GB2232451A

GB2232451A - Rotary gland for feeding fluid and cable to a drill pipe

Info

Publication number: GB2232451A
Application number: GB8912020A
Authority: GB
Inventors: Kevin John Burke; Clive Robert Bavington; Roger Michael Nursaw
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1989-05-25
Filing date: 1989-05-25
Publication date: 1990-12-12
Also published as: GB8912020D0

Abstract

A water gland includes a hollow barrel member (1) having at least one side aperture (11, 12) in flow communication with an inlet (10) formed in a housing (6) which is releasably clamped to the member (1). A releasable split sleeve member (17) is provided for engagement with one end of the barrel member (1) and a restrictor (5, 15, 16) is provided for engagement at the other end of the barrel member (1). <IMAGE>

Description

WATER GLAND This invention relates to a Water Gland and is particularly concerned with a Water Gland for use in connection with drill pipes in an inseam borehole drilling device which uses a probe having a trailing cable. Such a device is described in our t/2021,6, copending application (,ref 4956) and as is stated in that application the invention is not restricted to inseam boreholes but can be applied to boreholes which cut through strata either vertically or at an angle.

When drilling boreholes in a strata a drill operates at the end of a borehole to cut away from the face being drilled and the cutting debris has to be removed from the face. This is usually done by using a fluid such as water to create a flood which washes the debris back down the borehole which has been drilled. The water can also be used to drive the motor operating the drill and to advance it.

In the drilling system, which is described in the said co-pending patent application, drill rods are fed consecutively from a magazine into a borehole as the length of the borehole increases and a probe is kept constantly down the borehole and is advanced with the drilling head. The probe has a wire which extends back through the borehole to instrumentation remote from the face being drilled. Normally the fluid to the borehole can be supplied through a hose which is coupled to the end of the drill pipes. However, problems arise with a probe which is constantly down the borehole, since the trailing cable does not allow the normal type of coupling to be made to the drill rods.It is thus necessary to produce a special form of rotary coupling or gland and it is an object of the present invention to provide a water gland which not only allows fluid to be inserted into the borehole, when the rods are rotating or stationary, but also, allows for the cable to a probe to be taken out through the gland without any substantial loss of fluid.

According to the present invention a water gland comprises barrel member having a side aperture adapted to receive a fluid inlet, release means for enabling the fluid inlet to be removed from the barrel, a releasable split sleeve member at one end of the barrel and restrictor means coupled to the other end of the barrel.

The barrel preferably has a groove and aperture slots in the area of connection of the fluid inlet to allow fluid to pass from the fluid inlet to the centre of the barrel. Preferably sealing means are provided between the fluid inlet and the outer surface of the barrel.

Conveniently the barrel has a flange on its front end and a split sleeve having a corresponding internal recess to receive the flange fitted about the front end. A split sleeve may be adapted to rotate on the barrel and may be provided with a threaded orother coupling means on its outer surface to connect it to the end of a drill rod.

Preferably the restrictor means includes a fixture having a central restricted passage with a low co-efficient of friction material in the restricted passage. The restrictor means may be screwed into the inside of the barrel.

The release means may be a quick release means such as a screwed hinged rod which can be readily removed to release the fluid inlet.

In order that the invention may be readily understood, one example of a gland, in accordance therewith will now be described with reference to the three figures of the accompanying drawings.

In the drawings Figure 1 shows a partial sectional view through the gland on the lines I-I of Figure 2. Figure 2 itself shows an end view of the gland and Figure 3 shows a sectional view of the gland on the lines III-III of Figure 1.

Referring now to the drawings the gland comprises a central barrel (1) having a through aperture (2) which has a flange (3) at its forward end, and a threaded internal portion (4) at its other end, into which a restrictor means (5) is inserted. A two part housing (6) surrounds the centre of the barrel (1) and two parts of the housing (6) are secured together by pivoted bolts (7) which have releasable nuts (8) to enable the housing (6) to be removed.

As can be seen in Figure 3 the bolts (7) are pivotally attached at (9) to the upper part of the housing.

The upper part of the housing has secured to it an inlet fitting (10) through which water is fed. The position of the fitting is such that it enables water to be fed into an anular recess (11) on the outer surface of the barrel (1) and water can pass from this recess through slots (12) in the wall of the barrel to the centre aperture (2).

