymer binder. The presence of this makes the primer layer capable of adhesion.

On the outer surface of a tool. The binder component includes a polymer that forms a thin film when heated to melt and is also thermally stable. This component is very popular for initiator applications in non-adhesive finishing processes for adhesion of fluoropolymer containing primer to base materials and to the film formed within it and as part of the primer. The fluoropolymer itself is slightly non-adherent to the soft base material. The binder is generally non-fluorine-containing and yet adheres to the fluoropolymer. Examples of thermally stable non-fluorine polymers include polyamideimide (PAI), polyimide (PI), polyphenylene sulfide (PPS), polyether sulfone (PES), polyarylene-etherketone, and poly( 1, 4 (2.6-dimethylphenyl)oxide (poly(l,4(2,6-dimethylephenyl)oxide), commonly known as polyphenylene oxide (PPO). These polymers are fluorine-free and are thermoplastic. All of these resins are thermally stable at a temperature of at least 140 degrees Celsius. Polyether sulfone is an amorphous polymer that has a temperature tolerance of 190 degrees Celsius. And a glass transfer temperature of 220°C. Polyimidiimide is thermally stable at a temperature of at least 250°C. They melt at temperatures of at least 290°C, polyphenylene sulfide melts at 285°C, and polyaryleneether ketones are thermally stable at at least 250°C and melt at temperatures of at least 300°C. Examples of a suitable powder coating composition include a perfluoropolymer and a polymer binder, where these components accompany another of the several component parts declared in

US Patents Nos. 6,232,372 and 6,518,349.

The polymer binder can be used as an undercoat for the outer surface of a tool after treatment to remove impurities and organic solvent solutions before using the primer. The thin dry layer resulting from the polymer binder can also improve the adhesion of the primer layer to the outer surface of the tool.

To simplify, only one link can be used to form the link component of the present invention. However, the multiple bonds are also perfected for use in the invention specifically when specific end-use properties such as flexibility, hardness or corrosion protection are required. Popular federations include PES/PAI, PPS/PAI, and PPS/PES. Typically, the polymer binder content of the polymer layer will be 10-60% by weight, depending on the combined weight of the containing perfluoropolymer and polymer binder.

Other ingredients can be found in primers such as dyes, fillers, high-boiling liquids, diffusion aids, and surfactants. The composition can be used to cover the outer surface of an instrument after removing impurities by spraying the composition consisting of liquid or dry powder from the hose. Dry powder primer can be sprayed using an electrostatic sprayer. Electrostatic spraying is conventional in the dry powder coating method.

The preferred liquid is capable of covering the composition so that the liquid is one or more organic solvents, including a perfluoropolymer present as molecules in the preferred representation, and the distribution and linkage of the polymer present either in dispersed molecules or in solution in the solvent. The properties of the organic liquid will depend on the determination of the polymer binder and whether the solution or dispersant is required. Examples of these fluids include N-methylpyrrolidone, butyrolactone, and methyl isobutyl ketone.

Isobutyl ketone, high-boiling aromatic solvents, alcohols, and mixtures thereof and between them. The amount of organic liquid depends on the flow characteristics required for the process

Special coverage.

A solvent must have a melting point between 50-200°C and not be highly volatile at room temperature but evaporate at reasonably high temperatures.

And lower than the roasting temperature of perfluoropolymer.

In the primer/top coat representation the thickness of the primer arises from experience with the composition of the particular primer chosen, the concentrations of the polymer binder and the relative amount of solvent that is present. It is preferable that the primer contain 40-75% by weight of the solvent depending on the combined weight of the solvent, polymer, and polymer binder.

In another embodiment the coating includes a barrier layer comprising a plurality of molecules that form a mechanical barrier against the penetration of water, solvents and/or gases into the device. The barrier layer has a typical thickness of about 1 - 10 mils (25 - 254 micrometers). The barrier layer system may be used on tools that can handle abrasion of approximately 5 mils (which reduces the abrasion diameter of the barrel by 10 mils). In the case of tools that cannot handle more than 1 or 1.5 ml of polish, a single component layer must be used with the polish between the primer/top coat system used.

