Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 1-
APPARATUS AND METHOD FOR FACILITATING SEPARATION OF
HYDROCARBONS FROM HYDROCARBON LADEN DRILL CUTTINGS
PRODUCED IN THE DRILLING OF WELLBORES
The present invention relates to an apparatus and
method for facilitating separation of hydrocarbons from
hydrocarbon laden drill cuttings produced in the drilling
of a wellbore.
In the drilling of a borehole in the construction of
an oil or gas well, a drill bit is arranged on the end of
a drill string and is rotated to bore the borehole. A
drilling fluid known as "drilling mud" is pumped through
the drill string to the drill bit to lubricate the drill
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 normal therefore
to recover and re-use the used drilling mud, but this
requires the solids to be removed from the drilling mud.
This is achieved by processing the drilling fluid. The
first part of the process is to separate the solids from
the solids laden drilling mud. This is at least partly
achieved with a vibratory separator, such as those shale
shakers disclosed in US 5,265,730, WO 96/33792 and WO
98/16328. Hydrocyclones and centrifuges may also be used
to separate the drill cuttings from the drilling mud.
The separated solids are contaminated with
hydrocarbons from the drilling mud or from natural oils
in the formation being drilled. The solids need to be
processed in order to remove the hydrocarbons therefrom.
The drill cuttings can then be disposed of without harm
to the surrounding environment or, for example, they can
be used as aggregate for building roads or in other
CA 02731553 2012-11-05
= - 2-
=
construction projects.
The prior art discloses a variety of systems and
methods for the thermal treatment of material and thermal
treatment of drilled cuttings material. For example, and
not by way of limitation, the following U.S. Patents
present exemplary material treatment systems: 5,914,027;
5,724,751; and 6,165,349.
In accordance with the present invention, there is
provided an apparatus for facilitating separation of
hydrocarbons from hydrocarbon laden drill cuttings, the
apparatus comprising a thermal treatment apparatus and a
feeder apparatus, the thermal treatment apparatus
comprising a reactor and the feeder apparatus comprising
a metering screw for receiving and feeding drill cuttings
material into the reactor, the apparatus further
comprising a control system for controlling the metering
screw. Preferably, the metering screw feeds directly into
the reactor.
Preferably, the control system ensures that the
metering screw is maintained full or nearly full of
material. Preferably, this can be achieved by having a
container from which the metering screw draws the
hydrocarbon laden drill cuttings and ensuring the
container always has a supply of hydrocarbon laden drill
cuttings. Advantageously, the control system controls the
mass flow rate of hydrocarbon laden drill cuttings into
the reactor by adjusting the speed of the metering screw
apparatus.
Preferably, the reactor has a material inlet and the
metering screw passes therethrough, an airlock maintained
between the metering screw and the material inlet.
Advantageously, the hydrocarbon laden drill cuttings in
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 3-
the screw feeder maintains the airlock. Preferably, the
apparatus further comprises at least one temperature
measuring device, the
control system providing for
control of temperature in the reactor by controlling the
mass flow rate of material into the thermal reactor by
controlling the metering screw that feeds material into
the thermal reactor.
Preferably, the thermal treatment apparatus has an
engine rotating friction elements within the reactor and
performance of the engine is optimized by controlling the
metering screw that feeds material into the reactor
vessel, for example, based on sensed speed in rpm's of
the engine.
