1. Field Of The Invention
The present invention is directed to the non-destructive testing of tubulars and, in certain particular aspects, to systems and methods for such testing which employ ultrasonic transducers with a polyvinylidenefluoride piezoelectric film.
2. Description of Related Art
Non-destructive testing of tubulars can indicate flaws in the tubular. The prior art includes a wide variety of systems and methods for the non-destructive testing of tubulars; e.g., but not limited to, the systems and methods disclosed in U.S. Pat. Nos. 5,063,776; 5,616,009; 5,975,129; 7,055,623; 5,715,861; 4,638,978; and in U.S. application Ser. No. 11/098,166 filed Apr. 04, 2005 (co-owned with the present invention), all patents and the application listed incorporated fully herein for all purposes.
In certain prior art methods ultrasonic beams generated by transducers can not cover the full body of a tubular under test; and in other prior methods in which the ultrasonic beams generated by all the transducers can cover the full body of the tubular under test, mechanical rotation of either the scanning head or the tubular has to be facilitated, or a high number of individually packaged transducers is used, which can lead to complicated system design, high cost, and difficulty of operation.
The present invention recognizes the problems and disadvantages of certain prior art systems and methods. The present invention provides reliable, relatively low-cost, and accurate systems and methods for the non-destructive testing of tubulars.
The present invention, in at least certain embodiments, discloses systems and methods which employ a plurality of spaced-apart ultrasonic transducers made with polyvinylidenefluoride (“PVDF”) (and its copolymers) piezoelectric films for measuring tubular wall thickness and/or detecting flaws.
In certain aspects of inspection systems according to the present invention with such transducers a tubular passing through an inspection system is not rotated and the transducers are not rotated.
When a mechanical stress, e.g. a stress due to an ultrasonic wave, is applied to a PVDF film which has two electrodes, each on a different surface of the film, the film that receives the wave generates a measurable electric voltage between electrodes on two surfaces. When an electric voltage is applied to the PVDF film through the electrodes, a mechanical strain is generated resulting in the generation of an ultrasonic wave. These two effects are combined in a PVDF ultrasonic transmitter-receiver (“transducer”) useful in systems and methods according to the present invention. PVDF films with electrodes and ultrasonic transducers with PVDF films are commercially available.
In certain particular aspects, the present invention provides systems and methods for measuring tubular wall thickness and for detecting defects with a plurality of PVDF ultrasonic transducers attached to and spaced apart around a body (e.g. a hollow cylindrical body or a hollow conical body, e.g. with at least one, two, three or more PVDF films) through which a tubular is movable (e.g., but not limited to oilfield tubulars; e.g., but not limited to risers, casing, tubing, pipe, drill pipe, mechanical tubing, boiler tubing, and drill collars) whose wall thickness along its entire length is to be measured or whose entire body is to be scanned for defects. Each separate PVDF ultrasonic transducer is electrically connected to a computerized control system with control electronics or a circuit board which is in communication with such a control system.
In certain aspects, between the PVDF transducers and an outer tubular surface is a coupler, e.g. an ultrasonic coupling agent, e.g. water. The PVDF transducers are excited by high voltage pulses produced by the control system to generate ultrasonic waves that propagate to the tubular through the coupling agent. In the case of a hollow cylindrical body, the propagation direction of the ultrasonic waves is perpendicular to the outer and inner surfaces of the tubular. The ultrasonic waves are reflected by both surfaces and go back to the PVDF transducers. The reflection from the outer surface is commonly called interface echo. The reflection from the inner surface is commonly called back wall echo Inside the tubular wall, the ultrasonic waves can also be reflected back and forth numerous times before their energy dies down, giving rise to multiple back wall echoes. The interface echo and the back wall echo or echoes are used to measure the tubular wall thickness since the time between two adjacent echoes is proportional to the thickness. In the case of a hollow conical body, the propagation direction of the ultrasonic waves is in an angle with the normal of the outer and inner surfaces of the tubular. The ultrasonic waves are reflected back to the PVDF transducers by defects, such as cracks, in the tubular wall. The returned waves are used to detect such defects. The control system communicates with (control, activates or excites; and/or detects return signals) the transducers.
The body, e.g. a hollow cylindrical or conical body, is a whole integral piece or it is two or more separate pieces. There can be one or more PVDF ultrasonic transducers on each PVDF film. In certain particular aspects of systems according to the present invention, multiple PVDF ultrasonic transducers positioned adjacent to each other are communicated with via a control system and excited at the same time, or each is communicated with and excited in order with a well defined delay pattern to form a composite wave, equivalent to one produced by a single PVDF transducer occupying the same area by the multiple transducers. The composite wave is used to obtain wall thickness measurements. Then a next group of transducers, i.e., one or more transducers from above and one or more transducers next to them, are excited in the same way to form another second composite wave that is partially overlapping with the first composite wave and the second composite wave is used to measure the tubular wall again. Multiple composite waves can also be formed at different circumferential locations of the tubular at the same time. By forming composite waves around the tubular, the system obtains wall thickness measurements and flaw detection for the entire surface of the tubular without any gaps and without mechanically rotating either the tubular or the transducers.
The present invention, in certain aspects, discloses a shoe apparatus for tubular inspection, the shoe apparatus including a body, a film on the body, the film made of piezoelectric material, a plurality of ultrasonic transducers on the film, and each ultrasonic transducer of the plurality of ultrasonic transducers.