It is preferable that the barrier layer include a fluoropolymer and a sheet in the form of a filler molecule that is relatively inert to chemical reaction. The molecules form a mechanical barrier against the permeation of water, and the solvent and base material are present in an amount of approximately 2 - 10 5 by weight, depending on the total dry weight of the barrier layer. In spray application the particles tend to line up parallel to the outside of the tool. Because oxygen, solvent and water do not pass through the same molecules. Reduces the presence of particles

The aligned molecule also has a rate of permeation through the covering that is formed. In the introductory layer/top cover representation, the barrier layer is formed between the introductory layer and the top cover. It is also within the scope of this invention that the coating may contain a plate in the form of filler particles with or without an intermediate barrier layer. Examples of typical particle-shaped filler sheets include mica, glass veneer, rust-resistant thin film, and particle-shaped sheet for the filler component of a barrier layer that favors mica particles, including mica particles coated with an oxide layer similar to iron oxide or titanium oxide. These particles have an average particle size of approximately 10 - 200 microns, preferably 20 - 100 microns, and no more than 50% of the thin-shell particles have an average particle size greater than approximately 300 microns. Mica particles coated with oxide layers are those described in US Patent No. 3,087,827 (Klenke and Stratton), US Patent No. 3,087,828, and US Patent No. 3,087,829.

The mica described in these patents covers the oxides or hydrous oxides of titanium, zirconium, aluminum, zinc, antimony, tin, iron, copper, nickel, cobalt, chromium, or vanadium. Mixtures of coated mica can also be used.

In representing the primer/top cover when a barrier layer is used, the barrier layer may include the multi-cover cover of the first user's cover on the primer layer so that the bottom layer of the top cover is of a fluoropolymer, most preferably a perfluoropolymer, and the composition containing the small amount of mica distributed here and attached with

Subsequently used cover on fluoropolymer/mica bottom layer for the fluoropolymer and again preferred perfluoropolymer for the fluoropolymer top layer which is mica free. Each of these layers can be used with powder coating or liquid coating. Additional details about the perfluoropolymer/mica composition are stated in US Patent No. 5,972,494, which states that mica consists of 2 - 15% by weight of the composition and 0.5 - 15% by weight of hydrated magnesium silicate that is also present. For the purposes of the present invention, these percentages refer to the combined weight of the perfluoropolymer, mica, and hydrated magnesium silicate, if present. The presence of this lower layer also improves the permeability efficiency of the casing when specific corrosion conditions require enhanced oil wells for tool protection.

Detailed description

The tool is configured according to the present invention as follows: It is preferable to expose the outer surface of the tool to cleaning and/or sandblasting to improve the adhesion of the fluoropolymer coating to the outer surface. The outer surface of a tool as manufactured is generally smooth but with rises and depressions and is generally covered with a preservative to reduce any rust. Before using a fluoropolymer coating on the outside of an instrument, clean the surface to remove preservatives. Traditional soap or detergents can be used. The tool can also be cleaned by high-temperature baking in air at a temperature of 800°F (427°C) or greater.

It is preferable to clean the inner surface cleaned with granular sand with abrasive particles such as sand or aluminum oxide in order to form a hardened surface in order to improve the adhesion of the primer. The sanding should be sufficient to remove any rust that may be present.

The hardness required for primer adhesion can be characterized as an average hardness of 70 - 250 microinches (1.8 - 6.8 micrometers).

In the preferred representation, where the primer layer and the top cover are used and the primer is used to the cleaned inner surface and the granular filler of the pipe by spraying the installation consisting of liquid from the hose, it is preferable to use the primer to the heated tool in order to prevent movement, subsidence and drooping. Initial heating of a tool is typically 110-125 degrees Fahrenheit (43-52 degrees Celsius), but higher temperatures may be used, but only about 20 degrees Fahrenheit. Below the boiling point of the solvent for synthesis. The cover is used for the outer surface of the tool according to the preferred representation of the present invention, where the indentation layer and top cover are used as follows. The primer can be used on the outside of the tool to remove impurities by spraying the composition consisting of a liquid or dry powder from the hose. Dry powder primer can be sprayed using an electrostatic sprayer, and electrostatic spraying is conventional in the dry powder coating method.

After the heating step, the upper cover is used to spray a composition consisting of a liquid or dry powder onto the primer layer using a pipe supported by lubricating elements and a hose similar to that used to apply the primer. It has been found that simply drying the liquid component primer to form a primer layer gives adequate unity to the 0 layer to complete the multiple uses of the primer top coat and roast the top cover used in this spray application so that it can perform the next spray application without protruding the lubricating elements or otherwise removing the top cover. From previous use. Provided that the upper cover must be dry powder, and the powder cover must be roasted

The resultant before using the next sprinkle of dry powder in case it is larger than the required cover thickness.