Advantageously, the feeder apparatus further
comprises a container, the metering screw arranged
therein or therebelow. Preferably, the container can
store between three and eighteen cubic metres of
hydrocarbon laden drill cuttings. Advantageously, the
container has an open top. Preferably, the container has
a lid, which is open and the interior of the container is
maintained at substantially atmospheric pressure,
although may be exposed to a slight increase in pressure
due to the inlet from a positive pressure pneumatic
conveying system introducing hydrocarbon laden drill
cuttings into the container. Advantageously, the
container has at least two sides which converge towards
the metering screw. Preferably, the container comprises a
slider mechanism for moving hydrocarbon laden solids to
the metering screw. [Preferably, the metering screw is
driven by a hydraulic double acting piston and cylinder
to draw the frame over an interior surface of the
container to move the hydrocarbon laden drill cuttings to
the metering screw. Advantageously, the container has a
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 4-
flat, substantially bottom section, the slider frame
apparatus sliding hydrocarbon laden drill cuttings on the
flat bottom. The bottom section may be planar and may be
horizontal. Advantageously, the apparatus further
comprises at least one load cell apparatus for weighing
the container to give an indication of how much
hydrocarbon laden drill cuttings there is in the
container. Preferably, the load cell is arranged beneath
the container to provide information to indicate an
amount of material in the container.
Advantageously, the reactor has a rotor therein, the
apparatus further comprising a speed measuring apparatus
to measure the rotational speed of the rotor and sends an
indication of the speed to the control system.
Preferably, if the speed of the rotor slows down, the
control system slows down the metering screw to reduce
the amount of hydrocarbon laden drill cuttings entering
the reactor.
Preferably, the apparatus further comprises a
drilling mud processing apparatus which comprises a shale
shaker, centrifuge, vortex dryer, hydrocyclone or other
solids control equipment.
Advantageously, the apparatus further comprises a
second feeder apparatus feeding the reactor. Preferably,
the apparatus further comprises a third feeder apparatus
feeding the reactor.
Preferably, the metering screw is inclined upwardly
towards the reactor. Most preferably, the screw feeder is
inclined at an angle of between three and ten degrees and
preferably about four degrees from horizontal.
Preferably, the apparatus further comprises a load
cell arranged to measure the weight of the reactor to
provide information to the control system to control the
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 5-
discharge rate of drill cuttings from the reactor.
The present invention also provides a method for
facilitating separation of hydrocarbons from hydrocarbon
laden drill cuttings using a thermal treatment apparatus
and a feeder apparatus comprising a metering screw the
method comprising the steps of the metering screw
receiving and feeding drill cuttings material into the
thermal treatment apparatus, the thermal treatment
apparatus comprising a reactor, the method further
comprising the step of a control system controlling the
metering screw. Preferably, the reactor has a rotor
therein, the apparatus further comprising a speed
measuring apparatus to measure the rotational speed of
the rotor and sends an indication of the speed to the
control system. Preferably, if the speed of the rotor
slows down, the control system slows down the metering
screw to reduce the amount of hydrocarbon laden drill
cuttings entering the reactor. Advantageously, the
apparatus comprises a torque measuring device to measure
the torque on the rotor and sends an indication of the
torque to the control system. Preferably, if the torque
of the rotor increases above a predetermined threshold,
the control system slows down the metering screw to
reduce the amount of hydrocarbon laden drill cuttings
entering the reactor.
Advantageously, the method further comprises the
step of measuring the weight of the reactor including the
hydrocarbon laden drill cuttings therein and providing
the measurement to the control system to control the
discharge rate of drill cuttings from the reactor.
Preferably, the control system controls the amount of
material in the reactor. Advantageously, the reactor
comprises a rotating drum, amount of material is
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 6-
controlled by monitoring the speed and/or torque of
rotation of the rotating drum and controlling the speed
of the screw feeder in response thereto. Preferably, the
control system controls the amount to maintain an airlock
at the discharge from the thermal reactor.
Advantageously, the control system maintains a desired
temperature in the thermal reactor by adjusting the speed
of the screw feeder.
The present invention, in certain aspects, discloses
a thermal treatment system for removing liquid from drill
cuttings material, the thermal treatment system having a
metering screw apparatus for receiving and feeding drill
cuttings material to a reactor system, including
apparatus and a control system for controlling the
metering screw apparatus and for insuring that the
metering screw apparatus is maintained full or nearly
full of material and/or for controlling the mass flow
rate into a reactor of the thermal treatment system by
adjusting the speed of the metering screw apparatus.
