Patent Application
20190025189
This patent application generally relates to corrosion testing, and more particularly to systems for multiphase, multimethod testing.
Performing corrosion measurements is often a time consuming process since it requires exposing test samples to a corrosive environment for an extended duration of time and then measuring the amount of corrosion of the test sample. Typically, one environmental condition is tested during each test process. Accordingly, if varying environments are to be evaluated, several separate corrosion tests must be performed. Moreover, test systems either rely upon measuring weight loss of the test samples during the test or, upon measuring electrical signals in the corrosive environment. However, typically these types of tests require different experimental setups and that further increase the number of tests required, which further increases time and costs.
The present invention provides a solution to these and other problems.
In one aspect of the invention, a multi-phase testing system for testing corrosive environments by providing a test fluid mixture that is at a different phase at different locations within the system in surrounding relation to a plurality of test coupons is provided. The corrosion rates can be determined via weight-loss means and electrochemical means on the plurality of test coupons. The testing system includes a housing defining an inner chamber a plurality of inserts disposed vertically within the housing. Each insert defines an interior area and an interior surface. At least one test coupon among the plurality of test coupons is disposed at an inner surface of each of the plurality of inserts. A plurality of electrical probes is provided. At least one electrical probe is disposed at an inner surface of each of the plurality of inserts, and each electrical probe has an electrical lead wire electrically connected to the electrical probe and extending outside the housing for reading electrical signals through the wire. A plurality of separator plates, wherein one of the plurality of separator plates is disposed between each adjacent insert. The separator plates are configured to maintain a separation between each of the phases of the multi-phase test fluid disposed within the housing so that each of the test coupons and electrical probes in each of the inserts is exposed to a different phase of the test fluid. Corrosion is measured by measuring the amount of weight-loss of each of the test coupons and by measuring the electrical signals from each electrical probe.
According to a further aspect, each insert includes a plurality of grooves disposed about the inner surface of the inserts, wherein the grooves are sized and shaped to receive test coupons and electrical probes, respectively.
According to a still further aspect, which can be combined in an embodiment constructed in accordance with one or more of the foregoing aspects, the grooves have a dovetail shape.
According to a further aspect, which can be combined in an embodiment constructed in accordance with one or more of the foregoing aspects, each insert includes at least one window that permits viewing of the interior area of the insert.
According to another aspect, which can be combined in an embodiment constructed in accordance with one or more of the foregoing aspects, a reference electrode and a counter electrode are disposed within the housing that provide a reference electrical signal and a counter electrode electrical signal that are capable of being used, in combination with the electrical signal from the electrical probes, to measure corrosion using electrical signals.
According to a still further aspect, which can be combined in an embodiment constructed in accordance with one or more of the foregoing aspects, the system further includes a stirring rod for stirring the test fluid disposed within the housing.
According to a further aspect, which can be combined in an embodiment constructed in accordance with one or more of the foregoing aspects, the system further includes a plurality of baffles supported by the inserts.
According to another aspect, a method for performing multi-phase testing of corrosive environments via a weight-loss method and an electrochemical method by providing a test fluid mixture that is at a different phase at different locations within the system is provided. The method includes the step of providing a test system. The test system includes a housing defining an inner chamber and a plurality of inserts disposed vertically within the housing, each insert defining an interior area and an interior surface. A plurality of test coupons is provided and at least one test coupon is disposed at an inner surface of each of the plurality of inserts. A plurality of electrical probes, wherein at least one electrical probe is disposed at an inner surface of each of the plurality of inserts, are provided. Each electrical probe has an electrical lead wire electrically connect to the electrical probe and extending outside the housing for reading electrical signals through the wire. A plurality of separator plates, wherein one of the plurality of separator plates is disposed between each adjacent insert, is provided. The separator plates are configured to maintain a separation between each of the phases of the multi-phase test fluid disposed within the housing so that each of the test coupons and electrical probes in each of the inserts is exposed to a different phase of the test fluid. The method includes the step of providing the test fluid in the inner chamber of the housing. The temperature and pressure are maintained within the housing such that the test fluid exists as a vertically stratified, multiphase fluid. An electrochemical corrosion rate is determined by measuring the electrical signals from the electrical probes. A weight-loss corrosion rate is determined by comparing a pre-test and a post-test weight of the coupons. The determined corrosion rates from the test coupons and electrical probes from each respective, vertically arranged insert corresponds to the corrosion rate for a corresponding, respective phase of the vertically stratified, multiphase fluid.
The accompanying drawing figures illustrate exemplary embodiments and are not intended to be limiting of the invention. Among the drawing figures, like references are intended to refer to like or corresponding parts.
The invention is now described with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, example implementations and/or embodiments of the present invention. It is to be understood that other embodiments can be implemented and structural changes can be made without departing from the spirit of the present invention. Among other things, for example, the disclosed subject matter can be embodied as methods, devices, components, or systems.
Furthermore, it is recognized that terms may have nuanced meanings that are suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment and the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter can be based upon combinations of individual example embodiments, or combinations of parts of individual example embodiments.
In accordance with the present application, embodiments are provided that are directed to systems and devices for providing high throughput screening and evaluation of materials and corrosion inhibitors under dynamic multiphase sour environments. In certain embodiments, each reactor includes three identical inserts. Each insert is a stationary cage system for performing corrosion evaluations. The inserts are arranged vertically in the reactor to study three environmental phases: aqueous, aqueous/hydrocarbon interface, and gas, which are vertically stratified within the reactor chamber. Moreover, the present system permits for measuring corrosion using both electrochemical and weight-loss methods. Accordingly, multiple samples can be evaluated under different environmental conditions within the same reactor vessel at the same time, which provides for an efficient, fast, and economical system for testing a variety of sample under a variety of conditions.