Accordingly, the present invention includes features and advantages which are believed to enable it to advance non-destructive tubular inspection technology. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings.
Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention.
What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain preferred embodiments of the invention, there are other objects and purposes which will be readily apparent to one of skill in this art who has the benefit of this invention's teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, non-obvious systems and methods for non-destructive tubular inspection;
Such systems and methods which use one or more ultrasonic transducers with PVDF piezoelectric film.
The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention's realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of certain preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent's object to claim this invention no matter how others may later attempt to disguise it by variations in form, changes, or additions of further improvements.
The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly from a cursory inspection or review the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention in any way.
It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention.
A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings which form a part of this specification. These drawings illustrate certain preferred embodiments and are not to be used to improperly limit the scope of the invention which may have other equally effective or legally equivalent embodiments.
Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and features of embodiments of the invention are described below and some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of preferred embodiments and are not intended to limit the invention or the appended claims. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiment, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference.
Each transducer 20 corresponds to a portion 15 of the body 12 and is connected directly to control electronics or, e.g. as shown connected to a printed circuit board (“PCB”) 30. A ground electrode of each transducer is connected to a ground plane of the PCB 30, and its signal electrode is connected to a signal trace on the PCB 30 (see traces 15,
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Accordingly, while preferred embodiments of this invention have been shown and described, many variations, modifications and/or changes of the system, apparatus and methods of the present invention, such as in the components, details of construction and operation, arrangement of parts and/or methods of use, are possible, contemplated by the patentee, within the scope of the appended claims, and may be made and used by one of ordinary skill in the art without departing from the spirit or teachings of the invention and scope of appended claims. Thus, all matter herein set forth or shown in the accompanying drawings should be interpreted as illustrative and not limiting, and the scope of the invention and the appended claims is not limited to the embodiments described and shown herein.
The present invention, therefore, provides in at least certain embodiments, a shoe apparatus for tubular inspection, the shoe apparatus including: a body; a film on the body, the film made of piezoelectric material; and a plurality of ultrasonic transducers on the film. Such a shoe apparatus may have one or some (in any possible combination) of the following: wherein the body is generally cylindrical and has a channel therethrough through which a tubular to be inspected is passable; a control system, each ultrasonic transducer in communication with the control system; wherein the control system controls any individual ultrasonic transducer, a series of adjacent ultrasonic transducers, or a plurality of series of adjacent ultrasonic transducers; a coupler for propagating ultrasonic waves from the ultrasonic transducers to a tubular to be inspected, the coupler adjacent the body for interposition between the body and a tubular to be inspected; the shoe is a plurality of individual shoes which are movable together to form a channel through which a tubular to be inspected is passable; movement apparatus for moving each individual shoe segment; each individual shoe segment overlaps an adjacent shoe segment; wherein the plurality of ultrasonic transducers are spaced-apart around the channel; a circuit board attached to the body, and each ultrasonic transducer connected to the circuit board; wherein the body is generally cylindrical and the body is generally cylindrical and the plurality of ultrasonic transducers are spaced-apart around the generally cylindrical body; wherein each ultrasonic transducer includes a portion of the film with a top surface, a bottom surface, a top electrode on the top surface, a bottom electrode on the bottom surface, each electrode connected to the circuit board; and/or a control system, each ultrasonic transducer in communication with the control system via the circuit board.
The present invention, therefore, provides in at least certain embodiments, a method for inspecting a tubular, the method including introducing the tubular into a shoe apparatus for inspecting tubulars, the shoe apparatus as any disclosed herein according to the present invention, controlling the ultrasonic transducers with a control system of the shoe apparatus, and activating ultrasonic transducers of the shoe apparatus using the control system to generate ultrasonic waves directed to the tubular to inspect the tubular. Such a method may have one or some (in any possible combination) of the following: wherein a body of the shoe apparatus is generally cylindrical and has a channel therethrough through which the tubular passes and wherein there is a plurality of ultrasonic transducers spaced-apart around the generally cylindrical body, the method further including with the control system, communicating with individual ultrasonic transducers to inspect the tubular; wherein the body is generally cylindrical and has a channel therethrough through which the tubular passes and wherein the plurality of ultrasonic transducers are spaced-apart around the generally cylindrical body, the method further including with the control system, communicating with a plurality of ultrasonic transducers to form a composite wave to inspect the tubular; wherein each of the plurality of ultrasonic transducers is used simultaneously; wherein each of the plurality of ultrasonic transducers is used in order according to a defined delay pattern; wherein the tubular has a circumference and a generally cylindrical body and has a channel through the body for tubular passage, and wherein the plurality of ultrasonic transducers are spaced-apart around the generally cylindrical body, the method further including activating pluralities of adjacent ultrasonic transducers to form a plurality of multiple composite waves around the tubular's circumference to inspect the entire tubular; and/or inspecting the tubular with the shoe apparatus without rotating the tubular and/or without rotating the ultrasonic transducers.
In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. §102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35 U.S.C. §103 and satisfies the conditions for patentability in §103. This specification and the claims that follow are in accordance with all of the requirements of 35 U.S.C. §112. The inventors may rely on the Doctrine of Equivalents to determine and assess the scope of their invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes.