Various industries, such as oil and gas, mining, agriculture and the like utilize equipment and/or methods to separating fluids from materials. For example, in the mining industry, the separation of a desired mineral component from the undesirable gangue of an ore is a necessary and significant aspect of mining. Tailings are the materials left over after the process of separating the valuable ore from the gangue. Mine tailings are usually produced from a mill in slurry form that is typically a mixture of fine mineral particles and water.
Another example of such a separation method is found in the oil and gas industry. For example, oilfield drilling fluid, often called “mud,” serves multiple purposes in the oil and gas industry. Among its many functions, the drilling mud acts as a lubricant for a drilling bit and increases rate of penetration of the drilling bit. The mud is pumped through a bore of the drill string to the drill bit where the mud exits through various nozzles and ports, lubricating the drill bit. After exiting through the nozzles, the “spent” fluid returns to the surface through an annulus formed between the drill string and the drilled wellbore. The returned drilling mud is processed for continued use.
Another significant purpose of the drilling mud is to carry the cuttings away from the drill bit to the surface. The drilling fluid exiting the borehole from the annulus is a slurry of formation cuttings in drilling mud, and the cutting particulates must be removed before the mud is reused.
One type of apparatus used to remove cuttings and other solid particulates from drilling mud is commonly referred to in the industry as a “shaker” or “shale shaker.” The shaker, also known as a vibratory separator, is a vibrating sieve-like table upon which returning used drilling mud is deposited and through which substantially cleaner drilling mud emerges. Typically, the shaker is an angled table with a generally perforated filter screen bottom. Returning drilling mud is deposited at the top of the shaker. As the slurry moves toward a discharge end that may be higher than an inlet end, the fluid falls through the perforations to a reservoir below thereby leaving the solid particulate material behind. The combination of the angle of inclination with the vibrating action of the shaker table enables the solid particles left behind to flow until they fall off the lower end of the shaker table. The above described apparatus is illustrative of an exemplary shaker known to those of ordinary skill in the art.
Screens used with shakers are typically placed in a generally horizontal fashion on a generally horizontal support within a basket or tray in the shaker. The shaker imparts a rapidly reciprocating motion to the basket and hence the screens. Material from which particles are to be separated is poured onto a back end of the vibrating screen and may be conveyed along the shaker toward the discharge end of the basket.
In some shakers, a fine screen cloth is used with the vibrating screen. The screen may have two or more overlaying layers of screen cloth and/or mesh. Layers of cloth and/or mesh may be bonded together and placed over a support. The frame of the vibrating screen is suspended and/or mounted on a support and vibrates by a vibrating mechanism to create a flow of trapped solids on top surfaces of the screen for removal and disposal of solids.
Embodiments disclosed herein are applicable to separation devices that may be used in many industries. While specific embodiments may be described as used in the oilfield industry, such as use with vibratory separators, the device may also be applicable in other industries where separation of liquid-solid, solid-solid and other mixtures may be desirable. The embodiments, for example, may be used in mining, pharmaceutical, food, medical and/or other industries to separate mixtures as needed.
In the following detailed description, reference is made to accompanying figures, which form a part of the disclosure. In the figures, similar symbols or identifiers typically identify similar components, unless context dictates otherwise. The illustrative embodiments described herein are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that aspects of the present disclosure, as generally described herein, and illustrated in the Figures, may be arranged, substituted, combined and designed in a wide variety of different configurations, all of which are explicitly contemplated and form part of this disclosure.
Referring now to
The pressure differential system 24 may be connected to, sealed to or otherwise positioned under a screen 28. In an embodiment, the screen 28 can be one of the screens 18, shown in
The pressure differential system 24 comprises a tray 30, a connection conduit 32, a pressure differential generating device 34 and/or an output conduit 36. The pressure differential system 24 may generate a pressure differential with respect to a top area 23 above the screen 28 and a bottom area 25 below the screen 28.
The pressure differential generating device 34 may be connected to a fluid source 38 through a conduit 40. The fluid source 38 can provide fluid, such as liquid or gas, for example, air, compressed air, nitrogen, carbon dioxide, wellbore fluid, drilling fluid or other fluids usable in the pressure differential generating device 34 to generate the pressure differential. The flow of fluid from the fluid source 38 to and/or through the pressure differential generating device 34 can cause the pressure differential across the screen 28. It should be noted that the movement of the fluid from the fluid source 38 through the pressure differential generating device 34 may provide motive force for air above the screen 28 to move into and through the pressure differential generating device 34. The motive force of the air moving through the pressure differential generating device 34 can cause or increase the pressure differential.
