GB2299599A

GB2299599A - Well cleaning apparatus

Info

Publication number: GB2299599A
Application number: GB9606896A
Authority: GB
Inventors: Ronald Potter
Original assignee: Rotary Drilling Supplies Europe Ltd
Current assignee: Rotary Drilling Supplies Europe Ltd
Priority date: 1995-04-01
Filing date: 1996-04-01
Publication date: 1996-10-09
Anticipated expiration: 2016-04-01
Also published as: GB2299599B; NO961276D0; NO305826B1; GB9606896D0; NO961276L

Abstract

Apparatus for cleaning the interior of well tubing comprises a body member 10 to which is attached at least one cleaning pad 14, comprising a body (32 figure 3) whose outer face is provided with bristles 38. A plurality of cleaning pads may be provided in an upper row at 120{ intervals around the body member, circumferentially offset to which is a lower row of cleaning pads also at 120{ intervals. The bristles may be nylon or hardened metal wire and the body may be a drillable material such as resin fibre or malleable metal. The apparatus may include at least one protection pad (50 figure 5) of a softer material than the well tubing mounted on the body member 10, a plurality of such pads may be circumferentially spaced around the body member. A row of protection pads may be provided above the upper row of cleaning pads and another row of protection pads may be provided below the lower row of cleaning pads.

Description

"Cleaning Apparatus" This invention relates to apparatus for cleaning the interior of a tubular member and especially, but not exclusively, for cleaning the inside of pipelines or oil, gas or water well tubulars, pipes or casings.

Due to the operating conditions and environment, oil, gas and water well tubulars, pipes or casings require regular cleaning. Conventionally, cleaning the inner structure of a drill casing, pipe or tubing would involve utilising a casing scraper assembly, such as the Best (trade mark) oiltool casing scraper assembly.

Such a conventional assembly incorporates steel casing scraper blades that scour the inside of the casing or tubing. Typically, each blade features several raised steel ribs that, once the scraper assembly has been lowered down the tubing or casing required to be cleaned, lie flush with the inner surface of said tubing or casing.

Typically there are six scraper blades per scraper assembly, three upper scraper blades positioned 60 apart around the scraper assembly and three lower scraper blades that are positioned 60 apart and 60 offset, when compared with the upper three scraper blades. Thus this conventional arrangement provides for a 360" cleaning capability of the assembly.

A disadvantage of the conventional scraper blade is that the raised steel rib arrangement is not efficient since it requires considerable drill string movement to clean the specified portion of the inner structure of the tubing or casing, and it rapidly becomes less effective with wear.

Another disadvantage of using conventional steel scraper assemblies is that, if they become dislodged from the scraper assembly apparatus, the cleaning operation must be stopped, the scraper assembly withdrawn and an attempt to retrieve the lost steel scraper must be initiated, which may take a long time.

There are also safety implications if a conventional steel scraper blade becomes dislodged from the scraper assembly apparatus, on the basis that if the assembly apparatus is not stopped quickly, then the steel scraper blade will be free to impede the rotating string.

The cleaning of pipelines may also present problems.

A first aspect of the present invention provides apparatus for cleaning the interior of a tubular member comprising a body member for insertion into the tubular member, and at least one cleaning pad mounted on the body member, the or each cleaning pad comprising a body having an inner face engaged with the body member and an outer face provided with protruding bristles.

Preferably, a plurality of cleaning pads are circumferentially spaced around the body member.

Typically, there is an upper row of three cleaning pads centred at 1200 intervals, and a lower row of cleaning pads centred at 1200 intervals and circumferentially offset with respect to the upper row.

The body member may comprise part of a pipeline pig or be adapted to be coupled to a pipeline pig.

Alternatively, the body member may form a portion of a length of drillstring.

The bristles may be of nylon. Alternatively, the bristles may be of wire, such as flame hardened steel or copper.

In a particularly preferred feature of the invention, the cleaning pad is constructed to be drillable; that is to be capable of being readily cut by a rock drill bit.

The body may be manufactured from a compressible material.

The inner portion of the body may be arranged so that the body is compressible, the inner portion of the body preferably being arranged in a honeycomb structure to aid compressibility.

The body may suitably be of a resin fibre compound, preferably a polyurethane fibre compound.

The bristles may be mounted in a backing secured to the body, suitably by adhesive. The backing may be fabric into which the bristles are sewn or woven, or may be an elastomeric soft compound rubber material.

