AU2012203430A1 - A system and method for transporting a bulk particulate material and discharging it in a controlled fashion - Google Patents

Abstract

A system and a method for transporting a bulk particulate material from a 5 source to a material use location is disclosed. The system 10 includes a container 12 for receiving a bulk particulate material defining a container outlet, and a delivery chute 16 defining a chute inlet through which the bulk particulate material enters the chute and a chute outlet spaced from the inlet through which particulate material can be discharged from the chute 16. The delivery 10 chute 16 includes a control arrangement having a control handle for enabling an operator to control the rate at which the bulk particulate material is discharged through the chute outlet. Conveniently the container 12 is an intermodal shipping container that is capable of being sealed off from the outside environment so that elements in the outside environment cannot come 15 into contact with the material. Fig 5 for publication 5/li _________ / 0 - N (.0 - / 0 ".5 Lt~

Description

A SYSTEM AND METHOD FOR TRANSPORTING A BULK PARTICULATE MATERIAL AND DISCHARGING IT IN A CONTROLLED FASHION 5 FIELD OF THE INVENTION This invention relates to a method of transporting a bulk particulate material from a source to a material use site and discharging the bulk particulate material in a controlled fashion at the material use site. The invention also 10 relates to a system for transporting a bulk particulate material from a source to a material use site and discharging the bulk particulate material in a controlled fashion at the material use site. Yet further the invention extends to a delivery chute for use in the system. 15 This invention relates particularly but not exclusively to a system and method for transporting a particulate material that is a proppant and discharging it in a controlled fashion at its material use site which is a well-site at which a fracking operation is to be carried out. It will therefore be convenient to hereinafter describe the invention with reference to this example application. However at 20 the same time it must be recognized that the invention is capable of broader application. The invention has potential application to the transport of all bulk particulate materials. DEFINITIONS 25 In the specification the term "comprising" shall be understood to have a broad meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This 30 definition also applies to variations on the term "comprising" such as "comprise" and "comprises". 1 In this specification the term "proppant" shall be understood to mean a particulate material that is used for hydraulic fracturing operations (fracking operations) in coal seam gas operations where the proppant is mixed with 5 water and is pumped into a well bore at high pressure. The proppant is often described in the art as "frac sand" and can be either a natural or a manufactured material. The proppant is however required to have a very specific particle size distribution and is required to be kept completely dry up to the point where it is delivered to the customer at a fracking site. 10 In this specification the term "delivery chute" shall be understood to mean a body defining a passage through which a flowable material including a particulate material can flow under the influence of gravity. 15 In this specification the term "container" shall be understood to mean a container having sufficient strength to withstand shipment, handling and storage when carrying a material. It includes but is not limited to an intermodal shipping container which is a reusable transport and storage unit for moving material from one location to another. In particular it may be twenty foot or forty foot 20 equivalent unit. It also includes an iron box shipping container which is used to transport iron ore. In this specification the term "well site" shall be understood to mean a compact area on the surface of the earth above a well bore within which all apparatus 25 associated with the well bore is received and within which all activities associated with drilling and collecting fuel from the well bore are conducted. BACKGROUND TO THE INVENTION 30 Coal seam gas (CSG) which comprises mainly methane (CH4) is a fossil fuel that is extracted from coal seams that are too deep to be mined economically. 2 In Australia the CSG industry is developing very rapidly in the Surat and Bowen Basins in Queensland, and also in NSW. Source rocks contain gas or liquid fuel and this fuel needs to flow out of the 5 source rocks to be recovered. Typically the fuel flows from a source rock into a reservoir rock from where the fuel can be drawn into a well bore. The reservoir rock is often porous sandstone, limestone or dolomite rocks but it also includes unconventional reservoir rocks such as shale rock or coal. Once it is received within the well bore the fuel can rise up through the well bore to the surface 10 from where it can be recovered and processed into fuel. The gas or liquid fuel travels through passages and channels in the rock when it moves from the source rock to the reservoir rock. Hydraulic fractures in the form of veins and dykes form naturally in rocks and can serve as conduits for 15 the movement of gas or liquid fuel from the source rock to the reservoir rock. However the flow of liquid or gas fuel along natural veins and dykes is quite limited and other measures are desired to increase the rate at which fuel flows from the source rock into the well bore. This is achieved by human intervention to increase the number of channels in the rock through which fuel can flow into 20 the well bore. A process of hydraulic fracturing which is often called "fracking" or "hydrof racking" has been developed to form additional passages or channels in the source rock and thereby increase the recovery of liquid and gas fuel from 25 subterranean natural reservoirs. During hydraulic fracturing, a liquid is pumped at high flow rate and under high pressure into the rock layer which fractures the rock. The fractures create new channels in the rock which can increase the recovery of gas or liquid fuel from the source rock via the well-bore. Hydraulic fracturing is performed in cased well bores which are laterally perforated at 30 different depths at which the rock is to be accessed. 