Patent Application
20250084735
The subject matter disclosed herein relates to carbon rich layers configured to reduce or prevent the formation of adherent scales on flow system surfaces, that is resilient solid deposits that can interfere with otherwise normal scale-free flow.
A variety of equipment and in general systems may be subject to scale formation. The equipment may include oil and gas equipment used for the extraction of hydrocarbons (e.g., oil and/or gas) from a well. The equipment also may include sequestration equipment configured to inject and store fluids (e.g., liquid water, steam, gases such as carbon dioxide, hydrogen, methane, and the like) in subterranean reservoirs. For example, the sequestration equipment may include carbon capture and storage (CCS) equipment. The foregoing equipment (e.g., downhole component) may include, for example, tubing, valves, chokes, packers, pumps, or other associated equipment. Unfortunately, the foregoing equipment may be operated in the presence of organic and inorganic scale-forming fluids, particularly fluids containing salts with anions such as carbonates, sulfide, oxides, hydroxides, and sulfates. In certain environmental conditions, such as when the scale-forming fluids undergo changes in temperature, pressure, and/or chemical equilibria, the salts may precipitate and form scales, that is more or less adherent solid deposits on the foregoing equipment surfaces. The scale deposits may in turn progressively decrease the performance of the foregoing equipment, such as by reducing or restricting the fluid flow, or by preventing a mechanical component to properly slide and actuate.
A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.
In certain embodiments, a system includes a substrate having a tensile strength of at least 10,000 psi at an ambient temperature. The system also includes a carbon rich layer deposited on the substrate. The carbon rich layer comprises at least one of a carbide, a nitride, a boride, a silicide, an oxide, a sulfide, or a transition-metal or non-metal ceramic-forming element. The carbon rich layer also comprises a carbon content including sp2 carbon and sp3 carbon. The carbon content has greater than 40 percent sp3 carbon, a sp2/sp3 ratio of the carbon content is less than 1.5, or both.
In certain embodiments, a system includes a substrate having a tensile strength of at least 10,000 psi at an ambient temperature. The system also includes a carbon rich layer applied to the substrate. The carbon rich layer includes a first portion having a first carbon content. The carbon rich layer also includes a second portion comprising at least one of a carbide, a nitride, a boride, a silicide, an oxide, a sulfide, or a transition-metal or non-metal ceramic-forming element. The second portion also comprises a second carbon content different from the first carbon content. The second carbon content includes sp2 carbon and sp3 carbon. The carbon content has greater than 40 percent sp3 carbon, a sp2/sp3 ratio of the carbon content that is less than 1.5, or both.
In certain embodiments, system includes a downhole component formed of a material having a tensile strength of at least 10,000 psi at an ambient temperature. The system also includes a carbon rich layer deposited on the downhole component. The carbon rich layer comprises at least one of a carbide, a nitride, a boride, a silicide, an oxide, a sulfide, or a transition-metal or non-metal ceramic-forming element. The carbon rich layer also comprises a carbon content including sp2 carbon and sp3 carbon. The carbon content has greater than 40 percent sp3 carbon, a sp2/sp3 ratio of the carbon content that is less than 1.5, or both.
Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:
One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
As generally discussed above, downhole components (e.g., tubing, valves, packers, pumps, etc.) operated in the presence of scale-forming fluids may develop scale deposits due to the changes in properties of the downhole environment (e.g., changes in temperature, pressure, and/or chemical equilibria). Scale deposits on or within the downhole component, such as a valve, may prevent or block a desired flow of a downhole fluid out of or into a downhole tool. Scale deposits, such as those that are highly adherent to the substrate, may prevent a mechanical component from properly actuating (e.g., a piston tube within a cylindrical pressure housing). Accordingly, a reduction or inhibition of the formation of scale deposits can improve both the longevity of these systems as well as general operational efficiency, whether for oil and gas production, water or gas injection, carbon dioxide sequestration or geothermal applications.