When the primer composition is used as a primer medium, the adhesive properties described above will appear upon themselves when the primer layer is dried and baked together with the next used layer baked in order to form a non-stick covering of the base material. When the primer is used as a dry powder, the adhesion property becomes apparent when the primer layer is baked. Then roast the pipe in order to melt the top cover, and again place the pipe in the oven heated to the required temperature. Typically the baking temperature used for the top cover through the pipe wall thickness and the indentation layer will be at least 20°C. Above the melting point of the top cover with sufficient temperature and exposure time to bake the top cover. The same conditions apply to baking the starting layer. Heating the primer is sufficient to dry the coating to form the primer and enough to bake the primer.

Before using the initial thin layer. Baking means that the fluoropolymer layer is heated sufficiently to a temperature above the melting temperature to cause the fluoropolymer to flow and form a continuous film-like layer. The melting temperature means the high absorption obtained in the DSC analysis of the fluoropolymer. If the barrier layer is used in the same way as the primer layer, it may be heated with the primer layer or used to dry the primer layer and then heated until dry or roasted before using the cover.

Fusion bonding means that the tool is heated sufficiently for the topcoat bond to melt the preferred thin layer to the primer or barrier layer. It means the initiator/top cover or the interface of the film or the interfaces of the film

/ Barrier Coat / Top Coat or Finish Coat as applicable and melts together sufficiently to adhere the top coat tightly to the layer(s). The melting point of the bond depends on the particular fluoropolymer present in the top coat or thin layer achieved. To PFA or PEP, the device (roaster) is heated by conventional means to a temperature between 600 - 700 degrees Fahrenheit (315 - 371 degrees Celsius). To ETFE, the tool is heated by conventional means to a temperature between 550-630 degrees Fahrenheit (228-332 degrees Celsius). The bond melting time will depend on the baking temperature used but is typically 5-60 minutes. The baking time and temperature must be sufficient to achieve strong melting of the bond between the top cover, the finished film, and the pad or barrier layer. When the tool is cooled, there is a tendency for the finished thin layer to shrink. Unexpectedly, the connection of the middle cover between the primer (and barrier layer, if present) and the top cover or completed thin layer is sufficient to prevent the thin layer from being pushed away from the primer or barrier layer.

The melting temperature of a coating will vary depending on its composition. The melting temperature means the high absorption obtained in the DSC analysis. Examples include tetrafluoroethylene/perfluoro(vinyl propyl ether) polymer

Covalent polymer tetrafluoroethylene/perfluoro (propyl vinyl) (PPVE/TFE)

(ether) (TFE/PPVE copolymer) melts at 305°C while tetrafluoroethylene/hexafluoropropylene melts at 260°C. (HEP/TFE copolymer) tetrafluoroethylene/perfluoroethylene/hexafluoropropylene Fluoro(vinyl ether) covalent polymer (PPVE/PMVE/TFE covalent polymer) has a melting temperature in between

Dissolution. Thus, in one embodiment of the present invention when the initiator layer includes a perfluoropolymer that is a covalent polymer TFE/PPVE/PMVE and includes a perfluoropolymer that is a covalent polymer HFP/TFE and the roasting may not have a roasting temperature. The top cover is high enough to bake the base layer, in which case the base layer will be heated to toasted conditions before the top cover is used to bake the base layer.

Alternatively, the primer may contain a dissolving grade perfluoropolymer

The lower one is the toasting state of the upper lid that will toast the starter layer. The devices of the present invention are capable of withstanding the high temperature conditions of 350°F (177°C) and 20,000 psi (138 mbar) found in a fairly high temperature/high pressure reserve. The invention may also be performed with tools used in the chemical processing industry (CPI) and to a specific extent in those applications where temperatures are such as to include those described above. At CPI temperatures of at least around 350°F (177°C) and as high as 400°F (204°C) are used. Tools exhibit superior permeability resistance to corrosion from construction chemicals i.e. to a limited degree when using a primer, topcoat, primer and finish liner, especially with the optional separating barrier layer and strong adhesion to the inner surface of the tool with primer assistance. The tools covered by the present invention are capable of resisting the conditions described above for continuous service for any duration

30 At least one day, preferably at least 60 days, and most preferably at least 12 months.

Because of all the advantages noted above, the present invention is capable of reducing the deposition of at least one of the asphaltene, paraffin wax, and inorganic shells by at least 40%, and preferably by at least 50%, compared to the inner surface of the aforementioned tool without the aforementioned cover being present. These depressions are also made compared to the tool lined with epoxy resin only on the inner surface of the tool. In fact, declines of at least 60%, 70%, 80%, and at least 90% level were achieved. It is preferable to use these dips for at least two of the precipitates and most preferably for three of them. Thus, according to the present invention there is also a method provided for reducing the deposition in the device of at least one of the asphaltenes, paraffin wax, or inorganic shell by at least 40% compared to the outer surface of the device without the coating present. The resulting device then has an adhesive fluoropolymer cover attached on its outer surface to the exposed surface of the fluoropolymer, which supplies the non-adhesive surface with oil to finally flow through the pipe and its components. The cover follows the highs and lows of the outer surface of the instrument and to some extent fills them with primer and top cover layers.

