METHODS AND SYSTEMS TO TRANSFER PROPPANT FOR FRACKING WITH REDUCED RISK OF PRODUCTION AND RELEASE OF SILICA DUST AT A WELL SITE
20180148269 ยท 2018-05-31
Inventors
Cpc classification
B65G65/30
PERFORMING OPERATIONS; TRANSPORTING
B65G69/185
PERFORMING OPERATIONS; TRANSPORTING
B65D83/06
PERFORMING OPERATIONS; TRANSPORTING
B65G47/19
PERFORMING OPERATIONS; TRANSPORTING
B65D88/30
PERFORMING OPERATIONS; TRANSPORTING
B65G15/30
PERFORMING OPERATIONS; TRANSPORTING
B65G15/42
PERFORMING OPERATIONS; TRANSPORTING
B65D2588/54
PERFORMING OPERATIONS; TRANSPORTING
B65G41/006
PERFORMING OPERATIONS; TRANSPORTING
B65D2585/00
PERFORMING OPERATIONS; TRANSPORTING
B65G15/58
PERFORMING OPERATIONS; TRANSPORTING
B65D2581/00
PERFORMING OPERATIONS; TRANSPORTING
International classification
B65G47/19
PERFORMING OPERATIONS; TRANSPORTING
B65G65/30
PERFORMING OPERATIONS; TRANSPORTING
B65D83/06
PERFORMING OPERATIONS; TRANSPORTING
B65G15/58
PERFORMING OPERATIONS; TRANSPORTING
B65G15/30
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Embodiments of methods and systems of transferring proppant for fracking to reduce risk of production and release of silica dust at a well site are provided. An embodiment of a method can include positioning a plurality of containers each having proppant for fracking contained therein onto a conveyor at a well site, downwardly discharging proppant from each respective container of the plurality of containers, funneling proppant from the one or more outlets of each of the plurality of containers through a plurality of conveyor hoppers, receiving proppant onto the conveyor belt, conveying proppant on the conveyor to a chute, and depositing the proppant into the chute for use in a blender or other location at the well site.
Claims
1. A method of logistically transferring and handling proppant for fracking at a well site, the method comprising: positioning a plurality of modular containers, each having proppant for fracking contained therein, onto a conveyor at the well site, the conveyor including a conveyor belt and a plurality of compartments each positioned to overlie the conveyor belt and to receive one of the plurality of containers therein; downwardly discharging proppant by gravity feed from each respective container of the plurality of containers, each respective container further having inclined lower inner portions, one or more outlets positioned to allow proppant to flow out of the inclined lower inner portions of each respective container, and one or more flow gates positioned adjacent the respective one or more outlets of each respective container, such that as proppant flows by gravity feed along the inclined lower inner portions to and through the one or more outlets risk of production and release of silica dust into the air is thereby reduced, and the respective container is substantially emptied of proppant; funneling proppant from the one or more outlets of each of the plurality of containers to thereby direct proppant from each of the plurality of containers by gravity feed to the conveyor belt so that risk of production and release of silica dust into the air is reduced; receiving proppant onto the conveyor belt as the proppant contacts the conveyor belt; and conveying proppant positioned on the conveyor belt toward a blender hopper, the conveyor belt having a first end portion and a second end portion, and the second end portion positioned between a last respective container on the conveyor and the blender hopper to reduce the risk of production and release of silica dust into the air as proppant contacts and is carried by the conveyor belt toward the blender hopper.
2. The method of claim 1, further comprising: depositing the proppant from the second end portion of the conveyor belt into a chute further to direct proppant to the blender hopper; and after proppant has been discharged from a respective container of the plurality of containers, removing the respective container from the conveyor for replacement with another respective container filled with proppant, such that the conveyor belt continuously conveys proppant at the well site from the plurality of containers to the chute.
3. The method of claim 1, further comprising: controlling the rate of proppant as it flows through the one or more outlets of each respective container using the one or more flow gates positioned within the track at the one or more outlets so as to be movable within the track to reduce the risk of production and release of silica dust into the air through the one or more outlets, the one or more flow gates optionally controlled by: (a) hydraulics, (b) electronics, or (c) both hydraulics and electronics, thereby to enhance opening and closing of the one or more flow gates along the track, and wherein the conveyor includes a plurality of conveyor hoppers positioned side-by-side and substantially aligned with the plurality of containers.
4. The method of claim 3, further comprising: arranging the plurality of containers in a side-by-side configuration along a length of the conveyor, the conveyor positioned to include an actuator connected to the one or more flow gates when the container is positioned on the conveyor, the actuator driving movement of the one or more flow gates along the track between an open position and a closed position to control the flow rate of proppant out of the container.
