Patent Application
20140336937
The present invention relates to a downhole mapping system for identifying completion components in a casing in a completion.
When performing operations downhole in completions, a downhole tool having one or more operational tools is inserted into the completion. The downhole tool is then moved down in the completion until it reaches the area within which it has to perform its operation.
Since for many completions, especially older completions, specific information on the position of different completion components is not available, it is difficult to perform operations downhole, as it is difficult to identify any completion components downhole which are to be activated, maintained or serviced. This makes downhole operations cumbersome and time-consuming.
It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide a downhole mapping system which can identify completion components present in a casing of a completion.
The above objects, together with numerous other objects, advantages, and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by a downhole mapping system for identifying completion components having an inner surface in a casing in a completion, comprising:
The system according to the present invention may further comprise a component scanning unit for scanning the inner surface for identifying a component and storing the data representing the component in the database.
In an embodiment, the component scanning unit may be an optical component scanning unit.
Also, the scanning unit may use laser, infrared light, ultraviolet light or visible light for scanning the component.
Thus, by optical component scanning unit is meant a unit adapted for emitting a beam of laser, infrared light, ultraviolet light or visible light for scanning the component.
Further, the component scanning unit may comprise a transmitter of an optical beam, such as a laser beam, an infrared light beam, an ultraviolet light beam or a light beam, and a receiver for receiving the reflected beam which has been reflected on the inner surface of the component or casing.
Additionally, the component scanning unit may comprise a transceiver for transmitting an optical beam, such as a laser beam, an infrared light beam, an ultraviolet light beam or a light beam, and for receiving the reflected beam which has been reflected on the inner surface of the component or casing.
The magnetic sensor tool may further comprise a second sensor arranged in the first plane and at a second distance from the first sensor along the longitudinal tool axis, also for detecting changes in the magnetic field.
When the tool has two sensors positioned at a distance from each other, the measurements of the first sensor can be compared with the measurements of the second sensor, which leads to a more precise estimate of a matching component.
Moreover, the magnet may have a magnetic field source axis substantially transverse to the longitudinal tool axis.
In one embodiment, the tool may be powered by a battery.
In another embodiment, the tool may be powered through a wireline.
Also, the downhole mapping system may further comprise an operational tool.
In addition, the completion component may at least partly be made of metal and may at least have a thickness along its extension which is different from a thickness of the casing.
Furthermore, the completion component may have varying thicknesses or configurations along its extension.
The completion component may be a collar of a casing, an inflow valve, a sliding sleeve, a rotational sleeve, a ball valve, a nipple, a screen, an annular barrier, a sensor, etc.
Moreover, the operational tool may be a stroker tool, a key tool, a logging tool, a drilling tool, a milling tool, etc.
Additionally, the operational tool may further comprise a driving unit, such as a downhole tractor, for propelling the system forward downhole.
The downhole mapping system as described above may further comprise a communication unit sending information of any matching completion components and a position of the matching completion components.
In an embodiment, the reference database may be arranged in the magnetic sensor tool or at subterrain or uphole.
Further, the processor may be arranged in the magnetic sensor tool or at subterrain or uphole.
The downhole mapping system as described above may further comprise a completion map unit of identified completion components of the completion.
Said completion map unit may be arranged in a first part of the casing nearest to a well head, in the magnetic sensor tool or in the well head, and the completion map unit may comprise data of the component present in the completion.
Furthermore, the magnetic sensor tool may comprise a communication unit sending information of any matching completion components and a position of the matching completion components to the completion map unit.
In addition, the magnetic sensor tool or another operational tool may comprise a reader for reading information from the completion map unit regarding the completion components and a position of the completion components present in the completion.
The present invention also relates to a completion diagram provided by the downhole mapping system as described above.
Also, the present invention relates to a data carrier comprising the completion diagram as described above.
Said data carrier may be a CD-ROM, a DVD, a Blu-ray, a memory disk or card, a processor, a barcode, or a hard disk.
