WO2014198299A1

WO2014198299A1 - Estimation of a condition of equipment

Info

Publication number: WO2014198299A1
Application number: PCT/EP2013/062035
Authority: WO
Inventors: Gerd Sissel LEGÅRD; Laila Merete ØKLAND; Mona Ledahl ROSTAD; Kjell Arne ULVUND; Robert JØRGENSEN; Søren LILTORP; Ingvill FØRDE; Kjartan SLETTEN; Tore LØLAND
Original assignee: Statoil Petroleum As
Priority date: 2013-06-11
Filing date: 2013-06-11
Publication date: 2014-12-18

Abstract

A method and apparatus for estimating a condition of equipment (1) having an insulating layer (2) on an external surface of the equipment (1). The method comprises extracting a fluid sample from a region substantially at an external surface of the equipment (1). Once extracted, the presence of at least one component of the fluid sample is detected. On the basis of the presence of the component, a condition of the equipment (1) is estimated. An advantage of the method and apparatus is that they allow the condition of equipment (1) to be estimated without having to remove the insulating layer (2), which may save time and money.

Description

Estimation of a Condition of Equipment

TECHNICAL FIELD The invention relates to the field of estimating a condition of equipment having an insulating layer on an external surface of the equipment.

BACKGROUND In the oil and gas industry, equipment such as pipes, valves, process equipment, vessels, towers and so on, will often have an insulating layer, providing a thermal barrier between the equipment and an external environment. Insulating layers usually totally envelop the equipment that they are insulating in order to provide adequate insulation. However, this means that it is not easy to visually inspect the underlying equipment.

The condition of equipment must be regularly checked in order to discover any defects or highlight any conditions that may lead to defects, in order to maintain the equipment and a safe working environment. For example, pipes carrying a fluid in an oil refinery will need to be regularly checked for signs of corrosion or leaks. Corrosion Under Insulation (CUI) is a known problem that can plague insulated equipment. If undetected, CUI can lead to a catastrophic failure of the equipment, which can potentially be dangerous and will have an economic cost. Not only does the insulating layer prevent visual inspection of the equipment to take place, the insulating layer itself may act to increase the chance of localised corrosion occurring on the equipment. For example, corrosion of metal such as iron, or its alloys, occurs when the iron is exposed to oxygen and water. Typically, the insulating layer will trap moisture, preventing it from evaporating into the atmosphere. This may result in an accelerated rate of corrosion of the equipment. Furthermore, the insulating layer may also act as a "conductor", allowing moisture to travel through the insulating layer to other parts of the equipment. The insulating layer itself may also be degraded by products of corrosion, and as a result may also need to be inspected. Equipment, such as pipes, may also develop leaks either as a result of corrosion, or any other reason, such as poorly fitted joints between pipes or worn seals and gaskets. The insulating layer may also initially hide the effects of a leak, increasing the potential cost of rectifying the leak.

Since CUI is usually highly localised, in order to check the condition of insulated equipment, the whole insulating layer, along with any other components holding the insulating layer in place, such as a cap, must be removed. A section of equipment may then be inspected for signs of corrosion, or potential corrosion, along with other defects such as leaks. After the section of equipment has been thoroughly inspected, a new insulating layer and cap must be installed over the equipment. The whole process is costly, both in terms of time and money. The equipment may also need to be temporarily deactivated during the inspection procedure, further increasing the inconvenience and cost associated with inspecting the equipment for CUI or leaks.

In light of the aforementioned problems, there remains a need for improving the way in which the condition of insulated equipment is ascertained.

SUMMARY

It is an object to provide a method for estimating a condition of equipment having an insulating layer on an external surface of the equipment.

According to a first aspect, there is provided a method for estimating a condition of equipment having an insulating layer on an external surface of the equipment. The method comprises extracting a fluid sample from a region substantially at an external surface of the equipment. Once extracted, the presence of at least one component the fluid sample is detected. This component may be in a solid, liquid and/or gaseous phase. On the basis of the presence of the component, a condition of the equipment is estimated. An advantage of the method is that it allows the condition of equipment to be estimated without having to remove the insulating layer, which can save time and/or money.