The present invention, in certain aspects, discloses
a thermal treatment system for treating drill cuttings
material in which apparatus and a control system are
provided to maintain an airlock at a material inlet to a
thermal reactor of the thermal treatment system by
maintaining a desired amount of material in a container
above a feeder system that feeds material into the
thermal reactor. In
one aspect in such a system
apparatus and a control system provide for control of
temperature in the thermal reactor by controlling the
mass flow rate of material into the thermal reactor by
controlling a metering screw system that feeds material
into the thermal reactor.
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 7-
For a better understanding of the present invention,
reference will now be made, by way of example, to the
accompanying drawings, in which:
Figure lA is a schematic view of an system in
accordance with the present invention;
Figure 1B is a top view of the system shown in
Figure 1A;
Figure 1C is a partial side view of part of the
system shown in Figure 1A;
Figure 1D is a view in cross-section of a feeder
system of the system shown in Figure 1A;
Figure lE is a view in cross-section of a feeder
system useful in a system like the system shown in Figure
1A;
Figure 1F is a view in cross-section of a container
of a feeder system in accordance with the present
invention;
Figure 2A is a side view partly in cross-section of
a feeder system in accordance with the present invention;
Figure 2B is an end view of the feeder system shown
in Figure 2A;
Figure 2C is a top view of the feeder system shown
in Figure 2A;
Figure 2D is a top view of part of the feeder system
shown in Figure 2A;
Figure 2E is an end view of a slide of the feeder
system shown in Figure 2A;
Figure 3 is a top view of a system in accordance
with the present invention;
Figure 4 is a schematic view of a system in
accordance with the present invention; and
Figure 5 is a schematic view of a system in
accordance with the present invention.
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 8-
Figures lA to 1D illustrate a system 10 in
accordance with the present invention which has a thermal
reactor section 12 and a feeder system 40 in accordance
with the present invention. Drill cuttings material M is
fed from the feeder system 40 into a reactor vessel 14
(mounted on supports 18) of the thermal reactor section
12 through an inlet 13.
Treated material exits the
vessel 14 through a discharge outlet 15. An
engine
section 16 has an engine 17 that rotates internal rotors
(or friction elements) 8 in the vessel 14. The vessel 14
has, optionally, a plurality of inlets 7 into which drill
cuttings material for treatment can be fed. Load cell
apparatuses 3 in communication with a control system CS
indicate the amount of material in the vessel 14. The
reactor vessel may be of the type disclosed in UK Patent
Application Publication No. 2,337,265.
Figures 1C and 1D illustrate the feeder system 40
which has a base 42 with sides 44, 44a, and 44b, and a
bottom 45 within which is mounted a container 46 for
holding drill cuttings material to be fed to the vessel
14. The bottom 45 may be a skid and the sides 44, 44a,
44b may be structural beams making up a frame. It is
within the scope of the present invention to have a
container 46 with a substantially horizontal level bottom
with a metering screw system beneath it which is also
substantially horizontal; or, as shown in Figure 1D, the
container 46 has an inclined bottom 48 with a trough 47
and a metering screw system 60, which receives material
from the container 46. The inclined bottom 48 may be at
an incline of between one and ten degrees, preferably
between three and five degrees and most preferably about
four degrees from horizontal. The system 60 inclined to
correspond to the incline of the bottom 48. Material
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 9-
falls into a trough 3 at the bottom of the container 46
(in which a screw 62 of the system 60 is located). The
bottom of the container 46 may be any suitable shape to
facilitate the flow and movement of material to the
system 60; for example as shown in Figure 1F, walls 46w
of a container 46a are inclined above a trough 47a.
Drill cuttings material from a wellbore drilling
operation indicated by an arrow 49 is fed by an auger
apparatus 50 through an inlet 51 into the container 46.
The drill cuttings material may come from any suitable
apparatus or equipment, including, but not limited to,
from shale shaker(s), centrifuge(s), tank(s), cuttings
storage apparatus, vortex dryer(s), hydrocyclone(s), or
any solids control equipment that produces a stream or
discharge of drill cuttings material.