Moreover, the completion map unit may be the data carrier.
The magnetic sensor tool may further comprise a second magnet, the first sensor being positioned in a first angle in relation to a longitudinal extension of the first magnet, and the second sensor having the first distance and angle in relation to a longitudinal extension of the second magnet.
In one embodiment, the sensors may be positioned at the same distance from the magnet.
The sensors may be anisotropic magnetoresistive sensors. By using anisotropic magnetoresistive sensors, the measurements of the sensors are independent of the velocity of the tool.
The magnetic sensor tool may further comprise a second magnet, the second sensor being arranged in a position in relation to the second magnet, which position is the same as the position in which the first sensor is arranged in relation to the first magnet, as if the first sensor and magnet had been displaced in parallel, and the magnet may be arranged in the same first plane as the first and second sensors. By arranging the sensors in the same plane, a more precise identification of a matching component may be obtained.
Moreover, the first distance may be equal to the second distance.
Furthermore, the first and second sensors may be arranged on one side of the magnet and a plurality of sensors may be arranged on the other side in the first plane.
The magnet may be arranged on one side of a plate, and an additional magnet may be arranged on the other side of the plate so that two repelling poles of the magnets are facing one another. The plate may be made of a non-conductive or non-magnetic material, such as porcelain, ceramics, mica, glass, plastics, or a combination thereof.
The tool may comprise a plurality of magnets, each of which is arranged opposite a sensor so that the first magnet is arranged opposite the first sensor, and the second magnet is arranged opposite the second sensor.
Furthermore, the at least one magnet may be a permanent magnet or an electromagnet.
Each sensor may measure the magnitude and/or direction of the magnetic field or the field vector, i.e. the strength and direction of the field.
The tool may have a cylindrical shape with a wall, and the detecting unit may be arranged inside the tool and surrounded by the wall.
The magnet may have a rectangular shape or a cylindrical shape.
The distance between two sensors may be between 5 and 150 mm, preferably between 5 and 100 mm, more preferably between 10 and 50 mm, and even more preferably between 10 and 30 mm.
The present invention furthermore relates to a mapping method for identifying completion components downhole comprising the steps of:
Said step of comparing may comprise a step of determining a best match where identification of a match is unobtainable.
This method for identifying completion components downhole may further comprise the step of storing the measured data of the match.
Also, the step of comparing may occur downhole or uphole.
The measured data may be stored with an identification tag of the known component.
The component scanned by the scanning unit may be stored in the reference database.
Moreover, the method may comprise the following steps for determining a position of the tool based on the measurements obtained from the magnetic sensor tool:
According to another aspect of the present invention a method of enhancing and improving a reference database may comprise the steps of:
The step of measuring a known component may occur downhole or uphole.
The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which
All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.
The downhole mapping system 100 further comprises an optical component scanning unit 53 for scanning an inner surface of the component for identifying the component and storing the data representing the component in the database. The scanning unit 53 uses laser or other optic light for scanning the component. The completion components may vary in dimension, such as thickness, and in position along the longitudinal axis and/or circumference of the casing, e.g. an open, partly open or closed sleeve. Furthermore, the completion components may vary in material as some components are made of cheramics, aluminium, stainless steel or other non-magnetic material. When having non-magnetic components, the detecting unit 2 comprising the first magnet 4 is not able to identify the component, and if the dimension vary, the detecting system is not able to provide a conclusive result. By having the optical component scanning unit 53, the system is able to identify all types of completion components in the well regardsless of material or varying dimensions. The scan performed by the optical component scanning unit 53 is processed in the processor and compared to data from scans of known components, and if no match is found, the data is stored in the reference database 34.