Alternatively, the body may typically be manufactured from a malleable metal such as aluminium.

Typically, the brush pads may be interchanged to different grades of bristle, to suit all types of cleaning environment.

Preferably, the brush pads are held in place on the body member by a sleeve, the sleeve being run along the body member until it engages with the brush pad. More preferably, the sleeve is threaded and most preferably, the sleeve is provided with locking means for locking the sleeve with respect to the body member.

The apparatus of the present invention may include a protection device comprising at least one protection pad, the or each protection pad being mounted on the body member and being constructed from a softer material than the tubular member.

Preferably, a plurality of protection pads are circumferentially spaced around the body member.

Typically there is an upper row of protection pads and a lower row of protection pads. Preferably the upper row of protection pads is above the uppermost row of cleaning pads and the lower row of protection pads is below the lowermost row of cleaning pads.

The protection pads may be permanently secured to the body member.

Alternatively the protection pads may be removable from the body member.

The tubular member may be a pipeline or a tubular for insertion into a borehole, such as well casing or tubing.

Examples of cleaning apparatus in accordance with the invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is an exploded perspective view of a first example of well cleaning apparatus; Fig. 2 is a perspective view showing the apparatus of Fig. 1 in assembled condition; Fig. 3 is a front perspective view of a cleaning pad of the apparatus; Fig. 4 is a rear perspective view of the cleaning pad; Fig. 5 is a perspective of a second example of well cleaning apparatus; Fig. 6 is a perspective view of a protection pad for use with the apparatus shown in Fig. 5; Fig. 7 is a sectional view of a cleaning pad of the apparatus; Fig. 8 is a perspective view of a first example of pipeline cleaning apparatus; Fig. 9 is a perspective view of a second example of pipeline cleaning apparatus.

Fig. 10 is a sectional side view of a third example of pipeline cleaning apparatus; and Fig. 11 is a side view of the apparatus shown in Fig. 10.

Referring to Figs. 1 and 2, a well cleaning apparatus comprises a mandrel 10 for inclusion in a drill string by means of a pin connector 12 and a box connector (not seen in the drawings) at the lower end.

The mandrel 10 carries six cleaning pads generally designated at 14. The cleaning pads 14 are arranged in an upper row of three equally spaced around the circumference of the apparatus and a lower row of three equispaced pads offset from those of the upper row.

The mandrel 10 has projecting formations providing upper and lower collars 16 and slots 19. Each cleaning pad 14 (see also Figs. 3 and 4) is formed with an upper lip 18, a lower lip 20, and angled side faces 22. Each pad 14 is secured in position on the mandrel by engaging one of the lips 18 and 20 underneath one of the collars 16 with the side faces 22 engaged in the slots 19. The inner ends of the pads 14 are then held in position by a two part collar assembly 24 secured together by screws 26. Each cleaning pad 14 is biased outwardly by a series of coil springs 28 each engaging in a corresponding bore 30 in the rear of the cleaning pad 14.

Referring particularly to Figs. 3 and 4, each cleaning pad 14 comprises a body 32 having an arcuate front face 34 and an arcuate rear face 36. Bristles 38 project from the front face 34 to provide, in use, a scrubbing action on the interior of the tubular being cleaned.

In a preferred form, the bristles 38 are formed from flame hardened steel wire or copper wire and may suitably be 1/8" diameter set at 1/8" spacings.

The body 32 is suitably a unitary moulding encapsulating a portion of each of the bristles 38 and is preferably moulded from a polyurethane fibre compound.

In order to assist manufacture, the bristles 38 may be set in a sheet of textile or rubber material before being incorporated in the body 32.

The cleaning pads 14 may readily be interchanged to provide a suitable cleaning effect from any particular application. For example the pads 14 may be interchanged for pads having smaller diameter wire bristles or nylon bristles.

The cleaning pads 14 may be constructed from a compressible material and further may have a honeycomblike centre 25, to aid compressibility, as can be seen in Fig. 7.

In the event that one or more of the cleaning pads 14 becomes dislodged from the mandrel 10, the nature of its construction is such that it is readily drilled through by a drill bit or other implement commonly used in a well tubular, since the polyurethane body is relatively easily drilled away leaving relatively small pieces of wire which can be handled in a manner similar to drill chippings.