The present disclosure is directed to techniques for scale reduction or inhibition on a downhole component by applying a material coating having at least one carbon rich layer to the downhole component exposed to scale-forming fluids. Again, the downhole component may include valves, chokes, pumps, packers, or other fluid control equipment. In general, the carbon rich layer may include one or more carbon regions and one or more additional chemical components (e.g., metallic sources and/or nonmetallic sources), such as one or more of a carbide, nitride, sulfide, silicide, or oxide. The carbon region may include a suitable amount of sp2 and sp3 carbon to produce desired combinations of properties among friction coefficient, surface hardness, contact angles, all generally having positive impacts for reducing a likelihood of scale precipitation (e.g., scale formation) on the surface of a coating. Carbon is stabilized in various multi-atomic structures with diverse atomic arrangements or configurations referred as allotropes: these includes amorphous carbon (a-C), graphite (with sp2 configuration) and tetrahedral amorphous carbon (ta-C) or defected diamond (with sp3 configuration). Carbon-rich layers include these allotropes in various proportions, among carbon and non-carbon phases. It is presently recognized that providing a carbon rich layer having greater than 40% sp3 carbon may reduce the amount of scaling as compared to a carbon rich layer including less than 40% sp3 carbon. For example, the carbon rich layer may have greater than 40, 45, or 50% sp3 carbon as generally measured by X-ray photoelectron spectroscopy. Additionally, the carbon rich layer may have a sp2/sp3 ratio less than 1.5 to help reduce the amount of scaling. For example, the carbon rich layer may have a sp2/sp3 ratio less than 1, 1.1, 1.2, 1.3, 1.4, or 1.5 to tailor a number of layer properties, including propensity towards scaling. Accordingly, in the presence of scale-forming fluids, a downhole component at least partially or completely covered with the carbon rich layer may be utilized for longer periods of time, because the carbon rich layer substantially reduces or inhibits the scale formation on the downhole component and thus helps to avoid any constraints to fluid flow (e.g., blockages or restrictions caused by the scale formation). While reduction if flow rates due to scaling is a major concern, interference with the proper functioning of downhole system creates major system reliability concerns, particularly with systems that rely less on hydraulic power and more on electrical power.
With the foregoing in mind,
In the illustrated example of
It should be noted that the actuation subsystem 32 and the valve housing 30 may be configured to operate with or without use of fluid or electrical control lines extending from the surface into the wellbore 14. For example, electrical power and/or fluid pressure may be provided from the surface using one or more electrical generators, a power grid, batteries, pumps, or a combination thereof. Additionally, or alternatively, the actuation subsystem 32 may be powered by one or more local power supplies, such as a battery pack, at the location of the valve 22.
The illustrated embodiment of the closure device 12 includes the valve controller 34 that may be utilized to adjust the position of the components in the valve housing 30. The valve controller 34 controls and/or adjusts a position of the valve 22 between open and closed positions (e.g., via the actuation subsystem 32). For example, the valve controller 34 may control and/or adjust the valve 22 based on messages that are transmitted by a transmitter of a transmitter subsystem 38.
In some embodiments, the transmitter subsystem 38 may receive sensor measurements (e.g., temperature sensor measurements, pressure sensor measurements, flow-rate sensor measurements, fluid composition measurements such as salinity levels, other parameters relating to the formation of scale deposits, or any combination thereof). The sensor measurements may be directed by surface sensors, downhole sensors, or completion sensors to the transmitter subsystem 38 via any suitable telemetry (e.g., via electrical signals pulsed through the geological formation 16 or via mud pulse telemetry). In some embodiments, the transmitter subsystem 38 may receive inputs from a user interface controlled by an operator. The transmitter subsystem 38 may process the sensor measurements and/or user inputs to determine a condition within the wellbore 14 or at the surface and determine whether to adjust the position of the valve 22 based on the condition of the wellbore 14 and/or the surface.