3 The fracking apparatus which is used to carry out the fracking operation includes a slurry blender, and one or more high pressure high volume fracturing pumps such as a powerful triplex or quintiplex pump, and a monitoring unit. The pumps pump a fracking fluid which is a liquid into the rocks at a pressure of 5 up to 10OMPa and a flowrate of 265 I/s. The apparatus includes ancillary equipment such as a blending tank, units for the storage and handling of proppant, a monitoring unit and gauges of various sorts. The fracking fluid which is pumped into the rock typically comprises a water slurry, proppants, and chemical additives which are mixed into the slurry. Additionally gels, foams and 10 compressed gases including carbon dioxide, nitrogen and air can be mixed into the fracking fluid. The proppant which is a particulate solid material operates to hold open the newly formed fractures and channels in the fractured rocks. The proppant is forced into the fractures within the rocks by the pumping of the fracking fluid and remains within the fractures after the fracking process has 15 been completed. The proppant holds the newly created fractures open to provide increased flow channels through the rock after the fracking operation has been completed. The proppant or fracking sand can be a natural particulate sand, e.g. such as a 20 sieved round sand, or a ceramic material. Instead the proppant can be a manufactured or man-made sand. The properties of the proppant that are very specific and become more important when the fracking is carried out at greater depths below the ground surface where there is commensurately greater pressure and stresses. Accordingly the proppant is required to be handled in a 25 very special way up to the point where it is fed into the blender of the fracking plant. In particular the proppant has to remain completely dry during transport and during storage on site prior to its use. Very often gas and oil wells or well bore sites are located in remote locations 30 and occupy a small footprint on the surface of the ground. As a result there is very little space at the well site within which to unload the proppant and feed it 4 into a storage unit and/or transfer it into the blender. One current technique includes transporting particulate proppant material to the well site in bulker bags. The bulker bags are carried on a trailer to the site and lifted off the trailer using a crane. The bulker bags are hoisted by the crane up above a storage 5 unit and then split open by an operator standing below the bulker bag releasing the proppant and allowing it to discharge into the hopper or silo storage. This is recognised as being a particularly dangerous operation as an operator has to stand beneath a heavy bag containing that is suspended from the crane and is not supported in any other way. Figure 1 is a schematic flowsheet showing a 10 bulker bag and an overview of the prior art method of shipping fracking sand to a coal seam gas well site in Australia. This prior art technique is somewhat inefficient because each bulker bag only contains about 200-500kg of proppant and has each bag has to be individually handled. Further as described above the prior art technique is dangerous particularly for the operator who cuts open 15 the bulker bag. Accordingly it would be advantageous if a new apparatus transporting and discharging a bulk particulate material such as fracking sand or proppant to a location at which it is to be used could be devised. 20 SUMMARY OF THE INVENTION According to one aspect of this invention there is provided a method of transporting a bulk particulate material from a source to a material use site and 25 discharging the bulk particulate material in a controlled fashion at the material use site, the method including: transporting the bulk particulate material in a container; discharging the bulk particulate material from the container into a delivery chute; and 30 controlling the rate at which the bulk particulate material is discharged from the delivery chute. 5 Transporting the bulk particulate material in a container may include transporting the material in a container that resists the ingress of moisture, and other components from the environment, into the container. That is the 5 container is able to seal off the bulk particulate material from the environment. Discharging the bulk particulate material from the container may include tipping the container to cause the particulate material to flow out of an opening in the container under the influence of gravity. 10 The container may be a substantially rectangular container having two ends and discharging the bulk particulate material from the container includes tipping the container such that the bulk particulate material is discharged through the opening which is positioned in one end of the container. 15 Transporting the bulk particulate material may include transporting the container on a vehicle by road and/or rail and the container may be an intermodal shipping container that is removably mounted on the vehicle. 