IMPROVED CLEANSING GEL WITH SCRAPING

Abstract

A method and device for performing ultrasonic inspection inside a tube while using the minimum amount of gel couplant is also described.

Description

IMPROVED CLEANSING GEL WITH DEVIL PREVIOUS RELATED APPLICATIONS This application claims priority from U.S. Provisional Application No. 62 / 967,773, filed on January 30, 2020, which is incorporated by reference in its entirety for all purposes. FIELD OF INVENTION In general, the disclosure describes a system and methodology for the inspection of pipes / tubes used to transport petroleum products, such as natural gas (NG). BACKGROUND OF THE INVENTION Pipe or conduit pigging is performed to remove internal scale, inspect pipe defects, or map the pipe's geographic location. Pigging is done by pumping a device, known as a pig, through a pipe. Smart pigs have sensors that can record information about the pipe's condition. Currently, transport pipelines, such as natural gas pipelines, are generally inspected using magnetic flux leakage (MFL) technology, checked with handheld external ultrasonic sensors, or inspected with conventional ultrasonic (UT) in-pipe inspection tools (ILI) during static pressure testing, when the pipes or tubes are flooded with water. MFL data only provides a qualitative measure of pipe health. It reflects the overall health of the pipes, but does not provide a quantitative measure of wall thickness or corrosion. Spot checks only examine a very small sample of the entire pipeline. Furthermore, they require that the asset be accessible to a person. Static pressure testing is performed infrequently and is very costly for the customer. Flooding the pipeline with water at any other time is undesirable due to increased operating costs and asset downtime. Batch inspections using water have been unsuccessful. The dosing pigs were not suitable for smooth flow through the pipeline, resulting in sudden pressure increases at the launch and receiving ends. Furthermore, the use of water as a couplant left large amounts of water in the pipeline after the inspection was completed, even with the dosing pigs. What is needed, therefore, is a more reliable method and system for inspecting pipelines that transport petroleum products, such as natural gas pipelines. αοζΑηη / ζζηζ / Ε / γίΛΐ BRIEF DESCRIPTION OF THE INVENTION This summary is provided to introduce a selection of concepts that are described further in the detailed disclosure. However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. This brief description is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. In one aspect of this description, a method for performing ultrasonic inspection of a pipeline is described, comprising: introducing a conduit inspection tool assembly into a pipeline, wherein the conduit inspection tool assembly comprises a gel reservoir and an ultrasonic inspection tool flanked by a pair of dosing pigs, wherein the gel reservoir contains a first gel couplant; and driving the conduit inspection tool assembly along the pipeline while performing an ultrasonic inspection; wherein a gel lump is formed between the pair of dosing pigs, and the gel lump facilitates the ultrasonic inspection. In another aspect of this disclosure, a method for performing ultrasonic inspection of a pipeline is described, comprising: introducing a pipeline inspection tool assembly into the pipeline, wherein the pipeline inspection tool assembly comprises an ultrasonic inspection tool between a pair of dosing pigs; and driving the pipeline inspection tool assembly along the pipeline while performing an ultrasonic inspection; wherein the ultrasonic inspection tool is surrounded by a coupling gel to facilitate ultrasonic inspection, and wherein the coupling gel is semi-rigid. In another aspect of this disclosure, a pipeline inspection tool assembly for performing ultrasonic inspection of a pipeline is described. The inspection tool assembly comprises a first dosing pig, a second dosing pig, and an ultrasonic inspection tool operatively coupled with a gel reservoir containing a first gel couplant, wherein the ultrasonic inspection tool and the gel reservoir are located between the first dosing pig and the second dosing pig, and wherein a piece of gel is formed around the ultrasonic inspection tool to facilitate ultrasonic inspection. In another aspect of this disclosure, a pipeline inspection toolkit for performing ultrasonic inspection of a pipeline is disclosed. The pipeline inspection toolkit comprises a first dosing pig, a second dosing pig, and an operatively coupled ultrasonic inspection tool. QozRnn / zznz / E / YiAi between the first dosing pig and the second dosing pig, wherein the ultrasonic inspection tool is surrounded by a semi-rigid gel coupler. BRIEF DESCRIPTION OF THE FIGURES Certain disclosure features will be described below with reference to the accompanying drawings, where similar reference numbers indicate similar features. It is emphasized that, in accordance with standard industry practice, several features are not drawn to scale. In fact, the dimensions of several features may be arbitrarily enlarged or reduced to clarify the discussion. However, it should be understood that the accompanying figures illustrate the various implementations described herein and are not intended to limit the scope of the various technologies described herein, and: Figure 1 is a comparison of the amount of coupling gel between a traditional