According to one aspect, as shown in
As shown in
Referring to
The inserts 106, 108, and 110 include a plurality of grooves 112. The grooves can have a dovetail shape. In one embodiment, the dovetail can be sized and shaped to receive and hold correspondingly shaped coupons 114 of material to be tested, as can be seen in
An additional electrical probe 122 can be provided at each insert 106, 108, and 110 and can be used to measure corrosion using electrical methods, as discussed in more detail below. As shown in
Referring to
In order to facilitate electrochemical corrosion measurement, a reference electrode 134 and a counter electrode 136 are provided as shown in
As discussed above, as shown in
A stirring rotor 150 can extend centrally through the three separator plates 142 and inserts 106, 108, and 110 to provide controlled stirring of the test fluid. A gate anchor impeller 162 can be attached at a lower end of the rotor 150 to provide controlled stirring of the aqueous phase 12 of the test fluid at the lower insert. A turbine impeller 164 can be attached at a mid-portion of the stirring rotor 150 to provide controlled stirring of the aqueous/hydrocarbon interface phase 14 of the test fluid at the middle insert. The turbine impeller 164 can be a 6-flat-blade disc turbine, for example. An impeller is not required to provide stirring at the upper portion of the stirring rotor 150 at the gaseous phase 16 of the test fluid. Rotating the stirring rotor 150 provides for controlled stirring of the test fluid so that test fluid moves across the surface of the coupons and electrical test probes, while baffles 140 and separator plates 142 prevent unwanted vortex that can disturb phase stratification of the fluid. A wobble preventer pin 166 can be disposed at a distal end of the stirring rotor 150 to prevent wobble of the stirring rotor 150 during rotation.
As one general example of a use of the test system described herein, coupons and working electrodes are loaded into the respective grooves of the inserts. Baffles of the construction described above are inserted into respective insert grooves and separator plates are disposed between adjacent inserts and a further separator plate is disposed on top of the upper most insert. The inserts and separator plates are bolted together. The inserts, separator plates, reference electrode, counter electrode, and stirring rotor are inserted into an interior of the outer vessel. The test fluid can then be added to the vessel and a head (e.g., cover) can be attached to the vessel to close the vessel. Electrode electrical lead wires (working, reference, and counter electrodes) extend through the head to an outside of the vessel. The volume, temperature and pressure of the test fluids inside the vessel are adjusted to achieve a multiphase condition (aqueous, aqueous/hydrocarbon interface, and gaseous phase) that occurs in a stratified condition such that the lower insert, middle inset, and upper insert, including their respective coupons/working electrodes, are each exposed to a different phase condition of the test fluid (i.e., aqueous, aqueous/hydrocarbon interface, and gaseous phase, respectively). The stirring rotor can be rotated to achieve controlled stirring of the fluid while baffles and separator plates help prevent vortex formation. Electrochemical corrosion rates can be measured by monitoring electrical signals from the working electrode using the reference and counter electrodes, which can be done during the test. After the test phase is complete, the inserts are removed from the vessel and the coupons are removed from the inserts so that a post-test weight of the coupons can compared to a pre-test weight of the coupons to determine weight loss, which can be used to determine corrosion rate.
Accordingly, a system and method is provided for high-through put corrosion testing in multi-phase environment using two different testing methods (weight-loss and electrochemical) as a result of a single test. Being able to test multi-phase environments greatly increases the number of environments that can be tested without the time and expense of multiple test procedures. Moreover, the ability to measure corrosion rates using two different methods simultaneously during the same test greatly increases accuracy while further eliminating the time and cost of having to conduct multiple, separate tests. A further advantage of performing two different corrosion measurement methods during same test environment further increases accuracy because performing two different, separate tests can introduce differences in results that are a result of difference in the test itself (volume, temperature, pressure, time, equipment setup variables, etc.), which are eliminated when these two different methods are employed as part of the same test procedure. Moreover, a transparent vessel and windows in the inserts provides for visual inspection during the testing, which can lead to insights about the corrosion test that may vary throughout the duration of the test, which may not be readily observable by conducting pre- and post-test inspections.
Notably, the figures and examples above are not meant to limit the scope of the present application to a single implementation, as other implementations are possible by way of interchange of some or all of the described or illustrated elements. Moreover, where certain elements of the present application can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present application are described, and detailed descriptions of other portions of such known components are omitted so as not to obscure the application. In the present specification, an implementation showing a singular component should not necessarily be limited to other implementations including a plurality of the same component, and vice-versa, unless explicitly stated otherwise herein. Moreover, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present application encompasses present and future known equivalents to the known components referred to herein by way of illustration.
The foregoing description of the specific implementations will so fully reveal the general nature of the application that others can, by applying knowledge within the skill of the relevant art(s) (including the contents of the documents cited and incorporated by reference herein), readily modify and/or adapt for various applications such specific implementations, without undue experimentation, without departing from the general concept of the present application. Such adaptations and modifications are therefore intended to be within the meaning and range of equivalents of the disclosed implementations, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance presented herein, in combination with the knowledge of one skilled in the relevant art(s). It is to be understood that dimensions discussed or shown of drawings are shown accordingly to one example and other dimensions can be used without departing from the invention.
While various implementations of the present application have been described above, it should be understood that they have been presented by way of example, and not limitation. It would be apparent to one skilled in the relevant art(s) that various changes in form and detail could be made therein without departing from the spirit and scope of the application. Thus, the present application should not be limited by any of the above-described example implementations.
