OSALAND, Espen (Håbamyrå 34, Sandnes, N-4325, NO)
C L A I M S
1. A cleaning tool device (1) for a pipe's (34) internal wall (36) , the cleaning tool (1) comprising a tool housing (2) and a connector (4) for connection to a cable, a tubing, a well tractor or another component provided to at least being able to pull the cleaning tool (1) in a first direction in the pipe (34) , c h a r a c t e r i s e d i n that the connector (4) is axially displaceable relative to the tool housingo (2) , the cleaning tool (1) being provided with at least one cleaning element (6) rollable against the pipe's (34) internal wall (36), wherein a displacement of the connector (4) in a first direction relative to the tool housing (2) causes the at least one cleanings element (6) to be displaced in the direction toward the internal wall (36) relative to the tool housing (2) .
2. A device according to claim 1, c h a r a c t e r i s e d i n that at least one cleaning element (6)0 is rotatably provided in a cradle (30) which is radially displaceable in the tool housing (2) .
3. A device according to claim 1, c h a r a c t e r i s e d i n that the cradle (30) is provided with an inclined plane (38) cooperating with an inclined5 plane (40) on a wedge block (22), the wedge block (22) following the connector (4) when the connector (4) is displaced in the first direction relative to the tool housing (2) .
4. A device according to claim 1, c h a r a c t e r -o i s e d i n that the cradle (30) is provided with at least two cleaning elements (6) , wherein at least two of the cleaning elements (6) have different surface patterns.
5. A device according to claim 1, c h a r a c t e r i s e d i n that at least two cradles (30) , each having at least one cleaning element (6) , are distributed about the cleaning tool (1) .
6. A device according to claim 1, c h a r a c t e r i s e d i n that at least two cradles (30) , each having at least one cleaning element (6) , are provided along the longitudinal direction of the cleaning tool (1) , the cradles (30) being mutually displaced along the circumference of the cleaning tool (1) .
7. A device according to claim 1, c h a r a c t e r i s e d i n that at least two cradles (30) , each having at least one cleaning element (6) , are sufficient to treat the whole of the internal surface (36) of the pipe (34) when the cleaning tool (1) in its activated position is displaced in the pipe (34) . |
CLEANING TOOL DEVICE
There is provided a cleaning tool. More particularly it concerns a cleaning tool for a pipe mantle surface where the cleaning tool comprises a tool housing and a coupling for connection to a cable, a tubing, a well tractor or another component provided to at least being able to pull the cleaning tool in a first direction in the pipe.
The further description is based on cleaning of a pipe with deposits; as such a work operation emphasizes in an adequate manner the favourable features of the cleaning tool . However the cleaning tool functions are in no way limited to such work as it will be useful for a range of work where pipe or boreholes are to be cleaned or expanded and where a so-called "pilot hole" is present.
During operation of different kinds of piping, it is well known that deposits over time can build up on the interior surface of the pipe. This is particularly unfortunate where long pipes with difficult access are concerned and where chemical cleaning methods are less efficient.
It is known to utilise cleaning tools, which at their free ends are provided with a cleaning element for cleaning of a pipe. The cleaning tool is displaced along the pipe while it is being rotated about the pipe longitudinal axis. Cleaning tools provided with rotatable cleaning elements have proved
to be efficient, as the cleaning elements during rolling against the internal pipe surface breaks up deposits. Norwegian patent 324515 discloses a cleaning tool of this kind.
It is also known to provide cleaning tools of this kind with centring wheel, see for example US patent 2418880.
To, among other things, reduce the danger of the cleaning tool sticking in the pipe, the outside working diameter of the cleaning tools are somewhat smaller than the inside diameter of the pipe . Experience has shown that the cleaning tool due to for example uneven thickness of deposits can be displaced from the longitudinal axis of the pipe whereby a helical opening is formed in the pipe.
In later work in the pipe, the somewhat helical opening in the pipe may cause a tool to get stuck.
It is known to provide the cleaning tool with a tool support just behind the free end portion to counteract the forming of a helical opening. The tool support is formed to be able to abut the internal pipe surface .
Prior art tool supports are typically designed with sliding elements, and possibly with a scraper blade abutting the internal pipe surface. The scraper blade is designed to be able to clean deposits from the internal pipe surface. Tool supports according to prior art have turned out to be relatively inefficient.
The object of the invention is to remedy or reduce at least one of the prior art drawbacks .
The object is achieved according to the invention by the features stated in the below description and in the following Claims .
There is provided a cleaning tool for the internal surface of a pipe, the cleaning tool comprising a tool housing and also a connector for connecting to a cable, a tubing, a well tractor or another component designed to at least be able to pull the cleaning tool in a first direction in the pipe, where the cleaning tool is characterised in that the connector is axially displaceable relative to the tool housing, and where the cleaning tool is provided with at least one against the interior pipe surface rollable cleaning element, where a displacement of the connector in a first direction relative to the tool housing effects the at least one cleaning element to be displaced in a direction towards the internal surface relative to the tool housing.
One aspect of the cleaning tool is that at least one cleaning element is rotatably placed in a cradle, the cra.dle being radially displaceable in the tool housing. The cleaning element is typically supported about a shaft approximately at right angles to the cleaning tool longitudinal axis.
A further aspect of the cleaning tool is that the cradle is provided with an inclined plane cooperating with an inclined plane on a wedge block, the wedge block following the connector when the connector is displaced in the first direction relative to the tool housing. The cradle inclined plane is thus abutting the wedge block inclined plane. The wedge block may be displaceable on a connector stem being connected to the connector. If the wedge block is displaceable on the connector stem, the wedge block is shaped to abut a shoulder connected with the connector stem when the connector stem is displaced in the first direction.