5. The method of claim 3, further comprising: controlling the rate of proppant downwardly flowing through each conveyor hopper of the plurality of conveyor hoppers via one or more hopper gate actuators controllably coupled to respective hopper gates, the hopper gates being moveable between an open position and a closed position to enable the proppant to flow from one or more controllable openings arranged at a bottom portion of each conveyor hopper of the plurality of conveyor hoppers.
6. The method of claim 1, further comprising: removing at least one container of the plurality of containers from a first stacked configuration, via a forklift, the first stacked configuration comprising at least two containers arranged one on top of the other, the containers having proppant stored therein and arranged proximate the well site, and the containers each having a frame, which includes one or more support members, positioned to form a cage-like structural configuration thereby to strengthen each container when proppant is stored therein; and returning at least one container of the plurality of containers to a second stacked configuration after the at least one container has been emptied of proppant, the second stacked configuration arranged separate from the first stacked configuration to identify containers having proppant positioned therein and empty containers.
7. The method of claim 6, further comprising: delivering at least one container of the plurality of containers to the well site via a truck, the at least one container having proppant positioned therein; removing the at least one container from the truck via the forklift, the forklift engaging one or more slots positioned at a bottom of the container; and positioning the at least one container in the first stacked configuration proximate the well site.
8. A method for reducing risk of production and release of silica dust at a well site during the transport of proppant for fracking, the method comprising: utilizing a plurality of containers having proppant for fracking contained therein, each respective container having an outlet and a top with a sealable opening, the top positioned to reduce risk of release of silica dust associated with proppant from the top of each respective container, each of the plurality of containers also having a flow gate positioned adjacent the outlet to allow flow of proppant from the outlet when the flow gate is in an open position and to prevent flow of proppant from the outlet when the proppant is in a closed position; positioning each respective container on an inner surface of a conveyor at the well site, the conveyor having a plurality of hoppers to receive proppant from one or more containers of the plurality of containers when an actuator drives movement of the flow gate positioned to movably open the outlet of each respective container, and each of the plurality of hoppers having a controllable opening, positioned at an elevation lower than an outer surface of the conveyor, that is in fluid communication with a conveyor belt that underlies the conveyor to reduce risk of production and release of silica dust associated with proppant as the proppant flows from each respective container; downwardly discharging the proppant from each respective container through each respective opening of each respective hopper onto the conveyor belt, the conveyor belt having a first end portion and a second end portion, the second end portion positioned downstream of the last respective container on the conveyor and arranged to reduce the risk of release of silica dust associated with the proppant into the air; controlling each flow gate of the plurality of containers by hydraulics or electronics to enhance opening and closing of the flow gate along the track to reduce risk of production and release of silica dust associated with proppant into the air as proppant flows out of the outlet; and conveying the proppant to a blender hopper.
9. The method of claim 8, further comprising: after proppant has been downwardly discharged from each respective container, removing each respective container of the plurality of containers from the conveyor at the well site with a forklift for replacement with a second respective container filled with proppant for fracking contained therein, wherein each of the plurality of containers comprises a frame, which includes one or more support members positioned along walls of each of the plurality of containers to form a cage-like structural configuration thereby to strengthen each container when proppant is stored therein; and continuously conveying proppant after discharge from the plurality of containers along the conveyor belt to the chute, the second portion of the conveyor belt including a shroud to define an arrangement to reduce risk of silica dust release associated with the propppant during movement along the second portion of the conveyor belt.
10. The method of claim 8, further comprising: controlling the rate of proppant flowing from each respective container using the flow gate positioned within a track at the outlet of each respective container so as to be movable within the track to reduce risk of production and release of silica dust associated with proppant into the air as proppant flows out of the outlet.
11. The method of claim 10, further comprising: arranging the plurality of containers in a side-by-side configuration along a length of the conveyor, the conveyor comprising the actuator coupling to the flow gate when the container is positioned on the conveyor and driving movement of the flow gate along the track between an open position and a closed position.
12. The method of claim 8, further comprising: controlling the rate of proppant downwardly flowing from each respective hopper using a hopper gate and a hopper gate actuator positioned at the controllable opening of each respective hopper, wherein the plurality of hoppers are positioned side-by-side and are substantially aligned with the plurality of containers; and controlling the hopper gate actuator by hydraulics or electronics to enhance opening and closing of the hopper gate to reduce risk of production and release of silica dust associated with proppant into the air as proppant flows out of the controllable opening.
13. The method of claim 8, wherein a top surface of the conveyor is substantially aligned with a plane of a respective top portion of each hopper of the plurality of hoppers.
