GB2393948A

GB2393948A - Removing drilling wastes

Info

Publication number: GB2393948A
Application number: GB0301548A
Authority: GB
Inventors: Arne Incoronato
Original assignee: ONSITE TREAT TECHNOLOGIES AS
Current assignee: ONSITE TREAT TECHNOLOGIES AS
Priority date: 2002-10-11
Filing date: 2003-01-23
Publication date: 2004-04-14
Anticipated expiration: 2023-01-23
Also published as: NO317712B1; NO20024912D0; GB2393948B; GB0301548D0

Abstract

The device regards a method and a device for implementing the method of filling and removing transport containers (19) for mass such as e.g. coarse and sticky drilling waste, by one or more transport containers (19) being placed within reach of an arm (10) movable in the horizontal and vertical planes, which arm is connected to an output device (1), and where the movable arm (10) and the output device (1) are connected to a vacuum piping system (5, 6) that continuously feeds mass to said output device (1), which conveys the mass in an essentially continuous manner to one or more transport containers (19) in an atmospheric environment. Preferably, the output device (1), has an outlet valve (30) with a cylindrical rotor (34, Fig 46) with end seals.

Description

::: e À METHOD OF CONTINUOUS PROPULSION AND FLEXIBLE DISPOSAL OF

MASS, AND A DEVICE FOR IMPLEMENTATION OF THE METHOD

The invention regards a method and a device designed to transport mass such as coarse and sticky drilling waste in a 5 piping system by means of an internal air flow, preferably generated by a vacuum suction device, and transferral of said coarse and sticky mass from the piping system to an atmospheric environment by means of an output valve.

The object of the invention is to provide a method and a lo device that, by means of a piping system incorporating an internal air flow preferably generated by a vacuum suction device, will work to provide a steady transport of mass such as drilling waste away from a given area, and dispose of said mass in an essentially continuous manner into an atmospheric 5 environment, preferably in a collecting receptacle, in a safe, efficient and environmentally friendly manner, while providing a device that is space-saving and flexible with regard to the point of disposal, both in the horizontal and vertical planes.

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À When drilling for oil and gas offshore and onshore, a large amount of drilling waste is produced, which must be stored temporarily on the drilling rig or the drilling installation (in the following denoted the drilling facility).

s As fragments of the borehole, so-called drill cuttings, come up from the borehole, the mass from the borehole is screened to separate part of the liquid and the fine mass from the coarse mass. The liquid and the fine mass are passed back to the borehole and used in the further drilling operations, 10 while the coarse mass must be removed. One of the methods used for transporting the coarse mass away from the screening devices involves generating a strong air flow in a piping system by connecting a vacuum suction device to the piping system in which the mass is being transported. One of the IS great challenges of using such a vacuum system for transporting mass is to convey the mass to an atmospheric environment while maintaining the air flow in the piping system. A known solution for conveying drilling waste from a vacuum 20 system to an atmospheric environment involves connecting said vacuum piping system to a silo-like, sealed vessel, which in technical terminology is called a loading tower. Such loading towers have a large internal cross sectional area in the direction of the air flow in the piping system, relative to 25 the cross sectional area of the vacuum piping system that feeds the drilling waste into said loading tower. This difference in area causes the velocity of the air and drilling waste to be reduced as the mixture enters the loading tower from the piping system. As a result of this, so drilling waste is deposited in the loading tower. When the

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À loading tower is filled with a predetermined amount of drilling waste, it must be emptied. This is normally done through an automatic valve device in the bottom section of the loading tower opening at a preset weight. From said 5 automatic valve device, the drilling waste passes into so-

called big bags or transport containers that are placed underneath said valve device.

A significant part of the process of removing the full containers and placing the empty containers underneath the lo loading tower consists of manual operations in which several persons must take part, and this in a work environment where the accident risk is very high and where there have been fatal accidents.

During normal offshore operations, approximately 20 tons of! 15 drilling waste is produced every hour. A normal loading tower with a height of 7 metres has a capacity of approximately 5 tons of drilling waste, making it necessary to empty the loading tower approximately 4 times an hour.