The pressure differential can increase separation of the slurry, such as additional fluid being removed from the cuttings that would otherwise be removed without the pressure differential. The pressure differential with respect to the top area 23 and the bottom area 25 of the screen 28 draws additional fluid from the slurry to pass through the screen 28. For example, the pressure differential can draw or pull additional fluid of the slurry through the screen 28. Where the slurry has the wellbore fluid and the cuttings, the additional wellbore fluid recovered can result in a lesser amount (or volume) of drill fluid being used, since, for example, the additional drilling fluid recovered may be processed and re-used. In addition, the additional wellbore fluid recovered can result in the cuttings on the discharge end 14 of the separator 10 being dryer, that is having less of the wellbore fluid contained on or within the cuttings. As a result, a total volume or amount of the wellbore fluid and the cuttings discharged from the discharge end 14 of the separator 10 may be reduced. Additionally, if oil based drilling fluid is within the slurry, the reduction of oil on cuttings can be significant from a disposal or further processing perspective.
A fluid control assembly 42 may be connected to the conduit 40 between the fluid source 38 and the pressure differential generating device 34. The fluid control assembly 42 may have logic and/or devices to actuate a device 39 to change or alter an amount of fluid provided to the pressure differential generating device 34. For example, the device may fully open, partially open, fully close or partially close fluid communication between the fluid source 38 and the pressure differential generating device 34.
In an embodiment shown by
As shown in
The floor panel 148 of the tray 106 may taper downwardly and inwardly from the lower circumferential edge 154 of the perimeter frame 144 towards the interface panel 150. The floor panel 148 may have a depth 154 defined between the lower circumferential edge 154 of the perimeter frame 144 and the bottom 142 of the tray 106. The interface panel 150 may be located at the bottom 142 of the tray 106. In an embodiment, the interface panel 150 may be located at the center of the floor panel 148. In another embodiment, as illustrated in
The taper of the floor panel 148 may cause the portion of the slurry passing through the screen 28 to move towards the interface panel 150. The interface panel 150 may have an opening 168. The interface panel 150 may be connected to a first end 169 of the connection conduit 32. In an embodiment, the interface panel 150 and the connection conduit 32 may be formed as a single assembly. In another embodiment, the basket 102, the tray 106 and the connection conduit 32 may be integrally formed as a single assembly.
The basket 102 and the tray 106 may be installed on support rails 156 on one or more sides. The support rails 156 may be connected to, for example, an industrial filtration system by resilient mounts. The resilient mounts may be springs, hydraulic dampers, pneumatic isolators and/or any other device known to a person of ordinary skill in the art that may isolate vibration. The support rails 156 may be connected to one or more vibration motors. In an embodiment, a clamping system 158 may secure the support rails 156, the separating screen 104, the basket 102 and/or the tray 106.
In an embodiment, the tray 106 and the pressure differential generating device 34 may be integrally formed with the screen 28 as shown in
As shown in
The pressure differential generating device 34 may be an air amplifier, line vacuum, or device having a structure to cause a Venturi effect, a particular case of Bernoulli's principle, upon the supply of fluid. The Venturi effect as used herein generally relates to increasing the velocity of the fluid provided from the fluid source 38 from a decrease in cross-sectional area in the pressure differential generating device 34. The fluid source 38, as shown in
The fluid may be injected into the fluid injection port 160. The fluid may reduce the available volume for particles and/or fluid entering the pressure differential generating device 34 through the input 162. A pressure change may be created between the input 162 and the output 164 of the pressure differential generating device 110.
Injecting the fluid into the pressure differential generating device 34 through the fluid injection port 160 may create a pressure change between the input 162 and the output 164 of the pressure differential generating device 34. The pressure change may create a low pressure area at the bottom area 25 of the separating screen 28. The low pressure area at the bottom area 25 may create a pressure differential between the top area 23 and the bottom area 25 of the screen 28. The pressure differential may assist and/or facilitate movement of a portion of the slurry, such as a portion of the wellbore fluid that may pass through the screen 28.
Referring now to
The separator 10 may have a mass flow measurement device, such as a cutting flow meter, to monitor the mixture that may be delivered to the input end of the screen 28. The amount of fluid provided to the pressure differential generating device 34 may be changed to adjust for changing mixture density during filtering. For example, when the industrial filtration system filters drill cuttings from the drilling fluid, the size and/or the quantity of the drilling cuttings may change. Additionally, the density of the drilling fluid may change.
A larger pressure differential can increase or enhance separation of a portion of the slurry through the separating screen 28. For example, a slurry with a relatively high density may demand a larger or more significant pressure differential. Injecting or providing more fluid to the pressure differential generating device 34 may cause a larger pressure differential and may increase the throughput of the wellbore fluid that may pass through the mesh 44.
The pressure differential generating device 34 may be utilized to generate a constant pressure differential, or it may be utilized to pulse or vary the pressure differential with respect to time. In some instances, depending upon the pressure differential, a constant pressure differential may cause the portion of the slurry that does not pass through the mesh 44 to stall on the screen 28. The pressure differential may remain constant but be reduced to permit the portion of the slurry not passing through the screen 28 to convey toward the discharge end 14 of the separator 10. For example, less fluid may be provided to the fluid injection port 160 to reduce or lower the pressure differential.