The fluid sample may be extracted via a drain hole in the insulating layer, thereby allowing extraction from a pre-existing aperture. The fluid sample may be extracted using a low pressure fan, or any other extraction means, which can be used to assist with the extraction of the fluid sample. Prior to detecting the presence of at least one component of the fluid sample, the fluid sample may be stored in a container. The container may be substantially evacuated before storing the fluid sample, so as to avoid contamination of the fluid sample.

The fluid sample may be analysed by using a mass spectrometer, or any other chemical analysis device.

The condition of the equipment may be estimated by comparing any of a presence and a quantity of the component with data from a database. The condition may comprise a likelihood of corrosion, and the estimation of the condition is an estimation of a degree of corrosion.

A quantity of the component may be determined, with the determined quantity being used to estimate the degree of corrosion. The component may be a by-product of corrosion or may indicate an environment that leads to corrosion. Therefore, a risk based assessment can be carried out on the condition of equipment, without having to fully remove the insulating layer.

Alternatively, it may be determined that the component corresponds to a component contained within the equipment, which would indicate a leak in the equipment. The component may comprise a hydrocarbon. If the equipment is carrying hydrocarbons, this may indicate that there is a leak in the equipment.

According to a second aspect, there is provided a computer device. The computer device has an input device for receiving data. The data relates to a detected presence of a component in a fluid sample, where the fluid sample has been obtained from a region substantially outside an external surface of an equipment, and where the external surface has a layer of insulation. The computer device is provided with a processor for estimating, on the basis of the presence of the component, a condition of the equipment. An advantage provided by the computer device is that a risk based assessment can be made on the condition of the equipment, without having to remove the insulating layer, which can save time and/or money.

The input device may be arranged to receive the data from a mass spectrometer, or any other chemical analysis device.

The processor may be arranged to estimate the condition of the equipment by comparing any of the presence and a quantity of the component with further data obtained from a database.

The computer device may further comprise a second input device arranged to receive the further data from an external source. For example, this may be data relating to components that are indicative of corrosion. According to a third aspect, there is provided a computer program. The computer program comprises computer readable code which, when run on a computer device, causes the computer device to behave as a computer device described in the second aspect. According to a fourth aspect, there is provided a computer program product comprising a non-transitory computer readable medium and a computer program as described above in the third aspect, wherein the computer program is stored on the non-transitory computer readable medium. According to a fifth aspect, there is provided a fluid sampling device for obtaining a fluid sample from equipment where the equipment has an insulating layer on an external surface, and the fluid sample is used to estimate a condition of the equipment. The device comprises an extraction tool which is arranged to extract a fluid sample from a region substantially at an external surface of the equipment. The device is provided with a detector which is arranged to detect the presence of at least one component of the fluid sample. Advantageously, the device allows the condition of insulated equipment to be estimated without having to remove the insulating layer, thus saving time and money. The fluid sampling device may also comprise a processor arranged to estimate on the basis of the presence of the component the condition of the equipment.

The fluid sampling device may also comprise a low pressure fan, or any other extraction means, which can be used to assist with the extraction of the fluid sample. The device may comprise a container for storing the fluid sample. As an option, the container may be substantially evacuated prior to storing the fluid sample in the container, so as to help maintain sterility.

According to a sixth aspect, there is provided a computer program. The computer program comprises computer readable code which, when run on a fluid sampling device, causes the fluid sampling device to behave as a fluid sampling device described in the fifth aspect.

According to a seventh aspect, there is provided a computer program product comprising a non-transitory computer readable medium and a computer program as described above in the sixth aspect, wherein the computer program is stored on the non-transitory computer readable medium.