During the emptying of the loading tower, the tower must 20 either be isolated from the vacuum system or the transport of drilling waste from the screening plant must be stopped while the emptying takes place, which leads to an interruption in the drilling operation. In order to avoid such shutdown of the drilling operation, two loading towers are normally Is installed, which towers receive the flow of air and drilling waste from the piping system in turns, ensuring that one of the loading towers is connected to the flow of air and drilling waste, thereby receiving drilling waste, while the other is isolated from the flow of air and drilling waste

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À À while being emptied of drilling waste. An arrangement incorporating two loading towers occupies a relatively substantial part of the often limited area available on a drilling facility. An arrangement of loading towers such as s described here is a stationary plant, which is not flexible with respect to the positioning of the big bag or transport container to be filled with drilling waste, which normally means that the individual big bags or transport containers must be moved several times in the course of the processes lO involved in the storage of empty big bags, the filling of these and the storage of the full big bags or transport containers. The object of the invention is to remedy the disadvantages of prior art, firstly by presenting a method of continuous

15 conveyance of drilling waste, the disposal point for which is relatively flexible, and secondly by providing a device for carrying out this method.

According to the invention, the first object is realised by proceeding in accordance with the specification below and the

so method given in the characterizing part of Claim 1. The

second object is achieved by means of a device, the favourable constructional features of which are described below and given in the characterizing part of the independent Claim 2.

25 The method for a preferably flexible output device from a vacuum conveying system consists in integrating a piping system in which drilling waste is being conveyed, and which is connected to a vacuum suction apparatus in a known manner, with a relatively movable arm that is attached to the

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drilling facility, preferably in a rotatable manner w.r.t.

the horizontal plane of the operating position, either directly or via an essentially vertical column structure arranged between the drilling facility and said, preferably 5 rotatable, movable arm.

The piping system may consist of rigid pipes, flexible hoses or a combination of these.

The other end point of the preferably movable arm is equipped with an output device consisting essentially of a receptacle lo under which is permanently mounted an air/vacuum tight output valve that causes the vacuum flow in the piping system to be maintained, even during the mass output process.

The preferably movable arm of a type that is known per se is equipped with at least one, preferably two or more joints 15 that may be rotated about the horizontal axis, which joints are located between the attachment point or end point of the arm where the output device is positioned, and in a manner such that the arm with the at least one joint makes it possible to vary the distance, in the operating position, so between the output device and said connection point for the arm on the drilling facility, both in the horizontal and vertical planes. Advantageously, the end portion of the arm can move in a telescoping manner. This scope of movement of said output device entails great logistic advantages, as 25 several big bags or transport containers may be placed within the reach of the output device and be filled and stored prior to being removed, without having to be moved around the deck of the drilling facility. In addition, removal of full big bags or transport containers and insertion of empty ones can

l l À be carried out while other transport containers are being filled. By using further known techniques for providing remote control of the preferably movable arm and the output rate of 5 the output device, a significant improvement can be achieved both in terms of personal safety and in the efficiency of the handling of big bags or transport containers.

In order to achieve continuous disposal of mass from the output device arranged on the preferably movable arm, the air o and mass flow in the piping system conveying the drilling waste up to the output valve must be maintained. Therefore, the output valve must be of a type that will tolerate the strain caused by the coarse and sticky drilling waste, while at the same time preventing air from escaping from or 15 entering into the air flow in the closed system. No output valves suitable for said purpose are known.

The second object of the invention has been to provide a device consisting of an output device that is suitable for conveying mass from a closed piping system through which so coarse and sticky drilling mud is moved by means of a powerful flow of air generated by e.g. a vacuum suction device connected to the piping system, to an atmospheric environment outside the piping system, while at the same time maintaining most of the air flow in the piping system. The 25 object is achieved by connecting a vacuum piping system to an output device constituted by a receptacle under which there is a permanently mounted output valve. Said vacuum piping system is connected to the receptacle by an inlet pipe and an outlet pipe, preferably in the upper horizontal portion of

. l l À the receptacle in the operating position. The primary function of the receptacle is to provide, in a known manner, an increase in volume relative to the piping system, thus to achieve a reduction in the velocity of the flow of air and 5 particles as the flow of air and particles enters the receptacle. This reduction in velocity results in the particles in the air flow falling towards the bottom section of said receptacle, while the air flows out of the receptacle and into the piping system through the outlet pipe in said lo upper end portion of the receptacle.

In order to achieve a further reduction of the velocity of the air flow in the receptacle relative to the air flow in the piping system out of said receptacle, the dimensions of the piping system that in operation leads the flow of air and particles into the receptacle, are smaller than those of the piping system that leads the air flow out of the receptacle.

The mass deposited in the bottom section of the receptacle falls out through an opening in said bottom section and into an output valve that is permanently mounted to the lower so portion of the receptacle, preferably by means of a flange connection. The output valve is made up of a cylinder element where the longitudinal axis of the cylinder is essentially horizontal.

A shaft is arranged to coincide with the longitudinal axis of Is the cylinder element, from which shaft preferably three or more fixed rigid plate elements project to the cylinder wall and the end faces of the cylinder. Said preferably three or more rigid plate elements divide the interior space of the

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cylinder into equal chambers essentially shaped as sectors of a cylinder.

