GB2344336A

GB2344336A - Apparatus for the handling of materials includes a receptacle and vibratory conveyors

Info

Publication number: GB2344336A
Application number: GB9928625A
Authority: GB
Inventors: Kevin William Grant; Glynn Hollier
Original assignee: APOLLO SERVICES UK Ltd
Current assignee: APOLLO SERVICES UK Ltd
Priority date: 1998-12-04
Filing date: 1999-12-06
Publication date: 2000-06-07
Also published as: GB9826679D0; GB9928625D0

Abstract

Apparatus or method for handling materials comprises a receptacle 7 to receive the material having motion movement means 1 such that the material is moved towards a predetermined location 5. The motion movement may be linear positive movement and/or vibratory and can comprise a motor 1, such as a cylinder and piston arrangement, adapted to provide a vibratory action to the receptacle. The material may be cuttings 20 which have been separated from drilling fluid using separating shakers above the receptacle, the cuttings may fall under gravity from a cuttings shakers 15. The apparatus may have mounting means which allow it to replace, be moved within, or be attached to, a conventional cuttings ditch 25. The receptacle may be formed from a series of tubular sections forming a stepped trough conveyor. Containment means 5 may be provided at the predetermined location and may feature means to remove the material, such as suction means 6. The receptacle may be moved more rapidly in one direction than another, to aid movement of the material to the predetermined location.

Description

"Handlinq of Material" This invention relates to handling of material, especially particulate solids resulting from drilling operations, but could also relate to other materials such as concrete, copper, pecans, nuts, tobacco, wheat, walnut shells, wood chips, zinc, coffee beans, bentonite, cocoa powder, grain, gravel, cornseed, corncobs, oats, rice, ruben, sand, sludge, cotton seed, bark, barley, raw sugar, sulphur, asphalt, aluminium, and other materials used in other industries such as agricultural, chemical, food, medical and the like. A method of handling, and apparatus suitable for performing the method, are described hereinafter. The invention finds particular utility in the oil and gas industry for disposal of well or drill cuttings ("hereinafter cuttings").

Cuttings are typically pieces of rock which have been chipped, ground or scraped out of a formation by a drill bit. Various types of drill or cutting tool are in use for this purpose and the invention hereinafter described is not limited to use of any particular type.

Therefore, it will be understood that the invention relates to the after-treatment of the materials removed during the exploration for deposits, and winning of target materials from a geological formation. The invention will be described hereinafter with reference to current practice in the oil and gas industry on offshore drilling installations.

The drilling operation is conducted several hundred metres or more below the operation control point which means that performance of the drill bit is critical to the operation. The effectiveness of the drill bit during a drilling operation relies upon the continual removal of cuttings, otherwise the drill would rapidly foul up due to accumulation of cuttings. Therefore, the cuttings are normally removed by delivery of a drilling fluid (often referred to as"drilling mud") down to and around the drill bit and procedures for doing so by use of the drill string and annulus casing are established in the industry. Recovery of the drilling fluid with the entrained cuttings presents the need to separate the cuttings and recover the drilling fluid for recycling. It will be understood that the drilling fluid itself is a multi-function product with a variety of roles to play in the drilling operation.

Therefore, recovery of that in a relatively uncontaminated and re-usable form is highly desirable.

Accordingly, the cuttings are commonly separated from the drilling fluid by devices such as the shale shaker, which captures cuttings and large solids from the drilling fluid during circulation thereof. Basically, such a device may have a sloping close mesh screen over which fluid returning from the drill hole passes over.

The screen may be typically of from 120 X 120 down to 30 X 30 mesh and is vibrated to facilitate separation.

The solids captured on the screen travel down the sloping surface to be collected in a cuttings ditch located below the shale shaker. Other devices which have a role in solids separation from drilling fluids include cyclone separators and centrifuges.

The shaker ditch typically comprises a pair of planar ditch arms, which are located directly beneath the exit point for the cuttings from the shale shakers, where the planer shakers arms are arranged to slope towards a central point. Conventionally, it is known to locate an exit pipe at the central point such that the cuttings may pass downwardly through the exit pipe to be dumped into the sea water directly below the drilling rig. However, due to the impact on the environment, it may not be possible to dump the cuttings into the sea in this way, particularly if the drilling mud is not a water based drilling mud, but is for instance, an oil based drilling mud. Particularly in this situation, environmental concerns and Government Legislation require that the cuttings are not dumped below the offshore drilling installation, and require that the cuttings are collected within a collection tank which is located at the central point for further processing such that the cuttings can be transported back to an onshore cutting processing plant.

Therefore, it is known to provide a plug at the central point such that the exit tube is obturated, and to provide a collection point over the plug at the central point in order to collect the cuttings.