The well tubing may change direction by a relatively high degree, thus requiring the drillstring to navigate this change in direction if, for instance, the drillstring is being run in or pulled out of the well tubing.

Fig. 5 shows a second example of well cleaning apparatus with protection pads 50 mounted on the mandrel 10 and arranged in an upper row and a lower row. The upper row of protection pads 50 are located above the upper row of cleaning pads 14, and the lower row of protection pads 50 are located below the lower row of cleaning pads 14. The protection pads 50 project outward from the mandrel 10 by a sufficient length so that if the mandrel 10 navigates a change in direction of the well tubing, the protection pads 50 are substantially the point of contact between the mandrel 10 and the well tubing. As the protection pads 50 are constructed from a softer material than the well tubing, the protection pads 50 are sacrificed in order to protect both the mandrel 10, the cleaning pads 14 and the well tubing. An individual protection pad 50 is shown in Fig. 6.

Fig. 8 shows a first example of pipeline cleaning apparatus, wherein a pig 55, 60 is run into a pipeline 53 that requires to be cleaned. Conventionally, the pig 55, 60 has a first module 55, and a second module 60 and is run into the pipeline 53 by means of a fluid pressure that is built up behind the second module 60.

Cleaning pads 14 can be mounted around the circumference of either the first module 55 or the second module 60. In Fig. 8 the cleaning pads 14 are mounted around the circumference of the second module 60. The cleaning pads 14 can be biased outwardly by a series of coil springs (not shown) as in the embodiment shown in Fig. 1.

Fig. 9 shows a second example of pipeline cleaning apparatus, wherein the cleaning pads 14 are mounted on a suitable body 62, which is connected to the second module 60 of the pig. Thus, the body 62 follows the pig down the pipeline 53 requiring to be cleaned.

Fig. 10 and Fig. 11 show a third example of pipeline cleaning apparatus, wherein the cleaning pads 14 are mounted on a body 65. One end of the cleaning pad 14 is held in place on the body 65 by two half shells 67, 69, which are welded together around the body 65. The other end of the cleaning pad 14 is held in place by a stabilizer sleeve 71, 73, each of which is threaded onto the body. When the stabilizer sleeves 71, 73 have been threaded onto the body 65 to the desired position, the stabilizer sleeves 71, 73 are locked in position by a locking nut 75 which engages a recess in the body 65, and hence the stabilizer sleeves 71, 73 are locked with respect to the body 65.

Modifications may be made to the aforegoing within the scope of the present invention.

Claims

1. Apparatus for cleaning the interior of a well tubing, comprising a body member for insertion into the tubing, and at least one cleaning pad mounted on the body member, the or each cleaning pad comprising a body having an inner face engaged with the body member and an outer face provided with protruding bristles.

2. Apparatus according to Claim 1, wherein a plurality of cleaning pads are circumferentially spaced around the body member.

3. Apparatus according to Claim 2, wherein there is an upper row of three cleaning pads centred at 1200 intervals, and a lower row of cleaning pads centred at 1200 intervals and circumferentially offset with respect to the upper row.

4. Apparatus according to any of the preceding claims, wherein the bristles are nylon bristles.

5. Apparatus according to any of Claims 1, 2 or 3, wherein the bristles are hardened metal wire bristles.

6. Apparatus according to any of the preceding Claims, wherein the cleaning pad body is constructed from a drillable material.

7. Apparatus according to Claim 6, wherein the cleaning pad body is constructed from a resin fibre compound.

8. Apparatus according to Claim 6, wherein the cleaning pad body is manufactured from a malleable metal.

9. Apparatus according to any of the preceding Claims, wherein the cleaning pad body is compressible.

10. Apparatus according to any of the preceding Claims, further comprising at least one protection pad mounted on the body member, the protection pad being manufactured from a softer material than the well tubing material.

11. Apparatus according to Claim 10, wherein a plurality of protection pads are circumferentially spaced around the body member.

12. Apparatus according to Claim 11, wherein there is an upper row of protection pads and a lower row of protection pads, where the upper row of protection pads are located above the upper row of cleaning pads and the lower row of protection pads are located below the lower row of cleaning pads.

13. Apparatus according to any of the preceding Claims, wherein a first end of the cleaning pad is mounted on the body member by a fixed collar, and a second end of the cleaning pad is mounted on the body member by a moveable sleeve.