Said shaft is supported in a manner that is known per se, at the centre of two disc-shaped end plates mounted on the end 5 faces of said cylinder by means of preferably four tension bolts that are passed on the outside of the cylinder element of the output device and through openings in said end plates, where nuts are placed. The shaft is coupled to a drive source such as a hydraulic or electric motor in a known manner, and lo the shaft with said preferably three or more plate elements rotates inside the cylinder element when driving power is applied to the shaft.

Two openings are formed in the, in the operating position, upper and lower portions of the cylinder element, whereupon 15 piping connections are rigidly mounted to the outside of the cylinder element, projecting essentially at right angles and vertically out from the surface of the cylinder element.

Advantageously, flanges may be fixed to said piping connections, where the flange for the upper piping connection so can be coupled to the flange on the underside of the receptacle. In order to achieve an essentially airtight connection between said rigid plate elements and the internal surfaces of the cylinder, a flexible replaceable packing material is 25 provided in a recess in the edge faces of the rigid plate elements, which packing material consists of e.g. aramide fibres that in an operating situation are in contact with said internal surfaces of the cylinder.

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As mentioned previously, drilling waste is a sticky material.

In order to be able to remove any so-called ibridging'' of mass in the lower portion of the receptacle of the output device, just above the three or more rigid plate elements of 5 the output valve, the receptacle may be provided with one or more nozzles to which pressurized fluid may be connected. The at least one optional nozzle is positioned in the lower portion of the receptacle of the output device.

There may also be one or more nozzles in one or both of the lo end faces of the output valve, the purpose of which nozzle(s) is dual; to supply pressurised fluid for cleaning any deposits out of the chambers of the output valve, and to possibly admit oil or other chemicals or substances suitable for lubricating the packing material effecting a seal between 15 the three or more rigid plate elements that are in contact with the internal surfaces of the cylinder.

In order to achieve the intended separation of solids and air in the receptacle of the output device, it is desirable but not necessary to maintain a layer of mass in the lower so portion of the receptacle, which helps isolate the individual chambers from the air flow in the receptacle, so that no air is removed from or added to the closed system via the spaces in the individual chambers. Experiments also show that packing wear is reduced when these are kept isolated from the 25 air in the receptacle.

In order for the particles to be able to settle in the receptacle, it is essential that they have a sufficient "drop". If the required drop is not present, the particles will follow the flow of air out of the receptacle. It is

l therefore crucial to the achievement of the intended particle separation that the receptacle of the output device not be filled excessively.

In order to enable the level of mass in the receptacle of the 5 output device to be optimised, a load cell may be provided in connection with this, which in a known manner controls the rotational speed of the output valve, and which also stops the flow of air and particles in the closed piping system if the level in the receptacle exceeds a predetermined level.

o The load cell control of the rotational speed of the output valve may be overridden by the operator controlling the rotational speed by remote control.

The following describes a non-limiting example of a preferred embodiment illustrated in the accompanying drawings, in 15 which: Figure 1 shows a side elevation of a device in accordance with the invention, where an output device is permanently mounted to the end of a movable arm; Figure 2 shows a cross section A-A of the arm in figure 1; go Figure 3 shows a scaled up view of the output device of figure 1; Figure 4a shows an elevation of the output valve;

r r I I rr I r r er À e Figure 4b shows an elevation of the rotor of the output valve; Figure 4c shows a cross section B-B of the rotor of the output valve in figure 4b; 5 Figure 5a shows the end plate of the output valve seen from the side that in the operating position faces the cylinder element; and Figure 5b shows the end plate of the output valve in figure 5a, seen from C-C in figure 5a.

lo In figure 1, reference number 1 indicates an output device movably suspended from an arm 10 at a fastening point 11'.

The arm 10 is of a type that is known per se, and is made up of two beam elements 10' and 10", where 10" is telescopic, interconnected in a rotatable joint 11 and installed on the 15 drilling facility via an essentially vertical column structure 15 that can rotate, in the horizontal plane of the operating position, about a rotatable fixture 17 of a type that is known per se.

Two pipes 5 and 6 pass through the column structure 15, the so arm 10' and part of the arm 10", protruding from said arm 10" near the output device 1, and are connected to the upper horizontal end cover 22 of said output device 1 via flange connections. Said end cover 22 forms the top of the receptacle 20 of the Is output device 1, the, in the operating position, upper and middle portions of which receptacle have essentially vertical

À r fir I t À À t À It À t wall portions. The lower portion 20' of the receptacle constitutes an essentially conical section that tapers off towards the lower portion of the conical portion 20', with said receptacle 20' being connected to an output valve 30 via 5 a flange connection 25.

