NO338234B1 - Method and system for processing cuttings - Google Patents

Abstract

A method and apparatus for processing drill cuttings, the method comprising obtaining drill cuttings from at least one of a shale shaker, hydrocyclone, centrifuge or drill cuttings dryer (801), measuring the moisture content of the drill cuttings preferably with a moisture sensor (821) to obtain a moisture value, comparing the moisture value to a predetermined threshold and conveying the drill cuttings in a dry cuttings route (825) if the moisture value is below the predetermined threshold or conveying the drill cuttings in a wet cuttings route (810) if the moisture value is above the threshold.

Description

METHOD AND SYSTEM FOR TREATMENT OF DRILLING CUTTINGS

The present invention relates to a method and system for treating drilling cuttings, and in particular, but not exclusively, for transporting wet drilling cuttings produced by forming an oil or gas well, or drying wet drilling cuttings before transporting the cuttings over a significant distance, and then transport the dry cuttings.

When drilling a borehole for an oil or gas well, a drill bit is arranged at the end of a drill string, and this is then rotated to drill the borehole. A drilling fluid known as "drilling mud" is pumped through the drill string to the bit to lubricate the bit. The drilling mud is also used to carry the cuttings produced by the drill bit and other solids to the surface through an annulus formed between the drill string and the borehole. The drilling mud contains expensive, synthetic, oil-based lubricants, and it is therefore common to recover and reuse the used drilling mud, but this requires that the solid components be removed from the drilling mud. This is achieved by treating the drilling fluid. The first part of the process is to separate the solids from the solids-saturated drilling fluid. This is achieved, at least in part, by the use of a vibration separator, such as the vibration screening devices described in US 5,265,730, WO 96/33792 and WO 98/16328. Process equipment for further processing, such as centrifuges and hydrocyclones, can be used to clean the sludge of solids. The solid components are covered by pollutants and residues.

The solid components that come out of this process, in this document called "drilling cuttings", are treated to remove essentially all residues and pollutants from the solid components. The solids can then be disposed of in a landfill or by dumping it in the sea in the area where the solids came from. Alternatively, the solid can be used as material in the building and construction industry or for other industrial applications. The solid components are usually treated on land, using methods such as those described in e.g. the present applicant's corresponding PCT application, Publication No. WO 03/062591. This process equipment may be located near an oil or gas platform. Alternatively, the process equipment can be located on land, far away from an offshore oil platform or far from a land-based rig. The solid components must therefore be transported from the outlet of the vibrating sieves, centrifuges and hydrocyclones, and to the equipment that will process the solid components. In some previously known systems, oily drilling cuttings are loaded into vessels, containers or drilling cuttings boxes that are lifted aboard supply ships. This can alternatively be partly carried out using a chute where a driven transport screw is arranged which transports the wet solid to storage tanks. Such a system is described in the present applicant's corresponding PCT application, publication no. WO 03/021074. After processing in a vibration screening device, drilling cuttings can contain approx.

10 to 20% by weight moisture (oil, water).

Today, it is often desirable and/or a statutory requirement that recovered drilling cuttings be transported to a treatment facility on land to remove the essentials of all oil and all pollutants, so that the drilling cuttings can be disposed of or used in an environmentally friendly and safe manner. Environmental agencies around the world are moving towards a "zero discharge" policy when it comes to offshore platforms. It is common for drilling on an offshore oil platform to take place continuously, and cuttings are stored on the platforms until they can be transported away using so-called supply ships, which pick up the oil-containing cuttings and transport them to another location for further processing. There is a need for efficient storage of oil-containing drilling cuttings on the platform, and also a need for efficient storage of the drilling cuttings on board supply ships. The solids can be added to a fluid such as water, so that a slurry is formed. The slurry can be pumped into ships, trucks, containers or sacks for transport to the treatment site. Alternatively or additionally, the wet solid from the storage tanks can be transported through pipes using compressed gas, as described in PCT publication no. WO 00/76889.

Previous publications describe various methods of transporting dry solids with low slurry density and low particle density, and non-continuous transport of wet material with high slurry density and high particle density, using continuous positive pneumatic pressure. Many low density slurries will typically have air-entrained particles with a specific gravity of less than 1.0. Previous publications describe various methods using suction transport of solids with high particle density and low particle density.

Thus, the problem of transporting, buffering and storing material with low slurry density and high particle density, and especially, but not exclusively, drilling cuttings from oil fields and other oily/wet waste materials, is handled by using a continuous, positive

pneumatic pressure.

WO 00/76889 describes a system where drilling cuttings are transported in the form of a non-free-flowing mass, where the system comprises a pressure tank with an outlet part shaped like a conical funnel, where the cone angle is sufficient to cause a mass flow. The cuttings are stored on a platform and on board a supply ship in ISO-sized storage tanks with a conically shaped funnel outlet, so that the ISO-sized tanks can be emptied from the platform to the ship and from the ship to the port. These ISO tanks are very tall and the amount of cuttings stored in them is limited due to the lower converging parts of the tanks.

German patent no. DE 40 10 676 describes an apparatus for transporting sewage sludge or concrete. The apparatus comprises a pressure tank with an inlet opening and a screw conveyor underneath. There are paddles that act as agitators and forcibly fill the screw conveyor through an opening in the pressure tank. The screw conveyor moves the sewage sludge or concrete into a nozzle where compressed air is used to move the sewage sludge or concrete in an uninterrupted flow through a pipe.

British Patent No. GB-A-2 330 600 describes a system for transporting drilling cuttings from a platform to land. The system includes the steps where the oily cuttings are mixed with a mud to form a slurry; the slurry is stored in holding tanks on the platform; and then the slurry is pumped to holding tanks on a ship for transport to shore.

WO 03/021074 describes, among other things, an apparatus for the transport of solid waste substances, where the apparatus comprises an upstream supply device for waste substances; a feeding device that transports waste materials from the waste supply device and to a compressed air conveyor, which compressed air conveyor comprises a pipe where the waste materials are transferred from the feeding device to a downstream waste collector, and where said pipe is connected to at least one blocking sensor and an electronic data processing device that processes output data from the blocking sensor.

WO 82/03066 describes a method of unblocking a conveyor for particulate materials, comprising introducing air into the tube at several spaced locations to reduce the length of the blocking material.

EP-A-0 224 353, Skinner, Atlantic Richfield Company, discloses a method and apparatus for treating well drilling fluids comprising drilling cuttings, using

an indirect dryer. The method and apparatus correspond to the preamble of claim 1 and claim 14. The apparatus comprises an indirect dryer which has an outlet for discharging dried solids into a channel which has a diverter valve for diverting dried solids

through a manifold. The manifold leads to a combustion chamber/oxidant and further to a solids/gas separator of the centrifugal or cyclone type, and the further dried solids are released through the channel via an air lock valve. The diverter valve directs at least a portion of the dried solids into the manifold to mix with drilling fluid comprising drill cuttings entering the dryer to control the moisture content of the input stream to reduce solids caking in the dryer.

This document describes an apparatus for selective storage of drilling cuttings material, preferably during the process of transporting drilling cuttings, comprising a tank with a first opening through which drilling cuttings material can be fed into the tank, and a second opening through which drilling cuttings material can be fed out of the tank, characterized in that the apparatus further comprises a movement device, the movement device comprising a movement element in the tank, which can be moved near the second opening to make it easier for the cuttings material to flow into the second opening. The movement device is preferably a mechanical movement device.

The apparatus preferably further comprises a box for receiving drilling cuttings material which flows through the second opening, the box having a drilling cuttings outlet which is connected to a transport channel. The box can be any space into which the cuttings can fall or be pushed down on the way into the transport channel. The box can form part of the transport channel. The transport channel can be a rigid pipe or a flexible hose, preferably with a diameter of between 50 and 200 mm, more preferably 100 to 150 mm, and most preferably approx. 125 mm in diameter.

It is an advantage if the device also includes a compressed gas inlet where compressed gas can be used against the cuttings to facilitate the movement of the cuttings through the cuttings outlet. The compressed gas inlet is preferably in line with the cuttings outlet. The gas is preferably air or an inert gas such as nitrogen. It is an advantage if there is an inlet for compensating compressed air in the tank, to provide an equalizing pressure that prevents drilling cuttings from being blown back from the box into the tank during emptying. Equalization in the pressure is ideally equal to the pressure in the box, but equalization in the pressure can be slightly lower or higher than the pressure in the box.

The tank is preferably a pressure tank. It is an advantage if the pressure tank has been pressure tested to withstand a working pressure of at least 2 bar, more preferably at least 4 bar and most preferably at least 7 bar. The device preferably further comprises an air valve which prevents the tank from being overloaded by the pressure in the tank.

A transport channel is essentially kept full and thus makes it possible to maintain a steady supply or dosage rate. The transport channel can be supplemented in certain aspects

drilling cuttings in such doses that the transport channel is full, so that the drilling cuttings move along the transport channel as one long mud plug. Alternatively, the drill cuttings can form a plurality of plugs along the transport channel, separated by pockets of pneumatic fluid. This is controlled through the speed at which the drill cuttings are dropped or pushed into the transport channel, known as dosage rate or dosage quantity. The dosing rate is dictated by, among other things, the consistency of the drill cuttings, the pneumatic pressure used against the drill cuttings, and the diameter of the transport channel, so that a predetermined transport rate is achieved. In a preferred embodiment, a quantity of thirty tonnes of drilling cuttings is transported per hour from the storage tank, through the transport channel and on to a receiving location.

The cuttings stored in the storage tank can be dry or wet. Wet cuttings contain water and/or oil. Wet cuttings can be free-flowing, non-free-flowing or pasty. Drilling cuttings are often wet after being processed in a vibrating screening device. The drilling cuttings can be dried using a vortex dryer, as described in this document, to produce essentially dry drilling cuttings which in some aspects can be free-flowing, solid components that follow Newton's laws of flow.

It is an advantage if the movement device further comprises a drive device which is connected to the movement element in order to move the movement element. The second opening preferably has a length, and the movement element comprises an elongated element with a length which is preferably substantially equal to or greater than the length of the second opening. It is an advantage if the elongate element has an edge which is shaped so that it facilitates the movement of drilling cuttings material to the other opening. The elongate element preferably has a front edge which is bevelled to make it easier for the elongate element to move under a pile of drill cuttings, and a rear edge which is designed so that it picks up drill cuttings to move them towards the other opening, i.e. the rear edge is preferably at right angles to the direction of movement of the elongated element, it can be step-shaped and/or concave, advantageously has a bucket edge for shoveling drilling cuttings into the opening, and is most preferably a sliding frame.

The second opening preferably has a width, and the movement element can be moved back and forth across the width. It is an advantage if the movement element comprises a frame with a steering shaft which is attached to at least one curved outer peripheral part. The weighing element preferably comprises a frame with an outer peripheral part which is essentially eye-shaped. Alternatively, a rack and pinion or rotating disk may be used with an arm placed on its circumference to convert a rotary motion into a reciprocating motion, similar to a crankshaft in a car engine. Such a thrust element can be used in many different tanks, including but not limited to a mass flow funnel, a core flow funnel, a flat-bottomed funnel, a so-called "chisel plane" type flow-through tank, or a conical tank.

The movement device preferably comprises or preferably also comprises a twist drill. The twist drill can form part of a screw conveyor, and can be any type of screw that moves drill cuttings. The twist drill is preferably placed under the second opening. The rotary drill is preferably placed in a chute. The chute can have a cover to prevent drilling cuttings from entering the chute when the device is out of use for a long time. The cover can optionally be moved with the movement element. The cover can be perforated or non-perforated. The box is preferably located at the outlet end of the drill. It is an advantage if the device also includes a motor that rotates the drill. It is an advantage if the device further comprises fingers which may be knife-like, placed at the end of the drill, to make it easier to detach the cuttings from the drill and preferably to make it easier to break up lumps of cuttings. The rotary drill preferably comprises at least one blade with a constant pitch. The drill can advantageously or alternatively include at least one blade with a variable pitch.

It is an advantage if the apparatus, in accordance with what is described above, further comprises a cover which is chosen to be used to cover the second opening. The cover preferably covers the second opening pneumatically. It is an advantage if the cover is made of a sieve, so that it is possible for gas to flow through. The cover is preferably connected to the movement device and moves with it.

The device preferably further comprises a central spindle and a plurality of fingers or bristles extending from this. The spindle can preferably be moved with a valve located in the first opening, in order to selectively release cuttings into the tank. The tank preferably has an essentially flat interior bottom. The tank bottom can be flat and/or mainly horizontal. By using a non-conical funnel or tank in some embodiments according to the present invention, bridging can be prevented and reduced compared to the bridging that can occur in some conical tanks. In one aspect, the sliding element(s) is/are substantially flat so that they can be slid over a flat bottom. In some aspects, the push element is rigid. The flat bottom is preferably circular and has a diameter of between 1.5 and 4 metres, and in one specific embodiment has a diameter of 2.7 metres. The flat bottom or the lower part of the tank can be provided with a plurality of small air holes that let compressed air through to supply air to the cuttings, so that it is easier to transport the cuttings through the other opening or down a chute if such exists .

It is an advantage if the tank has at least one substantially vertical wall. The tank preferably has a dome-shaped top. It is an advantage if the tank is essentially cylindrical with an essentially circular bottom, where the second opening passes through the essentially circular bottom.

It is an advantage if a valve is arranged in the first opening which controls the inflow of drilling cuttings. The valve can be of the type described in GB-A-1 539 079 or US-A-3 586 383.

The first opening preferably has a non-return valve which prevents drilling cuttings from flowing out through the first opening.

It is an advantage if the tank has two sides that slope towards each other. The tank may be of any suitable type; wedge-shaped, plane-flow, chisel-shaped, pyramidal, square or other.

The tank preferably has a conical funnel section. The conical funnel part advantageously has a cone angle and forms a lower part of the tank, and the cone angle is below the critical value necessary to achieve a mass flow of drilling cuttings material.

It is an advantage if the tank has a capacity of between 0.15 cubic meters and one cubic meter, so that the device is preferably not used to store drilling cuttings, but is used for continuous transport of drilling cuttings. The device can be as small as 0.05 and 0.2 cubic meters.

The tank preferably has a capacity of at least three cubic metres, as it is preferably used to store drilling cuttings, either on a platform or on a barge, boat, truck, train or in a storage area on land. The tank is usually between ten and 30 cubic metres, and preferably between 12 and 16 cubic metres.

It is an advantage if the device also includes a moisture meter that measures the moisture content in the drill cuttings. The apparatus preferably further comprises a funnel, where the moisture meter is placed in the funnel. It is an advantage if the moisture meter is located in the tank. The apparatus preferably further comprises a control unit which collects data from the moisture meter, and a device which diverts the drill bit as a reaction to the data. The device preferably comprises a diversion valve which diverts the drill cuttings. It is an advantage if the device comprises a screw conveyor, preferably with a motor that drives the screw conveyor, and which can optionally rotate the conveyor clockwise and counter-clockwise to reverse the cuttings transport from a first direction to a second, opposite direction.

The apparatus preferably further comprises a storage tank for storing dry drilling cuttings. It is an advantage if the device also includes a storage tank for storing wet drilling cuttings. It is advantageous if the storage tank for storing dry cuttings is the internal bulk tank on a drilling rig. The storage tank for storing dry cuttings is preferably the internal hold of a ship or barge. The storage tank for storing dry cuttings is preferably a further device according to the invention. It is an advantage if the storage tank according to the present invention is fed using a blowing tank. Alternatively, in addition to or instead of blow tank(s), a pump, such as a displacement pump or a cement pump (or pumps), may be used to move the drill cuttings, for example from vibratory screeners or a chute or vortex dryer to the storage tanks. The floor area and total available space around vibration screening devices is often limited, and the storage tanks or containers that will contain the drilling cuttings are therefore often placed relatively far from the screening devices, usually several tens or hundreds of meters.

The device is preferably frame-mounted.

A method for transporting drilling cuttings is also described, where the method includes the steps where a conveyor is filled with drilling cuttings and an overpressure is used to move the drilling cuttings along this, characterized in that the step where the conveyor is filled is carried out using a mechanical movement or transport device. The cuttings can be a free-flowing mass or a non-free-flowing mass, dry lumps, dry, free-flowing particles, moist, a slurry or in another form.

The conveyor is preferably provided with a pressurized gas inlet, as the method includes the step where pressurized gas is supplied through the pressurized gas inlet to make it easier to move the drill bit through the conveyor. It is an advantage if the mechanical transport device includes a rotary drill, where the drill is rotated to fill the conveyor with drilling cuttings. The drill is preferably located in a pressure tank, as the method further comprises the step where the pressure tank is filled with drilling cuttings, after which the drill is rotated to fill the conveyor with drilling cuttings from the pressure tank. Preferably also a step where the pressure tank is put under pressure to prevent drilling cuttings from going back into the pressure tank from the drill or the conveyor.

It is an advantage if the pressure tank has an inlet opening and a valve which is placed in the inlet, as the method further comprises the step where the valve is activated to selectively release drilling cuttings into the pressure tank.

The pressure tank preferably has an inlet opening and a non-return valve placed in the inlet, the method further comprising the step where the drilling cuttings are allowed into the pressure tank, gas underpressure and drilling cuttings being prevented from flowing out through the non-return valve.

The procedure is preferably carried out on a ship or on a drilling platform off-shore.

It is an advantage if all cuttings movement devices are in a controlling connection with a control device, as the method includes controlling the cuttings movement device with the help of the control device.

A method is also described for storing drilling cuttings in a storage tank and allowing this to flow out from there into a pressurized conveyor, the method comprising the step where the drilling cuttings is filled into a storage tank, and the method further comprises the steps where a mechanical movement device is activated for to move the cuttings towards an opening in the storage tank to facilitate outflow of cuttings. The storage tank is preferably pressurized, preferably by means of a pressurized gas.

It is an advantage if the storage tank has an essentially flat bottom, where the opening is located in the essentially flat bottom. The mechanical movement device preferably comprises a contact arm, the method further comprising the step where the contact arm is moved to move at least some of the drill bit towards the opening. The contact arm preferably forms part of a frame, as the method comprises the step where the frame is moved to move at least some of the drill bit towards the opening. The contact arm preferably comprises fingers or bristles/stiff hairs which move at least some of the drill bit towards the opening. It is an advantage if the mechanical movement device further comprises a piston and cylinder, as the method further comprises the step where the piston and cylinder are activated to move the contact arm. The piston and cylinder can be actuated using a hydraulic supply or compressed air supply.

Previously known methods make use of a drilling cuttings dryer which, together with a compressed air system for transporting drilling cuttings, reduces waste quantities and liquid content and requires less storage volume. Transport and disposal costs are also reduced. As a result of the fact that dried drilling cuttings tend to be a lead phase when a pressurized air system is used for transport, it is important in certain aspects to react as quickly as possible to any change in production from drying. It is known that it is difficult to transport a product when it does not have a uniform consistency. Having a storage tank with a mixture of dried drilling cuttings and wet drilling cuttings can make it necessary to have a transport system that alternates between different flow forms, between continuous and non-continuous flow. The flow regime for cuttings in a pipe is not suitable for such alternations, as wet cuttings tend towards a heavy phase with either shear flow or plug flow/piston flow, whereby the cuttings plugs behave as a pulsating layer that moves smoothly/non-uniformly, and which can fill the entire pipe cross-section; and dried cuttings tend towards suspension flow. The transfer rate must be reduced considerably if this "mixing" of flow forms becomes necessary. It is not desirable to reduce the transfer speed when a vessel is located side by side with a platform and takes on board a cargo. In order to obtain the greatest possible transfer speed, it is an advantage if one maintains an even consistency of drill cuttings in the storage tank.

The flow of cuttings out of a dryer with a screen can be radically changed if the screen is stopped and thus does not let liquid through, leading to a wet output. It is known that this can sometimes happen when a change in the formation being drilled through leads to a change in the size of the particles produced by the drill bit.

In some systems according to the present invention, a moisture meter is used for continuous monitoring of the drying flow. The moisture meter can be based on the principle of near infrared radiation (NIR), where it is known that several molecular compounds absorb infrared light at specific wavelengths. Common compounds are O-H in water, C-H in organic compounds and oils, and N-H in proteins. The level of light absorption at these specific wavelengths is proportional to the amount of the constituent in the sample material. Infrared filters in the instrument sensors generate a series of light pulses, and one of these pulses is selected so that it is at the specific absorption wavelength for the component to be measured, while the other pulses are selected so that they determine the material's reflection properties. The light pulses illuminate the measured sample, as the reflected light is collected and focused on a detector, and electrical signals from the detector are converted into a ratio to give a value that is proportional to the concentration of the component - this can be in percent or other technical units , and thus the content of water and oil-based sludge can be monitored. This technology is well defined and provides great accuracy and quick response, so that you can more easily have online measurement and control of the drying process.

Alternative methods according to the present invention in obtaining a "moisture value" include passing the product through an open screen and measuring the resulting pressure drop. An increase in pressure drop indicates that the product is stuck in the grid, probably because the "moisture value" has become higher. Instruments based on dielectric constant or vibration-sensitive instruments can also be used to monitor changes in consistency.