However, conventional shaker ditch arms are arranged such that when the cuttings land on the arms, it is often required to provide a means to encourage the cuttings to move toward the central point, otherwise the cuttings will simply accumulate on the arms.

Conventional methods to encourage movement of the cuttings on the shaker ditch arms include jetting sea water onto the drill cuttings whilst they are falling, and/or after they have fallen, onto the arms in order to encourage the cuttings to move toward the central point. However, this method has a disadvantage in that the sea water simply adds to the weight of the cuttings being collected in the collection tank, and means that less cuttings can be collected in each collection tank.

It is also known to provide screw conveyors arranged on the shaker ditch arms in order to move the cuttings towards the central point. However, this practice is considered to be relatively dangerous in that the screw conveyor presents a danger to personnel.

It is also known to provide a flexible pipe attached to a vacuum pump means, where the entrance to the flexible pipe is located just above the central point, so that an operator can move the flexible pipe up and down the shaker ditch arms. However, this conventional arrangement has the disadvantage that a person is constantly required to operate the flexible pipe so that the cuttings do not build up into a mound on the arms.

According to a first aspect of the present invention, there is provided an apparatus for handling material, the apparatus comprising a receptacle which is adapted to receive material (where the material is cuttings, preferably after the cuttings have been substantially separated from drilling fluid) wherein the receptacle is provided with a vibration means and/or a motion movement means (which may be a linear positive motion movement means) such that the received material is moved substantially toward a predetermined location.

According to a second aspect of the present invention there is provided a method of handling material, the method comprising providing a receptacle which is adapted to receive material (where the material is cuttings, preferably after the cuttings have been substantially separated from drilling fluid), and subjecting the receptacle to vibration and/or a motion movement (which may be a linear positive motion movement), such that the received material is moved substantially toward a predetermined location.

Typically, the material is cuttings.

Typically, the receptacle is located in a suitable location such that the material is delivered onto the receptacle following a separation process, and where the material is cuttings, the cuttings are substantially removed from drilling fluid.

Typically, the receptacle is located in a suitable location below a drilling fluid and cuttings separation system, and preferably, the receptacle is suitably located such that the cuttings fall under gravity onto the receptacle.

Preferably, the receptacle is located in a suitable location below a cuttings shaker.

Typically, the receptacle is adapted to provide a surface onto which the material is delivered, and preferably, the surface is at an angle to the horizontal plane.

Typically, the vibration means is coupled to the receptacle and is preferably arranged to provide vibration to the receptacle along the longitudinal axis of the surface.

The receptacle may be mounted on a conventional cuttings ditch, or alternatively, the receptacle may replace a conventional cuttings ditch. Where the receptacle is mounted on a conventional cuttings ditch, the receptacle is preferably provided with a mounting means to mount the receptacle on the conventional cuttings ditch, and the mounting means typically permits the receptacle to move with respect to the conventional cuttings ditch.

Preferably, the surface has a concave cross-section to facilitate reception of the material. Preferably, the surface is provided with at least one formation which may further aid movement of the material in the direction of movement toward the predetermined location, and preferably deters movement of the material in the direction of movement away from the predetermined location.

Typically, a containment means is provided, and is preferably located substantially at the predetermined location, and preferably, the containment means is adapted to accommodate the material, whether for subsequent removal of the material from the containment means or otherwise. Preferably, the containment means is provided with a removal means which is adapted to remove the material from the containment means.

Typically, the removal means is a suction means.

In a particular embodiment of the invention, the receptacle is preferably a substantially semi-circular tubular, and may comprise a plurality of sections which are coupled together to form a stepped tubular.

Preferably, the vibration means and/or the motion movement means (which may be a linear positive motion movement means) is arranged to provide a faster movement to the receptacle in one direction than the other, and more preferably, the vibration means and/or the motion movement means (which may be a linear positive motion movement means) is arranged to provide a faster movement to the receptacle in the direction of movement of the receptacle away from the predetermined location.

Preferably, and if required or desired, an obturation means is provided to obturate a cuttings exit tubular which may be located at the predetermined location.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a schematic side view of an apparatus in accordance with the present invention; and Fig. 2 is a flow diagram of a cuttings processing system suitable for incorporating the apparatus of Fig. 1.

A floor 10 of a drilling rig is shown in Fig. 1 as supporting four rig shale shakers 15 which are well known in the art. The rig shakers 15 are aligned and arranged such that the output of the rig shakers 15, that is the cuttings 20 and relatively small remaining proportion of drilling fluid, exit the rig shakers 15 and fall by gravity through an aperture in the floor 10 in the direction of arrows 20.

