WO2000026497A1

WO2000026497A1 - Roller reamer

Info

Publication number: WO2000026497A1
Application number: PCT/GB1999/003573
Authority: WO
Inventors: Niels Christian Olaf Friis; Carl Shears
Original assignee: International Petroleum Equipment Limited
Priority date: 1998-11-02
Filing date: 1999-11-02
Publication date: 2000-05-11
Also published as: AU1053600A; GB9823798D0

Abstract

A roller reamer has a body with a plurality of circumferentially spaced recesses extending along a portion of its length. Each recess has a central section for receiving a rotary roller and end section for receiving a retaining means for retaining the rotary roller, in a manner which enables a simple and efficient release mechanism to allow for maintenance of the roller assemblies.

Description

ROLLER REAMER

This invention relates to roller reamer for use in compacting soil forming the walls of a borehole.

As boreholes are formed using an appropriate drilling bit there is a need to stabilise the soil which forms the wall of the borehole being formed. Unless this action is taken there is an increased probability of the walls of the borehole collapsing in on itself.

This action is generally carried out using a reamer which follows on in the hole being drilled. Typically borehole reamers have a generally cylindrical body which has a number of circumferentially spaced recesses in which are located rotatable reamer rollers. The rollers are rotable on a spindle which is retained by appropriate fixing means at either end.

By the very nature of the downhole environment and the operation of the reamers they can easily become jammed with soil and also commonly become damaged or worn in use. There is therefore a need for easy and quick maintenance of such assemblies. Previous arrangements are deficient in this area as removal of the reamer roller requires removal of several bolts at either end of the reamer. These may be difficult to remove as a result of the effects of the problems noted above.

It is therefore an object of the present invention to provide a roller reamer having a means of attachment to a support structure which obviates or at least mitigates the aforementioned disadvantages.

According to the present invention there is provided a roller reamer comprising a reamer body having a plurality of circumferentially spaced recesses extending along a portion of the length of the body, each recess having a central section for receiving a rotary roller and end sections for receiving rotary roller retaining means, characterised in that one of said end sections of said each recess extends beyond the section for receiving the rotary roller retaining means and is provided with a selectively operable means for restraining the roller retaining means against movement along the recess.

Preferably said selectively operable means for restraining the roller retaining means comprises a retaining plate provided with means for releasably securing it to the reamer body.

Said means for releasably securing the retaining plate to the reamer body are preferably threaded fasteners.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a side elevation of a roller reamer in accordance with the present invention;

Figure 2 is a partial cross-sectional side elevation of the reamer of Figure 1 ; and

Figure 3 is a cross sectional end elevation of the reamer of Figure 1.

Referring to the drawings a roller reamer in accordance with the present invention comprises a reamer body 1 having a central throughbore 2 and having a middle section 3. The reamer body 1 is generally cylindrical and the middle section 3 has, equally spaced around its external circumference, three roller locators 4 each provided with a recess shown generally at 5. The recesses 5 each have a middle section 6 shaped to allow free rotation of a roller 7 and end sections 8, 9 for receiving roller retainers 10 and 11. The roller 7 has a spindle 12 which extends into the end sections 8 and 9 where it is held by the retainers 10 and 11.

The overall length of the recess 5 is greater than the roller 7 and retainer 10 and 11 assembly which leaves a short section 13 configured to receive a retaining plate 14. The retaining plate 14 fixes to the reamer body 1 by virtue of fixing bolts 15 and is sized and configured such that it retains the roller assembly snugly in the recess 5 positioned against the opposite end of the recess 5.

In use the reamer is inserted downhole following on from the drilling bit, the rollers 7 are free to rotate on their spindles 12 and function to compact the soil forming the walls of the borehole in a conventional fashion.

In time there may be a need to remove the reamer from the borehole for maintenance of the roller assemblies. Obviously this should involve a minimum of non productive time. Therefore in the event that a roller assembly has to be removed it is a quick and simple procedure to loosen the fixing bolts 15 and remove the retaining plate 1 so that the roller assembly, now free to move along the recess 5, can be simply extracted from the recess 5 and replaced with another assembly as required which once in position is retained by the retaining plate 14. The reamer assembly is thus quickly ready for re-use.

The method of retention of the roller assembly thus not only provides for easy and simple release but is also less likely to be adversely affected by soil jamming or wear and tear in use. Maintenance costs can therefore be less then those incurred with the conventional prior art assemblies. Modifications and improvements may be incorporated without departing from the scope of the invention herein intended.

Claims

1. A roller reamer comprising a reamer body having a plurality of circumferentially spaced recesses extending along a portion of the length of the body, each recess having a central section for receiving a rotary roller and end sections for receiving rotary roller retaining means, characterised in that one of said end sections of said each recess extends beyond the section for receiving the rotary roller retaining means and is provided with a selectively operable means for restraining the roller retaining means against movement along the recess.

2. A roller reamer as claimed in Claim 1 wherein said selectively operable means for restraining the roller retaining means comprises a retaining plate provided with means for releasably securing it to the reamer body.

3. A roller reamer as claimed in Claim 2, wherein said means for releasably securing the retaining plate to the reamer body are threaded fasteners.