SYSTEM, AND METHOD

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Application No. 62/346150, filed on June 6, 2016, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common. The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and alternatively for C02 sequestration. To increase the production from a borehole, the production zone can be fractured to allow the formation fluids to flow more freely from the formation to the borehole. The fracturing operation includes pumping fluids at high pressure towards the formation wall to form formation fractures. To retain the fractures in an open condition after fracturing pressure is removed, the fractures must be physically propped open, and therefore the fracturing fluids commonly include solid granular materials, such as sand, generally referred to as proppants. Due to the large amount of hydraulic fracturing fluid used in some operations, correspondingly large amounts of proppants are employed which can lead to a significant amount of dust in a vicinity of the sand delivery equipment and conveyor apparatuses. Dust control systems have included the placement of large vacuums on site, as well as shielding areas of known dust locations.

[0003] Elutriators are used in some processes to separate particles pneumatically. Lighter, smaller particles rise to the top, while larger products settle to the bottom. The larger particles can be cleaned by wash air to further separate the smaller particles from the larger particles. Elutriators have been used by scientists to separate cells and to test soil and air samples. Elutriators have also been used in recycling processes to separate lighter plastic materials from heavier glass and metals.

[0004] In the mining industry, dust control rings have been attached to the discharge end of conveyor belt systems for spraying conveyed material as it discharges from the end of the conveyor belt and passes through the middle of the ring. While useful for controlling dust at the discharge, such control rings do not protect the environment from dust as the material is conveyed. [0005] The art would be receptive to dust control systems and methods of controlling dust, as well as dust control systems adapted for the needs of a hydraulic fracturing operation.

BRIEF DESCRIPTION

[0006] A dust control system includes a housing having an interior; a first inlet including a passage configured to pneumatically convey bulk material into the housing, the passage including an opening disposed within the interior of the housing; a first outlet configured to discharge dust from the interior of the housing; a coating assembly within the housing, the coating assembly arranged to direct a coating fluid onto the bulk material to provide coated material; and, a second outlet configured to discharge the coated material from the interior of the housing. The coating assembly is disposed between the opening and the second outlet.

[0007] An operating system includes a dust control system including a housing having an interior; a first inlet including a passage configured to pneumatically convey bulk material into the housing, the passage including an opening disposed within the interior of the housing; a first outlet configured to discharge dust from the interior of the housing; a coating assembly within the housing, the coating assembly arranged to direct a coating fluid onto the bulk material to provide coated material; and, a second outlet configured to discharge the coated material from the interior of the housing. The coating assembly is disposed between the opening and the second outlet. The operating system further includes a source of the bulk material; a blower configured to blow the bulk material from the source of the bulk material into the first inlet of the dust control system; and, a receiving member configured to receive the coated material from the second outlet.

[0008] A method of controlling dust includes pneumatically conveying bulk material into a first inlet of a housing; passing the bulk material in an upward direction through a passage of the first inlet and out an opening of the first inlet, the opening disposed within an interior of the housing; collecting dust from the bulk material through a first outlet of the housing; directing particles of the bulk material in a downward direction past a coating assembly within the housing; coating the particles with a coating fluid as they pass the coating assembly to produce coated material; and, passing the coated material through a second outlet of the housing; wherein the coating assembly is disposed between the opening of the first inlet and the second outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

[0010] FIG. 1 depicts a schematic view of one embodiment of a dust control system;

[0011] FIG. 2 depicts a plan view of one embodiment of a coating assembly for use in the dust control system of FIG. 1; and,

[0012] FIG. 3 depicts a schematic view of one embodiment of an operation system employing the dust control system of FIG. 1.

DETAILED DESCRIPTION

[0013] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0014] With reference now to FIG. 1, a dust control system 10 is shown

schematically. The dust control system 10 includes a housing 12. The housing 12 has a first end portion 14 and a second end portion 16. During use, the dust control system 10 relies partly on gravity, and therefore, in use, the first end portion 14 is disposed above the second end portion 16. The housing 12 has an exterior surface 18 and further includes an interior 20 having an interior surface 22. The housing 12 may be substantially cylindrical in shape, and extend along longitudinal axis 24, however the housing 12 may take on various shapes.