ultrasonic inspection and a modality of this disclosure. Figure 2 is a cross-sectional view of one modality of this disclosure as applied to a pipe. Figure 3 is a cross-sectional view of another modality of this disclosure as applied to a pipe. Figure 4 is a cross-sectional view of another modality of this disclosure as applied to a tube. DETAILED DESCRIPTION The following description provides numerous details to facilitate understanding of some of the modalities covered in this disclosure. It should be understood that the following description provides many different modalities, or examples, for implementing various features of these modalities. Specific examples of components and arrangements are described below to simplify the disclosure. These are, of course, only examples and are not intended to be exhaustive. Furthermore, the description may repeat reference numbers and / or letters in the various examples. This repetition is for the sake of simplicity and clarity and does not, in itself, dictate a relationship between the various modalities and / or configurations discussed. However, those skilled in the art will understand that the system and / or methodology can be practiced without these details and that numerous variations or modifications of the described modalities are possible.This description should not be taken in a limiting sense, but is provided simply to outline the general principles of the implementations. The scope of the implementations described should be determined with reference to the claims made. As used herein, the terms connect, connection, connected, in relation to, and connecting mean directly connected to or connected to via one or more elements; and the term “assembly” is used to mean “an element” or “more than one element.” In addition, the terms couple, coupling, coupled, coupled to each other, and coupled to are used to refer to being directly coupled or coupled via one or more elements. As used herein, the terms above and below; upper and lower; up and down; and other similar terms indicating positions relative to a given point or element are used to describe some elements more clearly. As used herein, the terms pipes and tubing are used individually or in combination to refer to elements for conveying petroleum products. As used here, pipeline inspection or ILI refers to the evaluation of pipes and conduits using non-destructive testing techniques to detect and measure any internal defects or flaws. ILI measures and records irregularities in pipes, including corrosion, cracks, deformation, or other defects. As used here, the term ultrasonic transducer refers to a device that converts a pulse of electrical energy into mechanical energy in the form of sound waves. For non-destructive testing, high-frequency sound waves are generated and received by ultrasonic transducers, and the corresponding data is then processed to determine if any defects exist. Typically, the active element of an ultrasonic transducer is a thin disc, a square or rectangular piezoelectric ceramic, or a composite material that converts electrical energy into acoustic energy, and vice versa. As used here, the term coupling refers to a material capable of providing acoustic coupling between the ultrasonic transducer and a test subject. Coupon is required due to the acoustic impedance mismatch between the air at the interface with the transducer and the test object. As is known in the field, for ultrasonic inspection, the couplant is typically a gel and can have a variety of compositions. Several selection criteria can be considered: corrosion inhibition, acoustic impedance, viscosity, temperature range, and drying or evaporation time. Specifically, the couplant used in this document must not cause any corrosion on the piping or the lining / plating of the equipment to prevent any failure of the part due to hydrogen embrittlement, stress corrosion cracking, or deep pitting. Furthermore, the couplant used here preferentially reduces surface noise and improves coupling on rough or curved metal surfaces. Coupons with high acoustic impedance provide better results for testing concrete and metals with less-than-perfect surface conditions. The viscosity of the couplants can also affect the test results. αοζΑηη / ζζηζ / Ε / γίΛΐ Coupons with higher viscosity provide improved coupling and reduce surface noise on curved surfaces, while exposure, adhesion to the part, and ease of application are also factors that affect couplant selection. The operating temperature range of the couplers would also be considered. For example, the temperature of the part under test or the duration of the inspection would affect the choice of couplant. Drying time, or evaporation time, is another factor to consider, as it affects how often the couplant needs to be reapplied, especially during extended inspections. Petroleum product pipelines often stretch for kilometers, so couplants with longer drying times are preferable. As used herein, gel reservoir refers to a storage unit within the pipe inspection toolkit for storing additional coupling gel, so that the coupling gel can be quickly reapplied when required. The location of the gel reservoir within the pipe inspection toolkit may vary, provided that the triggering mechanism can introduce the additional coupling gel to the intended area. As used here, "digger" refers to fluid-driven entities that are pumped through a pipeline from one point to another where launching