14. The method of claim 8, further comprising: transporting at least one container of the plurality of containers to the well site via a truck, the truck receiving and supporting at least one container of the plurality of containers; unloading the at least one container of the plurality of containers off of the truck at the well site via a forklift, the forklift engaging slots positioned at a bottom of the at least one container to lift the at least one container off of the truck; and arranging the plurality of containers in a stacked configuration at the well site, the stacked configuration comprising at least two containers, a first container stacked on top of a second container.
15. The method of claim 8, further comprising: positioning curtains along the conveyor belt extending from the first end portion to an end of the conveyor, the curtain positioned to reduce risk of production and release of silica dust as proppant flows from the plurality of hoppers to the conveyor belt.
16. The method of claim 8, further comprising: conveying the proppant to a chute positioned between the conveyor and the blender hopper, the chute having an inlet positioned to receive the second end of the conveyor belt conveying proppant and one or more outlets positioned such that as proppant is deposited into the chute by gravity feed, proppant flows out of the one or more outlets to the blender hopper.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0020] The foregoing aspects, features, and advantages of the present invention will be further appreciated when considered with reference to the following description of embodiments and accompanying drawings. In describing the embodiments of the invention illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
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DETAILED DESCRIPTION
[0050] The foregoing aspects, features, and advantages of the present invention will be further appreciated when considered with reference to the following description of embodiments and accompanying drawings. In describing the embodiments of the invention illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose.
[0051] Embodiments of methods and systems are useful at a well site 30 of a hydraulic fracturing operation. These well sites 30, as shown in
[0052] As described in detail in the background section, prior art methods of transferring fracking sand or proppant 38 resulted in the production and release of harmful silica dust 50 at the well site. As shown in
[0053] The flow chart depicted in
[0054] Operators or machines utilize hydraulics or electronics to selectively open a series of gates, for example, a flow gate 932 at the bottom 906 of each respective container 900, and a conveyor hopper gate 612 at the bottom 608 of each respective conveyor hopper 600, that control a series of openings, for example, one or more outlets 924 of a container 900 and one or more controllable openings 610 of a conveyor hopper 600, through which the proppant 38 is funneled. The close positioning and design of the containers 900 and conveyor 1000, for example, minimize the risk of production and release of silica dust 50 as the proppant 38 is funneled to the conveyor belt 700. For example, once the sealed containers 900 are positioned on the conveyor 1000, operators or machines downwardly discharge 110 the proppant 38 from each respective container 900 until each respective container 900 is substantially emptied of proppant 38. Proppant 38 then is funneled 120 from the one or more openings 924 of each of the plurality of containers 900 to and through the plurality of conveyor hoppers 600 that are adapted and positioned to reduce the risk of production and release of silica dust 50.
[0055] Proppant 38 is received 130 onto the conveyor belt 700 by a plurality of partitions 712 associated therewith, such that the plurality of partitions 712 is positioned to reduce production and release of silica dust 50 into the air as proppant 38 contacts and is carried by the conveyor belt 700. These plurality of partitions 712, for example, include a plurality of fingers 714 spaced-apart from each other on the top surface 702 of the conveyor belt 700. The plurality of partitions 712 further can include outside walls 716 of the conveyor belt. The plurality of partitions 712, therefore, can guidingly accept proppant onto the conveyor belt 700 while, for example, breaking up any clumps of proppant 38, if any, that may pass through each respective conveyor hopper 600, and further reduce any production and release of silica dust 50 as the proppant 38 contacts the conveyor belt 700. The conveyor belt 700 is also closely positioned beneath or adjacent the bottom portion 608 of each conveyor hopper 600 to further reduce the fall-height for the proppant 38 to a matter of inches, for example, as it contacts and is transported by the conveyor belt 700.
[0056] The one or more conveyor belts 700 then conveys 140 the proppant 38 to and through a shrouded portion 802 adapted and positioned to reduce the risk of release of silica dust 50 to a chute 822. This shrouded portion 802 can be optionally omitted if the conveyor 1000 is designed to directly deposit proppant 38 from the conveyor belt 700 into a blender hopper 810, for example, as shown in embodiments described herein, including
[0057] Once the respective containers 900 are substantially emptied of proppant 38, forklifts 34, cranes 35, or other machinery can remove 160 the empty containers 900 for replacement with containers 900 having proppant 38 for fracking at the well site 30 so that proppant 38 is continuously flowing toward the blender hopper 810 or other location at the well site 30 while in operation. Containers can be stacked 900S1, 900S1 at the well site 30, for example, up to three-high to be refilled with proppant or transported off the well site 30 to be refilled with proppant 38. The containerized aspects of the embodiments of the invention allow for the continuous flow of proppant 38 to the wellbore 42 at a well site 30 while the conveyor 1000 is in operation.