The fluoropolymer coating on the tool of the present invention both serves as a non-stick oil sealer and its assembling parts but also insulates the steel mount of the tool as well as the pipe from corrosion. In oil wells, downhole temperatures can reach 500°F (260°C) but will more typically be in the range of 350-450°F (177-232°C). The fluoropolymer in the cap is chosen to have a melting temperature greater than the temperature at the bottom of the well. The phoropolymer creates a natural corrosion barrier

Environmental hot oil. This permeable fluoropolymer also resists environmental corrosion through the thickness of the cover. The upper cover provides effective permeability resistance. It provides the same corrosion protection to the conduit as in a surface piping network where the temperature will be lower but contact with the oil will occur for an extended period of time.

The cover of the device of the present invention can reduce or eliminate the deposition of asphaltene, paraffin wax, or inorganic shell, whereby removing the deposition from the device reduces or therefore blockage in the oil pipe or either reduces or reduces corrosion to the outer surface of the device. The reduction in deposition can be described as at least 40% and preferably at least 50% from at least one of the asphaltenes, paraffin wax or inorganic shell. Decreases of at least 60%, 70%, 80%, and even at least 90% can be perceived. It is preferable to use these dips for at least two material deposition and most preferably three of them.

These decreases are determined by the asphaltene deposition test, the paraffin deposition test, and the inorganic crust deposition test reported in the examples, and results that are even better than those shown in these model tests are expected due to the rapid flow of oil through the oil pipe during field use of the tool. The corrosion protection afforded by the outer surface coating of an instrument can be described by significant impermeability to strong brine solutions at high temperatures for a long period of time according to the salt water permeability test described in the examples. It is within the scope of the invention that an oil pipe may be used in such a lined device with covers as described above in relation to the device. The combination of these coatings on both pipes and tools can also improve the benefits of sedimentation reduction and corrosion resistance offered by a covered tool as described above.

Test methods

Paraffin deposition test

The cold indicator device available through the Westport International Technology Center (Houston, Texas) is used for acceptable covers such as those prepared in the examples for the degree of release (non-adhesive) that are exposed to them. The device includes a dispensing cup (with two walls) filled with mineral oil and connected to the first temperature bath, which is placed on the magnetic mixing plate. The stainless steel cup with a magnetic stir bar is immersed in the mineral oil and has a temperature set at 140 degrees Fahrenheit (60). The cold indicator (tube protrusion) is connected to the water bath to distribute the temperature of the second, a set temperature of 60 degrees Fahrenheit.

Rust-resistant connecting sleeves (6 lengths, 0.5 inner diameter and 0.625 outer diameter), closed and flat at the bottom, which are covered as described in the examples, washed with solvent (toluene, then methanol) and placed in a convection oven to ensure a clean surface on which to apply the wax. The connecting sleeve is also weighted and secured over the index with a set pin at the top to create a tight fit and allow for 30 minutes of cooling. After 30 minutes, the connecting sleeve is glued over the cold indicator in a tight fit and immersed in crude oil for 24 hours.

The known crude oil has a high wax content with a wax appearance temperature of approximately 150 degrees Fahrenheit. It is used for this test. The wax was initially heated to 150 degrees Fahrenheit (66 degrees Celsius) and centrifuged twice to remove any water and sediment. The raw source sample was kept at 150 degrees Fahrenheit (66 degrees Celsius) during the testing period to ensure that the wax remained in solution.

After 24 hours of testing time, the conductive sleeve is removed from the ore and left to settle for one hour at 60 degrees Fahrenheit (16 degrees Celsius). In the nitrogen environment, the final weight is measured and the weight data collected before and after the dive is used to calculate the wax deposition on the conductive sleeve. Calculation was made from the material budget mass per unit area for comparison purposes. The baseline comparison is a paraffin adhesion test performed on a commercially available epoxy resin covering oil pipes, where the paraffin deposition on the composite epoxy resin coating is 0.0652 g/cm2.