In an embodiment, the pressure differential generated by the pressure differential generating device 34 may be toggled or pulsed by changing the amount of fluid provided to the pressure differential generating device 34. For example, the fluid control assembly 42 or the device 39 may control the fluid provided to the pressure differential generating device 34 to change the pressure differential from a first value to a second value. The first value may be higher than the second value. In some embodiments, the second value may be zero. In an instance where a minimal or no pressure differential is desired, further fluid may not be provided to the injection port 160 of the pressure differential generating device 34.
At the second value, for example, the pressure differential can permit the stalled portion of the slurry to move further toward the discharge end 14 of the separator 10. In an embodiment, changing the pressure differential from the first value to the second value may occur at predetermined intervals and/or may be controlled by the fluid control assembly 42. Additionally, the changes in the pressure differential can occur at irregular intervals and/or may be controlled by an operator.
A person having ordinary skill in the art will appreciate that there may be numerous values of the pressure differential. The portion of the slurry passing through the screens 18, 28 may continue to move into the tray 106 and through the pressure differential generating device 34 if the fluid provided to the pressure differential generating device 34 is temporarily reduced or halted.
The fluid control assembly 42 may be manually adjusted or automatically adjusted to control the amount of the fluid that may be injected or provided to the pressure differential generating device 34. An algorithm, software or other logic may control the pressure differential such that the value provided is optimized based on the density of the fluid, flow rate of the slurry at the inlet end 12, deck angle of the separator 10, speed or force of the motors 16, volume of slurry on the screen 18 closest to the inlet end 12 of the separator 10 or other factor that will be appreciated by those having ordinary skill in the art.
As an example, the second value may not generate sufficient pressure differential to draw any additional portion of the slurry through the screen 28 as compared to the portion of the slurry that moves through the screen 28 without the pressure differential. The second value may prime the pressure differential generating device 34 by continuous providing the fluid through the injector port 160. The second value may minimize performance degradation of the pressure differential generating device 34 caused by blinding or otherwise clogging or blocking the injector port 160. In some examples, the first value may have a pressure differential of 50-150 PSI. In some examples, the second value may have a pressure range of 0-50 PSI. The first value may be provided for a first duration, and the second value for a second duration. The first duration and the second duration may be the same or different.
The fluid control assembly 42 can control the first duration and the second duration. For example, the ratio between the first duration and the second duration may range from 1:1 (one unit of time for the first duration to one unit of time for the second duration) to 30:1 (thirty units of time for the first duration to one unit of time for the second duration) and may be biased toward either the first value or the second value.
In one or more embodiments, the fluid control assembly 42 may control the pressure differential generating device 34 to remove the maximum fluid portion of the slurry by maximizing resonance time on the screen 28 for a predetermined processing rate of the slurry. The predetermined processing rate may be related to the rate at which the slurry is provided to the separator 10 or a desired degree of separation of the slurry. For example, the predetermined processing rate may be a rate at which the separator 10 can process a given flow rate of the slurry and reduce fluid on cuttings of the slurry to less than a predetermined threshold.
As shown in the embodiment illustrated in
In the embodiment of
The converging-diverging nozzle 99 may utilize the Venturi effect to convert the pressure energy of the fluid to velocity energy which creates a low pressure zone that draws in the slurry passing through the screen 28. After passing through a throat 97 of the pressure differential generating device 34, the fluid and the slurry may expand, and the velocity may reduce which may result in recompressing the fluid and the slurry by converting velocity back into pressure energy.
The fluid provided to pressure generating differential device 34 may be any of the afore-mentioned fluids. Advantageously, the embodiment of
The fluid source 38 to provide the motive force may utilize pumps, such as, a positive displacement pump, a momentum transfer pump or an entrapment pump, reciprocating pump, centrifugal pump, vacuum pump, pneumatic pump, air pump, piston pump, rotary piston pump, rotary vane pump, screw pump, scroll pump, liquid ring pump, external vane pump, Wankel pump, Toepler pump, and Venturi vacuum pump, and others. Blowers may be utilized at the fluid source 38, such as, a booster pump, a rotary lobe blower, and a vacuum blower. The fluid source 38 may utilize ejectors or aspirators, such as steam ejectors, water aspirators, or ejectors and aspirators utilizing other motive fluids. In some embodiments, drilling fluid may be used as the motive fluid for the pressure differential generating device 34.
While the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as described herein. Accordingly, the scope of the present disclosure should be limited only by the attached claims.
This application claims the benefit of U.S. Provisional Patent Application No. 61/866,956 filed on Aug. 16, 2013; U.S. Provisional Patent Application No. 61/909,162 filed on Nov. 26, 2013; U.S. Provisional Patent Application No. 61/909,163 filed on Nov. 26, 2013; U.S. Provisional Application No. 61/934,700 filed on Jan. 31, 2014; U.S. Provisional Patent Application No. 61/945,824 filed on Feb. 28, 2014; and U.S. Provisional Patent Application No. 62/004,752 filed on May 29, 2014, and the disclosures of each provisional patent application identified is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62004752 | May 2014 | US | |
61945824 | Feb 2014 | US | |
61934700 | Jan 2014 | US | |
61909163 | Nov 2013 | US | |
61909162 | Nov 2013 | US | |
61866956 | Aug 2013 | US |