Conventionally, the cuttings 20 would fall onto a cuttings ditch 25 which basically consists of two angled metal sheets which are arranged at either side of a central point, where the metal sheets are angled upward, away from the central point, to the horizontal plane. Conventionally, the cuttings 20 would fall onto the cuttings ditch 25, and would either have to be moved to the central point by either a screw conveyor or by washing the cuttings 20 down with sea water.

In accordance with the present invention, there is provided a step tube support frame 3 which carries three nylon rollers 4 which mount the support frame 3 on the cuttings ditch 25, and the rollers 4 also permit the support frame 3 to move relative to the cuttings ditch 25.

A plurality of semi-circular tube sections 7 are mounted on the upper side of the support frame 3, where the tube section 7 are arranged in a cascading manner, such that an upper tube 7 has its lower end overlapping the upper end of the next lower tube 7. Thus, the combination of the tube sections 7 provide a stepped profile, the reason for which will be detailed subsequently.

A pneumatic cylinder 1 is coupled to the upper end of the support frame 3, where the cylinder 1 is mounted to the cuttings ditch 25 by means of a cylinder support frame 2.

Thus, in the apparatus shown in Fig. 1, there are two separate apparatus in accordance with the present invention, with one apparatus being provided on either side of a central point.

A cuttings and fluid collection tank 5 is located at a central point within the cuttings ditch 25, where a plug 30 is provided to obturate a rig overboard line 35 which can be used (in the absence of the plug 30) to allow cuttings to fall therethrough for dumping below the rig.

In use of the apparatus, the cuttings 20 follow the path shown by the arrows 20 after having been output, together with a residual amount of drilling fluid from the rig shakers 15. The cuttings 20 fall onto the tube section 7, and are thus received thereby. The cylinders 1 are operated such that they preferably provide a slower forward action (that is the direction of movement of the tube sections 7 toward the collection tank 5) and a more rapid return (that is the direction of movement of the tube sections 7 away from the collection tank 5). Thus, the vibratory action of the cylinders 1 encourages movement of the cuttings 20 in the direction toward the collection tank 5. In addition, the stepped configuration of the tube section 7 encourages movement of the cuttings 20 in the direction toward the collection tank 5 since the steps between each tube section 7 effectively provide a pushing action upon the cuttings 20. In addition, the stepped arrangement provides a deterrent to movement of the cuttings 20 in the direction away from the collection tank 5.

Thus, with the preferred combination of the stepped configuration, and the off-balanced vibration action of the cylinders 1 provide for a positive mechanical push of cuttings toward the collection tank 5.

It should be noted that the vibratory action provided by the cylinders 1 need not be exclusively linear along the longitudinal axis of the tube sections 7. For instance, the vibratory action could be provided in a direction perpendicular to the longitudinal axis of the tube sections, or could be in a combination of longitudinal and perpendicular such as would be provided if the cylinders 1 produced an elliptical movement output.

Once the cuttings 20 drop into the collection tank 5, a six inch diameter vacuum suction line 40 transfers the cuttings 20 out of the collection tank 5 and into a vacuum hopper 50, which can be viewed in Fig. 2.

As shown in Fig. 2, the cuttings are introduced through a centrifuge 45 as soon as they have come out of the wellbore, where the centrifuge 45 is a primary separation equipment. After being centrifuged, the cuttings 20 are then introduced to the secondary separating equipment, this being the rig shakers 15.

It is intended that the support frame 3, and the tubes 7 will be arranged to be mounted on the cuttings ditch 25 shown in Fig. 2, although they are omitted for clarity purposes. The cuttings 20 are then removed from the collection tank 5 by the vacuum suction line 40 which is coupled to the vacuum dump hopper 50. The cuttings 20 are then pumped by a suitable pumping means, for example as described in our British Patent Application No 9812544.6, into containers 55 for eventual shipment to shore base for disposal.

Thus, the embodiment obviates the requirement to wash the cuttings 20 located in a conventional cuttings ditch 25 with sea water spray which merely adds to the bulk to be removed.

Therefore, the embodiment provides an economic solution in providing a positive means to remove the cuttings 20 into the ditch centre for a proper vacuum pick-up point, without the requirement for expensive ditch modifications.

Modifications and improvement can be made to the embodiment without departing from the scope of the invention. For instance, the tube 7 and collection tube 5 may also be utilised for cuttings transfer into cuttings re-injection equipment for applications where injection into predetermined geological formations are the preferred method of disposal rather than the abovementioned disposal back to shore. Furthermore, although the embodiment relates to cuttings, the skilled person will understand that the invention could be used for other materials such as concrete, copper, pecans, nuts, tobacco, wheat, walnut shells, wood chips, zinc, coffee beans, bentonite, cocoa powder, grain, gravel, cornseed, corncobs, oats, rice, ruben, sand, sludge, cotton seed, bark barley, raw sugar, sulphur, asphalt, aluminium, and other materials used in other industries such as agricultural, chemical, food, medical and the like.