Adhesion tests

Test plates for adhesion test plates for cold rolled steel 4.0 The panels have a granular blasting surface. Cover the panels according to the description in each example. The panels shall be subjected to the following two adhesion tests:

1- Nail adhesion after boiling water (PWA)

Immerse the covered test plates in boiling water for 20 minutes. Allow the water to come to a full boil after inserting the covered plate before the start of the time. After treatment with boiling water, the board is cooled to room temperature and dried completely. The nail scratch test involves using a fingernail to cut or peel the coating away from the edge of the knife's intentional scratch in the film in order to test the degree of adhesion of the film. In the event that the cover can be pulled away from the reactant for 1 cm or more and the cover is considered to have failed the test, the plates are subjected to two adhesion tests. In the event that the unstable cover cannot be pulled out for a distance of 1 cm and the cover is considered to have passed the test, the panels are subjected to two adhesion tests.

2- Cross-junction adhesion

The covered material is subjected to a cross-cross test for adhesion. The sample covered with the blade of a utility razor blade is scratched through a stainless steel die to make 11 parallel cuts about 32/3 inch (2.4 millimeters) apart through the thin layer to the metal surface. This procedure is repeated at the right corners of the first sectors to produce a grid of 100 squares. Immerse the covered and scratched sample in boiling water for 20 minutes, then remove it from the water and cool it to room temperature without refrigerating the sample, then turn the transparent tape (class 3M No. 898), 0.75 by 2.16 inches (1.9 by 5.5 cm), and press it evenly. Seal over the scratched area with tape directed in a direction parallel to the scratched lines. Then the tape is pulled at a 90 degree angle quickly but without shaking. This step is repeated at 90 degrees to the first step with a new piece of tape, and is repeated twice more a second time at 90 degrees from the previous step, each time with a new piece of tape. Passing the test requires not removing any squares from the 100-square grid.

Examples

The following examples illustrate the effect of the present invention on cover coupons in accordance with the present invention.

In the following examples, the base materials for a cover are cleaned by roasting for 30 minutes at 800 degrees Fahrenheit (427 degrees Celsius), and the granules are expanded with 40 corundum oxide granules to a roughness of approximately 70 - 125 microinches Ra. Liquid coatings are used using a spray gun, model number 510, available from Davebs located in Glendale Heights, 3rd. Powder coatings are used using manual electrostatic powder spray guns from

Nordson type, and Versa spray type No. 1 located in Amherst, Ohio.

To determine the degree of release of the covers, the covered base material must be a rust-resistant connecting sleeve suitable for use in the device described above in the paraffin deposition test to determine the quality of adhesion, and the covered base material must be a carbon steel plate suitable for use in testing boards subjected to two adhesion tests and a test. Adhesion via the junction described above.

The layers of starting materials formed in the examples have the following pre-baking composition:

Table No. 1 Liquid starting materials

<img file="SA2290B1_D0001.tif" />

• NMP is N-methyl-2-pyrrolidone

• Other organic materials may include aromatic solvents such as MIBK (methyl isobutyl ketone), hydrocarbons such as heavy naphthalate, xylene, etc., furfuryl alcohol, triethanol amine, or mixtures of these.

• HFP / TFE: FEP fluoropolymer containing 11-12.5 wt% HFP, average particle size 8 µm and dissolution flow rate 6.8-7.8 g/10 min measured at 372°C by ASTM D method No. 1238.

• PFBE / TFE /E: ETFE with an average particle size of 8 micrometers and a dissolution flow rate of 6 - 8 g/10 minutes measured at 298°C by ASTM D method No. 1238.

Toppers formed in examples with the following pre-roasting compositions:

Table No. 2

Powder top layer

Top covers

<img file="SA2290B1_D0002.tif" />

HFP / TFE: FEP fluoropolymer resin containing 11 - 12.5 wt% HFP, average particle size 35 micrometers, and dissolution flow rate 6.8 - 7.8

g/10 minutes.

PPVE/TFE: PFA fluoropolymer resin containing 3.8 - 4.8 wt % PPVE, average particle size 35 micrometers and dissolution flow rate 10 - 17 g/10 min.

PFA modified with PEVE / PPVE / TFE: PPVE fluoropolymer resin containing 6.8-7.8% by weight of PEVE prepared according to the techniques of US Patent No. 5,932,673 (Aten et. Al./DuPont) and an average volume The particle size is 8 micrometers and the dissolution flow rate is 13-18 g/10 minutes. Fluorinated PFA PEVE PPVE / TFE: Fluorinated fluoropolymer resin containing 3.8 - 4.8% by weight of PEVE prepared according to the techniques of US Patent No. 4743658 (Imbalzano et al./Du Pont) and an average particle size of 25 micrometers. And the dissolution flow rate is 12 - 20 g/10 minutes.