and receiving facilities exist. A dosing digger or batch digger refers to a digger with a pipe seal to separate the liquid from the gas or medium in the pipeline. The dosing digger used in this description has a profile that conforms to the inner wall of the pipeline to minimize the amount of couplant residue after the inspection is completed. As used herein, gel chunk refers to a relatively short section within the pipe that is primarily occupied by gel As used here, a gel recovery device refers to a device that recovers the couplant after testing for the area has been completed. For example, a scraper disc may be included in the pipe inspection tool assembly behind the ultrasonic transducer, so that once the ultrasonic transducer passes through a section of pipe, the scraper disc can scrape the inner wall of the pipe to collect and substantially remove the couplant. In some configurations, the scraped couplant is collected and fed back to the front of the pipe inspection tool assembly. Another gel recovery device may be used. The use of the word "a" or "an" when used together with the term comprising in the claims or specification means one or more than one, unless the context otherwise indicates. The term “approximately” means the stated value plus or minus the margin of measurement error, or plus or minus 10% if no measurement method is stated. The use of the term or in the claims means and / or unless explicitly stated to refer to alternatives only or if the alternatives are mutually exclusive. The terms “comprise”, “have”, “include”, and “contain” (and their variants) are open linking verbs and allow the addition of other elements when used in a claim. The phrase “which is stated in” is closed and excludes all additional elements. The phrase “which essentially consists of” excludes additional material elements, but allows the inclusion of non-material elements that do not substantially change the nature of the invention. This disclosure describes a system and methodology used to inspect pipes / tubes used for transporting petroleum products, primarily natural gas (NG), using a gel-like substance. Natural gas pipelines and tubes are a common asset within the power, oil, and gas industries, and routine inspection is required to properly maintain, repair, and / or replace them. Ultrasonic inspection, although widely used, was problematic in natural gas pipelines because ultrasonic inspection tools typically require coupling gel around the tools to obtain accurate readings, and coupling gel residues within the gas pipeline pose performance and safety issues. Filling the pipeline, often miles long, with coupling gel for ultrasonic inspection is time-consuming and costly. Therefore, a pipeline inspection toolkit capable of inspecting a natural gas pipeline using a minimal amount of coupling gel is described. A method for inspecting petroleum product pipelines using the pipeline inspection toolkit is also described herein. With reference to Figure 2, which shows one embodiment of the self-contained pipeline coupler (SLIC) described herein. In Figure 2, a pipeline inspection tool set (ILI) 200 is introduced into a petroleum product pipeline 220, such as natural gas. A piece of coupling gel or a gel train may first be introduced into the pipeline 220, after which the ILI 200 tool set is inserted into the gel piece. Alternatively, the gel piece may be injected from a gel reservoir 211 into the ILI 200 tool set. In Figure 2, the flow direction within the pipeline 220 is clockwise, and the product, such as natural gas, 201 behind the ILI 200 tool set is carried downstream. The ILI 200 tool set comprises a first dosing pig 203 at the front end and a second dosing pig 205 at the rear end.Both dosing pigs 203, 205 provide an annular seal so that product 201 would not leak into the space between dosing pigs 203, 205. An ultrasonic inspection tool 207 is placed between batch pigs 203, 205. To enable the ultrasonic inspection tool 207 to obtain accurate readings, a pressurized couplant plasma gel storage unit 211 is provided, along with a plasma gel extruder 209, so that a small amount of plasma coupling gel 215 is provided around the ultrasonic inspection tool 207. To reduce the amount of plasma gel used, gel containment seals 213 are provided in front of and behind the ultrasonic inspection tool 207. The gel containment seals 213 provide an additional annular seal to form a closed chamber encompassing the ultrasonic inspection tool 207 and prevent the plasma gel couplant 215 from escaping the chamber as the assembly 200 moves within the pipe 220.This configuration allows ultrasonic inspection within a petroleum product pipeline 220, while reducing the amount of plasma gel couplant 215 used to an economically acceptable range. The coupling gel 215 used will minimize residue left in the 220 pipe because the containment seals effectively contain and carry the coupling gel 215 as the ILI 200 tool set moves along the 220 pipe. The gel will be used as a couplant for the ultrasonic inspection of the 220 pipe and will not contribute any harmful effects to the 220 pipe. In some embodiments, since 220 pipes are periodically treated with chemicals that inhibit corrosion and other harmful effects, the 215 plasma gel coupling may also comprise the chemicals necessary to treat the 220 pipes in addition to being used as a coupling agent. Referring to Figure 1, which shows a comparison of the plasma gel used between the