According to an eighth aspect, there is provided a method of populating a database. A fluid sample is obtained from a region substantially at an external surface of equipment. A presence of at least one or more components of the fluid sample is detected. The condition of the equipment is determined. The presence of the at least one or more components of the fluid sample can then be correlated with the condition of the equipment. A database is populated with data relating to a correlation between the presence of at least one component of the fluid sample with the condition of the equipment. Advantageously, a database can be built up over time, correlating components with the condition of equipment. This helps to identify components that may be products of corrosion, or indicative of a corrosive environment.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows schematically an exemplary cross section of a pipe; Figure 2 shows schematically in a block diagram the components of an exemplary device;

Figure 3 shows schematically an exemplary cross section of a pipe and device according to an embodiment of the invention;

Figure 4 is a flow diagram illustrating exemplary steps of an embodiment;

Figure 5 shows schematically in a block diagram an exemplary computer device; and

Figure 6 is a flow diagram illustrating exemplary steps of an embodiment. DETAILED DESCRIPTION The condition of insulated equipment must be regularly checked in order to highlight any defects or conditions, such as an environment, that may lead to defects in the equipment, in order to maintain safe working of the equipment. The insulating layer provides a physical layer shielding the equipment, and so signs of corrosion are hidden from an external observer. Furthermore, the insulating layer itself may act to maintain an environment that can lead to corrosion of the equipment, or the insulating layer itself.

Figure 1 shows equipment, in this example a pipe 1 , with an insulting layer 2, insulating the pipe 1 from an external environment. The insulating layer 2 may comprise any suitable insulating material, such as mineral wool. It is to be understood that while a pipe 1 is described, the following may equally apply to any other equipment surrounded either wholly or partially, by an insulating layer 2. The insulating layer 2 has a drain hole 3, for draining excess fluids from around the pipe 1 and/or within the insulating layer 2, such as condensation. A region 4 is shown, substantially at an external surface of the pipe 1 . This region 4 may comprise an environment that facilitates corrosion, and/or the region 4 may comprise an environment that exhibits signs of corrosion and/or a leak in the pipe 1 . This may be related to corrosion on the surface of the pipe 1 . While only shown in one location, it will be appreciated that the region 4 may be located anywhere along the pipe 1 , and is merely used as an example of a region to be checked. Currently, the only way in which the region 4 can be checked is to physically remove the insulating layer 2 and visually inspect the pipe 1 . Operators of a facility using the pipe 1 in Figure 1 may carry out routine inspections on a regular basis, in which the entire insulating layer 2 is removed, the pipe 1 is checked, and a new insulating layer is installed. This procedure is both costly and time consuming.

The description below provides a method and equipment to allow the condition of the equipment to be estimated, without the need to remove the insulating layer 2.

Figure 2 shows a block diagram of an exemplary field device 5, suitable for obtaining a fluid sample from the region 4. The field device 5 has an extraction tool 6 for extracting the fluid sample. For example, the extraction tool 6 may comprise a flexible tubular member 7 having an opening (not shown), and suction means 8. The suction means 8 may be provided by, for example, a pumping device, a vacuum device, or a low pressure fan. In use, the tubular member 7 is inserted between the pipe 1 and the insulating layer 2 such that the opening is placed in region 4. Note that the region 4 may extend into the insulating layer 2, and/or exist between the pipe 1 and the insulating layer 2. The tubular member 7 may be inserted into the region 4 via a pre- existing aperture, such as the drain hole 3. Alternatively, a small hole may be created by drilling into the insulating layer 2, such that the tubular member 7 can be inserted. Other alternatives may be envisaged. Once inserted, the suction means 8 draws in the fluid sample from the region 4, through the tubular member 7, and into the field device 5. While only one opening is described, it will be appreciated that the tubular member 7 may have more than one opening, and that any of the openings may be located anywhere along the tubular member 7.

Alternatively, the extraction tool 6 may comprise a chamber having an aperture and means for opening or closing the aperture. The chamber is placed in the region 4, and the aperture is opened, and then closed. During a time when the aperture is open, a fluid sample may be collected in the chamber. Once the aperture is closed, the chamber containing the fluid sample may be removed from the region 4.