PPVE/TFE: PFA fluoropolymer resin containing 3.8-4.8% by weight of PPVE with an average particle size of 35 micrometers and a dissolution flow rate of 10-17 g/10 minutes.

Table No. 3.

Liquid toppers

<img file="SA2290B1_D0003.tif" />

Table No. 4

Medium materials covered with liquid

<img file="SA2290B1_D0004.tif" />

Roasting conditions are presented in examples. Good adhesion from the primer layer to the top coat is indicated by its efficiency in the post-boiling nail adhesion test and the cross-adhesion test.

The non-stick property of toaster lids is confirmed in examples by subjecting the lids to a paraffin deposition test as previously described. The main line of comparison is a paraffin deposition test performed on a commercially available epoxy resin covering the oil pipe where the paraffin deposition on the composite epoxy resin coating is 0.0652 g/cm2. Examples of this invention all have it

Covers with wax deposition under the perfect epoxy resin cover.

Comparison example A

Epoxy veneer epoxy standard

Cover layer A (epoxy powder) is used for the fitted stainless steel connecting sleeve by baking at 316°C for 20 minutes. The thickness of the dry thin layer of the paint layer is 100 - 125 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of 0.0652 g/m is obtained.

poison .

Comparison example B

ETFE starting material/ETFE top cover

Primer layer No. 2 (water-based ETFE) is used for the prepared rust-resistant coupling sleeve and the prepared carbon steel plate attached by baking at 150°C for 10 minutes. The thickness of the dry thin layer of the paint layer is 12 - 19 micrometers. Use top cover B over the layer of dry primer. It is roasted at 316 degrees Celsius for 20 minutes. The total DFT is 100 - 125 micrometers and the total thickness

Top cover 81 - 113 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of 0.0327 g/cm2 is obtained. When the covered carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-cross adhesion test, the plate passes through both tests.

Water-based primers are not preferred for use in this invention due to their low potential for corrosion resistance over a long period of time. The ETFE top cover is inferior to the perfluoropolymer top covers of this invention.

Comparison example C

The prepared uncoated corrosion-resistant conductive sleeve is subjected to a paraffin deposition test to obtain a deposition of 0.0296 g/cm2.

Example No. 1

FEP primer/modified PFA topcoat

Primer layer No. 1 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the starting material layer is 12 - 19 micrometers. Use top coat 1 (PEVE powder with modified PFA) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of the top layer. It is roasted at 371 degrees Celsius for 20 minutes. The total DFT is 81-113 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0168 g/cm2 is obtained. When the coated carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-cross adhesion test, the plate passes through both tests.

Example No. 2

FEP primer/fluoro-forming PFA topcoat

A layer of primer No. 1 (liquid) is used for the prepared rust-resistant connecting sleeve and the prepared carbon steel plate attached to it by baking at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the starting material layer is 12 - 19 micrometers. Use top coat 2 (fluoro-forming PFA powder) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 0.6 - 75 micrometers. Use the second layer of top layer No. 2. It is roasted at 371 degrees Celsius for 20 minutes. The total DFT is 100 - 125 micrometers and the total thickness of the top coating is 81 - 113 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0145 g/cm2 is obtained. When exposing carbon steel plate

Covered to the nail adhesion test after boiling water and the cross-adhesion test and passes through the two tests.

Example No. 3

FEP primer/PFA top coat

Primer layer No. 1 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the initiating material layer is 12 - 19 micrometers. The coater uses topcoat 3 (liquid PFA) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of top layer No. 3.

Roasting was done at 371°C for 20 minutes. The total DFT was 100 - 125 micrometers and the total thickness was 18 - 113 micrometers.

When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0124 g/cm2 is obtained. When the covered carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-adhesion test, the plate passes through both tests.

Example No. 4

FEP primer/PFA top coat

Primer layer No. 1 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the initiating material layer is 12 - 19 micrometers. The coated layer uses top coat 2 (PFA powder) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of top layer No. 4. It is roasted at 371 degrees Celsius for 20 minutes. The total DFT was 100 - 125 micrometers and the total thickness was 81 - 113 micrometers. The total DFT is 81 - 113 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0124 g/cm2 is obtained. When the covered carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-link adhesion test, it passes through both tests.