Using information can reduce the "mixing" of drilling cuttings in the storage tank to a minimum. In one aspect, a separate storage tank is used if a desired value for "moisture" is exceeded. In such a system, a number of storage tanks are filled with drilling cuttings that have a satisfactory consistency and oil content; if the desired value for humidity is exceeded, the flow is diverted to a "wet" storage tank, and an alarm is triggered to enable the operator to resolve the situation. In another system according to the present invention, a screw conveyor which is used to feed the transport system after the drying can be immediately reversed to feed into a separate "wet" tank. In another system according to the present invention, two dryers are used which are equipped with sieves with different mesh sizes. If one dryer is stopped or fails and causes "wet" cuttings to flow out, the cuttings can be redirected by activating an appropriate valve under the feed conveyor to the dryer, so that the alternative dryer is used. In another system according to the present invention, the total height is reduced through the use of screw conveyors.

The invention provides a method for treating drilling cuttings, the method comprising retrieving drilling cuttings from at least one of a vibrating screening apparatus, a hydrocyclone, a centrifuge or drilling cuttings dryer; measuring the moisture content of the cuttings to obtain a moisture value; comparing the humidity value with a predetermined threshold value; and transport the cuttings along a path for dry cuttings if the moisture value is below the predetermined threshold value, or transport the cuttings along a path for wet cuttings if the moisture value is higher than the threshold value.

The path for dry drilling cuttings preferably comprises a feeding device and a compressed air driven conveyor, the method further comprising the steps where drilling cuttings are fed into the feeding device, which feeds drilling cuttings into the compressed air conveyor. It is an advantage if the compressed air conveyor is an overpressure conveyor. The excess pressure is used to push the drill cuttings through the conveyor. So the pressure behind the drill bit should ideally be higher than the pressure in front of the drill bit, so that the drill bit is moved through the conveyor. The conveyor can consist of a rigid pipe or a flexible hose. The compressed air conveyor preferably leads to a storage tank, as the method further comprises the step where the drill cuttings are transported through the compressed air conveyor to the storage tank. The storage tank is preferably of the type described and required in this document. It is an advantage if the compressed air conveyor leads to a bulk tank on an oil or gas platform, as the method further includes the step where the drill cuttings are transported through the compressed air conveyor to the bulk tanks. The compressed air conveyor preferably leads to a hold on a ship, as the method further comprises the step where the drill cuttings are transported through the compressed air conveyor to the hold. The hold can be pressure-tight and have its own overpressure conveyor device that can remove drill cuttings from the hold, or it is not pressure-tight, and a stand-alone blow tank device according to the invention, as described in this document, or a vacuum device such as that manufactured and sold by The Fuller Company is used (now called FL Smidth), which sucks the cuttings out of the hold and transfers it to other means of transport in the port, such as containers or storage tanks on trains, barges or trucks. The step where the moisture content of the cuttings is measured is preferably carried out using a moisture meter which is placed in the feeding device. It is an advantage if the feeding device comprises a hopper and a pressure tank, as the step where the moisture content in the cuttings is measured is carried out with a moisture meter placed in the hopper.

The path for wet drilling cuttings preferably comprises a feeding device and a compressed air driven conveyor, the method further comprising the steps where drilling cuttings are fed into the feeding device, which feeds drilling cuttings into the compressed air conveyor. It is an advantage if the compressed air conveyor is an overpressure conveyor. The excess pressure is used to push the drill cuttings through the conveyor. So the pressure behind the drill bit should ideally be higher than the pressure in front of the drill bit, so that the drill bit is moved through the conveyor. The conveyor can consist of a rigid pipe or a flexible hose. The compressed air conveyor preferably leads to a storage tank, as the method further comprises the step where the drill cuttings are transported through the compressed air conveyor to the storage tank. The storage tank is preferably of the type described and required in this document. It is an advantage if the compressed air conveyor leads to a cuttings dryer for further drying, for example a vortex dryer or a dryer of the type described in GB-A-2 297 702. The drier cuttings are then sent back in stages in the process to have the moisture measured . It is an advantage if, in the cases where a sieve is used in the cuttings dryer, a different mesh size is used than that used in the device from which the cuttings come, i.e. vibrating sieve, hydrocyclone, centrifuge or cuttings dryer, in the case of the high moisture content in the cuttings is caused by grain boundary clogging. The step where the moisture content of the cuttings is measured is preferably carried out using a moisture meter which is placed in the feeding device. It is an advantage if the feeding device comprises a hopper and a pressure tank, as the step where the moisture content in the cuttings is measured is carried out with a moisture meter placed in the hopper.

It is an advantage if the cuttings from at least one of a vibrating screening device, a hydrocyclone, a centrifuge or a cuttings dryer are fed into a feed device, whereupon the moisture content of the cuttings is measured using a moisture meter placed therein to obtain a moisture value, the feeding device feeds the cuttings into a compressed air conveyor, the conveyor contains a diverter valve, the method further comprising the steps where the drill cuttings via the diverter valve are directed to a path for dry cuttings if the moisture value is below the predetermined threshold value, or the cuttings are guided to a path for wet cuttings if the moisture value is higher than the threshold value.

Beneath at least one of a vibrating screening device, a hydrocyclone, a centrifuge or a cuttings dryer, there is preferably placed a screw conveyor that receives the cuttings, the screw conveyor comprising a drive device which is such that the screw conveyor can be reversed to move the cuttings in one direction to the path of dry cuttings and in another direction to the path for wet cuttings.

It is an advantage if the predetermined threshold value is a moisture content of one percent, three percent or five percent. The moisture content includes water content and oil content. The ratio between oil and water in drilling cuttings varies greatly, but is often in the range of half water and half oil.

The invention also provides an apparatus for carrying out the above method. The apparatus preferably comprises a moisture meter and a device which can send the cuttings along a path for dry cuttings or a path for wet cuttings. It is an advantage if the device further comprises a control unit which receives data from the moisture meter and compares the data with a predetermined value and activates the device according to the data.

The invention also provides a method for transporting drill cuttings, as the method includes the steps where a channel is filled with drill cuttings, an overpressure is applied to the drill cuttings to push the drill cuttings through the channel, characterized by the overpressure coming through inlets placed at intervals along the channel, so that the movement of the cuttings through this is facilitated.

The air pressure in the duct is preferably measured at intervals along the duct, the pressure measurements are reported to a control unit, and the control unit controls the application of air pressure through said inlets placed at intervals along the duct. It is an advantage if the control unit turns each of the spaced inlets off or on as a reaction to the pressure measurements. Preferably, the pressure introduced through each subsequent inlet is lower than in the previous inlet. It is an advantage if pipes run to the inlets placed at intervals along the canal, where the pipes include non-return valves that prevent drilling cuttings from entering the inlets.

The pressure of each of the inlets placed at intervals is preferably variable, the pressure of these being varied according to the pneumatic pressure in the channel, measured at regular intervals.

It is an advantage if the pressure to each of the inlets placed at intervals is fixed. For example, the pressure may be 4 bar at the first inlet, 3.5 bar at the second inlet, 3 bar at the third inlet, 2.5 bar at the fourth inlet, 2 bar at the fifth inlet and 1.5 bar at the sixth inlet. The inlets can be placed at fixed intervals along the channel, for example every 25 metres. The distance can be reduced to, for example, every ten meters where there is a bend in the channel. The inlet can be placed in the angle piece of the channel.

The invention also provides a feeding device for filling cuttings in an overpressure channel, comprising a pressure tank, an inlet, a valve which selectively releases cuttings into the pressure tank, and an outlet leading to a channel, the outlet comprising a pipe bend below the pressure tank , characterized by the fact that the pipe bend has an inlet for compressed air where an excess pressure is applied which pushes the drill bit through it. The inlet is preferably led in a horizontal direction, preferably in line with the channel. A further valve is preferably placed between the pressure tank and the outlet. It is an advantage if the outlet runs together through the pipe bend, for example an outlet with a circular cross-section runs together from a diameter of 150 mm to a diameter of 125 mm.

In order to provide a better understanding of the present invention, reference will now be made by way of example to the accompanying drawings, where:

Fig. IA shows a storage tank according to the present invention, seen from above and along line I-1 in Fig. IB; Fig. IB is a cross-section of the storage tank of Fig. IA, seen from the side; Fig. 1C shows another embodiment of a storage tank according to the present invention, seen from the same angle as Fig. IA; Fig. ID is a top plan view of an alternative part for the storage tank shown in Fig. IA; Fig. 2 is a schematic diagram showing the device according to the invention in operation; Fig. 3 is a schematic cross-section showing a prior art feed tank used in the apparatus shown in Fig. 2; Fig. 3A is a side view of a feed tank according to the present invention, which tank may be used instead of the feed tank shown used in the apparatus of Fig. 2; Fig. 3B is an end view and fig. 3C is a side view of the feed tank shown in Figure 3A; Fig. 4 is a schematic side view of a feed tank according to the present invention; Fig. 5A is a cross-section, taken along line VA-VA, of a frame part shown in Fig. IA; Figs. 5B to 5D are alternative forms of the cross-section of the frame part for the storage tank of Fig. IA; Fig. 6 is a schematic diagram of a storage tank arrangement according to the present invention; Fig. 7A and 7B are sectional perspectives of a further embodiment of a storage tank according to the present invention seen from above, showing steps in its use; Fig. 7C is a sectional perspective of a further embodiment of a storage tank according to the present invention seen from above; Fig. 7D is a cross-section of the storage tank of Fig. 7C seen from the side, without drilling cuttings in; Fig. 7E is a cross-section of the storage tank of Fig. 7A seen from the side, with drilling cuttings in; Fig. 8A is a schematic side view of an apparatus according to the present invention; Fig. 8B shows a part of the apparatus of Fig. 8A seen from above; Fig. 9A is a schematic diagram of a feeding device according to the present invention; Fig. 9B is an end view of part of the feeding device of Fig. 9A;

Fig. 9C is a side view of part of the feeding device of Fig. 9A; and

Fig. 10 to 15 are schematic diagrams showing devices according to the present invention.

Referring to Figures IA and IB, a storage tank 1 according to the present invention has a substantially cylindrical pressure tank 2 with a circular cross-section, a substantially circular, flat bottom 3 and a dome-shaped top 4. The flat bottom 3 and the dome-shaped top can be formed in one piece with or welded to the wall of the pressure tank 2.