Optionally drill cuttings material is introduced
into the container 46 through a line 53 from a system 54
(not directly from drilling operation equipment, like
shale shakers or centrifuges) that transfers and/or
transports drill cuttings material (for example, but not
limited to, the known BRANDT FREE FLOW (TRADEMARK)
cuttings transfer and transportation system).
Optionally, the material is fed to a vortex dryer VD for
processing and the solids output of the vortex dryer is
fed to the container 46.
A valve assembly 56 is used to selectively control
the flow of free flowing material (for example liquids)
from the system 60 into the vessel 14 as described below.
Such liquids are not moved so much by the screw 62 as
they flow freely past the screw 62 to the valve 56
through the system 60.
Optionally, (especially for material that may be
easily compacted) if additional lubricant is needed for
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 10-
the material to be introduced into the vessel 14, the
lubricant is injected into material in the system 60
through injection ports or nozzles 57 from a lubricant
system 58 (for example, but not limited to, a lubricant
that is base oil, an oil component of a drilling fluid).
In one aspect, if a load on a motor 52 which rotates the
screw 62 (for example an hydraulic motor) is increased
beyond a pre-selected set point, lubricant is injected
through the nozzles 57 to facilitate material flow within
the system 60 and lessen the load on the motor 52.
Optionally, a pump 70 in fluid communication with
the interior of the container 46 pumps free liquid from
within the container 46 to reduce the liquid content of
the material. This can optimize the performance of the
system by insuring that the feed to the vessel 14 has a
reduced amount of free liquid. Optionally, as shown in
dotted line in Figure 1D, a pump 70a may be located
within the container 46 (in one aspect, in the material
M).
As shown in Figure 1E, a conveyor apparatus for
conveying material to a vessel like the vessel 14 can
have a constant pitch screw 62s; or, as shown in Figure
1D, the screw 62 of the system 60 has areas of different
pitch, for example areas 62a, 62b, (with the tightest
pitch at the end near the motor 52) and 62c which reduce
the likelihood of material compaction in the system 60
and facilitates material flow in the system 60. In one
particular aspect, the system 60 is about ten inches in
diameter; the container 46 has a volume of about eighteen
cubic meters; and the bottom 45 is about four meters
long. In certain aspects, the container 46 has therein,
at any given time, between three to sixteen cubic meters
of material and, in one particular aspect, about sixteen
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 11-
cubic meters. The screw may have two, four or more areas
of different pitch.
In one aspect, during operation of the system 10, an
amount of material is maintained in the container 46 (for
example in one aspect, a minimum of about three cubic
meters) so that an airlock is maintained at the inlet 13.
By insuring, using the control system CS as described
below, that a sufficient amount of material is within the
vessel 14, an airlock is maintained at the discharge
outlet 15 of the system 12.
Load cell apparatuses 72 (one, two, or more)
indicate how much material (by weight) is in the
container 46.
This correlates with the level of the
material so that, as shown in Figure 1C, a level "a" can
be maintained indicative of the volume of material
sufficient to maintain the airlock at the inlet 13
described above. The load cell(s) is also used with the
control system CS to calculate the rate of metering of
material into the vessel 14 and to set and control
maximum and minimum levels of material in the container
46. In
one aspect the level "a" is between 50mm and
1000mm and, in one particular aspect, is 500mm.
Optionally, or in addition to the load sensor(s) 72, a
level sensor and indicating apparatus 79 is used to
obtain data to determine the amount of material in the
container 46 and its level. In one aspect, the apparatus
79 is an ultrasonic distance measuring apparatus with an
integral or separate display and interface for the
control system CS.
Personnel P can, optionally, remove free liquid from
the top of material in the container 46 (for example from
the top thereof) by manually placing an end 75a of a pipe
75 within a conduit 77 connected to the container 46 to
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 12-
pump free liquid (for example drilling fluid and some
water, inter alia); from the container 46 thereby
reducing the liquid content of material introduced into
the vessel 14. In one aspect the pipe 75 is connected to
the pump 70; or some other pump is used. In one aspect a
pump system is placed within the container 46.