To this end, the transmitter subsystem 38 may be any electronic data processing system that can be used to carry out the systems and methods of this disclosure. For example, the transmitter subsystem 38 may include a processor 40 which may execute instructions stored in memory 42 and/or storage 44. As such, the memory 42 and/or the storage 44 of the transmitter subsystem 38 may be any suitable article of manufacture that can store the instructions. In some embodiments, the memory 42 is a tangible, non-transitory, machine-readable-medium that may store machine-readable instructions for the processor 40 to execute. The memory 42 may include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The memory 42 may store data, instructions, and any other suitable data. Additionally, the transmitter subsystem 38 may include an input/output (I/O) port 46, which may include interfaces coupled to various components such as input devices (e.g., keyboard, mouse), input/output (I/O) modules, sensors (e.g., surface sensors and/or downhole sensors), and the like. For example, the I/O port 46 may include a display (e.g., an electronic display) that may provide a visualization, a well log, or other operating parameters of the geological formation 16, the wellbore 14, or the surface to an operator, for example. In this embodiment, the transmitter subsystem 38 (e.g., data processing system) has been represented at the well site. However, all or part of the transmitter subsystem 38 (e.g., all or part of the processor, the display, the memory, etc.) may be situated remotely from the well site and configured to communicate with the well site via a network connection. It should be noted that, at least in some instances, all or part of the data processing system may be cloud-based.
As discussed herein, a carbon rich layer may be applied to one or more surfaces of the downhole component to reduce, block, or generally inhibit the precipitation of scale onto surfaces of the downhole components, thereby reducing the possibility of blockage of fluid flow or the improper actuation of a mechanical component.
It should be noted that the above discussions of
Furthermore, in embodiments where the disclosed carbon rich layer is applied onto a surface of a piston, it should be noted that the carbon rich layer may be configured to provide a relatively low friction coefficient under certain conditions, such as dry and lubricated conditions. For example, the carbon rich layer may be deposited on opposing surfaces or an entire circumference of multiple parts (e.g., a first part such as a piston and a second part such as a shaft including the piston) the downhole component. Additionally, the carbon rich layer may have a coefficient of friction less than approximately 0.30, 0.25, 0.20, 0.15, 0.10, 0.09, 0.08, 0.07, 0.06, or 0.05 against a metal under dry conditions, particularly alloys of iron, nickel, titanium. Example Alloys that may be used in accordance with the disclose techniques are included in certain standards such as ISO 15156, certain stainless steels, among martensitic stainless steels (e.g., 13Cr, modified 13Cr), duplex and superduplex stainless steels (22Cr, 25Cr) and nickel-based alloys such as Alloy 925, Alloy 718, among others. In certain applications, a polymer composite material that is non-interfering with downhole measurements; in others, a carbide component may be utilized to mitigate erosion. When applied to these components, the carbon rich layer may mitigate, prevent, or reduce scale formation as well as not reduce efficiency of operation of components that may be partially in contact during operation.
At block 68, the process 62 includes depositing a carbon source 70 and one or more additional chemical components 72 (e.g., metallic sources 74 and/or non-metallic sources 76) onto the substrate 66 (e.g., the downhole component, such as those described with respect to
The substrate 66 may be part of a downhole component, such as a valve (e.g., ball valve, gate valve, or flapper valve), a packer, sliding sleeves, and a choke, as discussed with respect to
In certain embodiments, the substrate 66 may be at least partially or entirely made of a polymer, a polymer composite, a metallized polymeric composite, and/or even an elastomeric component. For example, at least 50, 60, 70, 80, 90, 95, 97.5, 99, or 100 percent by volume of the substrate 66 may include a polymer, a polymer composite, a metallized polymeric composite, and/or an elastomeric component. In certain embodiments, the polymer has a tensile strength that is greater than 10,000 psi (e.g., greater than 11000 psi, greater than 14000 psi, greater than 20000 psi, greater than 30000 psi) at ambient temperature (e.g., 75° F. in order to offer typical minimal structural requirements). For example, Table 1 shows several examples of polymer composites that may be employed as the substrate 66 for the carbon rich layer 64.