Yet another aspect of the cleaning tool is that the cradle is provided with at least two cleaning elements where at least two of the cleaning elements are given a different surface pattern. The external area of one cleaning element may for example be formed with several pyramid-shaped points while another may be given knife-like ridges surrounding the cleaning element or running axially along the cleaning element. The ridges may possibly follow a helix about the cleaning element .
When the cleaning tool is pulled in the pipe, deposits on the inside surface of the pipe will be exposed to various strain depending on the kind of surface the cleaning element has and this causes the deposits to come easier loose from the pipe wall .
Another aspect of the cleaning tool is that at least two cradles, each having at least one cleaning element, are distributed about the cleaning tool. Practically it has turned out that a housing section of the cleaning tool may comprise three cradles distributed about the cleaning tool.
Still another aspect of the cleaning tool is that at least two cradles, each having at least one cleaning element, are provided along the longitudinal direction of the cleaning tool, as the cradles are displaced relative to each other along the circumference of the cleaning tool .
Still another aspect of the cleaning tool is that a number of cradles, each having at least one cleaning element, are sufficient to treat the whole of the pipe internal surface when the cleaning tool in its activated position is displaced in the pipe. This is achieved for example by interconnecting three housing sections each having three cradles, as each
housing section is somewhat displaced relative to an adjacent housing section.
A spring is provided to pre-tension the cleaning elements against the pipe wall .
The provided cleaning tool is suitable for being displaced back and forth in a pipe, e.g. by means of a well tractor possibly with an actuator fitted. When the cleaning tool is displaced in the first direction, the cleaning elements are forced against the pipe wall with a force dependent on the force being applied to the connector. When the cleaning tool is displaced in a second direction, which is opposite to the first direction, the cleaning elements are relieved since only the spring force tries to displace the cleaning elements against the pipe wall. The necessary force to displace the cleaning tool in the second direction is thus modest. The cleaning tool ' s own weight may be enough if the pipe is close to vertical .
In the following is described an example of a preferred embodiment which is illustrated in the accompanying drawings, where :
Fig. 1 shows a cleaning tool in a pipe;
Fig. 2 shows in somewhat greater scale an end view of the cleaning tool, an end portion of a cradle being i shown in section;
Fig. 3 shows a section II - II of fig. 2; and
Fig. 4 shows in perspective and in greater scale a cradle with cleaning elements fitted.
In the drawings, the reference numeral 1 indicates a cleaning tool comprising a tool housing 2, a connector 4 for
connection to a not shown actuator 5 or the like, and a number of cleaning elements 6.
The tool housing 2 is assembled from a first end portion 8 which is closest to the connector 4, three housing sections 10 and a second end portion 12 in the opposite end of the tool housing 2 relative to the first end portion 8. The end portions 8, 12 and the housing sections 10 are interconnected by means of bolt connections 14.
The connector 4 is connected to a connector stem 18 by means of a threaded connection 16. The connector stem 18 runs concentrically through borings 20 in the end portions 8, 12 and the housing sections 10.
In each housing section there is provided a wedge block 22. The wedge block 22, which in this embodiment is displaceable along the connector stem 18, abuts a ring flange 24 being fixedly attached to the connector stem 18. The ring flange 24 and hence the connector stem 18 is pre-tensioned in the direction towards the connector 4 by a spring 26 exhibiting a force between the ring flange 24 and the second end portion 12.
The cleaning elements 6 are shaped as barrel shaped rollers and are each rollably mounted on a shaft 28. Four cleaning elements 6 are provided one after the other in the rolling direction in a cradle 30, and the shafts 28 are attached to the cradle 30.
The cradles 30 are radially displaceable in one recess each, in the respective housing sections 10, see figs. 2 and 3. In this preferred embodiment three cradles are distributed about each housing section.
The cradles 30 in one housing section 10 is slightly displaced relative to the cradles 30 in the adjacent housing section (s) 10 for the cleaning elements together to cover the largest possible part of the internal surface 36 of a pipe 34.
Each cradle is provided with two inclined planes 38, which cooperate with inclined planes 40 on the respective wedge blocks 22, as a displacement of the wedge block 22 in the direction towards the connector 4 causes the cradle 30 with the cleaning elements 6 to be displaced radially outwards toward the internal surface 36.
The cleaning elements have different surfaces. In fig. 4 two of the cleaning elements 6 are provided with a relatively large number of points 42, while two cleaning elements 6 are provided with relatively sharp surrounding ridges 44.
During cleaning of such as deposits 46 from the internal surface 36, the cleaning elements 6 abuts somewhat against the deposits 46 due to the spring 26. A certain rolling resistance arises between the cleaning elements 6 and the deposits 46. When the connector 4 is pulled in a first direction away from the tool housing 2, the pull "in the connector stem 18 contributes to displace the wedge blocks 22 in the direction towards the connector 4 relative to the tool housing 2, whereby the cradles 30 with the cleaning elements 6 are displaced further into the deposits 46.
The surfaces of the cleaning elements 6 thus come into a desired engagement with the deposits 46, applying considerable point loads onto the deposits 46, which contributes to break up the deposits so that they come loose from the internal surface 36.
When the connector 4 is pushed in the direction toward the tool housing 2, the cleaning elements 6 are considerably relieved, whereby the cleaning tool 1 with a relatively small force may be displaced in a second direction, which is opposite to the first direction.
The cleaning tool may be displaced back and forth in the pipe 32 until the desired cleaning is achieved.
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