The pressure tank 2 can be made of steel of the type defined by British Standard 1501 224-49B, and can be designed to withstand an operating pressure of between one and 20 bar, and in one particular aspect seven bar. The dome-shaped top 4 optionally has an inlet 5 with an attached supply line 6, which in one particular aspect has a diameter of 52 mm (two inches), for supplying pressurized gas such as air and/or nitrogen and/or a other inert gas, which is used against the top of the drill bit DC in the tank. The dome-shaped top 4 is also provided with a cuttings inlet 7 which is provided with a valve 8, for example a gate valve or a full flow (full bore) ball valve, which can be manual or remotely controlled, for example by means of a stepper motor. Alternatively, the drill cuttings can be introduced through the inlet 7 using any known system, for example, but not limited to, a conveyor system.

The cuttings inlet 7 has, in one particular aspect, an internal diameter of 125 mm (five inches). The flat base 3 has an opening 9. The opening 9 can have any suitable shape, seen from above, and is, as shown, usually rectangular. A tube 10 has an opening which fits together with and is fixed around the circumference of the opening 9 in the flat bottom 3, so that a pressure-tight closure is formed. The pipe 10 can be welded to or otherwise designed with the flat bottom 3. The pipe 10 optionally accommodates a twist drill, which in one aspect is a screw conveyor 11 which is rotatably mounted in the pipe 10 and is driven by means of a hydraulic motor 12 with variable rpm.

The motor 12 can alternatively be electric, petrol-driven, pneumatic or driven in some other way. The screw conveyor 11 has a shaft 13 and a spiral or screw-shaped

blade 14. The helical blade 14 has, in one aspect, a diameter of between 150 mm and 600 mm (six and 24 inches), and in one particular aspect has a diameter of between 350 mm and 400 mm (14 and 16 inches). The shaft 13 has a first end which is connected to the hydraulic motor 12 with variable speed, and a second end which is rotatably arranged in a bearing 15 in an end wall 16 in the pipe 10. The pipe 10 extends past the outer edge of the flat bottom 3. The helical blade 14 runs essentially across the entire diameter of the flat bottom 3 and extends into a part of the tube 10 which extends past the outer edge of the flat bottom 3, where the blade ends. In some aspects where there is no drilling device or conveyor 11, pressurized gas in the tank is used to convey the material in the tank to the outlet opening.

Four, six or more radially projecting fingers 17 (two shown) extending from the shaft 13 (or may be connected to the inside of the tube 10) are spaced from the end of the helical blade 14. The part of the tube 10 which protruding beyond the outer edge of the flat bottom 3, has an outlet box 18 with a lower chamber 18a, where a compressed gas inlet 19 is arranged under the end of the helical blade 14. The outlet box 18 tapers from an upper part which has a width of substantially equal to the diameter of the pipe 10, to a smaller width that substantially equals the diameter of an outlet 20. The air supply inlet 19 leads into the lower chamber 18a in the outlet box 18 and lies in line with a cuttings outlet 20. The cuttings outlet 20 has one particular aspect has an internal diameter of 125 mm (five inches) and is attached to a drill casing porter (not shown) of the same or similar internal diameter, which may be flexible tubing or rigid tubing.

Inside the pressure tank 2, a sliding frame 21 is placed on the flat bottom 3 around opening 9. The sliding frame 21 can have any desired shape, seen from above, which helps to move drilling cuttings towards the opening 9. In one aspect, the frame 21 has two symmetrical curved parts 22 and 23 which make an eye shape arranged on four arms 24 which are connected to a central part 25. The curvature in the two symmetrical curved parts is slightly less than the curvature along the outer edge of the flat bottom 3. External edges 27 of the two symmetrical, curved parts 22 and 23 and of the four arms 24 are beveled in one aspect, while internal edges 28 (see figure 5A) which face the opening 9, are at right angles to the plane of the flat bottom 3. The curved parts 22, 23 have a flat underside 29. The bevel cutting angle is in some aspects between 45 and 20 degrees in relation to the flat underside 29. This can be clearly seen in figure 5A. It is within the scope of the present invention for a frame or part to be of such size and configured to move over the opening 9 of any shape, for example but not limited to a part 102 as shown in Figure 1C, or a substantially circular frame, as shown at frame 21a in Figure ID. The opening 9 can have any desired shape with any desired width and length; and, as shown, may be approximately the same width as the drilling device located below the opening (or the drilling device may be slightly wider than the opening).

A hydraulically operated piston and cylinder assembly 26 is connected at one end to the wall or flat bottom 3 of the pressure tank 2, and at its other end to the slide frame 21, to cause the slide frame 21 to move back and forth across the flat bottom 3 within the pressure tank's 2 boundaries, as shown by the arrow. Alternatively, some of the frame's movement device can be located outside the tank.

The curved parts 22 and 23 may have different profiles so that they can slide under the drill cuttings DC as they move away from the opening 9, and act as a rake or a bucket that scoops, digs or moves the drill cuttings into the discharge opening 9. In one aspect, the space around the conveyor 11 in the pipe 10 is kept essentially full, so that a uniform dosing rate can be maintained, depending on the speed of rotation of the conveyor 11, during the transport of drilling cuttings from the storage tank.

Figures 5A to 5D show an exemplary, but not the only possible list of alternatives for the curved parts 22, 23. Figure 5b shows a curved part 22 (part 23 is equivalent) with a beveled front side 31 and a concave back side 32. Figure 5C shows a curved part 22 (or 23) with a bevelled front side 32 and a stepped rear side 33 with a shoulder 34. Figure 5D shows the curved part 22 (or 23) with a stepped front side 35 and a slightly angled rear side 36, so that in use, an acute angle is formed between the angled back 36 and the flat bottom 3.

The storage tank 1 is in one aspect attached to a skid frame (skid) not shown to facilitate the transport of the storage tank 1 on trucks, supply ships, railcars, and on land and offshore platforms. The skid frame may also comprise a frame surrounding the storage tank 1, which may be of a standard ISO size to make it easier to transport on ships, trains and trucks equipped with fasteners with ISO distances. The height of the storage tank 1 mounted on the skid frame is in one aspect 3.26 meters, the length of the skid frame is 3.95 meters and the width is 2.9 meters. It should be noted that the height of the tank is very small compared to the internal volume.

A pressure relief valve 8a is placed on the pressure tank 2 and is set to between 10% and 20% above normal operating pressure, which is preferably seven bars. There may also be a removable and/or movable hatch 8b in the wall of the pressure tank 2 which provides access for inspection, inspection and maintenance.

Figure 1C shows a storage tank corresponding to storage tank 1, except that instead of a sliding frame 21, this has a raking device 100 and associated movement device. Like reference numbers indicate like parts. The raking device 100 (or the sliding frame 21 etc.) can be used with any tank or container described in this document. The rake device 100 has a part 102 on a shaft 104 which is moved back and forth over the opening 9 by means of a movement device 110. A drive mechanism 112 (for example any suitable motor, or reciprocating mechanism such as, but (not limited to, a piston/cylinder assembly such as that of Figure IA) moves the shaft 104 back and forth to move the member 102 over the opening 9, so that the drill bit moves more easily down the opening 9. Optionally, a vibration mechanism 114 outside the tank 2 may vibrate the shaft 104 to vibrate the part 102 and/or induce vibrations in the drill bit through the tank 2. A vibration mechanism 106 may optionally be arranged on the shaft 104 inside the tank 2 to vibrate the shaft 104 and the part 102, so that the drill bit moves more easily. Optionally, a vibration mechanism 108 on the part 102 can promote movement in the drill cuttings.

With reference to figure 2, wet cuttings come from a number of vibration screening devices 50 on a drilling platform.

The sieved, wet drilling cuttings fall from the sieves in the vibrating screening devices 50 into a chute 48. The wet drilling cuttings are moved along the chute 48 using a screw conveyor or a conveyor belt, or fall directly into a funnel. Wet cuttings are optionally fed into a dryer (not shown), such as a vortex dryer or a dryer of the type described in GB-A-2 297 702, to remove a significant amount of moisture. This is described in more detail in the corresponding PCT publication no. WO2004/083597 (PCT application no. PCT/GB2004/000762) and in the corresponding American application with serial number US 10/764 825, submitted by the present applicant. Under certain conditions, the moisture content in the cuttings is reduced to between one and five percent by weight, and under other conditions down to one percent by weight. "Wet" cuttings typically have an oil content of five percent or more, and "dry" cuttings have an oil content of less than five percent.

The wet or dry cuttings fall directly into a funnel 51 in a blow tank 52, shown in more detail in Figure 3. The blow tank 52 can be of the type described in GB-A-

1,564,311, the description of which is fully incorporated into this document for all purposes. A valve 53, which can be of the type described in GB-A-1 539 079, is placed between the funnel 51 and a small pressure tank 54 which in one aspect has a capacity of approx. 0.3 cubic meters, although the capacity in other aspects is between 0.1 and one cubic meter; or larger or smaller. The size of the small pressure tank is in some designs dependent on how much space is available near the vibrating screening devices, and/or the number of cycles necessary to transfer the material at, for example, a rate of 30 tonnes per hour. hour. The small pressure tank 54 has a part 55 in the shape of a truncated cone. An air inlet 56 is arranged in an upper part of a wall in the pressure tank 54, and a cylindrical part 57 with a circular cross-section is arranged between the valve 53 and the wall in the part 55, which leaves a small annular gap 58 where compressed air can flow from the air inlet 56 into in the lot 55 with the shape of a truncated cone. This aspect is also described in US-A-3 586 383, in the name of William Trythall. A further valve 59 (which is optional) is arranged at the outlet end of the section 55, between the small pressure tank and a supply line 60. The further valve 59 can be of the same type as valve 53. The supply line 60 can be a flexible hose or a rigid pipe, and in one aspect has an internal diameter of 125 mm (five inches). In one embodiment, the further valve 59 can be omitted. In one aspect, the valve 53 and the further valve 59 operate in cycles that are essentially phase-shifted, so that the valve 53 is open so that the small pressure tank 54 can be filled with drilling cuttings that moves by natural fall from the funnel 51, while the valve 59 is closed to prevent drilling cuttings from flowing into the supply line 60. The valve 53 is closed, so that a charge of drilling cuttings is trapped in the small pressure tank 54. The further valve 59 is opened. In one aspect, air at a pressure of between one and eight bar flows into the small pressure tank through slot 58 and puts the top of the cuttings charge under a positive pressure, so that a charge of cuttings can be pushed out into supply line 60. The further valve 59 can be opened with a small delay, so that the pressure can build up in the small pressure tank 54 before the valve is opened. The portion 55 in the shape of a truncated cone can be inclined to effect a mass flow, which is well known in the prior art, for example as described in publication US-A-3 604 758. Alternatively, the inner wall in the part having shape of a truncated cone, be coated with a friction-reducing material, such as plastic, fiberglass, PTFE or a paint or varnish. The part 55 can alternatively be designed as a chisel, pyramid, wedge, transition or with a square opening. So to speak, the entire charge flows out into the supply line, and then the cycle repeats. Many cycles may occur per minute. The supply line 60 leads to the inlet 7 to the storage tank 1, which is located on the offshore platform 49 or close to the rig if it is a land-based rig, for example within 100-300 meters, although it can be located up to many kilometers (for example three or more ) away.