In some embodiments, the substrate 66 may include one or more metals. For example, the substrate 66 may be at least partially or entirely made of a ferrous-based alloy, a nickel-based alloy, a cobalt-based alloy, a copper-based alloy, an aluminum-based alloy, or a magnesium based-alloy. For example, at least 50, 60, 70, 80, 90, 95, 97.5, 99, or 100 percent by volume of the substrate 66 may include a ferrous-based alloy, a nickel-based alloy as described herein. The substrate may also include a cobalt-based alloy, a copper-based alloy, and even though uncommon, also an aluminum-based alloy or a magnesium based-alloy. In some embodiments, the substrate 66 may include a ceramic material such as a silicon carbide or boron carbide. In some embodiments, the substrate 66 may include both metals and ceramic materials, such as in a cermet. For example, the substrate 66 may include a tungsten carbide cermet, such as a material comprising 60 to 94 wt. % carbides complemented by a corrosion-resistant binder of cobalt, nickel, chromium, among others.
The carbon source 70 is a source precisely including the carbon element and delivering this carbon element to one or more substrates. For example, the carbon source 70 may be a hydrocarbon gas such as methane, ethane, and/or ethyne, an alkyl silane such as trimethyl silane, and/or a metal carbonyl. To produce elemental carbon that would deposit rapidly onto a target substrate, the carbon source gas may be ignited by an AC voltage, which may cause carbon and hydrogen atoms to recombine as a dense carbon rich layer onto the substrate.
The additional chemical components 72 generally include metallic sources 74 (e.g., transition metal sources, main-group metal sources) and nonmetallic sources 76. For example, the metallic sources 74 may include tungsten, titanium, chromium, nickel, iron, and/or cobalt, such as corresponding metal carbonyls, metal hydrides, metal halides, and metal chalcogenides. The nonmetallic sources 76 may include silicon, oxygen, nitrogen, fluorine, and/or chlorine, such as silanes, metal halides, fluorine gas, nitrogen gas, ammonia, and alkylamines.
In certain embodiments, the carbon rich layer 64 includes one or more regions, areas, or locations having a carbon content with a particular amount of sp2 carbon and/or sp3 carbon. Additionally, the carbon rich layer 64 may include one or more dispersed phases that include mixtures of carbon with elements from the one or more additional chemical components 72, such as metal carbides. Further, the carbon rich layer 64 may include combinations of different elements from the additional chemical components 72, such as metal chalcogenides, as discussed in further detail herein.
Further, the carbon rich layer 64 may include a total thickness between 500 nm and 30,000 nm. For example, the total thickness of the carbon rich layer 64 may be between 500 nm and 30,000 nm, between 750 nm and 15,000 nm, between 1000 nm and 5000 nm, or between 1250 nm and 2500 nm. In certain embodiments, the total thickness of the carbon rich layer 64 may include both a thickness of one or more carbon rich layers and a thickness of one or more other layers deposited on the substrate 66, such as a top surface layer, a buffer layer (i.e., a layer introduced to accommodate (e.g., increase the binding strength of) the carbon-rich layer on the substrate), and a dispersed phase layer, as discussed in more detail with respect to
To further illustrate various embodiments of the carbon rich layer 64, Table 2 provides example embodiments of the carbon rich layer 64 produced by the PACVD process, wherein the carbon rich layer 64 has different carbon contents, among others. For example, example embodiments of the carbon rich layer 64 may have a sp3 carbon content greater than 40%, greater than 45%, greater than 50%, between 40%-60%. Additionally, or alternatively, example embodiments of the carbon rich layer 64 may have a carbon content with a sp2/sp3 ratio less than 1.5, less than 1.0, less than 0.8, less than 0.7, less than 0.6, or between 1.5-0.6, between 1.5-1.0, between 1.0-0.6, and other ranges represented in Table 2. In examples presented in table 2, the carbon rich layers were produced with a range of thickness between approximately 200 nm (0.2 μm) and 30,000 nm (30 μm), and fall under a broad range of designations. These carbon rich layers include hydrogen and silicon. Some of the carbon-rich layers are single layered and other double-layered. As a result of their different deposition process parameters and compositional differences, carbon layers with average Vickers hardness between 925 and 1550 were produced, indirectly