[0015] A first inlet 26 for the dust control system 10 includes a passage 28 configured to pneumatically convey bulk material 30 into the housing 12. Exterior of the housing 12, the passage 28 is connected to a source 32 of bulk material 30, such as a bulk truck or other bulk material delivery system. The bulk material 30 may include, but is not limited to, sand. A blower 34, either associated with the source 32 or between the source 32 and passage 28, is configured to blow the material 30 into the dust control system 10. In one embodiment where the source 32 is a tank on a truck and the blower 34 is provided on the truck, the blower 34 pressurizes the tank and provides air to the passage 28. The blower 34 may be, but is not limited to, a positive displacement blower. The passage 28 directs the bulk material 30 into the interior 20 of the housing 12 through an opening 36 at the end of the passage 28. In one embodiment, the opening 36 is substantially centrally located between first and second opposing sides 38, 40 of the housing 12. In an embodiment where the housing 12 is substantially cylindrically shaped, the opening 36 may be substantially concentric with a cross-section of the housing 12. The passage 28 may include a first section 42 to direct the bulk material 30 from the source 32 into the housing 12, a second section 44 to direct the bulk material 30 to the opening 36, and a substantially 90 degree bend 46 to connect the first and second sections 42, 44. In one embodiment, the second section 44 and opening 36 substantially align with the longitudinal axis 24 of the housing 12 as shown. The first section 42, bend 46, and second section 44 are all fluidically communicable and may take on other bends and configurations as necessary to transmit the bulk material 30 from the source 32 to the opening 36.

[0016] The dust control system 10 further includes a kick plate 48 within the interior 20 of the housing 12. The kick plate 48 may, in one embodiment, include a conical shape member having a tip 50 pointing towards the first end portion 14 of the housing 12 and substantially aligned along the longitudinal axis 24. Although supporting structure may additionally be provided to suspend the kick plate 48 within the interior 20, the kick plate 48 is substantially spaced from the interior surface 22 of the housing 12 to provide a gap 52 for the escape of aerated dust 54. As the bulk material 30 is injected into the housing 12 through the passage 28 and exits the opening 36 in the upward direction 56, the bulk material 30 collides with an impingement surface 58 of the kick plate 48, which causes the sand to disperse along the angled impingement surface 58 and rain down, substantially in downward direction 60 towards the second end portion 16. The kick plate 48 disperses the bulk material 30 while the dust 54 is aerated in the process and movable towards the first end portion 14 of the housing 12 through the gap 52. The dust control system 10 includes a first outlet 62 at the first end portion 14. The first outlet 62 includes a duct 64 for dust collection. The dust 54 will get sucked up by a vacuum system 66, and dust 54 will exit the housing 12 and into a dust storage container 68. So dust 54 will be aerated and float in the air within the housing 12 to be removed from the housing 12 via the first outlet 62, and the heavier particles of the bulk material 30 will fall back down in the housing 12, in the downward direction 60.

[0017] As the particles 70 of the bulk material 30 fall in the downward direction 60 towards the second end portion 16 of the housing 12, the particles 70 pass by a coating assembly 72 secured within the interior 20 of the housing 12. Due to the air and bulk material 30 forcefully exiting the opening 36, the material 30 re-directed from the kick plate 48 will not fall back into the opening 36, but will instead fall towards the coating assembly 72. The coating assembly 72 is longitudinally disposed between the first and second end portions 14, 16 of the housing 12, as well as between the opening 36 of the first inlet 26 and the second end portion 16 of the housing 12. The coating assembly 72 sprays the particles 70 of the bulk material 30 with a fine mist of coating fluid 74. The coating fluid 74 may include any one or more of surfactants, lubricants, resins, and other chemicals. The coating fluid 74 may further include a base fluid, such as brine, water, etc. The coating fluid 74 is capable of at least partially adhering to the particles 70. The purpose of the coating fluid 74 is to keep any dust 54 not collected by the dust vacuum system 66 from getting into the air. Any remaining dust 54 that has not been drawn towards the first end portion 14 of the housing 12 will be connected to larger particles 70 of the bulk material 30 by the coating fluid 74. The coating assembly 72 may include a spray ring structure, and in one embodiment, may include either or both of an inner ring 76 and an outer ring 78. The outer ring 78 may be disposed on the interior surface 22 of the housing 12, and the inner ring 76 may be spaced in a radially inward direction from the outer ring 78. A ring-shaped space 80 may be formed between the inner and outer rings 76, 78 through which the particles 70 of the bulk material 30 pass. In an embodiment where the coating assembly 72 includes only one ring, the ring may be the inner ring 76 or the outer ring 78, or may alternatively be a ring disposed elsewhere within the space 80. As shown in FIG. 2, each ring 76, 78 includes a plurality of nozzles 82 to spray the passing material 30. The nozzles 82 are fluidically connected with an interior of the inner and outer spray rings 76, 78, and the rings 76, 78 are connected to a source 84 (FIG. 1) of the coating fluid 74, where the coating fluid 74 is a liquid. The nozzles 82 may be misting nozzles, such as fine spray nozzles. Also, the nozzles 82 may be cluster nozzles that point in varying directions from the rings 76, 78. The nozzles 82 may be at least substantially evenly dispersed about the inner periphery of the outer ring 78 and the outer periphery of the inner ring 76 as shown, however alternate patterns of nozzles 82 can be arranged. For example, in an embodiment where only a single ring is included and arranged within the space 80, the ring may include nozzles 82 on both an inner and an outer periphery of the ring. Also, each nozzle 82 may include an outlet that disperses fluid in a number of different directions. For example, even if the nozzle 82 is pointed generally radially inwardly with respect to the outer ring 78, or the nozzle 82 is pointed generally radially outwardly with respect to the inner ring 76, the spray from the nozzles 82 may be substantially conical. The inner and outer rings 76, 78 may be positioned at a substantially same longitudinal location along a longitudinal axis 24 of the housing 12. Alternatively, the rings 76, 78 may be longitudinally spaced from each other. Also alternatively, while only one inner ring 76 and one outer ring 78 are disclosed, multiple spray rings at varying longitudinal locations may be provided within the housing 12.