In one exemplary embodiment, the fluid sample is then passed to a field detector 9, in order to detect the presence of at least one component of the fluid sample. The field detector 9 may also detect a quantity of the component, for example, the amount of the component, or a ratio of one component with respect to other components. Data obtained from the field detector 9 is passed to a processor 10. The processor 10 then estimates the condition of the pipe 1 , based on the results from the field detector 9.

The field device 5 may comprise a receiver 12, for receiving data usable by the processor for estimating the condition of the pipe 1 . This data can also be stored in a database 1 1 . The data may relate to elements or components that are indicative of a corrosive environment or that are by-products of corrosion. The database 1 1 may be accessed by the processor 10 in order to estimates the condition of the pipe 1 . The processor 10 may estimate the condition of the pipe by comparing one or more components of the fluid sample with data stored in the database. The field detector may generate a spectral profile based on the fluid sample. This may then be compared to data in a database. For example, pattern recognition software may be used to determine the components of a fluid sample from a spectral profile.

Alternatively, in further exemplary embodiment, once the fluid sample has been extracted, it is stored in a container (not shown) to be analysed elsewhere, such as at a laboratory. Such a container may be evacuated prior to receiving the fluid sample, so as to maintain a sterile environment.

Alternatively, instead of storing the sample in a container, the fluid sample could be sampled using a solid phase extraction method, where a filter containing components of the fluid sample is brought to a laboratory for chemical analysis.

Note that liquid extraction can be used and the liquid brought to a laboratory for chemical analysis.

Alternatively, instead of extracting a fluid sample, a portion of the insulating layer 2 may be removed and analysed. This may be a small portion that does adversely affect the insulating layer's ability to insulate. The small potion may contain components that indicate corrosion of the equipment, or that may lead to corrosion.

The components that are detected may be by-products of corrosion, or may indicate an environment that leads to corrosion. For example, if iron oxides are found to be present in the sample, it would provide a strong indication that the pipe 1 may be experiencing oxidization, leading to corrosion. Other measurements can be taken that may indicate conditions for corrosion, such as measurements of water dew point, temperature and/or presence of chloride. Measurements of trace hydrogen may also indicate ongoing corrosion.

Alternatively or additionally, the presence of water, or acidic compounds, may indicate an environment that will lead to corrosion of the equipment. The detected components may be related to the fluid that the pipe 1 is carrying, and would act as a strong indication that there is a leak in the pipe 1 . For example, the detection of hydrocarbons in the region 4, where the pipe 1 is carrying hydrocarbons, would indicate the possible presence of a leak. The amount of the component detected may need to be higher than a threshold value in order to provide a positive indication of a condition. For example, trace amounts of hydrocarbons within the sample may not necessarily indicate that there is a leak in the pipe 1 . However, the detection of a large amount of hydrocarbons would indicate that it is likely that the pipe 1 has a leak. Data in the database 1 1 may indicate such a threshold value, for any given condition.

Figure 3 shows the field device 5 during operation according to an embodiment of the invention. The tubular member 7 is paced into the region 4 via the drain hole 3, although it will be appreciated that the tubular member 7 may be inserted in any suitable opening. The field device 5 is then able to extract a fluid sample from the region 4 via the tubular member 7.

In order to better describe embodiments of the claims, Figure 4 shows steps according to an embodiment of the invention.

S1 . A tubular member 7 is inserted between an insulating layer 2 and a pipe 1 , such that an opening of the tubular member 7 is place in a region 4. The tubular member 7 may enter through any suitable opening, such as a drain hole 3. 52. Suction means 8 draw in a fluid sample from the region 4, through the opening in the tubular member 7. The fluid sample may be stored in a container.

53. The fluid sample is analysed in order to determine one or more components of the fluid, and/or quantities of the one or more components. This may be carried out at a detector 9 within the device 5, or externally, such as at a laboratory. Detection may be achieved by using known techniques, such as mass spectrometry.