In use, the storage tank 1 is vented to the atmosphere, either by using a valve or by disconnecting the air supply line 6 from the air inlet 5. Cuttings charges flow into the storage tank 1 through the supply line 60 from the blow tank 52, and gradually fill the storage tank 1. The storage tank 1 can in one aspect take up to 12 cubic meters of drilling cuttings, but in other aspects can be of such a size that it can take between five and 20 cubic metres. When the storage tank 1 is full or nearly full, a valve (not shown) is opened in the supply line to divert the cuttings charges to another storage tank 61. Alternatively, the supply line can be disconnected from the cuttings inlet 7 and connected to the cuttings inlet of another storage tank 61. It can be arranged several storage tanks forming a series of 62 storage tanks.

At a convenient time when the supply ship or the vehicle that will transport the cuttings is in the vicinity of the row of storage tanks 62, for example when a supply ship 64 is moored at or less than three - four hundred meters from the offshore platform, one end of a flexible hose is connected 63 to one of the storage tanks 1, 61. The other end of the flexible hose 63 is connected to at least one storage tank 65 in a row 66 of storage tanks on board the supply ship 64. The storage tank 65 is in one aspect of the type described with reference to figure IA to ID. The flexible hose 63 can be equipped with flotation collars 67 to prevent it sinking into the sea.

Air supplied from a compressor not shown at approx. seven bar, and in another aspect four bar, is supplied through air supply hose 6, and into through the air inlet 5 to a space above the drill shaft surface in the pressure tank 2. The variable speed hydraulic motor 12 is activated to drive the screw conveyor 11. Air at, for example, approx. seven bar or slightly less, is supplied through an air inlet 19 in the outlet box 18. The same or a slightly lower pressure in the lower chamber 18a of the outlet box 18, compared to the pressure exerted over the cuttings, prevents the cuttings from being pushed backwards by the screw conveyor 11 and back into the pressure tank 2. The hydraulic piston-and-cylinder assembly 26 is activated to push the slide frame 21 back and forth to more easily move the drill cuttings into opening 9. The beveled edges on the side of the slide frame parts 22, 23, 24 ensure that when moving away from the opening 9, the parts of the sliding frame slide under the drill bit; and when moving towards the opening 9, the surfaces on the opposite side, which are either at right angles or have a bucket shape, pull the drill cuttings towards the opening 9. The drill cuttings move through the opening 9 and into the screw conveyor 11, which transports the drill cuttings further towards the lower chamber 18a in outlet box 18. Towards the end of the screw conveyor, a double spiral blade can be arranged which makes it easier to break up the drill cuttings. There can also be arranged fingers 17 which more easily break up the drill cuttings, which then fall into the discharge box 18 and are driven forward through the opening 20, into the flexible hose 63, and into the storage tank 65 on the supply ship 64.

The supply ship then transports the filled storage tanks 66 to shore. The storage tanks can be lifted by the supply ship 64 and placed on railway wagons, trucks with flatbed wagons or directly in the processing plant. Alternatively, the drilling cuttings can be released in the same way as that described above for the transfer of drilling cuttings from an offshore platform to the supply ship 64.

Figure 4 shows an alternative feed tank 70, which can be used instead of the blow tank 52 shown in Figure 3A. The tank 70 has a cuttings inlet 71 which leads from a funnel or other container (not shown) into a pressure tank 72 through a filling valve 73. The lower end of the pressure tank 72 is provided with a part 74 in the shape of a truncated cone, which leads to an outlet opening 75. The outlet opening has an outlet valve 76 which selectively opens and closes the opening 75. The outlet valve 76 and the filling valve 73 are in a fixed relationship to each other via a piston 77 which extends from the outlet valve 76 through the filling valve 73 and to a working cylinder 78. The piston 77 can is actuated pneumatically, hydraulically or by the use of a stepper motor to open and close the filling valve 73 and the discharge valve 76, which are arranged so that they operate essentially in an unsynchronized (phase-shifted) manner. An air inlet 81 is arranged at the top of the small pressure tank 72 where air is supplied under pressure, for example approx. seven bar, although it can be supplied at a pressure of between one and ten bar. Air holes are provided

79 in the wall on lot 74, so that cuttings are prevented from sticking to the wall, and to prevent bridging in the cuttings around the outlet opening. Radially from the piston 77 in the small pressure tank 72, fingers or stiff hairs/brushes 80 extend which are moved up and down together with the valves to brush away any drill cuttings that are stuck to the wall or have formed a bridge around the outlet opening (with the exception of the rigid

hair 80, the tank 70 is similar to a previously known tank).

In use, the filling valve 73 and the outlet valve 76 operate in cycles that are essentially not synchronous, so that the filling valve 73 is open so that the small pressure tank 72 can be filled with drilling cuttings that moves by natural fall from the funnel 51, while the outlet valve 75 is closed to prevent cuttings from entering the supply line 60. The filling valve 73 is closed, so that a cuttings charge is trapped in the small pressure tank 72. The discharge valve 76 is opened by activation of the piston 77, which closes the filling valve 73. Air at a pressure of, for example, between one and eight bar flows into the small pressure tank 72 and exerts an overpressure against the top of the cuttings charge to push a charge of cuttings out into the supply line 60. With a relatively small pressure tank, the valves can go through several cycles within a minute. With a pressure tank of 0.3 cubic metres, the valves will go through one or two cycles per minute or every other minute. The supply line 60 leads (as in Figure 2) to the inlet 7 of the storage tank 1, which is located on the offshore platform 49 or close to the rig if it is a land-based rig, for example less than 300 meters away, although it may be up to three or four kilometers away. Necessary ventilation is provided via a ventilation line 82.

This type of feed tank 70 was manufactured by Klockner-Becroit and is shown and described on pages 290-291 of the textbook "Pneumatic Conveying of Solids - a theoretical and practical approach", by Klinzing and Marcus, published in 1997.

Figure 6 shows a system 150 that brings improvements to systems and apparatus described herein, and also to systems described in US Patent 6,702,539, issued March 9, 2004, British Patent Application No. 9913909, filed June 16, 1999; US Patent Application 10/018,124, filed as application PCT/GB00/02158 on June 14, 2000, and European Patent EP 1,187,783 Bl, published on September 24, 2003.

Drilling cuttings flow through a pipe 157 and into containers 151. Each container 151 has a lower, cone-shaped part 155 with a lower opening 158. Near each opening 158 is a device 160 (which is similar to any device or any system described in this document, and which facilitates the movement of drilling cuttings from a tank or a container, for example, but not limited to the device described in figures IA to ID, for example with a movable frame 21 and/or a movable element 102 and associated movement mechanisms). The devices 160 move cuttings into a pipe 159 (for example, like pipe 19, US patent 6,702,539) from which the cuttings can be fed into any suitable tank or container for transport, such as storage tanks 1

or the containers 31 shown in US-A-6 702 539. The containers 31 in said US-A-

6 702 539 may have devices such as device 160 to facilitate the movement of the cuttings.

Compressed gas (for example air and/or nitrogen or another inert gas) can optionally be introduced into the tanks 151 at the same time as or after drilling cuttings have flowed into the tanks 151 through line 157. Compressed gas can optionally be introduced into the tanks 151 through a line 161 and is used against and/or over the drill cuttings, as previously described and/or discussed for any embodiment described in this document. Optionally, compressed gas is used against the devices 160 through lines 162, as described above in the system on figure IA. Compressed gas can optionally be used inside conduit 159 with one or more devices 163 to facilitate the flow of drilling cuttings material through conduit 159. Each of the devices 160 can optionally have a movement element (for example similar to frame 21 or element 102) which makes it easier to move cuttings out of tanks 151.

Figures 3A to 3C show a feed device 470 for supplying drill cuttings (for example, from vibrating screeners or dryers to storage tanks), which has a pressure tank 472 with a non-conical lower portion 474 having two sloping sides 475. In some aspects, the pressure tank has a capacity of between 0.15 cubic meters and one cubic meter, and in one particular aspect 0.33 cubic meters. Cuttings flow into the pressure tank 472 from an overhead inlet funnel 476 through an opening 477. An inlet valve 478 (for example, a dome valve) selectively controls the inflow of cuttings into the pressure tank 472, and in one aspect delivers a predetermined charge cuttings, in one aspect for example 0.15 cubic meters to one cubic meter, and in one particular aspect 0.3 cubic meters.

Optionally, a moving element 482 (for example, similar to the above-mentioned moving element 102 or frame 21) can be moved by means of a moving device 484 (shown schematically; for example, any moving device described in this document) to facilitate the movement of cuttings to and through opening 479 and out of the tank. A twist drill in direction 480 can optionally be used (for example as any twist drill in direction described in this document, and in one aspect similar to the conveyor 11, figure IA) with the tank 472.

Figures 7A, 7B and 7E show a storage tank 200 according to the present invention, which tank has a pressure tank 202 (for example similar to the storage tank 2, Figure IA) with a domed top 204, a generally cylindrical wall 206 and a bottom 208 Drilling cuttings 220 is fed into the tank 202 via an inlet 210 where the flow is controlled by a valve 212. Valve 212 can simply be a check valve of the flap type, which lets cuttings into the pressure tank 202, but does not let cuttings or compressed air out of the pressure tank 202. Optionally, compressed gas can be introduced through a gas inlet 214.

A frame 230 (for example corresponding to the frame 21, figure IA) is pushed over the bottom 208. The frame 230 includes a solid closing element 232, but this can be perforated or made of a screening material. The closing element 232 will selectively close an opening 234 in the bottom 208, where this opening is located above a screw conveyor 236 (similar to the conveyor 11, figure IA) which is rotatably mounted in a tube 240.

As shown in Figure 7A, the closing element 232 will stop, inhibit or reduce the flow of the screw conveyor 236 when the movement device 250 is in the fully retracted position. This closed position is assumed when the storage tank 200 contains drilling cuttings to be stored, to prevent drilling cuttings from being left in the screw conveyor pipe

240. If drilling cuttings are left in the screw conveyor 236 for too long, there is a risk that the drilling cuttings may settle and inhibit or prevent rotation of the screw conveyor when the tank is to be emptied of drilling cuttings. This closed position is also assumed when the storage tank 200 is empty, to prevent cuttings from falling into the screw conveyor 236 and being compressed in the screw conveyor 236. As shown in Figure 7B, the frame has been moved by means of movement device 250 (similar to any movement device described herein), and the opening 234 is no longer closed, and receives material flowing down from the tank 202. The flow of cuttings from the tank 202 to a cuttings outlet end 242 of the pipe 240 is facilitated by means of screw conveyor 236.