Thus, the downhole mapping system 100 can be used to identify a completion component such as if a component is a sliding sleeve, a rotational sleeve or another kind of valve. In order to close the valve, the valve has to be identified to mount the right key for gripping into a corresponding groove in the valve. The optical component scanning unit 53 is therefore used to scan the inner surface to detect the dimensions and orientation of the groove to be engaged by the key in order to open or close the sleeve. Furthermore, it is very important to identify whether the sleeve is sliding in the axial direction or rotates in order to mount the key on the right tool capable of rotating the key if it is a rotational sleeve or slide the key along the axial direction if the sleeve is a sliding sleeve. The movement direction of the sleeve can be detected from the scan performed by the optical component scanning unit 53 and the right key tool can be rigged up while the mapping system is in operation or emerges at surface, since data from the mapping system is sent up while mapping.
The downhole mapping system 100 may also be used to map a whole completion in order to verify that a component appearing in the completion diagram is actually mounted in the completion, that the component is mounted in the right position and in order to identify components not appearing in the completion diagram. The magnetic sensor tool 1 is moved along the casing in the completion measuring the casing profile, and the measured data is compared, section by section, with data of known completion components in the database.
In
The completion component 33 is at least partly made of metal and at least has a thickness along its extension which is different from a thickness of the casing, whereby it is possible to measure a set of data of the component with the sensor tool 1. Furthermore, the completion component 33 has varying thicknesses or configurations along its extension, which also facilitates the identification of the measured set of data of the component.
The completion component 33 may for instance be a collar of a casing, an inflow valve, a sliding sleeve, a rotational sleeve, a ball valve, a nipple, a screen, an annular barrier, a sensor, etc.
The magnetic sensor tool 1 has a substantially cylindrical shape, and the magnets are arranged in the centre of the tool crossing a centre axis 30 of the tool, extending along the length of the tool. The plate 8 is fastened to the wall 31 of the tool 1. When the tool 1 moves down the casing 3, the magnetic field changes depending on the surroundings, and the sensors 5, 6 detect a direction θ of the magnetic field lines and/or changes in a magnitude of the magnetic field when the tool moves. By performing substantially continuous measurements of the direction and/or magnitude, small variations are measured while the tool 1 moves along the casing 3 between casing collars, completion components or just the casing wall. The sensors are also capable of detecting if no changes occur in the magnetic field, i.e. if the thickness of the casing is unchanged along the measured distance or if the tool has stopped.
The detecting unit 2 of
As it appears from
The magnet/magnets 4 can be positioned on a plate 8, such as a circuit board. As it appears in the cross-sectional view of
The magnet 4 is surrounded by a housing 16 of non-magnetic material in order to hold it in place. The non-magnetic material may be any type of substantially non-magnetic material, such as aluminum, porcelain, ceramics, mica, glass, plastics or a combination thereof.
The plate 8 may be any type of plane substance, and it may be made of any suitable non-magnetic material, such as aluminum, porcelain, ceramics, mica, glass, plastics or a combination thereof.
In
The distance between the sensors 5, 6 does not have to be the same, and the distance between the first two sensors in a row of four may therefore be different than the distance between the second and third or the third and fourth sensors.
The distance d1 from a sensor to the magnet is the distance from the longitudinal axis of the detecting unit on which the centre of the magnet is arranged as shown in
As e.g. shown in
The sensors 5, 6 may be arranged in different positions relative to the magnetic sources, as shown in
The sensors 5, 6 detect the direction and/or the magnitude of the magnetic field, and the magnet 4 has a magnetic field source axis substantially transverse to the longitudinal tool axis, as shown in
A partly cross-sectional view of the magnetic sensor tool 1 is shown in
In another embodiment, the detecting unit 2 is positioned elsewhere in the system, as shown in
In
The magnets 4 may be permanent magnets, electromagnets or any other suitable type of magnets. By using permanent magnets 4, no extra equipment is needed in order for the magnet to function.
The distance between the sensors 5, 6 may vary according to design. In
If the sensors are placed with a long distance between them, the variations in tractor speed may be missed or at least not detected instantaneously. In one embodiment, the distance between the two sensors 5, 6 is between 5 and 150 mm, preferably between 5 and 100 mm, more preferably between 10 and 50 mm, and even more preferably between 10 and 30 mm.
