Scanning apparatus and method

Abstract

A sub-sea apparatus 1 for scanning a sub-sea asset (fig 5,14), comprising an IR scanner 2, comprising an IR detector for detecting IR radiation; and a positional mechanism 9 for establishing and maintaining a desired spacing between the IR scanner and the asset. Also disclosed is an associated method for scanning a sub-sea asset using the apparatus, comprising deploying the positional system to establish a start position of the apparatus at a desired spacing from the asset; deploying the IR scanner; moving the scanner along the asset substantially maintaining the desired spacing and deactivating the IR scanner at a finish position. The positional mechanism may comprise one or more arms which in use abut the asset to position the IR scanner at a preferred spacing from the asset.

Description

The present invention relates to a scanning apparatus and a scanning method, and particularly to a scanning apparatus and method for use in a sub-sea environment, for example for use in inspection of subsea assets and structures within the oil and gas industries and renewables. Current equipment for performing such inspection sub-sea has for example included the use of high-resolution ultrasonic inspection tools, such as disclosed in GB2573794, owned by the present applicant. Apparatus of this nature can be used to perform various operations such as corrosion mapping and weld inspection of subsea assets. Although ultrasonic inspection offers excellent resolution for close detailed operations such as spot checking localised areas of pipelines for defects, the use of such apparatus for inspecting large sections or extents of an entire pipeline would be excessively time consuming and not cost effective. In the case where removal of a pipeline coating is required for ultrasonic inspection, using such localised ultrasonic inspection techniques to scan large sections can become even more arduous. An object of the present invention is provide a scanning apparatus and method which seeks to alleviate such problems. According to a first aspect of the present invention there is provided a sub-sea apparatus for scanning a sub-sea asset, the apparatus comprising: an IR (infrared) scanner; the IR scanner comprising: an IR (infrared) detector for detecting IR radiation; and a positional mechanism for establishing and maintaining a desired spacing between the scanner and the asset. Using IR technology subsea offers advantages over known subsea scanning technologies in terms of speed and coverage, extending asset range capabilities, for example to subsea electrical cables. Preferably, the positional mechanism comprises one or more arms which in use are configured to abut the asset to position the IR scanner at a preferred spacing from the asset. Whilst one or arms may be provided for spacing the scanner from the asset, the positional mechanism may take alternative suitable forms. For example, one or more positional sensors may be employed to control thrusters to position and hold the apparatus at a preferred spacing between the scanner and an asset surface. The one or more arms may be adjustable to alter the extent of their outward projection in relation to the scanner. In this respect, the one or more arms may be retractable and / or may be telescopic. The one or arms may alternatively or additionally be pivotally mounted, in order to swing to allow deployment to different outward projections. Preferably, the arms are each provided with a low friction end, and may be provided with a low friction coating, low friction surface finish, a bearing, wheel or roller. In this regard, the apparatus can be urged into contact with the asset surface and moved along the asset, the low friction ends allowing such movement with low resistance, whilst maintaining at least intermittent contact with the asset. Preferably, the apparatus may have propulsion means for propelling it within its local liquid environment, for example in order to establish and maintain a desired spacing from the asset. The propulsion means may include one or more thruster propellers. Additionally or alternatively, the apparatus can be moved by way of an ROV, into position in relation to the asset and along the asset’s surface. The apparatus may have suitable docking means for coupling with such an ROV Preferably, the scanner may itself be mounted for movement on the apparatus, for optimising relative positioning of the scanner with respect to the asset. In this regard, the apparatus may comprise a frame on which the scanner is mounted for movement of the scanner relative to the frame. The apparatus may have a tether for connecting to, for example, a host vessel. The tether may be responsible for sending signals to manoeuvre the apparatus but also to relay communication from the apparatus back to the host vessel, such as a live video feed and live data transfer. According to a further aspect of the present invention there is provided a scanning method for scanning a sub-sea asset using the apparatus of any preceding claim; the method comprising: deploying the positional system to establish a start position of the apparatus at a desired spacing from the sub-sea asset; deploying the IR scanner; moving the scanner along the asset substantially maintaining the desired spacing; and deactivating the IR scanner at a finish position. Preferably, the positional system comprises one or more arms which on deployment of the positional system are adjusted to vary their outward projection in relation to the scanner. Preferably, the one or more arms each have a low friction end such that the apparatus can be urged into engagement with the asset whilst being moved along the asset, so as to maintain at least intermittent contact with the asset from the start to finish positions. The low friction end may take the form of a low friction coating, a low friction surface finish, a bearing, a wheel or a roller. Whilst IR is conventionally not thought to be operationally viable in a sub-sea environment, it has been found that with suitable positional calibration and processing, results can be secured which afford a user a high level overview scan, allowing subsequent more precise measurement techniques to be deployed at points of interest. The scanning apparatus can either measure, monitor and / or image the asset’s surface thermal signature by detecting infrared radiation (wavelengths up to around 14 pm) and translating it into a temperature reading. The sensor of the scanner is moved at the optimum distance from the test surface to allow the measuring, monitoring and / or imaging to take place; the optimum sensor position relative to the test surface geometry and diameter would be controlled via a positional mechanism. Certain embodiments of the present invention will now be described by way of example and with reference to the accompanying drawings, of which: Figure 1 shows a perspective view of a scanner apparatus according to the present invention disposed above an asset; Figure 2 shows a plan view of the scanner apparatus from above; Figures 3A and 3B are side views of the scanner apparatus deployed for different arm member projections; Figures 4A and 4B shows perspective views of a scanner apparatus according to the present invention disposed above assets having an arcuate and flat profile respectively; and Figure 5 shows a view of the scanner apparatus in use subsea above a section of pipework. Referring to Figure 1, there is shown sub-sea scanning apparatus 1 according to the present invention. The apparatus comprises a frame, formed of side members 8, connected with cross-struts 15. Four arm members 9 are moveably mounted within the side members. The arm members include pins 12 that run in arcuate slots 