[0018] The dust control system 10 may further include a ramped surface 86 configured to direct the bulk material 30, returning from the kick plate 48, towards the coating assembly 72. The ramped surface 86 may be disposed between the opening 36 and the coating assembly 72, and angled radially outwardly from the opening 36 towards the coating assembly 72. In one embodiment, the ramped surface 86 may be substantially frustum-shaped, and, in particular, may be frusto-conical shaped as illustrated. At least a portion of the second section 44 of the passage 28 may pass through the ramped surface 86. The ramped surface 86 may include a first end 88 adjacent the opening 36 and a second end 90 adjacent the inner ring 76 of the coating assembly 72. The inner ring 76 may be connected to the second end 90 of the ramped surface 86. This way, the only available space for the falling particles 70 of the bulk material 30 to pass is through the space 80. The discharge of coating fluid 74 to the passing bulk material 30 may be selectively controlled by an operator. For instance, some material 30 may require coating while other material 30 may not, and therefore an operator may choose whether or not to coat the material 30. Also, the type of coating fluid 74 may be altered depending on the material 30 that passes through the system 10.

[0019] The dust control system 10 may further include a second inlet 92 configured to pass a stream of gas, such as air from an air source 94. The stream of gas is pushed into the housing 12 through the second inlet 92 to push any additional fine particles (dust 54) to the first end portion 14 of the housing 12 so that they can be collected by the vacuum system 66 and dust storage container 68 attached to the duct 64. Thus, the "wash air" from the second inlet 92 carries off the small particles (dust 54) by fluffing up the falling particles 70 of the bulk material 30 to push more of the dust 54 out. Also, in one embodiment, the second inlet 92 may be located at substantially a same longitudinal location as the coating assembly 72 so that the bulk material 30 passing through the space 80 is moved (rotated, spun, etc.) within the space 80, and separated from adjacent particles 70, such that the coating fluid 74 can reach as much of the surface area of each particle 70 as possible. That is, the wash air helps to disperse the fallen material 30 to ensure that the material 30 is evenly dispersed as it passes through the coating assembly 72, helping to coat the particles 70 of the material 30 more evenly. In one embodiment, the wash air entering the housing 12 through the second inlet 92 may be approximately half of the air volume that is used to convey the material 30 into the housing 12 through the first inlet 26. For example, if using approximately 1,000 cubic feet per minute ("cfm") of air to push the material 30 into the housing 12 through the first inlet 26, then the wash air may be introduced through the second inlet 92 at approximately 500 cfm.

[0020] After the bulk material 30 passes through the ring-shaped space 80 and is coated, the coated material 96 drops further down within the housing 12 towards the second end portion 16 of the housing 12 (a bottom of the housing 12) and into a coated material receiving area 98. From the receiving area 98, an operator may selectively dispense the coated material 96 from the housing 12 through a second outlet 100 at the second end portion 16 of the housing 12. In one embodiment, the second outlet 100 may include a rotary valve 102. During rotation of the rotary valve 102, the rotary valve 102 breaks up clumps of the coated material 96 during discharge. A control system (not shown) may control the rotary valve 102 to turn on and off, and may further control the speed of rotation of the rotary valve 102 to thereby control the speed of discharge of coated material 96. A source 104 of boost air may be used to push the coated material 96 discharged from the second outlet 100 towards a receiving member 106 in a plant or operating system. Alternatively, an eductor may be used to create a Venturi to discharge the coated material 96 from the housing 12. In an another embodiment, the second outlet 100 may be positioned above the receiving member 106, such as, but not limited to, a conveyor belt, tub, or tank, for directly dispensing the coated material 96 into or onto the receiving member 106.