The sensors 5, 6 do not have to be arranged on a flat substance such as a plate 8. They may be positioned in individual plates or clamps as long as they are arranged in substantially the same plane.
The sensors 5, 6 conduct measurements at a sample rate between 1 and 5000 measurements per second, preferably between 100 and 2000 measurements per second, and more preferably between 250 and 1000 measurements per second.
The calculation of the velocity of the tool 1 is based on between 1 and 300 times per second, preferably between 10 and 100 times per second and more preferably between 10 and 50 times per second.
The magnetic sensor tool 1 may comprise a calculation unit, such as a processor, for calculation of the velocity or the position of the tool.
The invention also relates to a system comprising a magnetic sensor tool 1 as described above and a calculation unit positioned at a distance from the tool, e.g. above surface on an oil rig or vessel. The tool itself may have a calculation unit, meaning that some of the calculations are performed downhole in order to reduce the amount of data transmitted to the calculation unit above surface.
The sensors 5, 6 may be any type of suitable magnetic sensors, such as an anisotropic magnetoresistive sensor capable of measuring the direction of the magnetic field from a magnet 4. By direction-sensitive sensor is meant a sensor capable of measuring the direction of the magnetic field surrounding the sensor such as from a magnet nearby. When the tool 1 has an anisotropic magnetoresistive sensor, the determination of the position of the tool is independent of the velocity of the tool. Many types of anisotropic magnetoresistive sensors are very commonly available and therefore inexpensive, without being less reliable.
The choice of magnet type depends on the temperature downhole.
When using several magnets 4 in the same plane, each magnet must have a certain distance to the adjacent magnets to ensure that the casing 3 and the casing collars 15 can influence the direction of the magnetic field generated by the individual magnet. The distance is preferably at least 5 mm, more preferably 5-50 mm, and even more preferably 10-30 mm.
Thus, the magnetic sensor tool 1 may also be used for locating the position of the tool and thus the position of a completion component, such as valve, an annular barrier, a sleeve, a patch, or even a crack or a leak in the casing, or any other feature resulting in a significant change in a magnetic field. Furthermore, the magnetic sensor tool 1 may also be used for determining the position of a tool downhole before performing an operation downhole.
Each sensor 5, 6 measures the same changes, e.g. the profile or signature of the casing or component, but there is a difference in time between the measurements due to the distance between the sensors. The data from the sensors 5, 6 is convoluted, and from the maximum value of the convolution, it can be deduced when a first sensor 5 passes the same position as a second sensor 6, and so forth. The period between the time when the first sensor and the second sensor pass the same positions is termed ΔT, and since the distance d2 between the first sensor 5 and the second sensor 6 is known, it is possible to calculate the velocity of the magnetic sensor tool 1 by means of the following equation:
The estimate of the velocity is based on a number of measurements, and by continuously calculating the velocity of the tool 1, it is possible to calculate the distance Δx travelled since the previous calculation by means of the following equation:
Δx=v·Δt
where Δt is the time between calculations and Δx is the estimated velocity. When adding these estimated distances, the distance from the top of the well at a specific time of e.g. an observation of an irregularity, such as a leak, is known.
Using convolution between datasets received from at least two sensors instead of only comparing the measurements from one sensor with measurements from the other measurement by measurement, the method is relatively insensitive to noise in the measurements. In this way, a more accurate result is obtained.
Furthermore, since the same characteristics are present in the two sets, the scale of the data is not important.
When the tool 1 passes a joint or collar where two casing parts are mounted together, the change in field direction is substantially increased. At this point, the distance from a collar is zero, and any errors in the estimated position of the tool can be eliminated. The number of collars passed and the distance from the last collar indicate the actual position of the tool since the distance between collars is known.
In
In
In this embodiment, the downhole mapping system 100 comprises the magnetic sensor tool 1, the component scanning unit 53, a communication unit 51 sending information of any matching completion components and/or a scan of the inner surface of the component and a position of the matching completion components to a completion map unit 50, all arranged in the tool operating downhole. The system 100 furthermore comprises the processor 34 and the reference database 35 which is arranged uphole and connected with the downhole operational tool via wireline 52.