traditional method and the methods described herein for a specific set of conditions, as shown in Figure 1, for the same set of pipe conditions, a traditional ultrasonic inspection required approximately 117 BBL of plasma gel per kilometer because the entire pipe section needed to be flooded with water, and under such conditions, a large amount of coupling gel was required. In contrast, for the same set of conditions, using the method described herein, only 4 BBL of plasma gel would be required per 5 kilometers, resulting in a 145-fold reduction in the amount of gel required for the ultrasonic inspection. αοζΑηη / ζζηζ / Ε / γίΛΐ With reference now to Figure 3, which shows another embodiment of this description, dosing pigs can be designed for each pipeline to be inspected in such a way as to minimize the amount of residual gel left in the pipeline. As shown in Figure 3, an in-pipe inspection tool (ILI) assembly 300 is introduced into a pipeline, such as a natural gas pipeline 320. The flow direction within the pipeline 320 is clockwise, and the product, such as natural gas, 301 behind the ILI tool assembly 300 carries it downstream. The ILI tool assembly 300 comprises a first dosing pig 303 at the front end and a second dosing pig 305 at the rear end. An ultrasonic inspection tool 307 is located between the dosing pigs 303 and 305. Unlike Figure 2, the ILI 300 tool set further comprises a plasma gel recovery scraper disc 317 for removing and recovering gel residue from the inner wall of the pipe 320. The dosing pigs 303, 305, and / or the ILI 300 tool comprise gel reservoirs 311 for replenishing any gel coupler 315 not captured by the final batch scraper 305. The extruder 309 can inject additional gel 315 into the pipeline from the reservoir 311. The dosing pigs 303, 305, and / or the ILI 300 tool can be designed to recirculate, reuse, or recover gel / coupler 315 that is no longer near the UT sensors. For example, a pump (not shown) can be included in the ILI 300 tool assembly to transfer the gel 315 collected by the scraper disc 317 to the front end of the ILI 300 tool assembly. With reference to Figure 4, which shows another embodiment of this description, the ultrasonic portion of the ultrasonic inspection tool 407 can be encapsulated in a more rigid gel 410 to reduce the amount of fluid gel 415 required for inspection. In this embodiment, the semi-rigid gel 410 encapsulates the ultrasonic inspection tool 407 and is used to transmit the ultrasonic signal to the pipe wall, thereby reducing, or possibly eliminating, the need for an additional coupler 415. Semi-rigid gels are less likely to run out or escape from the space between the first and second dosing pigs 403, 405. The inspection method described herein has the advantage of using only a limited amount of a gel-like couplant introduced into the pipe or conduit in a contained manner. In this way, the couplant gel is present only in a small area of ​​the pipe. The UT tool is then inserted into this gel, and the contained gel is propelled through the pipe or conduit by natural gas or air pressure. The gel used will minimize residue left on the inspected pipe and will conduct ultrasonic signals. The gel will be used as a couplant for the ultrasonic inspection of the pipe and will not contribute to any harmful effects on the pipe. Preferably, the gel has a long drying time to reduce the time required for reapplication and a wide operating temperature range to avoid this. Currently, pipes are periodically treated with chemicals that inhibit corrosion and other harmful effects. The gel can also be used to apply this treatment, while also serving as a couplant. The amount of gel used for each individual pipe or conduit will be calculated and optimized to minimize the total amount used. This calculation will be based on the pipe or line diameter, the length of the pipe or line being inspected, and the amount of gel residue left in the pipe or line after the final dispensing pig has passed through. The inspection method can be implemented to minimize or eliminate gel leakage at any taps or other conduits connected to the pipe or duct currently under inspection. In the SLIC method, the ILI tool is sealed at both the front and rear ends to carry the couplant with it during the inspection, thus preventing leakage. Furthermore, the couplant gel can be recovered and recirculated through active and / or passive processes. The inspection method described in this disclosure enables effective and efficient inspection of petroleum assets, such as natural gas pipelines, using ILI ultrasonic tools, while minimizing the amount of fluid / gel / coplant required for the ultrasonic inspection. Furthermore, this method provides a comprehensive quantitative measurement of the remaining service life of the pipelines. Although a few variations of disclosure have been described in the preceding details, those skilled in the art will readily appreciate that many modifications are possible without materially departing from the teachings and advantages of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. The scope of the invention is to be determined solely by the language of the following claims. The term “comprising” within the claims is intended to mean “including at least” so that the list of elements mentioned in a claim is an open set. The terms “a,” “an,” and other singular terms are intended to include the plural forms thereof unless specifically excluded.