[0058] Embodiments of containers 900, for example, can be adapted for and positioned to reduce the risk of production and release of silica dust 50 at a well site 30. As depicted in FIGS. 9A-9E, each respective container 900 is in the nature of a box with an exterior frame 902 having two sets of parallel sides 901A1, 901A2, 901B1, 901B2 that are each perpendicular to a top 904 and a bottom 906. The container 900 can be a ten-foot ISO container. The container can have a ladder 903 for an operator to climb to the top 904 of the container 900 and inspect the contents within the container 900, for example. This means that the container 900 can have a length of ten feet, a width of eight feet, and a height of eight-and-a-half feet, for example. The height can also be nine-and-a-half feet. This embodiment, for example, can hold approximately twenty-three tons of proppant 38 (approximately 43,000-48,000 lbs.), in each such container 900. The containers 900 are designed to drain the proppant 38 contained therein in under two minutes, or at a rate of 25,000 pounds per minute. Because of the weight and magnitude of the proppant 38, the container 900 is made of steel or other similar material and the exterior frame 902 is cage-like or lattice-like and useful for the structural support and positioning of each container 900 onto the compartments 1002 of the conveyor 1000 that are adapted to receive each respective container 900. The frame 902 also includes a plurality of slots 901, including, for example, two slots 901, by which a forklift 34 can lift and position the plurality of containers 900 on the conveyor 1000.
[0059] The top 904 of each container 900 has an inlet 905 that may be opened and closed by a door 914, hatch, gate, or other closing mechanism. This door 914 can provide a seal, or an air-tight and water-tight connection, to the container 900, as it is preferable for the proppant 38 to remain substantially dry. Although proppant 38 can flow through embodiments of the system with some degree of moisture content, it is preferable to prevent the clumping of proppant 38 caused by moisture. The door 914 is also important to prevent the escape of silica dust 50 from the proppant 38 contained therein before and during the transfer of proppant 38 from the containers 900 through an embodiment of a system. A person having skill in the art can grasp the available options to design, affix, or attach a door 914 to accomplish this sealing function.
[0060] The container 900 is made of steel or other similar material. As viewed from the outside of the container 900, and as shown in
[0061] As can be seen in from the partial break-away view of a container 900 shown in
[0062] A flow gate 932 is positioned within tracks 933 located on the bottom 906 over or adjacent the opening or openings 924 of the inclined lower inner portions 922 of each respective container 900, as shown in
[0063] The containers 900 described herein are adapted to fit onto compartments 1002 of a conveyor 1000 adapted to receive the containers 900 thereon. As shown in
[0064] As shown in
[0065] As can be seen in
[0066] The conveyor 1000, having a plurality of compartments 1002 adapted to receive containers 900, also can have a plurality of openings 1028 in the top surface 1020 of the conveyor 1000. The plurality of openings 1028 is positioned beneath the respective plurality of containers 900 on the conveyor 1000 such that proppant 38 flowing from each respective container 900 will pass through each respective opening 1028. Each opening 1028 has one or more forks 500 positioned above or adjacent the opening or openings 1028, the one or more forks 500 adapted to receive a handle 934 of a flow gate 932 of a container 900 to engage, contact, or communicate with the corresponding handle 934 of the flow gate 932 of the container 900, as shown in an embodiment depicted in
[0067] Embodiments of the conveyor 1000, for example, also can include a plurality of conveyor hoppers 600 positioned adjacent or beneath the plurality of openings 1028 in the top surface 1020 of the conveyor 1000. The plurality of conveyor hoppers 600 is positioned such that when containers 900 are placed onto the conveyor 1000, each respective conveyor hopper 600 is beneath the flow gate 932 of the one or more openings 924 of each respective container 900. As shown in
[0068] The conveyor hopper 600 has a top portion 606 and a bottom portion 608, and the bottom portion 608 can include one or more controllable openings 610. The top portion 606 of the conveyor hopper 600 can be in the same plane, above it, or below the top surface 1020 of the conveyor 1000. The top portion 606 of the conveyor hopper 600 can be in the same plane or higher than the top surface 1020 of the conveyor 1000, as can be seen in
[0069] Embodiments of methods and systems, for example, also can include one or more conveyor belts 700. Each respective conveyor belt 700 has a top surface 702, a bottom surface 704, and two sides 706A, 706B. Each respective conveyor belt 700 is manufactured as one long piece, or is zippered together to form one long piece. Each respective conveyor belt 700 has a first end portion 705 and a second end portion 707. Each respective conveyor belt 700 is suitably wound around rollers 708 to travel a desired path. Each respective conveyor belt 700 is powered by one or more engines 710. These engines 710 can be diesel, electric, or a combination of the two. Diesel engines 710 have been used in the filed for many years and are reliable in remote locations. Electric engines 710, however, are cleaner to use but may require, for example, an on-site generator, batteries, or access to electric power to run. The industry, however, is moving towards cleaner power sources, and the various engines 710 available will be known to a person of skill in the art. As shown in