[0021] With reference now to FIG. 3, the dust control system 10 is depicted at a location within an operation system 150. In the illustrated embodiment, the location is a wellsite 120 and the operation system 150 is for a hydraulic fracturing operation. While the dust control system 10 may be used in a number of different manufacturing and industry environments, the dust control system 10 is particularly useful in a hydraulic fracturing operation for pumping a fluid, such as a hydraulic fracturing fluid, from a surface 112 to a borehole 115. The borehole 115 may be cased or uncased, or include any other tubular 117 provided with perforations or openings for fracturing fluid to pass towards the formation wall 119. The operation system 150 (a fluid processing system) includes a blender 122. The blender 122 includes, in part, a blender tank or tub 124 for blending components of the fracturing fluid. Components of the fracturing fluid may include a base fluid (such as water), proppant (such as sand), and various other additives to form a slurry of the hydraulic fracturing fluid. The base fluid may be stored in one or more water tanks 126 in a fluid supply 128. In one embodiment, prior to blending, the base fluid may be passed through a hydration system 130, which combines the base fluid with additives for a sufficient amount of residence time within a hydration tank 132 of the hydration system 130 to form a gel. In one embodiment, the additives may be deposited therein using a conveyor system 134. The gel from the hydration tank 132 may then be directed to the blender 122 for combining with bulk material 30, such as proppants, stored in sand trucks, silos or other sources 32, which may be positioned to pass the bulk material 30 through the dust control system 10 prior to delivering coated material 96 to the blender 122. The coated material 96 may, in one embodiment, be delivered using a conveyor system 134. The fracturing fluid is pumped from the blender 122 to a fracturing pump assembly 138 along flow line 140. The fracturing pump assembly 138 may include one or more fracturing pumps 142 (also known as "frac" pumps). While only one fracturing pump assembly 138 is depicted, a manifold may provide the fracturing fluid to multiple fracturing pump assemblies 138. The hydraulic fracturing fluid is then deliverable into the borehole 115 at high pressures by the one or more fracturing pump assemblies 138.

[0022] Any or all of the components of the system 150, including the blender 122, hydration system 130, conveyor system 134, fluid supply 128, dust control system 10, and fracturing pump assembly 138 may be provided on trailer beds, trucks, or other movable / wheeled platform or transportable surfaces 146 to assist in delivery of the components to the well site 120, and to enable such components to be reconfigured as needed at the wellsite 120, and quickly removed from the well site 120 when the process is completed.

Alternatively, in an embodiment where the system 150 is utilized for an offshore well, the components may be positioned on a suitable fracturing and stimulation vessel (not shown).

[0023] The dust control system 10 may be a portable system for providing dust control that may be modularly incorporable into any operating system. While the dust control system 10 removes dust 54 using the principles of an elutriator, the dust control system 10 additionally, advantageously and uniquely further includes a coating assembly 72 between an outlet 62 for dust 54 and an outlet 100 for the coated material 96. This allows an operator to selectively coat bulk material 30, such as sand, at an operation location, such as a well site 120, with a coating fluid 74, such as a surfactant. Further, the dust control system 10 may include the rotary valve 102 to insure that the coated material 96 does not clump as it is discharged.

[0024] Set forth below are some embodiments of the foregoing disclosure:

[0025] Embodiment 1 : A dust control system comprising a housing having an interior; a first inlet including a passage configured to pneumatically convey bulk material into the housing, the passage including an opening disposed within the interior of the housing; a first outlet configured to discharge dust from the interior of the housing; a coating assembly within the housing, the coating assembly arranged to direct a coating fluid onto the bulk material to provide coated material; and, a second outlet configured to discharge the coated material from the interior of the housing; wherein the coating assembly is disposed between the opening and the second outlet. [0026] Embodiment 2: The dust control system of any of the preceding embodiments, further comprising a ramped surface configured to direct the bulk material towards the coating assembly.

[0027] Embodiment 3 : The dust control system of any of the preceding embodiments, wherein the ramped surface is at least substantially frustum-shaped.