13 in the frame side members. In this regard, the side members each comprise a pair of plate elements 11 running parallel to one another within which the arm members 9 are mounted. As shown in Figure 3A, struts 10 are pivotally connected to both the arm members and the side members 8 of the frame such that the arm members 9 follow a specific swinging movement. An IR scanner 2 is mounted on a carrier element 3 that can move along a pair of flexible tracks 5. The scanner may be a single unit or may comprise an array of IR sensors. Motor 6 can be activated to control the movement of the carrier element 3 and through suitable gearing movement of the arm members 9. In order to accommodate different asset profiles and to vary the spacing of the scanner from the asset surface, the arm members 9 can be moved so that they swing out or in. In Figures 1 and 4A, the arcuate profile of the assets is different whilst in Figure 4B, the asset has a flat profile. The flexible tracks may be formed of a spring steel that can be bent to the required radius. However alternative materials may be used according to requirements. The flexible tracks are coupled between the arm members 9 such that as the arm members move in and out, each flexible track is accordingly curved to a greater and lesser extent. The amount of deflection of the flexible tracks is carefully determined by the curvature of the slots 13 in which the pins 12 can slide and the extent of pivoting of the arm members permitted by limb members 10. It will be understood that movement of the arm members changes the spacing of the scanner 2 from arm member ends 16 and hence the spacing of the scanner from the asset surface. In this respect, depending upon requirements the spacing of the scanner from the asset’s surface can be adjusted as needed. The arm members may at their ends 16 have a low friction end, in the form of a low friction coating, a low friction surface finish, a bearing, a wheel or roller, so that the apparatus can be urged into contact with the asset’s surface and moved along the surface with minimal resistance impeding the movement. In this respect, the ends 16 may be arranged to have at least intermittent contact with the asset as the scanner apparatus is moved along the asset. A number of thruster propellers (not shown), for example provided at respective corners of the frame, may be used to manoeuvre the apparatus within its liquid environment. The thruster propellers can in this respect afford an element of a positional adjustment for establishing and maintaining a desired spacing between the scanner apparatus and an asset. In the embodiment shown, the scanning apparatus may itself be separate modular unit, attachable to a ROV (Remotely Operated Underwater Vehicle), the ROV being controllable to manoeuvre the scanning apparatus for operational purposes. The IR scanner itself may take the form of any suitable IR scanner, for detecting radiation of wavelengths up to around 14 pm). The scanner 2 may in this respect comprise an array made up of a plurality of individual scanner units. In use, the scanning apparatus is deployed from a host vessel (not shown) and guided by an ROV 17 (shown schematically in Figure 5 coupled to the scanning apparatus), to the vicinity of the asset to be scanned. In this connection, in an alternative embodiment the apparatus may have thrust propellers that can operate as required to move the apparatus as desired in any direction, and can be used to allow the apparatus to maintain a fixed “hover” position above the asset 14. The apparatus may further have a buoyancy control mechanism for positional adjustment within the liquid environment. As described above, the one or more arm members 9 are used to position the apparatus so that the scanner is at a desired initial spacing from the asset’s surface. The extent of projection of the arms can be adjusted to suit requirements. To commence a scanning operation, with the scanner apparatus at a start position relative to the asset, the ROV 17 (or thrusters where provided) move the apparatus along an asset as shown in Figure 5. Once the scanning operation is complete, i.e. where a finish position is reached, the apparatus can be manoeuvred back to the host vessel. The precise spacing of the scanner from the asset may vary due to the nature of the environment conditions, but will need to be kept within certain tolerances in order to guarantee useful scanning data for analysis. In this respect, the apparatus may additionally comprise local environment detectors for detecting for example currents, flow rates so that these factors can be taken into account. A tether may be provided for sending signals to manoeuvre the apparatus but can also be used to relay communication from the apparatus back to the host vessel, such as a live video feed and live data transfer. In this connection, the apparatus may have processing means, memory means and a power source, for allowing local on-board collection and processing of the scanning data. The data may alternatively be sent in a raw unprocessed form by way of the tether to the host vessel for processing. It will be understood that the various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one aspect can typically be combined alone or together with other features in different aspects of the invention. Any subject matter described in this specification can be combined with any other subject matter in the specification to form a novel combination. Various aspects of the invention are described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary aspects and implementations. The invention is also capable of other and different examples and aspects, and its several details can be modified in various respects, all without departing from the scope of the present invention. Accordingly, each example herein should be understood to have broad application, and is meant to illustrate one possible way of carrying out the invention, without intending to suggest that the scope of this disclosure, including the claims, is limited to that example. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. In particular, unless otherwise stated, dimensions and numerical values included herein are presented as examples illustrating one possible aspect of the claimed subject matter, without limiting the disclosure to the particular dimensions or values recited. All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein are understood to include plural forms thereof and vice versa. Language such as "including", "comprising", "having", "containing", or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Thus, throughout the specification and claims unless the context requires otherwise, the word “comprise” or variations thereof such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention. In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of’, "consisting", "selected from the group of consisting of’, “including”, or "is" preceding the recitation of the composition, element or group of elements and vice versa. In this disclosure, the words “typically” or “optionally” are to be understood as being intended to indicate optional or non-essential features of the invention which are present in certain examples but which can be omitted in others without departing from the scope of the invention. References to directional and positional descriptions such as upper and lower and directions e.g. “up”, “down” etc. are to be interpreted by a skilled reader in the context of the examples described to refer to the orientation of features shown in the drawings, and are not to be interpreted as limiting the invention to the literal interpretation of the term, but instead should be as understood by the skilled addressee.