causing a range of desirable coefficient of frictions. Because of the carbon film thickness, hardness was converted from Berkovich nano- and micro-indentation tests conducted with a computerized indenter and reported as average of a minimum of ten measurements. Friction coefficient was measured against a standard stainless-steel ball under dry and dynamic conditions as per a procedure modified from ASTM G99. To quantify the relative amounts of sp2 carbon and sp3 carbon, measurements by Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS) were complementarily carried out using different procedures. In this example, Raman spectroscopy was first utilized to rapidly characterize specially-designed carbon layers. In the Raman spectroscopy of carbon-rich layers, the measured spectrum produced by scattered laser light depends on the ordering of sp2 sites and indirectly on the fraction of sp3 sites in all amorphous carbons, both hydrogenated and hydrogen-free. Carbon rich layer spectra depict two strong Raman peaks around 1350 cm−1 (D-band), and 1580 cm−1 (G-band). The G-peak is assigned to in-plane stretching of the sp2 bonded carbon; the D-band is assigned to the breathing mode of aromatic carbon atoms which appears in case of the defects or discontinuities in the network symmetry. The integrated intensity ratio of D-peak to G-peak, referred as “I(D)/I(G)”, can be correlated to sp2/sp3, which decreases with an increase of sp3 fraction in the carbon rich layer. The I(D)/I(G) values for the various carbon rich layers are populated in Table 2 and are seen to vary considerably. The I(D)/I(G) values were extracted from the Raman spectrum of the carbon rich layer after deconvoluting of the peak (in the range of 900 cm−1-1800 cm−1) to D and G bands. Raman spectrum is recorded from the carbon rich surface using an excitation laser source at 532 nm. The ratios of sp2/sp3 were also measured by X-ray Photoelectron Spectroscopy (XPS). The C1s XPS peak was recorded from the surface of the carbon rich layer. The C1s peak was deconvoluted to four Gaussian peaks attributed to sp3 (˜284.5 eV), sp2 (˜285.1 eV), C—O (˜286.8 eV) and C═O (˜288.4 eV). The sp2/sp3 was calculated based on their peak areas. The results indicate that there is a correlation between sp3 content by XPS and by Raman spectra, as the sp2/sp3 shows a positive trend with I(D)/I(G).
The performance of carbon-rich films was measured using a variety of tests on test coupons exposed to both static and dynamic flowing conditions with scale forming brines. For illustration purposes, results from carbonate scale deposition tests have been included to demonstrate that carbon-rich layers as per Table 2 can be effective against scale deposition. Tendency towards scaling can be determined using a number of measures, particularly scale mass gains and scale adhesion strength. Both of these measures have been found to identify carbon-based films resisting scale deposition. In this example, to determine the amount of calcium carbonate scale that would accumulate on carbon rich film test coupons, dynamic scaling tests were conducted using cationic and anionic brine injected into a rotating autoclave (570 rpm). Each of the test coupons, with dimensions 2″×12″×⅛″, were suspended in a test fluid comprising a 50:50 mixture of the anionic and cationic brines (Table 3), which was then constantly circulated through the autoclave at a rate of 2.5 milliliters per minute. After addition of the coupons the pressure, temperature, and shear rate were increased to 4500 PSI (using nitrogen), 167° F., and 570 rpm, respectively. The coupons were then aged under dynamic conditions for seventy-two hours. After aging, the test coupons were photographed, dried, and weighed to determine the amount of scale which had accumulated on them. Pictures of 4 test samples (e.g., indicated by arrows 118, 122, 120, and 124), including front (e.g., right) and back (e.g., left) surfaces, are shown in
Accordingly, the present disclosure relates to a carbon rich layer 64 with an improved ability to prevent, mitigate, or block scale formation (e.g., scale precipitation) on various equipment, such as downhole components. As discussed herein, it is presently recognized that improved scale mitigation is achieved with a carbon rich layer 64 having one or more regions with a carbon content greater than 40 percent sp3 carbon and/or a sp2/sp3 ratio of the carbon content is less than 1.5, wherein the improved scale mitigation is substantially better than coatings with a carbon content with less than 40 percent sp3 carbon.
The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/019084 | 3/7/2022 | WO |