Example No. 5

FEP primer/PFA top coat

Primer layer No. 1 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the initiating layer is 12 - 19 micrometers. The coater uses Top Coat 5 (PFA powder) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of top layer No. 5. It is roasted at 371 degrees Celsius for 20 minutes. The total DFT is 81 - 113 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0116 g/cm2 is obtained. When the covered carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-adhesion test, the plate passes through both tests.

Example No. 6

FEP primer/FEP top layer

Primer layer No. 1 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the starting material layer is 12 - 19 micrometers. The coated layer uses top coat 6 (PFA powder) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of top layer No. 6. It is roasted at 371 degrees Celsius for 20 minutes. The total DFT was 100 - 120 micrometers and the total thickness was 81 - 113 micrometers.

When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0110 g/cm2 is obtained. The covered carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-cross adhesion test, and the plate passes through both tests.

Example No. 7

FEP primer/PFA top coat

The primer layer No. (Liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer of the primer layer is 12 - 19 micrometers. The coated layer uses top coat 5 (PFA powder) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of top layer No. 5. It is roasted at 371 degrees Celsius for 20 minutes. Additional layers of top layer No. 1 are used and baked at 343°C for 20 minutes until the total DFT is 950 - 1050 micrometers and the total thickness of the top layer is 931 - 1038 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0098 g/cm2 is obtained. When the covered carbon steel plate is subjected to the nail adhesion test after water penetration and the cross-linking adhesion test, the plate passes through both tests.

Example No. 8

FEP/PFA top layer

Primer layer No. 1 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for

10 minute . The thickness of the dry thin layer (DFT) of the starting material layer is 12 - 19 micrometers. The covered layer uses top layer No. 2 on top of the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60-75 micrometers. The second layer of top layer No. 2 (PFA consisting of fluoro) is used. It is roasted at 371 degrees Celsius for 20 minutes. Additional layers of top layer No. 4 are used and baked at 343°C for 20 minutes until the total DFT is 950 - 1050 micrometers and the total thickness of the top layer is 931 - 1038 micrometers. The total DFT is 81 - 113 micrometers. When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0042 g/cm2 is obtained. When the covered carbon steel plate is subjected to the nail adhesion test after boiling water and the cross-adhesion test, the plate passes through both tests.

Example No. 9

FEP primer/PFA top coat

Primer layer No. 3 (liquid FEP) is used for the prepared stainless steel connecting sleeve and the prepared carbon steel plate attached and baked at 150°C for 10 minutes. The thickness of the dry thin layer (DFT) of the initiating material layer is 8-12 micrometers. The coated layer uses top layer 2 (fluoro-forming PFA) over the dry primer layer. It is roasted at 399 degrees Celsius for 20 minutes. The total DFT is 60 - 75 micrometers. Use the second layer of top layer No. 2. It is roasted at 371 degrees Celsius for 20 minutes.

When the covered conductive sleeve is subjected to a paraffin deposition test, a deposition of only 0.0042 g/cm2 is obtained. When exposing the covering carbon steel plate to

Nail adhesion test after boiling water and cross-adhesion test and the board passes through both tests

Example No. 11

Inorganic crust deposition test

<img file="SA2290B1_D0005.tif" />

The number of layers of the cover covering the upper layer (FEP and PFA) from the aforementioned examples was substituted for the immersion test of the coupon in a salt solution in order to determine the decrease in the deposition test on the inorganic crust of the covering coupon, and the result of that crust was reduced to more than 50%. By weight compared to uncovered coupons. These tests were accomplished by soaking covered and uncovered metal coupons in brine solutions of calcite and barite with the following compositions:

Coupons were suspended for 2 days under a pressure of 100 psi (6.9 μbar) in saline A heated to 140°F (60°C) in preheated saline B

At 90 degrees Fahrenheit (32 C) and weight acceleration (precipitation crust. Comparison was made

of covered coupons to those of uncoated solid coupons in order to illustrate the reduction in crust deposition for coupons covered with covers of the present invention.