Claims

1. A sub-sea apparatus for scanning a sub-sea asset, the apparatus comprising: an IR (infrared) scanner; the IR scanner comprising:an IR (infrared) detector for detecting IR radiation; and a positional mechanism for establishing and maintaining a desired spacing between the IR scanner and the asset.

2. The sub-sea apparatus of claim 1, wherein the positional mechanism comprises one or more arms which in use are configured to abut the asset to position the IR scanner at a preferred spacing from the asset.

3. The sub-sea apparatus of claim 2, wherein the one or more arms are adjustable to alter their outward projection in relation to the scanner.

4. The sub-sea apparatus of claim 3, wherein the one or more arms are retractable and / or telescopic.

5. The sub-sea apparatus of claims 2 to 4, wherein the one or arms are pivotally mounted.

6. The sub-sea apparatus of claims 2 to 5, wherein the arms are each provided with a low friction end.

7. The sub-sea apparatus of claims 2 to 6, wherein the arms are each provided with any one of a low friction coating, a low friction surface finish, a bearing, a wheel or roller.

8. The sub-sea apparatus of any preceding claim, further comprising propulsion means for propelling the apparatus within its local liquid environment.

9. The sub-sea apparatus of claim 8, wherein the propulsion means comprises one or more thruster propellers.

10. The sub-sea apparatus of any preceding claim, wherein the apparatus comprises a frame and wherein the scanner is mounted for movement on the apparatus frame.

11. The sub-sea apparatus of any preceding claim, further comprising a distance detection means for detecting distance from an asset.

12. A scanning method for scanning a sub-sea asset using the sub-sea apparatus of any preceding claim; the method comprising:deploying the positional system to establish a start position of the apparatus at a desired spacing from the sub-sea asset;deploying the IR scanner;moving the scanner along the asset substantially maintaining the desired spacing; anddeactivating the IR scanner at a finish position.

13. The scanning method of claim 12, wherein the positional system comprises one or more arms which on deployment of the positional system are adjusted to vary their outward projection in relation to the scanner.

14. The scanning method of claim 12 or 13, wherein the one or more arms have low friction ends.

15. The scanning method of any one of claims 12 to 14, wherein the one or more arms have any one of a low friction coating, a low friction surface finish, a bearing, a wheel or a roller.

16. The scanning method of any one of claims 12 to 15, wherein the scanner detects the asset’s infrared radiation at wavelengths up to substantially 14 pm.

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