The piping system 5, 6 is connected to a vacuum suction device in a manner that is known per se, so as to generate an air flow suitable for conveying coarse and sticky drilling waste through the pipe 5 from another area (not shown) via 10 the receptacle 20, 20, and the output valve 30 to a transport container 19.

Due to the large cross section of the receptacle 20, 20' relative to the cross section of the feed pipe 5, the velocity of the flow of air and drilling waste will decrease Is considerably as it flows into the receptacle 20 at the upper end cover 22 of the receptacle. This decrease in velocity causes drilling waste to separate out from the air flow and fall towards the bottom section of the receptacle 20'. The air, which is now substantially free of drilling waste zo particles, is sucked out of the receptacle 20 through the return pipe 6 in the upper end cover 22 of the receptacle.

In order to further reduce the velocity of the flow of air and particles inside the receptacle 20, the feed pipe 5 is of a smaller size than the return pipe 6.

25 In order to prevent any 'bridging" of particles of drilling waste across the output valve 30, which would entail said particles of drilling waste not falling through the receptacle 20, 20', the receptacle 20' is equipped with a

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r I À I À # nozzle 27. The nozzle 27 can be connected (not shown) to a fluid that is introduced into the receptacle 20' at high pressure to loosen the solid mass.

The drilling waste that has separated out from the air flow 5 in the feed pipe 5 and has fallen down into the lower section of the receptacle 20', now falls into the output valve 30, which is an air and vacuum tight gate valve that transports the particles into an atmospheric environment over the transport container 19.

lo Figure 4a shows an output valve 30 in accordance with the invention having a cylinder element 31 equipped with two flanged piping connections 32, 32' in the, in the operating position, top and bottom sections of the cylinder element 31.

The two end portions of the cylinder element 31 are sealed by 5 two end plates 40 being fixed sealingly to said end portions by means of four tension bolts 33 passed though openings 46 in the end plates 40 and to the outside of the cylinder element 31 of the output valve 30.

The tension bolts 33 have been tensioned by nuts 39 so positioned on the outside of the end plates 40.

Figures 4b and 4c show the rotor 34 of the output valve 30, which is constituted by a shaft 35 with small shaft journals 37 in the centre of the two end faces of the shaft 35, and where four rectangular plate elements 36 are fixed at 25 essentially right angles to the surface of the shaft 35. The longitudinal direction of the plate elements 36 is essentially parallel with the longitudinal direction of the shaft 35.

r - - d À r À I d À d r I. . À The free edge faces 38 of the plate elements 36, which in the operating position face the internal surface and end plates 40 of the cylinder element 31 (fig. 4a), are, in the longitudinal direction of the edge faces 38, provided with an 5 essentially centred opening 42 in which is arranged a packing 44 that touches the internal surface and end faces 40 of the cylinder element 31 (fig. 4), whereby four airtight chambers are formed, each of which is defined by the shaft 35, the plate elements 36 with packings 42 and the cylinder element 10 31.

It is vital to the invention that the packings 42 on the plate elements 36 of the rotor 34 form an air and vacuum tight surface against the internal surface of the cylinder 31, to ensure that the openings in the top and bottom sections of the output valve 30 do not release or admit air to/from the closed system that consists of the piping system 5, 6 and the output receptacle 20 together with the equipment that generates the air flow (not shown).

The end plate 40 shown in figures 5a and 5b is equipped with zo four openings 46 for tension bolts 33, a centred bearing bush 47 that is known per se, and which is complementary to the shaft journal 37 (fig. 4b), and two nozzles 48.

The nozzles (48) may be connected (not shown) up to a pressurized fluid for cleaning out any drilling waste -

25 deposits from the chambers of the output valve 30, or the nozzles can be connected (not shown) up to oil or another chemical or substance suitable for lubricating the packings 42 (fig. 4c) that form a seal between the four plate elements

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r 1 1 118 111 1 1 1 l l l r I I, I 1 1 36 (fig. 4b) that are in contact with the internal surfaces (not shown) of the cylinder element (31).

In order to ensure accurate centring of the end plate 40, that side of said end plate 40 which in the operating 5 position faces the cylinder element 31 (fig. 4a) is equipped with a countersinking projecting from the outer edge face of the end plate 40 in towards the centre in a manner such that the countersunk part of the end plate 40 abuts the end face of the cylinder element 31 (fig. 4a), and the not countersunk lo part of the inside of the end plate 40 is fayed to and projects slightly into the cylinder element 31 (fig. 4a).