The outer surface of the barrel is supplied with sealing means (14) to ensure no leakage of water from the gland.

The restrictor means (5) which is screwed into the end of the barrel (2) has a restricted aperture (15) through which a cable can pass and part of this aperture is lined at (16) with a low co-efficient of friction material which closely fits about a wire to be passed through the gland and to ensure that there is a minimum of leakage.

The sealing is achieved by a rubber gland which fits over the cable and inside a threaded recess. The rubber gland is compressed by a centrally operated oil screwed plug, thus improving seal around the cable.

A two part split sleeve (17) is fitted at the front end of the barrel with a recess in the internal surface of the sleeve locating about the flange (3). The sleeve is able to rotate on the barrel since it fits into a groove (18) on the outer surface and this enables a threaded tapered front end portion (19) to be screwed into the end of a drill rod (20) to secure the gland to the end of the drill rod.

In operation the threaded end (19) of the split sleeve is screwed into the end of the drill rod (20) projecting from the seam being drilled and a cable (not shown) extends through the drill rod (20), the barrel (1), and the restrictor means (5) to a winch and indicating equipment. The inlet fitting (10) is coupled up to a drilling fluid supply and the fluid is fed into the circular aperture (11) through the slots (12) into the central aperture (2) of the barrel and thence into the body of the drill pipe.

Due to the effect of the sealing gland there is very little leakage of drilling fluid back along the cable.

When a new drill rod is to be fitted to the drill rod (20) and the probe advanced, a drill rod is taken from a magazine such #9/t021. 6 as is described in our co-pending patent application tref 4956) which has been pre-threaded with the cable and is screwed into the end of drill rod (20) after the gland has been removed.

However, to position the new length of drill rod, it is necessary since the cable is threaded through it to pass it over the gland and the water in the pipe (10) would normally preclude this. However, by operating the release mechanism constituted by the bolts (7) and (8), the water inlet can be removed swiftly from the gland and the split sleeve (17) is unscrewed from the end of the pipe (20). The new rod is now able to pass freely over the barrel and the sleeve (17) and to be screwed into the rod (20) and the threaded end (19) of the sleeve (17) can then be connected to the end of the newly positioned drill pipe. Since this drill pipe was already threaded with the cable there is no need for the probe to be removed and the pipe will move over the length of the cable as it passes over the barrel and the sleeve (17) so as to leave the cable in position. When the new length of drill pipe has be connected the water inlet pipe can be resecured around the barrel and water can be fed back to the drill pipes.

The seal (14) and the bearing material (18) provide a means of rotating the barrel inside the split sleeve without loss of drilling fluid.

The present invention enables fresh sections of drill pipe to be readily connected without the need for any major disruption in the drilling process or the withdrawal of a probe and its trailing cable from the borehole and thus assists in speeding up the whole of the drilling and measuring operation.

Claims

1. A water gland comprising a barrel member having a side aperture adapted to receive a fluid inlet, release means for enabling the fluid inlet to be removed from the barrel member, a releasable split sleeve member at one end of the barrel member, and restrictor means coupled to the other end of the barrel member.

2. A water gland according to claim 1 in which the barrel member has a groove and aperture slots in the area of connection of the fluid inlet to allow fluid to pass from the fluid inlet to the centre of the barrel member.

3. A water gland according to claim 1 or claim 2 in which sealing means are provided between the fluid inlet and the outer surface of the barrel member.

4. A water gland according to any one of the preceding claims in which the barrel member has a flange on its front end, the releasable split sleeve having a corresponding internal recess to receive the flange.

5. A water gland according to claim 4 in which the releasable split sleeve is adapted to rotate on the barrel member.

6. A water gland according to claim 4 or 5 in which the releasable split sleeve is provided with a coupling means for connection to an end of a drill rod.

7. A water gland according to any one of the preceding claims in which the restrictor means includes a fixture having a restricted passage provided with a lining of a low coefficient of friction material.

8. A water gland according to any one of the preceding claims in which the restrictor means is screwed into the inside of the barrel member.

9. A water gland according to any one of the preceding claims in which the fluid inlet is formed in a two part housing surrounding a central part of the barrel member.

10. A water gland according to claim 9 in which the release means are constituted by pivoted bolts adapted to clamp together the two parts of the housing to the barrel member.

11. A water gland substantially as hereinbefore described with reference to the accompanying drawings.