The reference database 35 may also be arranged at a remote location as shown in
The magnetic sensor tool 1 detects the completion components 33 as it moves down through the completion as described above and shown in
However, in circumstances in which it is difficult to identify a matching component in the reference database 35, the downhole mapping system 100 may use the component scanning unit 53 for scanning the inner surface for identifying the component 33 and storing the data representing the component 33 in the reference database 35. The scanning unit 53 may use laser or another optic source, such as a light emitting diode (LED), an infrared emitter or an ultraviolet emitter, for scanning the component 33. Hereby, the unidentified component 33 becomes a known component and the measured set of data and the scanned inner surface of the component may be communicated to the completion map unit 50 and to the reference database 35 as shown in
The completion map unit 50 comprises the identified completion components 33 of the specific completion so that the information of different completion components present in the completion is accessible for later operations downhole. In
The completion map unit 50 may also be arranged in a first part of the casing in a well head or nearest to the well head 54 as shown in
As the downhole mapping system 100 moves downhole and identifies the completion components by comparing the measured set of data with the reference database, it creates a completion diagram 55 of the completion which is being mapped. In the event that the component cannot be recognised, the data is stored. The scanning unit scans the inner surface of the component and the component can be manually identified and the completion diagram be updated. An example of a completion diagram 55 is shown in
The completion diagram may be stored on the completion map unit 50. The completion map unit 50 may be a data carrier, wherein the data carrier may be a CD-ROM, a DVD, a Blu-ray, a memory disk or card, a processor, a barcode, a server, or a hard disk, or any combination thereof.
In
Even though the operational tool 56 is entering an already mapped completion, it may also comprise the downhole mapping system according to the present invention. Hereby, the mapping system of the operational tool 56 may identify any completion components on its way down into the completion and thereby verify the accuracy of the completion diagram and, more importantly, the accuracy of its own positioning measurements.
In other circumstances in which a completion has not been mapped yet and an operational tool is entering the completion for performing one or more operations, it is an advantage that the operational tool comprises the downhole mapping system, so that a partial or full mapping of the completion may be performed during the operations.
For instance, the creation of the reference database 34 may be performed by the suppliers of the completion components delivering the magnetic set of data for each completion component, which data is then stored in the reference database 34, enabling the downhole mapping system 100 to compare the measured set of data with the data present in the reference database for identifying a match.
Furthermore, the suppliers of completion components may also deliver scanned images of an inner surface of the completion components, which images are also stored in the reference database. The images may additionally be used for facilitating the procedure of matching completion component data with the data present in the reference database 34. If a certain component is to be located or its presence downhole is to be verified, the component can be scanned at surface and the data stored in the database before the tool enters the well for performing an operation on the component.
Thus, if data from the supplier is not available, the reference database 34 may be improved and enhanced by moving the magnetic sensor tool 1 past a known component for measuring a set of magnetic data representing the known component, and storing the set of measured data with an identification tag of the known component in the reference database 34. The measuring of the known component may occur downhole or uphole.
The reference database may be further improved by scanning the inner surface of the completion component for creating an image of the component. The scanned image is then stored together with the magnetic data of the component in the reference database 34.
By fluid or well fluid is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By gas is meant any kind of gas composition present in a well, completion, or open hole, and by oil is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil, and water fluids may thus all comprise other elements or substances than gas, oil, and/or water, respectively.
By a casing is meant any kind of pipe, tubing, tubular, liner, string etc. used downhole in relation to oil or natural gas production.
As mentioned above, the magnetic sensor tool 1 may be connected with a driving unit 9, such as a downhole tractor, as shown in
Although the invention has been described in the above in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 11195021.8 | Dec 2011 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2012/076347 | 12/20/2012 | WO | 00 | 6/4/2014 |
