DRILL CUTTINGS TREATMENT SYSTEMS

[0001] This application is a continuation-in-part of co-pending application Ser. No. 12/288,670, filed Aug. 14, 2008, which is incorporated fully herein by reference.

[0002] 1. Field of the Invention

[0003] Generally, the present disclosure relates to systems and methods for separating hydrocarbons and/or other liquids from the drill cuttings material from a wellbore being drilled in the earth, and, in certain particular aspects, to such systems and methods which employ a feed apparatus for feeding drilled cuttings material to a thermal reactor.

[0004] 2. Description of the Related Art

[0005] 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: U.S. Pat. Nos. 5,914,027; 5,724,751; and 6,165,349—all these patents incorporated fully herein for all purposes.

[0006] The following presents a simplified summary of the present disclosure in order to provide a basic understanding of some aspects disclosed herein. This summary is not an exhaustive overview of the disclosure, nor is it intended to identify key or critical elements of the subject matter disclosed here. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

[0007] 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.

[0008] 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.

[0009] One illustrative embodiment disclosed herein is directed to a system that includes, among other things, a thermal reactor that is adapted to remove liquid from drill cuttings material by heating the drill cuttings material to at least a first temperature that is sufficiently high enough to vaporize the liquid. The illustrative system also includes a feeder system that is adapted to controllably feed a flow of the drill cuttings material to the thermal reactor, and a control system that is adapted to control the flow of the drill cuttings material from the feeder system so as to maintain a temperature in the thermal reactor at or above the first temperature.

[0010] Also disclosed herein is a thermal treatment system that includes a thermal reactor that is adapted to remove liquid from drill cuttings material, a feeder system that is adapted to controllably feed a flow of the drill cuttings material to the thermal reactor; and a control system that is adapted to control the feeder system so as to increase the flow of the drill cuttings material to the thermal reactor when a temperature in the thermal reactor decreases.

[0011] Another illustrative thermal treatment system disclosed herein includes, among other things, a thermal reactor having a plurality of rotatable friction elements, wherein the thermal reactor is adapted to remove liquid from drill cuttings material. The thermal treatment system also includes an engine that is adapted to controllably rotate the plurality of rotatable friction elements, wherein the plurality of rotatable friction elements are adapted to generate heat during the controllable rotation. Furthermore, the thermal treatment system is made up of a feeder system that includes a metering screw apparatus and a container positioned above the metering screw apparatus, wherein the container is adapted to receive the drill cuttings material and the feeder system is adapted to controllably feed a flow of the drill cuttings material to the thermal reactor. Additionally, the thermal treatment system includes a control system that is adapted to control the feeder system so as to increase the flow of the drill cuttings material to the thermal reactor when a temperature in the thermal reactor decreases, and to decrease the flow of the drill cuttings material to the thermal reactor when the temperature in the thermal reactor increases.

[0027] While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0028] Various illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0029] The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.

[0030] FIGS. 1A-1D illustrate a system 10 according to the present invention which has a thermal reactor section 12 and a feeder system 40 according to 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.

[0031] FIGS. 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. 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 FIG. 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 system 60 inclined to correspond to the incline of the bottom 48. Material falls into a trough 47 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; e.g. as shown in FIG. 1F, walls 46w of a container 46a are inclined above a trough 47a.

[0032] 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.

[0033] 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 (e.g., 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.

[0034] A valve assembly 56 is used to selectively control the flow of free flowing material (e.g. 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.

[0035] Optionally, (especially for material that may be easily compacted) if additional lubricant is needed for 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 (e.g., 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 (e.g. 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.

[0036] 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 FIG. 1D, a pump 70a may be located within the container 46 (in one aspect, in the material M).

[0037] As shown in FIG. 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 FIG. 1D, the screw 62 of the system 60 has areas of different pitch, e.g. 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 cubic meters. The screw may have two, four or more areas of different pitch.

[0038] In one aspect, during operation of the system 10, an amount of material is maintained in the container 46 (e.g. in one aspect, a minimum of about three cubic meters) so that an “airlock,” or sealing condition, may be created and substantially maintained at the inlet 13, thereby substantially preventing ingress of oxygen into the vessel 14. Additionally, by using the control system CS described below to ensure that a sufficient amount of material is maintained within the vessel 14, an airlock, or sealing condition, may also be created and substantially maintained at the discharge outlet 15 of the system 12. For example, in some illustrative embodiments, the system 10 may include a hopper (not shown) at the discharge outlet 15, and the control system CS may be adapted to control the flow of drill cuttings material through the vessel 14 such that a sufficient level of material is present in the hopper so as to thereby create and/or substantially maintain the previously described airlock condition at the outlet 15. In certain embodiments, the hopper (not shown) at the discharge outlet 15 may be, for example, a substantially vertically oriented pipe and the like, or a similar type of structure in which an appropriate level of drill cuttings material may be maintained. Furthermore, in at least some embodiments, the hopper (not shown) may include a level detection system, such as a level sensor and the like, which may provide information to the control system CS regarding the level of drill cuttings material in hopper, thereby enabling additional control of the airlock condition at the discharge outlet 15 as noted above.

[0039] 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 FIG. 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 50 mm and 1000 mm and, in one particular aspect, is 500 mm. Optionally, or in addition to the load sensor(s) 72, a level 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.

