Plugging devices are used in oil and/or gas wells for sealing an upper section of the well from a lower section of the well. Such plugging devices comprise one or two anchoring devices and a sealing device. The anchoring device provides anchoring of the plugging device to the inner surface of the well. The sealing device comprises a sealing element and supporting devices for sealing the upper and lower sections of the well from each other, thereby preventing fluid from passing between the sections.
The plugging device is first run into the well in a run or radially retracted state by using a setting tool. At the desired location in the well, the plugging device is set in the well by actuating the plugging device to a set or radially expanded state, in which the anchoring device and sealing element are brought into contact with the well pipe. The supporting devices are supporting the sealing element, thereby preventing extrusion of the sealing element due to the pressure difference between the upper and lower sections.
After use, the plugging device may be retrieved from the well by using a retrieval tool. First, the pressure difference between the upper and lower section of the well is equalized. Then the anchoring device and sealing device are brought to a retrieval, or radially retracted, state, in which the plugging device may be pulled out of the well. Such plugging devices are known for example US 2004194969.
Junk catching devices are also used in oil and/or gas wells for catching junk, i.e. to prevent junk such as debris, metal fragments, metal parts or other unwanted objects to travel (i.e. fall or sink) further down into the well. Such unwanted objects are often also referred to as “fish”, as such objects must be fished or picked up from the well before other types of operations can be performed. If not, these objects may present obstructions which may prevent well tools from passing their location in the well.
It is known to use a junk catching device above plugging devices, such as bridge plugs, straddle packers etc. in order to prevent drilling fluid to enter the annular space between the plugging devices and the inner surface of the well pipe. Such well fluid tend to precipitate solid matter over time, and if the solid matter reaches the anchoring device or supporting devices for the sealing element of the plugging devices, then the plugging device may be difficult to retrieve from the well. Such situations may occur of it is necessary to interrupt an offshore oil/gas well due to bad weather conditions, where it may take several weeks to continue the well operation.
The problem is that the use of such junk catching devices together with the plugging device is first of all that it requires several running operations in the well. First, the plugging device is run into the well and set, then the junk catching device is run into the well and set. During retrieval, first the retrieval tool for the junk catching device must be inserted into the well and the junk catching device must be retrieved, then the retrieval tool for the plugging device is inserted into the well and the plugging device must be retrieved.
Another problem is that well fluids and junk often will fall onto the plugging device during the retrieval of the junk catching device and during the insertion of the retrieval tool for the plugging device. Hence, the effect of the junk catching device is reduced. Consequently, a bailing operation may still be required between the retrieval of the junk catching device and the retrieval of the plugging device.
The object of the present invention is to provide a well tool where the above disadvantages are avoided. Hence, the object is to reduce the number of operations needed during setting and retrieval of the well tool, and to reduce the risk of the plugging device being stuck in the well.
The present invention relates to a well tool comprising:
a plugging device comprising an inner mandrel, an anchoring device and a sealing device;
a junk catching device comprising an outer housing, a bore provided inside the housing and a receiving device provided in an upper end of the housing;
where a lower end of the outer housing is connected to an upper end of the inner mandrel of the plugging device;
where the receiving device comprises a receiving opening providing an opening into the bore and a junk guiding device for guiding junk into the bore via the receiving opening;
where the well tool further comprises a valve device having a run state and a set state, where the valve device is forming a termination of a junk container in the set state.
In one aspect, the valve device is a flapper valve.
In one aspect, the valve device is provided in the bore within the outer housing or in a further bore provided within the inner mandrel.
In one aspect, the plugging device comprises a first connection interface, where the first connection interface is provided for connection to a first connection interface of a setting tool.
In one aspect, the junk guiding device is configured to be provided in a run state and a set state, where:
the outer diameter of a guiding section of the junk guiding device is less than the outer diameter of the housing in the run state;
the outer diameter of the guiding section of the junk guiding device is larger than the outer diameter of the housing in the set state.
In one aspect, the junk guiding device is funnel-shaped in the set state.
In one aspect, the junk guiding device is funnel-shaped when unaffected by external forces.
Embodiments of the invention will be described with reference to the enclosed drawings, where:
It is now referred to
The well tool 1 has a run state, a set state and a retrieval state, which will be described in detail below. A setting tool 2 (
The plugging device 20 will now be described with reference to
The anchoring device 22 and the sealing device 23 can be brought from a run state, in which they are radially retracted, to a set state in which they are radially expanded. The run state is shown in
It should be noted that that plugging device 20 itself is considered to be known. Therefore, not all details of the plugging device 20 will be described in detail. The anchoring device 22 and the sealing device may for example be as described in the above-mentioned US 2004194969.