[0028] Embodiment 4: The dust control system of any of the preceding embodiments, wherein the ramped surface is at least substantially frusto-conical shaped.

[0029] Embodiment 5 : The dust control system of any of the preceding embodiments, wherein the ramped surface is disposed between the opening and the coating assembly.

[0030] Embodiment 6: The dust control system of any of the preceding embodiments, wherein at least a portion of the passage passes interiorly of the ramped surface, the opening is disposed at a first end of the ramped surface, and at least a portion of the coating assembly is disposed adjacent a second end of the ramped surface.

[0031] Embodiment 7: The dust control system of any of the preceding embodiments, wherein an inner ring of the coating assembly is disposed at the second end of the ramped surface, and an outer ring of the coating assembly is spaced radially outwardly of the inner ring, and a space between the inner and outer rings sized to allow passage of the bulk material there through to receive the coating fluid from the coating assembly.

[0032] Embodiment 8: The dust control system of any of the preceding embodiments, wherein the coating assembly includes at least one of an outer spray ring disposed along an interior surface of the housing and an inner spray ring spaced from the interior surface of the housing.

[0033] Embodiment 9: The dust control system of any of the preceding embodiments, wherein the coating assembly includes both the outer spray ring and the inner spray ring, and a space between the inner and outer rings sized to allow passage of the bulk material there through to receive the coating fluid from the coating assembly.

[0034] Embodiment 10: The dust control system of any of the preceding

embodiments, further comprising a kick plate disposed between the opening and the first outlet, wherein the kick plate is arranged to redirect at least a portion of the bulk material from the opening towards the coating assembly, a gap between the kickplate and an interior surface of the housing sized for passage of the dust to the first outlet.

[0035] Embodiment 1 1 : The dust control system of any of the preceding

embodiments, further comprising a second inlet, the second inlet arranged to blow a gas towards the bulk material. [0036] Embodiment 12: The dust control system of any of the preceding embodiments, wherein the second inlet is a wash air inlet arranged adjacent to the coating assembly.

[0037] Embodiment 13 : The dust control system of any of the preceding

embodiments, wherein the second outlet includes a rotary valve configured to break up clumps of the coated material.

[0038] Embodiment 14. An operating system comprising: the dust control system of any of the preceding embodiments; a source of the bulk material; a blower configured to blow the bulk material from the source of the bulk material into the first inlet of the dust control system; and, a receiving member configured to receive the coated material from the second outlet.

[0039] Embodiment 15. The operating system of any of the preceding embodiments, wherein the material receiving member includes a conveyor belt.

[0040] Embodiment 16: The operating system of any of the preceding embodiments, wherein the material receiving member includes a blender.

[0041] Embodiment 17: The operating system of any of the preceding embodiments, wherein the blender uses the coated material to blend a hydraulic fracturing fluid, and further comprising a high pressure fracturing pump configured to receive the hydraulic fracturing fluid from the blender.

[0042] Embodiment 18: A method of controlling dust comprising: pneumatically conveying bulk material into a first inlet of a housing; passing the bulk material in an upward direction through a passage of the first inlet and out an opening of the first inlet, the opening disposed within an interior of the housing; collecting dust from the bulk material through a first outlet of the housing; directing particles of the bulk material in a downward direction past a coating assembly within the housing; coating the particles with a coating fluid as they pass the coating assembly to produce coated material; and, passing the coated material through a second outlet of the housing; wherein the coating assembly is disposed between the opening of the first inlet and the second outlet.

[0043] Embodiment 19: The method of any of the preceding embodiments, wherein directing particles of the bulk material in the downward direction past the coating assembly includes employing a ramped surface between the opening and the coating assembly to guide the particles towards the coating assembly.

[0044] Embodiment 20: The method of any of the preceding embodiments, wherein coating the particles with the coating fluid as they pass the coating assembly includes spraying the particles with the coating fluid using at least one of an outer spray ring disposed along an interior surface of the housing and an inner spray ring spaced from the interior surface of the housing.

[0045] Embodiment 21 : The method of any of the preceding embodiments, further comprising blowing wash air through a second inlet of the housing towards the coating assembly.

[0046] Embodiment 22: The method of any of the preceding embodiments, wherein passing the coated material through the second outlet of the housing includes using a rotary valve to break up clumps of coated material.

[0047] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should further be noted that the terms "first," "second," and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier "about" used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).

[0048] The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and / or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi- solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

[0049] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.