[0040] Personnel P can, optionally, remove free liquid from the top of material in the container 46 (e.g. from the top thereof) by manually placing an end 75a of a pipe 75 within a conduit 77 connected to the container 46 to pump free liquid (e.g. 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.

[0041] A control system CS controls the various operational parts and apparatuses of the system 10 as shown schematically in FIGS. 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 (e.g. torque and/or speed in rpm's) and from sensor(s) 52a on the motor 52 (e.g. 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 an 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; e.g., 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 40 at a sufficient rate such that the temperature within the vessel 14 is maintained at a sufficiently high level to effectively heat the drill cuttings material so that most, or substantially all, of any liquid phase(s) present in the material may be vaporized, however without exceeding a pre-defined maximum temperature—i.e., within an optimal temperature range.

[0042] For example, in certain illustrative embodiments, when the control system CS detects a temperature drop within the reactor vessel 14, it may be indicative that there is insufficient drill cuttings material inside of the vessel 14 to interact with the rotating friction elements 8 so as to thereby maintain the temperature at a sufficiently high level, as previously described. Accordingly, the control system CS may operate to control the feeder system 40 in such a manner as to increase the flow of drill cuttings material to the reactor vessel 14, thereby ensuring that there is sufficient drill cuttings material in the vessel 14 to interact with the friction elements 8, and so that the temperature within the vessel 14 may be substantially maintained above a pre-defined minimum value. On the other hand, when the control system CS detects a temperature increase within the reactor vessel 14, it may be indicative that, for example, the amount of drill cuttings material inside of the vessel 14 may be too great, or that the composition of the drill cuttings material being fed into the container 46 of the system 60 may have changed. In such circumstances, the control system CS may also operate to control the feeder system 40 so as to decrease the flow of drill cuttings material to the reactor vessel 14, thereby enabling the temperature within the vessel 14 to be controlled so that it is substantially maintained below the pre-defined maximum value, as noted above.

[0043] In various embodiments of the thermal treatment system disclosed herein, the motor 52, engine 17, pump 70 and/or other powered items in these systems can be powered electrically, pneumatically, or hydraulically.

[0044] 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.

[0045] 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 (e.g., 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, and depending on the specific of the material content of the solids and/or liquid phase(s), the temperature within the vessel 14 may be maintained by the control system CS between a pre-defined minimum value of approximately 250 degrees Centigrade and a pre-defined maximum value of approximately 400 degrees Centigrade.

[0046] It is also desirable for efficient operation that the engine 17 operate at an optimal loading, e.g. 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 maximized provides the maximum energy available to generate the heat required within the vessel 14.

[0047] 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.

[0048] The container 46 may be filled continuously or in batches.

[0049] FIG. 1E 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 SS (or other processing equipment) whose drill cuttings material output (e.g. 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; e.g., but not limited to: a system according to the present invention (e.g., but not limited to a system as in FIG. 1A, 2A, or 3); a storage system for drill cuttings material; a skip system; a cuttings containment and transfer system (e.g., but not limited to, a known system as disclosed in U.S. Pat. No. 7,195,084, co-owned with the present invention); or a transfer/transport system, e.g., but not limited to, the BRANDT FREE FLOW (TRADEMARK) systems.

[0050] FIG. 2A shows a system 10b like the system 10 described above and like numerals indicate like parts.

[0051] 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 an 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. Pat. No. 7,195,084.

[0052] The slider frame 82 has a central beam 86, and, optionally, beveled end edges 88. The slider frame 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.

[0053] FIG. 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 FIG. 3).

[0054] FIG. 4 illustrates improvements to systems of U.S. Pat. No. 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 according to the present invention) which feeds material into a reactor chamber or vessel 201 with a rotor 202 including friction elements 203. The rotor 202 further includes a shaft 204 sealed in the reactor with mechanical seals 205. The friction elements 203 are pivotably mounted in rotor plates 207 (as in U.S. Pat. No. 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. Pat. No. 5,914,027).

[0055] 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 (e.g., 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.

[0056] 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 solids separated from the cyclone 214 are 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.

[0057] In certain illustrative embodiments, a control system, such as the control system CS of the thermal treatment system 10 shown in FIGS. 1A-1D above, may control the rotating valve 219 so that an airlock condition may be created and/or substantially maintained at the discharge outlet of the reactor vessel 201, as previously described. Furthermore, in certain embodiments the rotating valve 219 may also be controlled by the control system so as to permit an increased flow of material from the reactor vessel 201 when, for example, the control system detects a reduction in the rotational speed of the rotating source 209, which, as previously described regarding the thermal treatment system 10 above, may be an indication that too much material is present in the reactor vessel 201.

[0058] 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. Pat. No. 5,914,027. The items downstream of the vessel 201 may be used with any system according to the present invention.

[0059] FIG. 5 illustrates that the present invention provides improvements to the systems and methods of U.S. Pat. No. 5,724,751 (fully incorporated herein for all purposes) and shows a system 300 according to 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 according to 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. Pat. No. 5,724,751. The items downstream of the process chamber of the system 300 may be used with any system according to the present invention.

[0060] 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.

[0061] 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.

[0062] Any system according to 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 (e.g., based on sensed 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 (e.g., 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.

[0063] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the method steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.