The junk catching device 30 will now be described with reference to
Details of the receiving device 40 are shown in
The receiving device 40 comprises a receiving opening 41 (
The junk guiding device 42 is configured to be provided in a run state (
The junk guiding device 42 comprises a guiding section 42A and an attachment section 42B. The outer diameter of the guiding section 42A of the junk guiding device 42 is less than the outer diameter of the housing 31 in the run state. In
A bending area 42C is defined between the guiding section 42A and the attachment section 42B. The junk guiding device 42 is in the present embodiment made of a semi-rigid material, such as short-aramid-fibre reinforced rubber material, carbon, aramid and/or textile fibre reinforced rubber material, plate spring material, thermosetting plastic or thermoplastic material, fibre fabric materials or similar materials.
The junk guiding device 42 may be molded in one process, resulting in one body comprising the guiding section 42A and the attachment section 42B. In the present embodiment the junk guiding device 42 is molded into one body being substantially funnel-shaped, i.e. substantially corresponding to the shape shown in
The flexibility of the material of the junk guiding device 42 makes it possible to compress the junk guiding device 42 into a substantially cylindrical shape, as shown in
Preferably, the guiding section 42A is molded into a funnel-shaped body having a diameter slightly larger than the expected inner surface of the well pipe in order to apply a pressure towards the inner surface of the well pipe.
The junk catching device 30 further comprises a sleeve device 35. The sleeve device 35 is fixed to the attachment section 42B of the junk guiding device 42. The sleeve device 35 is axially displaceable within the bore 31 of the outer housing 30. In
The well tool 1 further comprises a valve device 50. The valve device 50 is also having a run state, a set state and a retrieval state. In the run state, the valve device 50 is held open, and in the set and retrieval states, the valve device 50 is held closed. The valve device 50 is forming a termination of a junk container 45 in the set and retrieval states. By the term “termination”, it is meant that the valve device 50 forms the lowermost closed part of the junk container 45, i.e. the bottom or end of the junk container 45. By the term “junk container” it is meant the interior compartment of the tool 1 wherein junk will be contained. In
In the present embodiment, the valve device 50 is a flapper valve with an opening 51 and a lid 52 for closing the opening 51. The opening 51 is sufficiently large to give access to the setting tool 2, so that the setting tool 2 can be inserted through the opening 51 and further down to the connection interface 26 in the lower end of the tool 1. The valve device 50 may for example be spring biased, so that the lid 52 closes the opening 51 automatically when the setting tool 2 is removed from the opening 51 of the valve device 52.
The operation of the well tool 1 will now be described. In the run state, the innermost and lower part 2a of the setting tool 2 is connected to the connection interface 26, as shown in
In this state, the tool 1 is guided to the desired location in the well. The setting tool 2 is now actuated to bring the tool 1 from the run state to the set state. In the present embodiment, this is performed by pulling the innermost and lower part 2a of the setting tool 2 upwardly (to the left in the drawings) and/or pushing the outermost and upper part 2b of the setting tool 2 downwardly. The relative axial movement between the upper and lower parts 2a, 2b will cause a relative axial movement between the outer housing 31 and the inner mandrel 21, thereby causing the anchoring device 22 and the sealing device to radially expand to their set state, as shown in
The setting tool 2 is now disconnected from the connection interface 26 and the outer housing 31 by pulling the setting tool 2 upwardly. The lower end 2a may for example be connected to the connection interface 21 by means of shear pins which break when the upwardly directed pulling force of the setting tool 2 exceeds a certain limit.
When the outer housing 2b is pulled up from the guiding section 42A, the guiding section 42A will expand to its set state, in which the junk guiding device 42 is substantially funnel-shaped, as described above and which is shown in
In addition, the removal of the setting tool 2 will cause the valve device 50 to close, as shown in
If there are no damages to the inner surface of the well, the junk guiding device 42 will seal against the entire circumference of the inner surface of the well, and thereby guiding junk through the opening 41 and further into the junk container 45 in an efficient way, i.e. no junk will be able to pass the area between the junk catching device 40 and the inner surface of the well. Hence, the anchoring device 23 and sealing device 22 will be protected from junk.
The well tool 1 may be retrieved from the well. A retrieval tool 3 is used for this operation. First the retrieval tool 3 is lowered into the well. The retrieval tool 3 comprises a circular interface 3a configured to contact an upper end rim 36 of the sleeve device 35. Moreover, the pulling tool 3 comprises a fish neck device (not shown) for connection to the upper end 31a of the outer housing 31. The fish neck device and its connection to the housing 31 are considered to be known for a person skilled in the art.
Hence, by using the fish neck device to prevent downward movement of the outer housing 31 and by using the circular interface 3a to push the sleeve device 35 down, the junk guiding device 42 together with the sleeve 35 is pushed down into the outer housing 31. Consequently, the junk guiding device 42 is brought into its retrieval state in which the guiding section 42A is substantially cylindrical again.
By pulling the circular interface 3a further upwards after entering the upper end of the housing 31, also the anchoring device and sealing device are radially retracted to their retrieval state, and the tool 1 may be pulled out from the well.
In
A perspective view of an alternative embodiment of the junk guiding device 42 is illustrated in
Number | Date | Country | Kind |
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20131042 | Jul 2013 | NO | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/061329 | 6/2/2014 | WO | 00 |