[0070] Referring to
[0071] Each side 706A, 706B of the one or more conveyor belts 700 has an outside wall 716 positioned at or near the margin or edge of the respective side 706A, 706B. The outside wall 716 can be in a continuous S shape to permit the conveyor belt 700 to compress and flex around rollers 708 as the conveyor belt 700 is moving to prevent the escape of silica dust 50. The outer wall 716 also prevents proppant 38 from spraying or falling out the sides 706A, 706B of the conveyor belt 700 as it is being conveyed to the chute 822. It also prevents wind from blowing the proppant 38 or silica dust 50 off the conveyor belt 700. Other shapes, for example, a wave or triangular shape, of the outer wall 716 are acceptable so long as the conveyor belt 700 does not release silica dust 50 or proppant 38 through the outer wall 716 as it passes along the rollers 708. The outer wall 716 may comprise a flat or rounded top 720, much the same as the plurality of fingers 714. As can be seen in an embodiment shown in
[0072] As shown in the embodiments of
[0073] Similarly to the curtain or curtains 1200 of an embodiment shown in
[0074] In an embodiment shown in
[0075] In an embodiment of a method, for example, where a conveyor 1000 is holding all of the containers 900 it is designed to hold, as shown, for example, in
[0076] In an embodiment, for example, shown in
[0077] Referring to
[0078] The chute 822 is positioned at the second end 1014 of the conveyor 1000 to receive the proppant 38 that is deposited by the conveyor belt 700 via gravity feed 812. The chute 822 can be tube-shaped, but a chute 822 may alternatively have a bottom portion and a top portion, for example. The chute 822 has an inlet 824 and one or more outlets 826, the inlet 824 positioned to receive the second end 1014 of the conveyor 1000 and the one or more conveyor belts 700 conveying proppant, and the one or more outlets 826 of the chute 822 positioned to deposit proppant 38 into a blender hopper 810 or another location on the well site 30. The chute 822, like the shroud 800, is adapted and positioned to reduce the risk of release of silica dust 50 at the well site 30, but also to prevent wind and rain from contacting the proppant 38. The chute 822, in one embodiment, for example, is rotatably connected to the shrouded portion 802 of the conveyor belt 700 such that an operator 806 or a machine can hold on to handles 823 attached to the chute 822 for positioning the opening or openings 826 of the chute 822 towards a blender hopper 810 or another location at a well site 30, as shown in
[0079] Well site operators also may be concerned about reducing the silica dust 50 that may be produced or released as proppant 38 flows from the one or more openings 826 of the chute 822 into the one or more blender hoppers 810 of one or more blenders 36 at a well site 30. As shown in
[0080] As demonstrated in
[0081] After proppant 38 has been discharged from a respective container 900 of the plurality of containers 900, the method further can include removing 160 the respective container 900 from the conveyor 1000 for replacement with another respective container 900 filled with proppant 38, such that the conveyor belt 700 continuously conveys proppant 38 at the well site 30 from the plurality of containers 900 to the blender 36. An operator 806 or machine may use a forklift 34, crane 35, or other heavy machinery to move containers 900 at the well site 30.
[0082] A flow gate 932 and inclined lower inner portions 922 of each respective container 900 help to control the flow of proppant 38 from the container 900 and thereby reduce the risk of production of silica dust 50 from the container 900. An embodiment of the method further can include controlling 170 the rate of proppant 38 as it flows through the one or more outlets 924 of each respective container 900 by one or more flow gates 932 positioned at the one or more outlets 924 to reduce the risk of production and release of silica dust 50 into the air through the one or more outlets 924. The flow gate 932 can be connected to an actuator 502 thereby to enhance opening and closing of the flow gate 932. The actuator 502 may be optionally controlled by hydraulics or electronics. If hydraulics are used, for example, a plurality of hydraulic pressure hoses 503 can connect the actuator 502 to the one or more engines 710 and controls 1017. If electronics are used, for example, a plurality of wires 505 can be used to connect the actuator 502 to the one or more engines 710 and controls 1017. Wireless connections are also contemplated. A person of skill in the art would understand the various connections to engines 710 and controls 1017 available for powering the actuator 502. The inclined lower inner portions 922 of each respective container 900 are inclined inwardly from inner walls of the respective container toward a bottom of the container at an angle 928 of about 31 degrees to about 37 degrees relative to a horizontal plane 920 of the bottom of each respective container 900 when each respective container 900 is level. This angle 928 helps to empty the container 900 of proppant 38 to reduce the risk of silica exposure for well site workers.