Example No. 12

Asphaltene precipitation test

Asphaltenes are a mixture of high-molecular-weight, amorphous, polynuclear aromatic compounds containing carbon, hydrogen, oxygen, sulfur, and often metals such as vanadium or nickel. Asphaltene is soluble in oil, but it becomes insoluble when it is exposed to pressure and changes in pH or change in dissolving ability, as happens in the benefit of an oil pipe. Asphaltene deposition can be measured by flow loop practiced by the Research Petroleum Center located at the New Mexico Mining and Technology Institute in Socorro. In a way that we summarize the material in order to be tested, it falls into the ring and the oil flows through the ring under the circumstances, causing the asphaltenes to become insoluble in the oil and therefore have a change in deposition on the inner surface of the ring. Asphaltene deposition is determined by the weight of the ring after the flow test is completed and comparing this weight with the weight of the ring before the flow test. In more detail, the tested ring must be 100 feet (30.5 m) long, have an internal diameter of 0.03 inches (0.75 mm), and be made of one of the perfluoropolymers covered with the upper layer mentioned in the previous examples, or of steel. The pipe is formed in the water bath remaining at 60 degrees Celsius. The mixture is 50/50 volume of asphaltene containing oil and n-pentadecane solvent measured through the loop at a rate of 0.24 ml/hour for 24 hours. The tested oil has the following characteristics: API gravity of 28.80 and viscosity of 30 at 20°C and contains 51.1% saturated, 28.3% aromatic, 14.5 resins, 6.1 asphaltenes, and contains 19 ppm of

Nickel and 187 ppm of vanadium, and for the uncovered metal ring, the weight gained for the precipitated asphaltenes is 0.51 g, while for FEP and PFA that make up fluoro, for Example No. 8, there is no weight gain, and the effect of the perfluoro polymer is indicated in order to reduce the precipitation of asphaltenes.

Example No. 13

Salt water permeability test

This test is conducted to determine the salt water permeability of the perfluoropolymer compared to epoxy resin by exposing 5 mil (127 micrometer) thick films of these materials on coupons.

The solid is exposed to salt water under harsh conditions and the highly exposed coupons are subjected to the well-known Z registered alternating current resistor spectroscopy. Resistance to alternating current flow of a cover before and after exposure comparison. A decrease in resistance to alternating current flow indicates the permeability of the cover. In the greatest detail, the coupons covered in the autoclave are attached

1 - The aqueous phase with 5% aqueous solution of sodium chloride (NaCl).

2 - Organic phase with 550% by volume kerosene and 50% by volume toluene.

3 - A gas phase with 5% by volume hydrogen sulfide, 5% by volume carbon dioxide, and 90% by volume methane, which remains at approximately 251 degrees Fahrenheit (122 degrees Celsius). In that case contact with part of the cover. The autoclave is maintained at 251 degrees Fahrenheit (122 degrees Celsius). And 1026 psi (70.8 microbar MPa) for 29 days. The resistance to the flow of alternating current is measured in the cover (before

After exposure to salt water) using an electrochemical cell

cell consisting of the covering coupon, the reference electrode, and the inactive counter electrode. The electrical measuring equipment consists of a voltage stabilizer, frequency response analyzer and computer with software

Resistance spectroscopy for alternating current flow. The resistance to the flow of alternating current through a cover is measured as a function of the user's frequency (AC volts). Frequency range from 0.001 - 100 kHz. There are

The resulting data is in the form of a function map consisting of the designed Z scale against the recorded f, where Z is the resistance to the flow of alternating current in the name of homs cm and f is the frequency in Hertz. The comparison of resistance results for alternating current flow takes 0.1 from the function map as follows:

<img file="SA2290B1_D0006.tif" />

Tests of a single PES/FEP system that should be used at a thickness of 2 mils are exposed to the same autoclave conditions and produce a resistance to alternating current flow Z recorded before exposure of 9.4 and after exposure of 5.8.

534 reduces the resistance to alternating current flow of the epoxy resin cover, which represents the basic permeability of this cover to salt water. In fact, the cover has been dotted in places of the embedded steel coupon. On the contrary, the resistance to the flow of alternating current does not change significantly in perfluoro covers with non-bonded ones, and there is no separation of the covers from the solid coupon (no dripping), indicating the great lack of permeability of these covers to salt water. Therefore, they can be characterized by their great impermeability in the absence of separation of the covers from the steel coupon cover or Quantitatively, the decrease in resistance to alternating current flow for Z registered less than

10% and preferably less than 5%. When the covered carbons are exposed to hydrogen sulfide gas (H2S gas) and a liquid mixture of methane and toluene in the same autoclave under the same conditions as the salt water test, it is observed that there is no change in the covers, indicating to a large degree the danger of exposure to salt water.

Example No. 14

Individual layer cover

Primer No. 1 is used for the single layer cover on the coupon and tested as specified in Example No. 11. The presence of non-fluorine precipitation containing a polymer binder (polyamide and polyether sulfone) in the composition of the starting material and the inorganic peel deposition on the cover is less than that of the exposed solid coupon and is almost similar to the FEP material covered by the top layer.