As shown by means of arrows 263 in Figure 7E, the conveyor 236 can be driven in reverse to circulate drilling cuttings in the tank 202, so that a more even cuttings mass is obtained. The arrows 264 indicate rotation of the screw conveyor 236 in the direction that causes cuttings to move from the tank 202.

The pipe 240 may optionally have an inclined end plate 247 which makes the drill cuttings move more easily towards the conveyor 236, and to facilitate the movement of the drill cuttings into and

inside the tank 202 when the conveyor is driven in reverse. The pipe 240 can optionally have an inclined end plate 248 placed near the outlet end which presses material down into an outlet chamber 245 and out of the pipe 240. Compressed gas can optionally be supplied in an inlet 243 to accelerate the movement of the cuttings from the outlet chamber and out of the outlet end 242 of the pipe 240.

As shown in Figures 7C and 7D, a storage tank 500 has a pressure tank 502 (for example, similar to the storage tank 2, Figure IA) with a dome-shaped top 504, a generally cylindrical side wall 506 and a bottom 508, and further comprises a plurality of air nozzles 561 through a bottom 508, through which nozzles pressurized gas is injected into a tank 502 (in some aspects upwards and/or downwards in the conveyor 536). The compressed gas supply to the nozzles 561 can be the same as to the inlet 514, or a separate compressed gas supply can be used. Figures 7C and 7D do not show the inlets for air and cuttings. The pressure fluid through the nozzles 561 can be at the same or a higher pressure than the pressure used to transport the cuttings. The cuttings are supplied with air by applying a pressurized fluid through nozzles 561. This is important when storing dry cuttings in the pressure tank 502. The dry cuttings are supplied with air and moved out through the screw conveyor 536. When the cuttings are supplied with air, they behave more like a fluid , and thus the transport of the drilling cuttings becomes more predictable. It may also facilitate the removal of blockages in the conveyor, and may also be used to flush/clean the screw conveyor 536 at any convenient time, such as when the storage tank 500 is empty. The storage tank 500 may optionally include a plurality of air nozzles 562 which project into the pipe 540 and supply the pipe 540 with compressed gas to accelerate the movement of the cuttings, to prevent the cuttings from being compressed and unmanageable plug formations occurring. In one particular aspect, there is a plurality of air nozzles along the entire length of the tube 540. When the closure element 532 is in the closed position, air will penetrate past the edges of the closure element 532 (and, if perforated, through any perforations therein) and ventilate the drill cuttings moving past the frame 530.

A sliding frame (eg, similar to frame 230, Figure 7A) for handling wet cuttings, dry cuttings, or cuttings carrying moisture, allows the discharge rate (from the discharge end 242) to be regulated by regulating the amount of material flowing into the conveyor 236 Adding air to the cuttings, for example cuttings that have been dried using a dryer, facilitates the movement of the cuttings by making the cuttings behave more like a fluid, and makes the cuttings run more predictable.

Figure 8A shows an apparatus 600 according to the present invention for storing and transporting drilling cuttings [which can be wet, dry or carry with it moisture (steam)], where the apparatus possibly has a vortex dryer 610, feeding device 620 and a transport system 650. The vortex dryer 610 delivers cuttings to the feed device 620. The feed device 620 has a pressure tank 622 that delivers cuttings to the conveyor 632. The feed system 620 may in some aspects be similar to the device shown in Figure 3B or 4, or similar to any blow tank or storage tank described -

ves in this writing.

With reference to Figure 8A, compressed gas which is to facilitate drilling along the track is supplied from a compressed gas supply 602 through a line 627 to a feed tank 622, which is identical to the feed device 470 shown in Figures 3A to 3C. Compressed gas from line 627 flows in a line 612 (where the flow is regulated by means of a valve 615) to an outlet box 624. A small amount of compressed gas is applied to the top of the pressure tank 622 through valve 616 to prevent cuttings from being blown back into the pressure tank 622 from a feed screw at the bottom of the pressure tank 622, which feed screw leads drill cuttings to the outlet box 624. Drill cuttings that come out of the outlet box 624 are driven with the help of the pressurized gas into and through the conveyor 632, from where the drill cuttings flow to further processing equipment (for example, a new vortex dryer) or to a storage tank such as the storage tank 1 shown in Figure IA, or to a previously known cuttings box placed on a platform, on land or aboard a ship.

A plurality of pressure monitors 640 are spaced along the conveyor 632, and all include a pressure gauge and interface with a control system, such as a programmable logic controller (PLS) 680. A plurality of gas injection devices 690 are spaced along the conveyor 632, and selectively injects pressurized gas into the conveyor 632 under the control of the PLC unit 680. The devices 690 are supplied with gas through a line 613. A valve 614 regulates the flow in line 613. Valves 614, 615, 616 are in connection with and controlled using the PLC unit 680. The motor-driven feed screw in apparatus 600 is connected to and controlled using the PLC unit 680.

Each device 690 includes a check valve 691 through which air flows and into a conveyor 632, the check valves 691 preventing drill cuttings from flowing into and blocking pneumatic line 613; a controllable valve 692 which selectively regulates the flow of fluid into the conveyor 632; and a control valve 693 which selectively lets pressurized fluid through and into the conveyor 632 when the pressure difference between the line 613 and the pressure at point 640 is less than a predetermined difference, so that the pressure drop through the conveyor is kept constant.

The monitoring and regulation system provides maximum throughput in a safe manner, i.e. avoiding clogging and solids being pushed into a conveyor in an uncontrolled manner. The use of devices 690 and 640 ensures, in one aspect, that the cuttings "flow freely" and move in the conveyor 632. The pressure is monitored at strategic points along its entire length. The observed pressures are maintained by varying the drill bit feed rate and/or auxiliary air flow for consistent (and in some aspects optional) performance. In order to reduce the total pressure drop over the length of the conveyor 632 to a minimum, the length and/or density of a conveyor 632 which is in dense phase flow mode is regulated, whereby the entire cross-section of the conveyor is filled.

The denser a plug is, the higher the friction at the wall, and consequently higher pressure is required to drive the plug down through the conveyor 632. In addition, the relationship between plug length and the pressure required to drive a plug forward is exponential tielt, i.e. that the pressure required to drive a series of plugs separated by "pads" of air is much less than that required to drive a single plug of a length equal to the sum of the plug lengths in the series of plugs.

The feeding device 620 feeds measured plugs of drilling cuttings into the conveyor 632, which plugs have a size determined from the screw or twist drill's external diameter, shaft size and pitch. The feed rate is directly proportional to the speed of rotation of the screw. Local supply of air in the transport/discharge chamber ensures that the drill bit "flows freely", and the auger's speed control/stop/start function, which is controlled by means of the PLC unit 680, provides precise control of the plug formation. This regulation is based on the pressure regime in the conveyor 632, which is strongly dependent on the flow form.

In one aspect, nominal set points are used in the conveyor 632 in terms of maximum pressure drop across the conveyor 632, where one is set to a low dilute phase value, for example two bar, which is used for dried cuttings, and the other, higher, to non-dried cuttings, for example four bar. In one particular aspect, the drill cuttings move in heavy phase through the conveyor at approx. 10 m/s; and in a thin or diluted phase, the drill cuttings move through the conveyor at approx. 30 m/s. The PLC 680 increases the screw speed to the speed necessary to feed the conveyor

632 in such a way that the pressure drop is kept at a certain level between the units 690. For example; with four units 690 placed at an equal distance from each other along the length of a straight conveyor 632, the conveyor 632 is fed with a measured amount of cuttings from the feeder 620. The air supply 602 is activated, and the cuttings plug moves along the conveyor. For example, the starting pressure is set to four bar, and it is expected that the pressure at the end of the conveyor will be slightly above atmospheric when the plug reaches the end. The units 690 regulate the pressure in the line so that there is a relatively constant pressure drop between the units 690. The pressure drop is, for example, 0.5 bar between each unit, so that the pressure after the first unit 690 is regulated to 3.5 bar, after the second unit to 3.0 bar, after the third unit to 2.5 bar, and after the fourth unit to 2 bar, so that the pressure

ket at the end of the conveyor 632 is expected to be approx. 1.5 bar, and one knows with a reasonable degree of certainty that the plug will come out of the end of the conveyor and enter a storage tank. If the pressure drop is within a certain percentage, for example 30%, and in one aspect 15%, and in one particular aspect 10% of the expected, the regulator will open the line 613 and release compressed air, which is regulated by means of the regulator 693, into in the conveyor at the correct pressure.

A standard "PID loop" (Proportional-Integral-Differential) is used, so that if the pressure drop exceeds the desired set point, the speed of the feed screw will be reduced or stopped accordingly. Feedback from the pressure monitors 640 along the conveyor, strategically placed slightly upstream of pipe bends/vertical rises or other areas where turbulence is known to occur in the channel, is used to activate auxiliary air valves in the device 690 if this becomes necessary. An auxiliary air valve is placed at a turbulence point downstream of a pressure monitor, and if the pressure at the monitor falls below a certain percentage value in relation to the sensor located directly upstream of it, for example 80%, air will be supplied directly from source 602 via bypass line 613, which runs along the entire length of the channel, and into the associated auxiliary point. The pressure setting for the auxiliary air is set, for example, to 90% of the pressure value at the monitor 640 located directly upstream, and if this pressure is reached, auxiliary air will also be sent to the next injection point directly downstream, and so on. Each of the valves 691 can supply gas to an associated gas injection nozzle 699 (see, for example, Figure 8B).

Figures 9A to 9C show a feeding device 700 according to the present invention, similar to the feeding device 470 shown in Figure 3B, and which further comprises a hopper 720 with a vibration motor 725 which vibrates the buffer hopper part 721, and further an air injector 722 and a modified outlet box 753. A control system 701 is connected to sensors in the funnel part 721 and the pressure tank part 740. The funnel 720 comprises the buffer funnel 721; an optional vibration motor 722 which vibrates the buffer hopper 721 and its contents; an expansion joint 722; and a valve 723 in an outlet opening 724, which regulates the flow of drilling cuttings from the hopper 721 to the storage tank system 740. The transport device 700 is used, for example, to transport drilling cuttings from vibrating screening devices to storage tanks, and in one particular aspect, the pressure tank 740 has a storage capacity of only about. 0.3 cubic meters.

The pressure tank portion 740 may be like the pressure tanks of Figures IA, 3B-D, 7A and 8A. The pressure tank part 740 has a tank 742 which receives drilling cuttings through an inlet 743. A vent valve 744 will selectively vent the tank 742 and a relief valve 475 will selectively depressurize the tank 742 at a preset level. A conveyor 750 transports cuttings from the tank 742 to an outlet box 751, and the cuttings flows out an outlet end 752 of a pipe 753 to flow into a channel (not shown; for example, as channel 632, Figure 8A). A motor/gear system 760 rotates the conveyor 750.