54. Once one or more components have been detected, an estimation can be made as to the condition of the equipment on the basis of the presence (or amount) of a component. This estimation may be based on the mere presence of a component (such as a product of corrosion or a component expected to cause corrosion), or may be based on an amount of the component. Figure 5 shows a computer device 13 suitable for estimating, on the basis of the presence and/or amount of a component of a fluid sample, a condition of the pipe 1 . The computer device 13 has an input device 14 for receiving data relating to the presence of one or more components in the fluid sample taken from the region 4. The input device 14 may receive the data from the field device 5, or may receive data from a detector in a laboratory. Such a detector may be a mass spectrometer, for example. The data may indicate a quantity of at least one or more components. For example, the quantity may be supplied as a ratio of one component with respect to other components of the fluid sample, or may reflect the absolute amount of a component. A processor 15 can then be used for estimating the condition of the pipe 1 , based on the data supplied to the input device 14. This may be achieved by the processor 15 comparing data supplied to the input device 14 against data in a database 16. For example, the database 16 may contain data relating to elements or components that are indicative of a corrosive environment, or by-products of corrosion, for a given material or materials, or that are indicative of a leak.

The computer device 13 may comprise a receiver 17, for receiving data to store in the database 17.

In an exemplary embodiment, a database is populated according to the steps illustrated in Figure 6. S5. A fluid sample is obtained from a region substantially at an external surface of an equipment, where the equipment has an insulating layer. S6. An analysis is performed on the fluid sample, identifying one or more components of the fluid sample.

57. A determination is made as to a condition of the equipment. For example, it may be determined that the equipment is undergoing corrosion. This may be determined by any known means, such as visually inspecting the equipment.

58. The one or more components, identified during the detailed analysis can be correlated with the condition of the equipment. For example, if the equipment is corroded, the one or more components may be correlated with corrosion of the equipment.

59. The one or more components are then entered into a database as data. For example, the data in the database may indicate the relative abundance of the one or more components. The one or more components, or a statistical value such as the relative abundance of such components, may be correlated with the degree of corrosion of the equipment. Alternatively, the one or more components may be added to the database only in cases where a threshold degree of corrosion has been detected in the equipment. In this way a database can be populated that empirically correlates components or quantities of components with an expected amount of corrosion. The database may also correlate a composition of the equipment that is corroded, with the one or more components. This may be helpful, since different materials produce different by-products when corroded. Furthermore, what may be indicative of a corrosive environment for equipment comprising one or more materials, may not be corrosive to further equipment comprising different materials.

S10. A further fluid sample is extracted from a region substantially at an external surface of further equipment having an insulating layer. The further equipment may be any equipment, including the equipment of step 5. 51 1 . The further fluid sample is analysed, and the presence of one or more components is detected.

512. The one or more components are then compared with the data in the database. An estimation can then be made of the condition of the equipment. This may be an estimate of the degree of corrosion experienced by the equipment, based on the presence, or the relative abundance of the one or more components. The estimation may also be based on the similarities of component conditions, such as equipment material, thickness and type of insulation, presence of other factors such as weld seams, ambient temperature and so on.

In this way, empirical data is built up over time, which can be used to estimate the condition of the equipment. For example, in the case of detecting corrosion, if components X, Y and Z are detected in step S6, and it is determined that the equipment is corroded in step S7, then components X, Y and Z can be added to the database, along with an indication that these components are associated with corrosion. Some time later, if a further equipment is analysed according to steps S10 and S1 1 , and components X, Y and Z are detected, it is likely that the further equipment is undergoing corrosion. Furthermore, if only components X and Z are detected, this may also indicate a likelihood of corrosion.

It will be appreciated that any the computer device 10 may be combined with the detector.

The techniques described above make it possible to estimate a condition of equipment having an insulating layer, without needing to remove the insulation layer. If it is determined that the equipment is likely to be experiencing corrosion, then the insulating layer may be removed, such that the equipment can be checked. However, if it is estimated that the equipment is not experiencing significant corrosion, then the insulating layer will not need to be removed, thus saving time and money. It will be appreciated by the person of skill in the art that various modifications may be made to the above-described embodiments without departing from the scope of the invention.