[0083] A hopper gate 612, a hopper gate actuator 613, and a plurality of inclined sides 602 of each respective conveyor hopper 600 help to control the flow of proppant 38 from each respective conveyor hopper 600 and thereby reduce the risk of production and release of silica dust 50 from the conveyor hopper 600. The method can also further include controlling 180 the rate of proppant 38 as the proppant 38 flows from the one or more controllable openings 610 of each respective conveyor hopper 600 to reduce the risk of production and release of silica dust 50 into the air through the one or more controllable openings 610, the one or more controllable openings 610 having a hopper gate 612 connected to a hopper gate actuator 613. The hopper gate actuator 613 is optionally controlled by hydraulics or electronics to enhance opening and closing of the one or more controllable openings 610 via the hopper gate 612. If hydraulics are used, for example, a plurality of hydraulic pressure hoses 614 can connect the hopper gate actuator 613 to the one or more engines 710 and controls 1017. If electronics are used, for example, a plurality of wires 616 can be used to connect the hopper gate 612 to the one or more engines 710 and controls 1017. Wireless connections are also contemplated. A person of skill in the art would understand the various connections to engines 710 and controls 1017 available for powering the hopper gate actuator 613. The plurality of inclined sides 602 can include, for example, a pair of short sides 604A1, 604A2 representing the depth of the conveyor hopper 600, and a pair of long sides 604B1, 604B2 representing the length of the conveyor hopper 600. The plurality of inclined sides 602 are positioned wherein pair of short sides 604A1, 604A2 have a funnel angle 605A or slope of approximately 35 to 40 degrees relative to a horizontal plane, and a pair of long sides 604B1, 604B2 have a funnel angle 605B or slope of approximately 28 to 33 degrees relative to a horizontal plane, in order to maximize the capacity of the conveyor hopper 600 and the flow of proppant 38 from the conveyor hopper 600, and to reduce the risk of production and release of silica dust 50 from each respective conveyor hopper 600.
[0084] In another embodiment, for example, and as illustrated in
[0085] The method also can include, for example, removing 160 each respective container 900 that has been substantially emptied of proppant 38 from the conveyor 1000 at the well site 30 with a forklift 34 for replacement with a second respective container 900 filled with proppant 38 for fracking contained therein such that the conveyor belt 700 is continuously conveying proppant 38 when in operation to the chute 822.
[0086] The method also can include, for example, controlling 170 the rate of proppant 38 flowing from each respective container 900 using a flow gate 932 positioned at the one or more outlets 924 of each respective container 900 to reduce risk of production and release of silica dust 50 associated with proppant 38 into the air as proppant 38 flows out of the one or more outlets 924, as shown in
[0087] The method also can include, for example, controlling 180 the rate of proppant 38 downwardly flowing from each respective conveyor hopper 600 using a hopper gate 612 with a hopper gate actuator 613 positioned at the one or more controllable openings 610 of each respective conveyor hopper 600, and optionally controlling the hopper gate actuator 613 by hydraulics or electronics to enhance opening and closing of the hopper gate 612 to reduce risk of production and release of silica dust 50 associated with proppant 38 into the air as proppant 38 flows out of the one or more controllable opening 610, as shown in
[0088] The method also can include, for example, positioning 245 a shroud 800 over a portion 802 of the second end 707 of the conveyor belt 700 thereby to define a shrouded portion 802, the shrouded portion 802 positioned between the last respective container 900 on the conveyor 1000 and the chute 822 at an angle 805 of approximately 30 to 60 degrees from a horizontal plane 1020 when the conveyor is level. The shroud 800 substantially encloses the one or more conveyor belts 700 to reduce the risk of release of silica dust 50 associated with proppant 38 in the air.
[0089] The method also can include, for example, positioning 102 each of the plurality of containers 900 side-by-side on the conveyor 1000.
[0090] The method also can include, for example, positioning 104 the plurality of containers 900 adjacent each other on the conveyor 1000, wherein each of the plurality of partitions 712 of the conveyor belt 700 extend upwardly from a top surface 702 of the conveyor belt 700 toward the conveyor hopper 600 when positioned to underlie the conveyor hopper 600 and each of the plurality of fingers 714 is spaced-apart from another one of the plurality of fingers 714 so that the top surface 702 of the conveyor belt 700 guidingly receives the proppant 38 thereon and between the plurality of partitions 714.
[0091] An embodiment of the system of the present invention can include, for example, a plurality of containers 900 each adapted to have proppant 38 for fracking contained therein, each respective container 900 having a sealed top 904, 914 to reduce risk of release of silica dust 50 associated with proppant 38 into the air when positioned therein. Each respective container 900 has interior portions 922 inclined toward an outlet 924 at a bottom 916 of each respective container 900 to reduce risk of production and release of silica dust 50 associated with proppant 38 as the proppant 38 flows from each respective container 900 until each respective container 900 is substantially empty.