Claims

NOVELTY OF THE INVENTION Having described the present invention as above, the following claims are considered novel and are therefore claimed as property: CLAIMS 1. A method for performing ultrasonic inspection of a pipe, characterized in that it comprises: a) introducing a conduit inspection tool assembly into the pipe, wherein the conduit inspection tool assembly comprises a gel reservoir and an ultrasonic inspection tool flanked by a pair of dosing pigs, wherein the gel reservoir holds a first gel couplant; and b) propelling the conduit inspection tool assembly along the pipe while performing the ultrasonic inspection; wherein a piece of gel is formed between the pair of dosing pigs, and said piece of gel facilitates the ultrasonic inspection.

2. The method according to claim 1, characterized in that the gel piece is formed by the release of gel from the gel reservoir in the tube between the pair of dosing pigs.

3. The method according to claim 1, characterized in that the duct inspection tool assembly further comprises seals adjacent to the ultrasonic inspection tool to form a closed chamber encompassing the ultrasonic inspection tool.

4. The method according to claim 3, characterized in that the piece of gel is formed inside the closed chamber.

5. The method according to claim 1, characterized in that the gel serves as a couplant for ultrasonic inspection.

6. The method according to claim 1, characterized in that the duct inspection tool assembly further comprises a gel recovery device for collecting and recycling the gel.

7. The method according to claim 6, characterized in that the gel recovery device comprises a scraper disc.

8. The method according to claim 6, characterized in that the gel recovery device recovers the gel after the ultrasonic inspection tool passes, and the recovered gel is re-supplied in front of the ultrasonic inspection tool.

9. The method according to claim 1, characterized in that it further comprises, before step (a): introducing a first gel coupling agent into the tube.

10. The method according to claim 1, characterized in that the ultrasonic inspection tool is further surrounded by a second gel couplant, wherein the second gel couplant has a different composition than the first gel couplant.

11. The method according to claim 10, characterized in that the second gel is semi-rigid.

12. The method according to claim 1, characterized in that it further comprises: supplying the first gel coupling agent between the first and second dosing pigs of the gel reservoir.

13. A method for performing ultrasonic inspection of a pipe, characterized in that it comprises: a) introducing a conduit inspection tool assembly into the pipe, wherein the conduit inspection tool assembly comprises an ultrasonic inspection tool between a pair of dosing pigs; and b) propelling the conduit inspection tool assembly along the pipe while performing the ultrasonic inspection; wherein the ultrasonic inspection tool is surrounded by a gel couplant for ultrasonic inspection, and wherein the gel couplant is semi-rigid.

14. A pipeline inspection tool assembly for performing ultrasonic inspection in a pipeline, said pipeline inspection tool assembly characterized in that it comprises a first dosing pig, a second dosing pig and an ultrasonic inspection tool operatively coupled with a gel reservoir containing a first gel couplant, wherein the ultrasonic inspection tool and the gel reservoir are located between the first dosing pig and the second dosing pig, and wherein a piece of gel is formed around the ultrasonic inspection tool to facilitate ultrasonic inspection.

15. The inspection tool assembly according to claim 14, characterized in that it comprises a first seal and a second seal, wherein the first and second seals flank the ultrasonic inspection tool to form a closed chamber comprising the ultrasonic inspection tool.

16. The inspection tool assembly according to claim 15, characterized in that the gel piece is formed inside the closed chamber.

17. The inspection tool assembly according to claim 14, characterized in that it further comprises a gel recovery device between the first and second dispensing pigs, wherein said gel recovery device recovers gel couplant after it passes ultrasonic inspection.

18. The inspection tool assembly according to claim 17, characterized in that the recovered gel is re-supplied in front of the ultrasonic inspection tool.

19. The inspection tool assembly according to claim 14, characterized in that it further comprises a second gel couplant surrounding the ultrasonic inspection tool, wherein the second gel couplant has a different composition from the first gel couplant.

20. A pipe inspection tool assembly for performing ultrasonic inspection in a pipe, said pipe inspection tool assembly characterized in that it comprises a first dosing pig, a second dosing pig and an ultrasonic inspection tool operatively coupled between the first dosing pig and the second dosing pig, wherein the ultrasonic inspection tool is surrounded by a semi-rigid gel coupler.

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