Compressed gas from a source 770 is delivered in a line 771 to an inlet 772 on the outlet box 753; in a line 773 to an inlet 774 on the outlet end 752 of the outlet box 753; in a line 775 to an inlet 776 on the outlet box 751; and in a line 777 to an inlet 778 on the pressure tank 742. The inlet 778 can have a very small diameter, as this should only equalize the pressure in the tank 742 with the pressure in the box 751 or in the outlet end 752. Each of the lines has a non-return valve 779. The funnel 721 can optionally be placed on insulation mounts or vibration-proof mounts 782.

All the operating components in the transport device 700 are in connection (see dashed line) with a control unit 701 (for example as the control unit 680, figure 8A).

Each of the lines 771, 773, 777 has an on-off valve for flow regulation, respectively 771a, 773a, 777a (for example similar to valves 692); a pressure regulator, respectively 771b, 773b, 777b (similar to pressure units 690; the pressure is set manually or with the help of the control system, as the setting pressure in reality determines the highest working pressure in the system, for example two bar for dry cuttings or four bar for wet cuttings from the vibrating sight devices); and flow control valves, respectively 771c, 773c, 777c, which regulate the rate of pressure change (can be, for example, needle valves, throttle discs or similar devices).

Via line 777, gas is fed to the tank 742 at a pressure equal to the pressure in the gas that is fed to the outlet box 753 in line 771, and in the gas that is fed to the outlet box 751 in line 773, so that the pressure drop across the conveyor (feed screw) 750 is minimal. The cuttings feed rate from the system 700 is therefore determined by the conveyor 750 rotational speed. In one aspect, gas is introduced downstream of an outlet valve 752a in conduit 773. With the outlet valve 752a closed, the tank 742 can be vented to the atmosphere, allowing the tank 742 to be refilled while drilling cuttings are transported downstream the outlet end 752.

The control system shown in Figures 9A to 9C can be used for any feeding device or storage tank described in this document.

Figure 10 shows a system 800 according to the present invention, with a drilling cuttings dryer 801 that dries drilling cuttings, for example a vortex dryer or a drilling cuttings dryer of the type described in GB-A-2 297 702. The vortex dryer 801 can be placed and fed immediately below the discharge end of a vibrating screening apparatus (not shown) or at the end of a chute (not shown) fed by a plurality of vibrating screening devices (not shown). The cuttings to be dried are, however, dried in the cuttings dryer 801 for a specific time or within a limited time interval. If the drilling cuttings are very wet, for example because the vibration screening devices have been exposed to "boundary particle clogging", where a large amount of drilling fluid will wash over the vibration screening device and into the cuttings dryer together with the cuttings, all or parts of the drilling cuttings will not be dry enough for transport with the pressure tank, or it will require further drying, further processing or storage and transport in or from a special storage tank. Thus, a transport system 802 with rotary drills 803, 804, which is driven by means of a motor/gear system 805, will selectively deliver drilling cuttings to a storage tank 810 or to a pressurized feeding device 820, on the basis of measurements carried out using a moisture sensor 821 (or sensors). Non-wet cuttings go to the pressurized feeder 820; if "wet" cuttings are detected, the drills will be reversed and the cuttings will be taken to storage tank 810 (which may be similar to storage tank 1). A sensor (or sensors) 821 reads the moisture content in the drill cuttings. If the sensor 821 reads "wet" cuttings (for example with a moisture content of one, three or five percent), the rotary drill is reversed and the cuttings are fed to the storage tank 810 for "wet" cuttings; and if

the cuttings is dry (for example, less than five percent moisture or oil content), the twist drill is set in forward motion and the cuttings are delivered to the pressurized feeder 820, which blows the cuttings to the dry cuttings box 825, which may be equal to the cuttings storage tank 1. In one particular arrangement, the cuttings, after it has been transported to the storage tank 810, could be transported to the box 825 for drying the cuttings. Optionally, the sensor 821 may have a protective shield 821a for components outside a funnel and a protective shield 821b for components 821c inside a funnel (which applies to any humidity sensor or sensing device in any system described herein). Such a shield 821b protects sensor components 821c from drilling cuttings falling down a funnel. Multiple sensors 821 placed at intervals around the funnel 822 may be used (which applies to any system according to the present invention with sensor devices). In some aspects, such sensors are effective with a cuttings quantity that is at least 2.5 cm (one inch) thick and has an area of at least 20 to 26 square centimeters (three to four square inches). Such sensors can provide continuous readings for a more accurate application in a control system 829 that controls communication with components of the system 800, as indicated by dashed lines.

The control system 829 can switch the cuttings flow from system 825 (for example for sufficiently dry cuttings) and to system 810 (for example for relatively wet cuttings). In any system described herein, a first storage device or a "dry" storage device may be a storage tank, the hold of a ship, or a hold or reservoir on board a platform or in one or more platform legs. Such a storage device can, regardless of its shape and according to the present invention, have an overpressure system and a bottom supply system for air, so that the drilling cuttings material can be supplied with air from below (for example through a perforated bottom plate or element), which gives a material in a diluted phase, which is easier to transport. In one particular aspect, the humidity sensors are models MCT 300, MCT 600 and MCT 101-T from Process Sensors Corporation, Milford, Massachusetts, USA. As with any pressurized tank in any system herein, a cuttings tank 820a in system 800 may have a volume of between 0.05 m<3> and 0.2 m<3>. Figure 11 shows a system 830 according to the present invention, where a conveyor 831 driven by means of a motor/gear system 832 feeds drilling cuttings into two vortex dryers 833. Drilling cuttings that are processed in the vortex dryers 833 are fed into a hopper 835 in a feeding system 836 (similar to system 820, figure 10) by means of a transport system 834. One of the vortex dryers 833 has a screen that is stopped if the cuttings particles have "limit size" ("limit size" means that the cuttings particles produced during drilling have a size distribution equal to the size distribution of the mesh openings of the sieves in the vibrating sieve apparatus; boundary particles can get stuck in the sieve openings and stop the sieve), and then wet drill cuttings will flow out of the vortex dryer. A sensor 831 notices this, and it sends a signal to the second vortex dryer, which is then switched on, and which has a screen with a different mesh size than the first vortex dryer and can thus handle this particle size. The system 836 produces treated drilling cuttings which flows out into a channel 837. Figure 12 shows a system 850 according to the present invention, corresponding to the system of Figure 11, with a transport system 851 driven by means of a motor/gear system 852, which transports drilling cuttings from vibration screening devices, hydrocyclones and/or centrifuges for vortex dryers 853 which in turn deliver dried drilling cuttings to a feeding device 856 (similar to the feeding device 836) via a chute 845, where the feeding device feeds the drilling cuttings into an outlet channel 857. Beneath the vortex dryers 853 there are hoppers 854 that feed the feeding device 856. Figure 13 shows a system 900 according to the present invention for a drilling platform R, where the drilling cuttings (for example from vibration screening devices, centrifuges) flows to a feeding device 906 (similar to feeding device 820, 836, 856) with a vortex dryer 907 The feed device 906 processes the drill cuttings and feeds it into a storage tank (which may be of the type v ist on Figure IA, 1C or 7A). If the reading from the moisture sensor in the feeding device 906 shows that the drill cuttings are dry, a control unit (not shown) sends the flow of drilling cuttings from the feeding device 906 either to the internal bulk storage 910 in the platform R, or to an internal hold 911 in the supply ship B (if a supply ship is available). If the reading from the moisture sensor shows that the cuttings are wet, the control unit sends the flow of cuttings to storage tank 1 for wet cuttings on platform R or on board ship B. The bulk storage units built into platform R and the internal hold of supply ship B can handle dry bulk material, but not wet bulk material. By assessing how dry the cuttings are, it is therefore possible to send the cuttings to storage in the internal bulk storage units 910 built into the platform R, or in the internal hold 911 in the supply vessel B. The wet cuttings can be filled and stored in a storage tank of the type shown in Figure 1, or reprocessed in a cuttings dryer such as a vortex dryer or a cuttings dryer of the type described in WO 2004/000762 and GB-A-2 297 702, and then the moisture is measured on new. Figure 14 shows a system 920 according to the present invention, where vibrating screening devices 921 feed cuttings material onto a screw conveyor or conveyor belt 922, which leads the material to a vortex dryer 923 which delivers dried material to a pressurized screw feed device 924 (similar to the feed screw device shown in figures 8A, 9A and 10 to 12). Material processed through the pressurized feed screw device 924 flows out and is carried on in line 925. Fluid recovered from the vortex dryer 923 flows in a line 926 to a storage tank 927, from where it is pumped by a pump 928 to a centrifuge 930 via a line 929. Solids from the centrifuge 930 are carried away in a line 931 for disposal, and liquid is pumped into a line 932 to a storage tank 933. A pump 934 pumps liquid from the storage tank 933, either in a line 939 to a sludge return system 935 ( with a valve 936 closed and a valve 938 open); or back to the vortex dryer 923 in a line 937 (with valve 936 open and valve 938 closed). Figure 15 shows a system 950 according to the present invention, where a pressurized feed screw device 952 selectively feeds cuttings material to a storage tank 953 for dried cuttings material or to a "wet" storage tank 954. A moisture meter 955 located in the funnel 968, reads the moisture content in the cuttings material, and the control unit 960, which is connected to the moisture meter 955, controls a diverter valve 956 in such a way that a sufficiently dry cuttings goes to the storage tank

953 with flow to the "wet" tank system 954 closed; and wet cuttings go to the "wet" tank system 954 with flow to the storage tank 953 closed. Optionally, each storage tank 953 can have its own associated diverter valve 957, so that the flow to each box is selectively controlled using the control unit 960.

In some aspects, the pressurized feed screw device 952 is similar to the device of Figure 8A; the wet storage tank 954 is similar to the wet storage tank of Figure 10; and the storage tanks 953 are similar to the storage tanks of Figures 1B, 3B and 10. The control unit 960 controls the motors of each of the conveyors in the system 950.

In each of the systems in figures 10 to 15, there is an appropriate control system that controls the various components and is connected to the humidity sensors, valves, conveyors and motors.