The control system CS controls the various
operational parts and apparatuses of the system 10 as
shown schematically in Figures 1A, 1B, and 1D. In
particular aspects, the control system CS receives
information from the load cell(s) 72, and from sensors 2
on the engine 17 (for example torque and/or speed in
rpm's) and from sensor(s) 52a on the motor 52 (for
example motor speed in rpm's). The
control system CS
controls the operation of the engine 17, the motor 52,
the valve 56, the auger apparatus 50, the system 60, the
system 58, the system 54, the pump 70, and a hydraulic
power supply HPP which supplies power to the motor 52 and
any other hydraulically powered item. In
one aspect,
sensing of the load on the motor 52 is done using a
pressure sensor 52a (shown schematically). In
one
aspect, thus monitoring the pressure of hydraulic fluid
applied to the motor 52 provides the information needed
to activate the injection of additional lubricant via the
nozzles 57. Via sensing of the temperature within the
vessel 14 (using a sensor or sensors; for example, in one
aspect three sensors along the top of the vessel 14), the
control system CS maintains the flow of material into the
vessel 14 by controlling the system 00 at a sufficient
rate that the temperature within the vessel 14 is
maintained at a sufficiently high level (without
exceeding a pre-set maximum) to effectively heat liquid
phase(s) in the drill cuttings material to vaporize the
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 13-
liquid phase(s). The motor 52, engine 17, pump 70 and/or
other powered items in these systems can be powered
electrically, pneumatically, or hydraulically.
In certain particular aspects, the oil content of
feed into the container 46 is maintained between 15% to
30% by weight and the water content is maintained between
8% to 20% by weight.
In other aspects, the solids content of the material
introduced into the container 46 is, preferably, at least
70% solids by weight; and the liquid content of the
material fed into the vessel 14 is 30% or less (liquid
includes oil and water). A pump or pumps (for example,
but not limited to, the pump 70) reduces (and, in certain
aspects, minimizes) the amount of free liquid fed to the
vessel 14. If too much liquid is fed into the vessel 14,
undesirable "wash out" may occur, a sufficient amount of
solids will not be present, and, therefore, sufficient
friction will not be developed to achieve a desired
temperature within the vessel 14 for effective operation.
In certain aspects, the temperature within the vessel 14
is maintained by the control system between 250 and 400
degrees Centigrade.
It is also desirable for efficient operation that
the engine 17 operates at an optimal loading, for example
at 95% of its rated capacity. If the control system CS
learns, via a speed sensor 2 on the engine 17 that the
RPM's of the engine 17 are dropping off from a known
maximum, this may indicate too much material is being fed
into the vessel 14. The control system CS then reduces
the mass transfer rate into the vessel 14 (by controlling
the system 60). Power generated typically drops off as
the RPM's drop off, as can be seen on a typical
performance curve. Insuring that the power generated is
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 14-
maximized provides the maximum energy available to
generate the heat required within the vessel 14.
Initially at start up, in one aspect, the valve 56
is opened slowly. As free flowing liquid and material
flow into the vessel 14, the temperature is maintained.
If there is no dramatic drop in temperature, this
indicates that the flow of material has an appropriate
liquid content so that a desired operational temperature
and effective operation can be achieved. Then the valve
56 is fully opened as the system 60 is controlled by the
control system CS and full flow commences.
The container 46 may be filled continuously or in
batches.
Figure lE shows a system 10a, like the system 10
described above, and like numerals indicate like parts.
The initial feed of drill cuttings material to the
container 46 is from one or more shale shakers 55 (or
other processing equipment) whose drill cuttings material
output (for example off the tops of the shaker screens or
from a centrifuge) is fed to a buffer apparatus BA to
maintain a desired liquid content of the material in the
container 46, and, in one aspect, to minimize this liquid
content. The buffer apparatus BA can be any suitable
system or apparatus; for example, but not limited to: a
system in accordance with the present invention (for
example, but not limited to a system as in Figures 1A,
2A, or 3); a storage system for drill cuttings material;
a skip system; a cuttings containment and transfer system
(for example, but not limited to, a known system as
disclosed in U.S. Patent 7,195,084, co-owned with the
present invention); or a transfer/transport system, for
example, but not limited to, the BRANDT FREE FLOW
(TRADEMARK) systems.