Claims

CLAIMS:

1 A method for estimating a condition of equipment having an insulating layer on an external surface of the equipment, the method comprising:

extracting a fluid sample from a region substantially at an external surface of the equipment;

detecting the presence of at least one component of the fluid sample; and estimating on the basis of the presence of the component a condition of the equipment.

2. The method according to claim 1 , further comprising extracting the fluid sample via a drain hole in the insulating layer.

3. The method according to any one of claims 1 and 2, further comprising extracting the fluid using a low pressure fan.

4. The method according to any one of claims 1 , 2 or 3, further comprising, prior to detecting the presence of at least one component of the fluid sample, storing the fluid sample in a container.

5. The method according to claim 4, further comprising substantially evacuating a volume of the container prior storing the fluid sample in the container.

6. The method according to any one of claims 1 to 5, wherein analysing comprises using a mass spectrometer.

7. The method according to any one of claims 1 to 6, further comprising estimating the condition of the equipment by comparing any of a presence and a quantity of the component with data from a database.

8. The method according to any one of claims 1 to 7, wherein the condition comprises a likelihood of corrosion, and the estimation of the condition is an estimation of a degree of corrosion.

9. The method according to claim 8, further comprising determining a quantity of the component, and using the determined quantity to estimate a degree of corrosion.

10. The method according to any one of claims 1 to 9, wherein the component is a by-product of corrosion.

11 . The method according to any one of claims 1 to 10, wherein the component indicates an environment that leads to corrosion.

12. The method according to any one of claims 1 to 7, further comprising determining that the component corresponds to a component contained within the equipment, the presence of the component indicating a leak in the equipment.

13. The method according to any one of claims 1 to 12, wherein the component com prises a hydrocarbon .

14. A computer device comprising:

an input device for receiving data relating to a detected presence of a component in a fluid sample obtained from a region substantially outside an external surface of an equipment, the external surface having a layer of insulation

a processor for estimating, on the basis of the presence of the component, a condition of the equipment.

15. The computer device according to claim 14, wherein the input device is arranged to receive the data from a mass spectrometer.

16. The computer device according to any one of claims 14 and 15, wherein the processor is arranged to estimate the condition of the equipment by comparing any of the presence and a quantity of the component with further data obtained from a database.

17. The computer device according to claim 16, further comprising a second input device arranged to receive the further data from an external source.

18. The computer program, comprising computer readable code which, when run on a computer device, causes the computer device to behave as a computer device as claimed in any one of claims 14 to 17.

19. The computer program product comprising a non-transitory computer readable medium and a computer program according to claim 18 wherein the computer program is stored on the non-transitory computer readable medium.

20. A fluid sampling device for obtaining a fluid sample from equipment, the equipment having an insulating layer on an external surface, the fluid sample being used to estimate a condition of the equipment, the device comprising:

an extraction tool arranged to extract a fluid sample from a region substantially at an external surface of the equipment; and

a detector arranged to detect the presence of at least one component of the fluid sample.

21. The fluid sampling device of claim 20, further comprising a processor arranged to estimate on the basis of the presence of the component a condition of the equipment.

22. The fluid sampling device of any of claims 20 and 21 , further comprising a low pressure fan.

23. The fluid sampling device of any of claims 20 to 22, further comprising a container for storing the fluid sample.

24. The fluid sampling device of claim 23, wherein the container is substantially evacuated prior to storing the fluid sample in the container.

25. The computer program, comprising computer readable code which, when run on a fluid sampling device, causes the fluid sampling device to behave as a fluid sampling device as claimed in any one of claims 20 to 24.

26. The computer program product comprising a non-transitory computer readable medium and a computer program according to claim 25 wherein the computer program is stored on the non-transitory computer readable medium.

27. A method of populating a database, the method comprising:

obtaining a fluid sample from a region substantially at an external surface of an equipment;

detecting a presence of at least one or more components of the fluid sample; determining a condition of the equipment;

correlating the presence of the at least one or more components of the fluid sample with the condition of the equipment;

populating a database with data relating to a correlation between the presence of at least one component of the fluid sample with the condition of the equipment.