Claims

CLAIMS 1. An apparatus for handling material, the apparatus comprising a receptacle which is adapted to receive material, wherein the receptacle is provided with a motion movement means such that the received material is moved substantially toward a predetermined location.
2. An apparatus according to claim 1, wherein the motion movement means is a linear positive motion movement means.
3. An apparatus according to either of claims 1 or 2, wherein the motion movement means is a vibration means.
4. An apparatus according to any preceding claim, wherein the material is cuttings.
5. An apparatus according to claim 4, wherein the receptacle is adapted to receive the cuttings after the cuttings have been substantially separated from drilling fluid.
6. Apparatus according to any preceding claim, wherein the receptacle is located in a suitable location such that the material is delivered onto the receptacle following a separation process.
7. Apparatus according to claim 6, wherein where the material is cuttings, the separation process involves the cuttings being substantially removed from drilling fluid.
8. Apparatus according to claim 4, or to any of claims 5 to 7 when dependent upon claim 4, wherein the receptacle is located in a suitable location below a drilling fluid and cuttings separation system.
9. Apparatus according to claim 8, wherein the receptacle is suitably located such that the cuttings fall under gravity onto the receptacle.
10. Apparatus according to claim 9, wherein the receptacle is located in a suitable location below a cuttings shaker.
11. Apparatus according to any preceding claim, wherein the receptacle is adapted to provide a surface onto which the material is delivered.
12. Apparatus according to claim 11, wherein the surface is at an angle to the horizontal plane.
13. Apparatus according to any preceding claim, wherein the motion movement means is coupled to the receptacle.
14. Apparatus according to claim 11, or to any of claims 12 or 13 when dependent upon claim 11, wherein the motion movement means is arranged to provide motion to the receptacle along the longitudinal axis of the surface.
15. Apparatus according to any preceding claim, wherein the receptacle is mounted on a conventional cuttings ditch.
16. Apparatus according to any of claims 1 to 14, wherein the receptacle replaces a conventional cuttings ditch.
17. Apparatus according to claim 15, wherein the receptacle is provided with a mounting means to mount the receptacle on the conventional cuttings ditch.
18. Apparatus according to claim 17, wherein the mounting means permits the receptacle to move with respect to the conventional cuttings ditch.
19. Apparatus according to claim 11, or to any of claims 12 to 18 when dependent on claim 11, wherein the surface has a concave cross-section.
20. Apparatus according to claim 11, or to any of claims 12 to 19 when dependent on claim 11, wherein the surface is provided with at least one formation which aids movement of the material in the direction of movement toward the predetermined location.
21. Apparatus according to claim 11, or to any of claims 12 to 20 when dependent on claim 11, wherein the surface is provided with at least one formation which deters movement of the material in the direction of movement away from the predetermined location.
22. Apparatus according to any preceding claim, wherein a containment means is provided, and is located substantially at the predetermined location.
23. Apparatus according to claim 22, wherein the containment means is adapted to accommodate the material, whether for subsequent removal of the material from the containment means or otherwise.
24. Apparatus according to either of claims 22 or 23, wherein the containment means is provided with a removal means which is adapted to remove the material from the containment means.
25. Apparatus according to claim 24, wherein the removal means is a suction means.
26. Apparatus according to any preceding claim, wherein the receptacle is a substantially semi-circular tubular.
27. Apparatus according to any preceding claim, wherein the receptacle comprises a plurality of sections which are coupled together to form a stepped tubular.
28. Apparatus according to any preceding claim, wherein the motion movement means is arranged to provide a faster movement to the receptacle in one direction than the other.
29. Apparatus according to claim 28, wherein the motion movement means is arranged to provide a faster movement to the receptacle in the direction of movement of the receptacle away from the predetermined location.
30. Apparatus according to any preceding claim, wherein an obturation means is provided to obturate a cuttings exit tubular which is located at the predetermined location.
31. Apparatus according to any preceding claim, wherein the motion movement means comprises a motor adapted to provide a vibratory action to the receptacle.
32. Apparatus according to claim 31, wherein the motor is a cylinder and piston arrangement.
33. A method of handling material, the method comprising providing a receptacle which is adapted to receive material and subjecting the receptacle to movement, such that the received material is moved substantially toward a predetermined location.
34. An apparatus for handling material as hereinbefore described with reference to the accompanying drawings.
35. A method of handling material as hereinbefore described with reference to the accompanying drawings.