[0092] The system further can include a conveyor 1000 positioned at a well site 30 and to receive each respective container 900 of the plurality of containers 900, the conveyor 1000 having one or more conveyor hoppers 600 that align closely with each respective outlet 924 of the plurality of containers 900 to reduce risk of production and release of silica dust 50 into the air, each of the one or more respective conveyor hoppers 600 having a lower portion 608 including an opening 610, such that when proppant 38 downwardly flows through each respective outlet 924 of each respective container 900 of the plurality of containers 900 when positioned therein, the proppant 38 passes to and through the opening 610 of each of the one or more respective conveyor hoppers 610.
[0093] The system further can include one or more conveyor belts 700 positioned to underlie the one or more conveyor hoppers 600 to receive proppant 38 as the proppant 38 passes to and through the opening 610 of each of the one or more respective conveyor hoppers 600, the conveyor belt 700 having a first end 705, a second end 707, and a plurality of partitions 714 associated therewith, such that the plurality of partitions 714 are positioned to reduce risk of production and release of silica dust 50 as proppant 38 contacts and is carried by the conveyor belt 700.
[0094] The system further can include a shroud 800 positioned to overlie a portion of the second end 705 of the conveyor belt 700 thereby to define a shrouded portion 802 of the conveyor belt 700, the shroud 800 substantially enclosing the shrouded portion 802 as the conveyor belt 700 conveys proppant 38 when positioned thereon from the plurality of containers 900 to reduce risk of release of silica dust 50 associated with proppant 38 into the air from the shrouded portion 802.
[0095] The system further can include a chute 822 having an inlet 824 positioned to receive the second end 707 of the conveyor belt 700 conveying proppant 38 and one or more outlets 826 positioned such that as proppant 38 is deposited into the chute 822 by gravity feed 812, proppant 38 flows out of the one or more outlets 826 to a blender hopper 810 or other location at the well site 30.
[0096] The system also further can include a blender hopper cover 1208 positioned to reduce risk of production and release of silica dust 50 as proppant 38 flows between the one or more outlets 826 of the chute 822 and the one or more blender hoppers 810 of the one or more blenders 36 at a well site 30.
[0097] The system also further can include a forklift 34 positioned at a well site 30 to load and unload each respective container 900 onto and off of the conveyor 1000 by one or more slots 901, wherein each of the plurality of containers 900 has one or more slots 901 positioned adjacent a bottom portion 906 of the respective container 900.
[0098] The system also further can include a plurality of curtains 1200 positioned on or adjacent the conveyor 1000 to reduce risk of production and release of silica dust 50 as proppant 38 flows from the plurality of conveyor hoppers 600 to the one or more conveyor belts 700.
[0099] Another embodiment of the system, for example, can include a plurality of containers 900 each adapted to have proppant 38 for fracking contained therein, each respective container 900 having a sealed top 904, 914 to reduce risk of release of silica dust 50 associated with proppant 38 into the air when positioned therein. Each respective container 900 has interior portions 922 inclined toward an outlet 924 at a bottom 906 of each respective container to reduce risk of production and release of silica dust 50 associated with proppant 38 as the proppant 38 flows from each respective container 900 until each respective container 900 is substantially empty.
[0100] The system further can include a conveyor 1000 positioned at a well site 30 and to receive each respective container 900 of the plurality of containers 900, the conveyor 1000 having one or more conveyor hoppers 600 that align closely with each respective outlet 924 of the plurality of containers 900 to reduce risk of production and release of silica dust 50 into the air, each of the one or more respective conveyor hoppers 600 having a lower portion 608 including an opening 610, such that when proppant 38 downwardly flows through each respective outlet 924 of each respective container 900 of the plurality of containers 900 when positioned therein, the proppant 38 passes to and through the opening 610 of each of the one or more respective conveyor hoppers 600.
[0101] The system further can include one or more conveyor belts 700 positioned to underlie the one or more conveyor hoppers 600 to receive proppant 38 as the proppant 38 passes to and through the opening 610 of each of the one or more respective conveyor hoppers 600, the conveyor belt 700 having a first end 705, a second end 707, and a plurality of partitions 714 associated therewith, such that the plurality of partitions 714 are positioned to reduce risk of production and release of silica dust 50 as proppant 38 contacts and is carried by the conveyor belt 700.
[0102] As shown in
[0103] As shown in
[0104] The system also further can include a forklift 34 positioned at a well site 30 to load and unload each respective container 900 onto and off of the conveyor 1000 by one or more slots 901, wherein each of the plurality of containers 900 has one or more slots 901 positioned adjacent a bottom portion 916 of the respective container 900.