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 15-
Figure 2A shows a system 10b like the system 10
described above and like numerals indicate like parts.
The system 10b has a slider system 80 with a slider
frame 82 selectively movable by a piston mechanism 84
with one part connected to the slider frame 82 and
controlled by the control system CS.
Power for the
piston mechanism 84 is provided by a hydraulic power pack
HPP (which also provides power to the motor 52). The
slider frame 82 moves material on the bottom 48 of the
container 46 to facilitate the flow of material down to
the screw 62 of the system 60. A slider frame may be
used as shown in U.S. Patent 7,195,084.
The slider frame 82 has a central beam 86, and,
optionally, bevelled end edges 88. The slide 82 moves
material facilitating its entry into a trough 47 in which
is located the screw 62. Optionally, the slider frame 82
is smaller than shown with no central beam 86 and is
movable to and from the trough 47 on both sides thereof.
Figure 3 illustrates a system 10c, like the system
10, and like numerals indicate like parts The reactor
section 12c has multiple material inlets 13c into which
material is introducible into a vessel 14c. One feeder
system may be used at one inlet 13c or multiple feeder
systems 40c may be used (three shown in Figure 3).
Figure 4 illustrates improvements to systems of U.S.
Patent 5,914,027 (fully incorporated herein for all
purposes) and shows a system 200 with a feeder system 210
(like any feeder system disclosed herein in accordance
with the present invention) which feeds material into a
reactor chamber or vessel 201 with a rotor 202 including
friction elements 203, such as flails. The
rotor 202
further includes a shaft 204 sealed in the reactor with
mechanical seals 205. The
friction elements 203 are
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 16-
pivotably mounted in rotor plates 207 (as in U.S. Patent
5,914,027). Each
pair of adjacent rotor plates 207
carries a number of friction elements 203. The friction
elements 203 are staggered relative to each other. The
staggered arrangement may achieve turbulent action in a
bed of grained solids in the vessel. The
friction
elements 203 are pivotably mounted in between adjacent
rotor plates 207 by rods extending over the length of the
rotor 202 (as in U.S. Patent 5,914,027).
The rotor 202 is driven by a rotating source 209
which can be an electrical motor, a diesel engine, a gas
or steam turbine or the like. The material is brought to
the reactor from the feeder system 210 via a line 211.
Water and/or oil (for example, base oil) can be added to
the flow from the pipe 212. Cracked hydrocarbon gases
(and, in one aspect, over saturated steam) leaves the
reactor via a line 213 and, in one aspect, flows to a
cyclone 214 and proceed to a condenser unit 215 which can
be a baffle tray condenser, a tubular condenser or a
distillation tower. The different fractions of the oil
can be separated directly from the recovered hydrocarbon
gases. The heat from condensation is removed by an oil
cooler 216 cooled either by water or air. The recovered
oil is discharged from the condenser by a pipe 217 to a
tank 218.
Solids leave the reactor via a rotating valve 219
and a transport device 220 which can be a screw or belt
conveyor or an air transportation pipe system to a
container 221. The air transportation system may be a
positive pressure system moving slugs of solids slowly
along the pipe or may use high speed air to transport the
solids in suspension. Alternatively, a vacuum system may
be used. The solids separated from the cyclone 214 are
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 17-
transported via a rotating valve 222 to the container 221
either by being connected to the transport device 220 or
directly to the container 221 by a cyclone transport
device 223.
Non condensable gases exit in a pipe 224 and can
flow from the pipe 224 to a filter unit or to a flare
tower or are accumulated in a pressure tank not shown.