When the rotor 34 rotates, e.g. by means of an electric motor (not shown), the chambers of the rotor 34 facing up towards the opening of the output receptacle 20' are filled with 15 drilling waste particles. The particles are kept shut in the chamber until the chamber is rotated so as to face down, when the particles fall out through the opening of the output valve 30 in the bottom section.

The fact that the arm 10 may be moved in the vertical and so horizontal plane will, together with the fact that the output device 1 maintains the vacuum generated air flow in the piping system 5, 6, give significant benefits in terms of logistics and safety, as several big bags (not shown) or transport containers 19 can be positioned within reach of the 25 arm 10 carrying the output device 1 and be filled and stored in the full state prior to being removed, without having to be moved around the deck of the drilling facility. In addition, the process of removing full and delivering empty big bags or transport containers 19 can be carried out

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coincident with the process of filling other transport containers 19.

As alternative embodiments, the output device 1 may be connected to a vacuum piping system 5, 6 in an arrangement s which does not include a movable arm 10, or the movable arm is replaced by lifting equipment in which the output device 1 with the piping system 5, 6 is suspended.

Claims

À 1 . c:.; cece::.: C 1 a i m s 1. A method of filling and removing

transport containers (19) for mass such as e.g. coarse and sticky drilling waste, c h a r a c t e r i s e d i n that one or s more transport containers (19) are disposed within reach of an arm (10) movable in the horizontal and vertical planes, which arm is connected to an output device (1), and where the movable arm (10) and the output device (1) are connected to a vacuum piping system t5, 6) that lo continuously feeds mass to said output device (1), which conveys the mass in an essentially continuous manner to one or more transport containers (19) in an atmospheric environment.
2. An output device (1) composed of a receptacle (20), the Is upper section of which is connected to a piping system (5, 6) through which drilling waste is moved by means of an air flow, and where the lower section (20') of said receptacle (20) is equipped with an outlet to an outlet valve (30) permanently fitted to the receptacle (20'), so which outlet valve (30) is constituted by a cylinder element (31) and is provided with openings in the upper and lower sections, the longitudinal axis of the cylinder element (31) being essentially horizontal, and where a rotor (34) supported in the end plates (40) of 25 the cylinder element (31) is arranged so as to coincide with the longitudinal axis of the cylinder element (31), c h a r a c t e r i s e d i n that the rotor (34) of the output valve (30) is equipped with preferably three or more plate elements (36) having packings (44) JO arranged in grooves (42) on the edge faces (38) of the

:.;.e:: c: t plate elements (36) to form an essentially airtight surface against the internal surface and end plates (40) of the cylinder element (31).
3. An output device according to claim 2, s c h a r a c t e r i s e d i n that the diameter of the feed pipe (5) is smaller than that of the return pipe (6).
4. An output device according to claim 2, c h a r a c t e r i s e d i n that the packings (42) lO of the plate elements (36) are replaceable.
5. An output device according to claims 2 and 4, c h a r a c t e r i s e d i n that the end plates (40) of the cylinder are fixed to the end faces of the cylinder (31) by tension bolts (33) being passed on the 15 outside of the cylinder element (31) of the output valve (30) and through openings (46) in said end plates (40).
6. An output device according to claim 2, c h a r a c t e r i s e d i n that preferably, the lower part (20') of the receptacle (20) is equipped with JO at least one nozzle (27) that may be connected to a fluid supply.
7. An output device according to claims 2 and 5, c h a r a c t e r i s e d i n that one or both of the end plates (40) of the output valve (30) is/are equipped 25 with at least one nozzle (48) that may be connected to a fluid supply.

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À. 8. An output device according to any of claims 2 - 7, c h a r a c t e r i s e d i n that the output device (1) is fixed to an arm (10) that may be moved in the horizontal and vertical planes.

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9. An output device according to claim 8, c h a r a c t e r i s e d i n that the arm (10) movable in the horizontal and vertical planes has a telescoping end portion (10").
10. An output device according to claims 8 and 9, lo c h a r a c t e r i s e d i n that the movable arm (10) is designed for remote control.
11. An output device according to claim 2, c h a r a c t e r i s e d i n that the output rate of the output device (1) is designed for remote control.

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12. An output device according to any of claims 2 - 10, c h a r a c t e r i s e d i n that the output rate of the output device (1) is controlled automatically by means of a load cell positioned between the receptacle (20) of the output device and the movable arm (10).

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13. An output device according to claims 2 and 11, c h a r a c t e r i s e d i n that the flow of air and particles entering the output device (1) is stopped by a signal from the load cell when the weight in the output device (1) exceeds a predetermined value.