1. Field Of The Invention
This invention is directed to systems and methods for separating hydrocarbons from drill cuttings from a wellbore being drilled in the earth; and, in certain particular aspects, to such systems and methods which employ a screw feed apparatus for feeding drilled cuttings material to a thermal reactor.
2. Description of Related Art
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.
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.
Accordingly, the present invention includes features and advantages which are believed to enable it to advance thermal drill cuttings treatment technology. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings.
Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention.
What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain preferred embodiments of the invention, there are other objects and purposes which will be readily apparent to one of skill in this art who has the benefit of this invention's teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, non-obvious thermal drilled cuttings treatment systems; and
Such systems with a screw feed for feeding drilled cuttings material to a thermal reactor.
The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention's realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of certain preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent's object to claim this invention no matter how others may later attempt to disguise it by variations in form, changes, or additions of further improvements.
The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly from a cursory inspection or review the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention in any way.
It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention.
Certain aspects, certain embodiments, and certain preferable features of the invention are set out herein. Any combination of aspects or features shown in any aspect or embodiment can be used except where such aspects or features are mutually exclusive.
A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings which form a part of this specification. These drawings illustrate certain preferred embodiments and are not to be used to improperly limit the scope of the invention which may have other equally effective or equivalent embodiments.
Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and features of embodiments of the invention are described below and some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of preferred embodiments and are not intended to limit the invention or the appended claims. 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. In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiment, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference. So long as they are not mutually exclusive or contradictory any aspect or feature or combination of aspects or features of any embodiment disclosed herein may be used in any other embodiment disclosed herein.
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 (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.
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.
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.
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
As shown in
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 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
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.
A control system CS controls the various operational parts and apparatuses of the system 10 as shown schematically in
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 (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, 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 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.
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.
The system lob 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.
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.
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.
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.
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.
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 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.
In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. §102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35 U.S.C. §103 and satisfies the conditions for patentability in §103. The inventor may rely on the Doctrine of Equivalents to determine and assess the scope of the invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.