The system 200 may be operated in any way described in
U.S. Patent 5,914,027. The
items downstream of the
vessel 201 may be used with any system in accordance with
the present invention.
Figure 5 illustrates that the present invention
provides improvements to the systems and methods of U.S.
Patent 5,724,751 (fully incorporated herein for all
purposes) and shows a system 300 in accordance with the
present invention with a process chamber with a rotor 302
and blades 303 driven by an engine 304. A
mass of
material is fed into the process chamber by a feeder
system 320 (any feeder system disclosed herein in
accordance with the present invention). The mass in the
process chamber is whipped by the blades and subjected to
energy or vibrations from the said blades and ribs 308,
which are sufficiently closely spaced to each other to
cause turbulence during the rotation of the blades.
Additional energy may be supplied in some form of heated
gas from a combustion engine 309. Gases, mist and vapors
leave the process chamber 301 via an output opening via a
vent fan 311 and on to either open air or to a condenser.
Dried material is led through an output opening 312 via a
rotating gate 313. The system 300 may be operated in any
way described in U.S. Patent 5,724,751. The
items
downstream of the process chamber of the system 300 may
be used with any system in accordance with the present
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 18-
invention.
The present invention, therefore, provides in some,
but not in necessarily all, embodiments a thermal
treatment system for removing liquid from drill cuttings
material, the thermal treatment system having a metering
screw apparatus for receiving and feeding drill cuttings
material to a reactor system, including apparatus and a
control system for controlling the metering screw
apparatus and for insuring that the metering screw
apparatus is maintained full or nearly full of material
and/or for controlling the mass flow rate into a reactor
of the thermal treatment system by adjusting the speed of
the metering screw apparatus.
The present invention, therefore, provides in some,
but not in necessarily all, embodiments a thermal
treatment system for treating drill cuttings material in
which apparatus and a control system are provided to
maintain an airlock at a material inlet to a thermal
reactor of the thermal treatment system by maintaining a
desired amount of material in a container above a feeder
system that feeds material into the thermal reactor.
Any system in accordance with the present invention
may include one or some, in any possible combination, of
the following: wherein apparatus and a control system
provide for control of temperature in the thermal reactor
by controlling the mass flow rate of material into the
thermal reactor by controlling a metering screw system
that feeds material into the thermal reactor; wherein the
thermal treatment system has an engine that rotates
friction elements within a reactor vessel of the thermal
reactor and performance of said engine is optimized by
controlling a metering screw system that feeds material
into the reactor vessel (for example, based on sensed
CA 02731553 2011-01-20
WO 2010/018399
PCT/GB2009/050999
- 19-
speed in rpm's of said engine); a sensor or sensors or at
least one load cell apparatus or two load cell
apparatuses beneath the container to provide information
to indicate an amount of material in the container; a
sensor or sensors or at least one load cell apparatus or
two load cell apparatuses beneath the thermal reactor to
provide information to assist in control of the discharge
rate of solids from the thermal reactor; wherein a
control system controls the amount of material in the
thermal reactor; wherein the control system controls said
amount to maintain an airlock at the discharge from the
thermal reactor; apparatus and a control system to
maintain a desired temperature in the thermal reactor; a
first feed of drilling cuttings material into the
container; wherein the first feed is from drilling
operations solids control equipment which is at least one
of shale shaker, centrifuge, vortex dryer, and
hydrocyclone; wherein the first feed is from a cuttings
conveyance system; a secondary feed into the container
from a cuttings storage or transfer system; and/or
apparatus and a control system for control of temperature
in the thermal reactor by controlling the mass flow rate
of material into the thermal reactor by controlling a
metering screw system that feeds material into the
thermal reactor; the thermal treatment system having an
engine that rotates friction elements within a reactor
vessel of the thermal reactor and performance of said
engine is optimized by controlling a metering screw
system that feeds material into the reactor vessel (for
example, based on sensed speed in rpm's of said engine);
at least one load cell apparatus or two load cell
apparatuses beneath the container to provide information
to indicate an amount of material in the container.