[0105] The system also further can include a plurality of curtains 1200 positioned on or adjacent the sides of the conveyor 1000 to reduce risk of production and release of silica dust 50 as proppant 38 flows from the plurality of conveyor hoppers 600 to the conveyor belt 700.
[0106] The owner of the present application conducted experiments to determine the amount of reduction to respirable crystalline silica particles using an embodiments of method and systems relative to conventional pneumatic delivery. The testing was carried out by Weston Solutions, Inc. of Lakewood, Colo. The tests were based on samples collected for personal breathing zone samples to assess likely employee exposure to respirable crystalline silica by job category at a well site. Personal breathing zone samples were collected in order to compare the results to those found in the NIOSH study.
[0107] Personal breathing zone samples were collected using conventional industrial hygiene techniques. A filter cassette and a particle sizing cyclone were affixed to each monitored worker's collar or shoulder seam within ten inches of the mouth and nose. A Tygon tube conducted airflow from the breathing zone collection device to a hygiene sampling pump worn in a pouch affixed to a belt around the worker's waist. Sample flow rates were determined before and after sampling using a primary standard flow calibrator.
[0108] Sixteen personal breathing zone monitoring samples were collected over three days, and during four work shifts. Three of the sixteen samples exceeded the OSHA Permissable Exposure Limit (PEL) for respirable dust containing silica, or about 19%. These were notably fewer results from this assessment above the PEL than in the NIOSH study cited in the Silica Hazard Alert, discussed in the background section, where 51.4% of breathing zone samples exceeded the PEL. No breathing zone sample in this assessment exceeded the PEL by more than a factor of five, whereas six breathing zone exposure monitoring results of forty total from a Minot area well fracture job using pneumatic sand delivery exceeded the PEL by a factor of ten or more. Four of the sixteen personal breathing zone samples, or 25%, exceeded the NIOSH Recommended Exploded Limit (REL). On a pneumatic delivery fracture job near Minot, twenty-four of the forty breathing zone samples, or 60%, exceeded the NIOSH REL. That result was somewhat less than in the NIOSH study where 68.5% of all samples exceeded the REL. In summary, the geometric mean result for breathing zone samples from t-belt operators in the NIOSH study was 0.327 mg/m.sup.3 as the REL, whereas the geometric mean exposure for sand workers in this assessment was 0.0874 mg/m.sup.3, a roughly four-fold reduction.
[0109] This application is a continuation and claims priority to, and the benefit of, U.S. patent application Ser. No. 14/943,182, filed Nov. 17, 2015, titled Methods and Systems to Transfer Proppant for Fracking with Reduced Risk of Production and Release of Silica Dust at a Well Site, which is a continuation of U.S. patent application Ser. No. 14/676,039, filed Apr. 1, 2015, titled Methods and Systems to Transfer Proppant for Fracking with Reduced Risk of Production and Release of Silica Dust at a Well Site, now U.S. Pat. No. 9,340,353, issued May 17, 2016, which claims priority to, and the benefit of, U.S. Provisional Application No. 62/012,160, filed Jun. 13, 2014, titled Process and Apparatus for Reducing Silica Exposure During the Delivery of Proppants to a Mine, U.S. Provisional Application No. 62/014,479, filed on Jun. 19, 2014, titled System and Methods for Reducing Silica Exposure at a Well Site, and U.S. Provisional Application No. 62/114,614, filed Feb. 11, 2015, titled Methods and Systems to Transfer Proppant for Fracking with Reduced Risk of Production and Release of Silica Dust at a Well Site. U.S. patent application Ser. No. 14/676,039 is also a continuation in part of U.S. patent application Ser. No. 13/555,635, filed Jul. 23, 2012, titled Proppant Discharge System Having a Container and the Process for Providing Proppant to a Well Site, now U.S. Pat. No. 9,718,610, issued Aug. 1, 2017. U.S. patent application Ser. No. 14/676,039 is also a continuation in part of U.S. patent application Ser. No. 13/628,702, filed Sep. 27, 2012, titled Proppant Discharge System and a Container for Use in Such a Proppant Discharge System, which is a continuation in part of U.S. patent application Ser. No. 13/555,635, filed Jul. 23, 2012, titled Proppant Discharge System Having a Container and the Process for Providing Proppant to a Well Site, now U.S. Pat. No. 9,718,610, issued Aug. 1, 2017, all of which are incorporated herein by reference in their entireties.
[0110] The foregoing disclosure and description of the invention is illustrative and explanatory of the embodiments of the invention. Various changes in the details of the illustrated embodiments can be made within the scope of the appended claims without departing from the true spirit of the invention. The embodiments of the present invention should only be limited by the following claims and their legal equivalents.