The present invention thus also relates to a method for transporting drilling cuttings from an offshore platform located in the water to a ship lying on the water next to said offshore platform, where said drilling cuttings are saturated with drilling fluid, and where the method includes feeding drilling cuttings from a drilling operation to a cuttings processor, the cuttings processor comprising a rotary ring screening device; treating the cuttings with the cuttings processor and producing treated cuttings and secondary material, where the secondary material includes cuttings and drilling fluid, and where the treated cuttings includes drilling mud; feeding the treated cuttings from the cuttings processor to a positive pressure blowing tank device, the positive pressure blowing tank device having a tank that receives the treated cuttings from the cuttings processor; feeding the secondary material from the cuttings processor to a secondary device; and supplying compressed air to the tank in the overpressure blowing tank device to drive cuttings out of the tank and drive the cuttings forward to a tertiary device. In one particular aspect, the secondary device is a decanter centrifuge device (decanting centrifuge), the method further comprising treating the secondary material with the decanter centrifuge device and producing a secondary drilling fluid and secondary drilling cuttings. In one aspect, the cuttings, before being passed from the cuttings processor to the blow tank facility, are fed into a crusher roll device to break up drill cuttings agglomerates, and then passed from the crusher roller device to the positive pressure blow tank device.

In one aspect, and in methods where the secondary device is a decanter centrifuge device, the methods include treating the secondary material with the centrifuge device and producing secondary drilling fluid and secondary drilling cuttings, recycling said secondary drilling fluid for reuse during a drilling operation, feeding said secondary drilling cuttings to a crushing roll device for to break up agglomerates of said secondary drilling cuttings, to feed secondary drilling cuttings from the crushing roller device to the overpressure blowing tank device; and/or said drilling cuttings are fed into a crushing roller device before being fed from the cuttings processor to the overpressure blowing tank device, to break up drilling cuttings agglomerates, and then said drilling cuttings are fed from the crushing roller device to the overpressure blowing tank device.

The invention thus also relates to a method for transporting drilling cuttings material, where the drilling cuttings material includes drilling cuttings and drilling fluid, as the method includes feeding the drilling cuttings material into a drilling cuttings processing apparatus, where the drilling cuttings processing apparatus comprises a rotating ring sieve device, treating the drilling cuttings material with the drilling cuttings apparatus and producing treated drilling cuttings and secondary material, where the secondary material includes drilling cuttings and drilling fluid, said treated drilling cuttings including drilling fluid, to transport treated drilling cuttings from the drilling cuttings processing apparatus to a flow pipe device by means of pressurized fluid, to apply air under overpressure to the flow pipe device to cause continuous movement of treated drilling cuttings through it, to continuously move the drill cuttings by means of the compressed air, to a separation device; and to carry out a continuous separation of treated drilling cuttings and air by means of the separation device.

The invention thus also relates to a system for transporting drilling cuttings, where the system has a transport device for transporting drilling cuttings, a drilling cuttings processing device that processes the drilling cuttings to be fed into a tank device, where the drilling cuttings processing device includes a rotating ring screening device, a tank device that receives drilling cuttings from the drilling cuttings processing device .

The invention thus relates to a method for transporting a mass, where the mass includes cuttings that are saturated with fluid, the method includes feeding the mass into a cuttings processor, where the cuttings processor includes a rotating ring sieve device; reducing the weight of said pulp with the cuttings processor by removing fluid from the pulp, the cuttings processor producing a produced material that includes cuttings and fluid; feeding the produced material from the cuttings processor into a tank; applying a pressurized gas to the tank to cause the produced material to flow out of the tank, the tank including a conical funnel portion which, at least during outflow of produced material, forms the lower part of the tank, and the taper angle is less than a critical value which is necessary to cause mass flow of the produced material.

The invention thus relates to systems and methods for transporting material that has a low slurry density (for example with a specific gravity of between 2.3 and 4.0, and in one aspect about 2.7 or less) and a high particle density (for example 2 Ibs/gal (approx. 240 kg/m<3>) - 4 Ibs/gal (approx. 480 kg/m<3>)), using a pneumatic fluid at excess pressure, such as air or steam. In other aspects, the cuttings to be processed, for example from vibrating screeners, have a specific gravity of 1.8 (1800 kg/m<3>; 15 Ibs/gal), and some types of high density cuttings have a specific gravity of 2.5 ( 21 Ibs/gal (approx. 2520 kg/m<3>)). In one particular aspect, the material is a slurry that includes cuttings from a wellbore, well drilling fluids, drilling mud, water, oil and/or emulsions, where the cuttings make up different weight percentages of the slurry. "Slurry density" refers to material from a well in an air stream, and "particle density" refers to the material before it enters an air stream.

In certain aspects, systems and methods ensure a continuous or near-continuous transport of material.

Systems with storage facilities for solids to be transported, and devices for mixing heavy solids to be transported with a pneumatic fluid, for example, but not limited to air or steam at overpressure, i.e. above atmospheric pressure. In one aspect, the movement speed of the solids is reduced by, for example, using a separator device, and then the solids are collected in a collection device (for example, tanks, boxes, storage containers). In some aspects, self-draining tanks are used which have an overpressure system for emptying solids. Such tanks can have systems that measure the amount of solids in the tanks and give an indication of this amount.

In one aspect, the apparatus will reduce the density of a material slurry. Such an apparatus includes a retardation/separation device.

Claims (16)

1. Method for treating drill cuttings, where the method comprises collecting drill cuttings from at least one of a vibration screening device, a hydrocyclone, a centrifuge or drill cuttings dryer (801, 907), measuring the moisture content of the drill cuttings to find a moisture value, where the method is characterized by compare the moisture value with a predetermined threshold value and transport the cuttings along a path for dry cuttings if the moisture value is below the predetermined threshold value, or transport the cuttings along a path for wet cuttings if the moisture value is higher than the threshold value. 2. Method according to claim 1, where the path for dry cuttings comprises a feeding device (820, 906, 952) and a compressed air conveyor, the method further comprising the steps where the feeding device (820, 906, 952) is filled with cuttings, which feeding device ( 820, 906, 952) feeds drilling cuttings into the compressed air conveyor. 3. Method according to claim 2, where the compressed air conveyor is an over-pressure conveyor. 4. Method according to claim 2 or 3, where the compressed air conveyor leads to one of: a storage vessel (1, 810, 953, 954), a bulk tank on an oil or gas platform (910) and a cargo hold in a supply boat (911) , the method further comprising the step where the drill cuttings are transported through the compressed air conveyor to one of the storage vessels (1, 810, 953, 954), the bulk tanks on an oil or gas platform (910) and the hold in a supply boat (911). 5. Method according to any one of claims 2 to 4, wherein the step of measuring the moisture content of the cuttings is carried out using a moisture meter (821, 955) which is placed in the feeding device (820, 952). 6. Method according to any one of claims 2 to 5, where the feeding device (820, 952) comprises a funnel (822, 968) and a pressure tank (820a), the step of measuring the moisture content in the cuttings being carried out with a humidity meter (821, 955) which is placed in the funnel (822, 968). 7. Method according to any one of claims 1 to 6, where the path for wet drilling cuttings comprises a feeding device and a compressed air conveyor, the method further comprising the steps where the drilling cuttings are filled in the feeding device, and where the feeding device feeds the compressed air conveyor with drilling cuttings. 8. Method according to claim 7, where the compressed air conveyor is an over-pressure conveyor. 9. Method according to claim 7 or 8, where the compressed air conveyor leads to a storage tank, the method further comprising the step where the drill cuttings are transported through the compressed air conveyor to the storage tank. 10. Method according to claim 7 or 8, where the compressed air conveyor leads to a cuttings dryer for further drying. 11. Method according to claim 1, where the drilling cuttings from at least one of a vibration screening device, a hydrocyclone, a centrifuge or a drilling cuttings dryer (907) is fed into a feeding device (952), whereupon the moisture content of the drilling cuttings is measured using a in this placed moisture meter (955) to find a moisture value, the feeding device (952) feeds the drill cuttings into a compressed air conveyor, where the conveyor contains a diverter valve (956, 957), the method further comprising the steps where the drill cuttings, if the moisture value is below that on predetermined threshold value, via the diverter valve (956, 957) is directed to the path for dry cuttings, or the cuttings is guided to the path for wet cuttings if the moisture value is higher than the threshold value. 12. Method according to any one of claims 1 to 11, wherein a screw conveyor (802) receiving the drill cuttings is placed under the at least one of a vibrating screening device, a hydrocyclone, a centrifuge or a cuttings dryer (801), the screw conveyor (802) comprises a drive device (805) which is such that the screw conveyor can be reversed to lead the cuttings in one direction to the path for dry cuttings and in another direction to the path for wet cuttings. 13. Method according to any one of claims 1 to 12, wherein the predetermined threshold value is a moisture content of one of: 5%, 3% and 1%. 14. A system for treating drilling cuttings, where the system comprises: - at least one of: a vibration screening device; a hydrocyclone; a centrifuge; and a cuttings dryer (907); the system further comprising a feeder (906, 952) for feeding cuttings received from at least one of: a vibrating screening apparatus; a hydrocyclone; a centrifuge; and a cuttings dryer (907), into a compressed air conveyor, characterized in that the system further comprises a dry compressed air conveyor path, a wet compressed air conveyor path and redirection means (956, 957) for guiding the cuttings into said dry compressed air conveyor path or said wet compressed air conveyor path, a moisture meter (955) for measuring moisture content in the drilling cuttings, where said moisture meter measures the moisture content in the drill cuttings to obtain a moisture value, a control unit (960) to obtain said moisture value from the moisture meter (955) and compare the moisture value with a predetermined threshold value and activate said redirection means in relation to said moisture value and transport the drill cuttings into said dry compressed air conveyor- road if the humidity value is below the predetermined threshold value or into said wet compressed air conveyor road if the humidity value is above the predetermined threshold value. 15. System according to claim 14, in which said diversion means comprise a diverter valve (956, 957). 16. System for treating drilling cuttings, where the system comprises: - at least one of: a vibration screening device; a hydrocyclone; a centrifuge; and a cuttings dryer (801); - a wet road comprising a storage tank (810); - a dry path comprising a pressurized feed device (820) for blowing the cuttings into a container (825) for dry cuttings; - a screw feeder (802) for guiding the drill cuttings received from at least one of: a vibrating screening apparatus; a hydrocyclone; a centrifuge; and a cuttings dryer (801), into selectively a storage tank (810) on said wet road or to said pressurized feeder (820) on said dry road; - a moisture meter (821) for measuring moisture content in the drill cuttings, where said moisture meter measures the moisture content in the drill cuttings to obtain a moisture value; and - a control system (829) for obtaining said moisture value from the moisture meter (821) and comparing said moisture value with a predetermined threshold value and activating said screw feeder (802) according to said moisture value, where said screw feeder is driven to move drilling cuttings to said pressurized feeder (820) if the moisture value is below the predetermined threshold value or said screw feeder is reversed to move cuttings to said storage tank (810) on said wet path if the moisture value is above the predetermined threshold value.