20 Transporting the bulk particulate material may include transporting the bulk particulate material on a road trailer that can be tipped to discharge bulk particulate material from the trailer. The method may further include an initial step of loading the bulk particulate 25 material into the container at the source prior to transporting the bulk particulate material. Loading the bulk particulate material into the container may include loading the bulk particulate material through an upwardly facing opening using a gravity feeding device. 30 Controlling the rate at which the bulk particulate material is discharged from the delivery chute may include adjusting the size of an outlet opening in the delivery chute through which particulate material is discharged. 6 The method may include discharging the bulk particulate material through the delivery chute onto a conveyor and conveying the bulk particulate material away from the delivery chute on the conveyor to a receiving arrangement. 5 The method may be used for transferring a bulk particulate material that is a bulk particulate material suitable for use as a proppant in a fracking operation, from a source of the bulk particulate material to a material use site that is well site, used for recovering hydrocarbon fuels. 10 Conveying the bulk particulate material away from the delivery chute may include conveying the discharged bulk particulate material towards a storage unit and feeding the material into the hopper by gravity. 15 Conveying the bulk particulate material away from the delivery chute may include conveying the discharged bulk particulate material towards a blender of a fracking apparatus and feeding the material into the blending apparatus by gravity. 20 The method may be particularly suitable for delivering a fracking sand from a source to a material use site that is a well bore for use in a fracking operation. In particular the well site may be used for extraction of coal seam gas or for extraction of shale gas. 25 According to another aspect of this invention there is provided a system for transporting a bulk particulate material from a source to a material use location, the system including: a container for receiving a bulk particulate material defining a container outlet; and 30 a delivery chute mounted on the container including a chute body defining a chute inlet through which the bulk particulate material enters 7 the chute and a chute outlet spaced from the chute inlet through which particulate material can be discharged from the chute body, and the container outlet opens into the chute inlet whereby the delivery chute includes a control arrangement for controlling the rate at which the bulk 5 particulate material is discharged through the chute outlet. The container may be capable of being sealed off from the outside environment so that elements in the outside environment cannot come into contact with the bulk particulate material in the container. In particular the container may be 10 sealed off from the outside environment during transit to resist the ingress of moisture into the container. The container may be an elongate rectangular box shaped container having two end walls and the container outlet may be formed in one end wall of the 15 container. The container outlet may be in the form of an opening defined in said one end wall having a flap closure mounted over the opening that swings open when the container is tipped up to permit the bulk particulate material to discharge from 20 the container. The container may be an intermodal shipping container for the transport of a bulk particulate material. In particular the container may be a 20 foot intermodal shipping container having a standard height of about 960mm. 25 Optionally the container may be an iron box used to transport iron ore having a length of 20 foot and a height of about 480mm, i.e. about half the height of the standard 20 foot container. Yet further the container could be a 40 foot intermodal shipping container. 8 In another form the container may have two loading doors on said one end wall of the container and the loading doors may be partially opened to define the container outlet though which particulate material can be discharged. 5 Further the container may include mounting formations for mounting it on a support, e.g. located towards the corners of the container. The support may be a chassis of a truck used for transporting intermodal shipping containers. The delivery chute may comprise a chute body for coupling to a container, the 10 chute body defining a chute inlet through which the bulk particulate material discharged from the container enters the chute body and a chute outlet spaced from the chute inlet through which particulate material can be discharged from the chute body. The delivery chute may also include a control arrangement for controlling the rate at which the bulk particulate material is discharged from the 15 chute outlet. The control arrangement may comprise a door which extends across the part of the chute outlet and leaves the remainder of the chute outlet open defining a discharge opening through which the bulk particulate material can be 20 discharged. The position of the door may be capable of being adjusted by an operator to vary the size of the discharge opening and thereby control the rate at which the bulk particulate material is discharged. The apparatus may further include a vehicle on which the container is 25 removably mounted for transporting the container by road or rail. The vehicle may be a road trailer mounted on wheels, and the trailer may be capable of being hitched to a towing vehicle, e.g. by means of a fifth wheeler coupling. The container may be mounted on the trailer during transport of the 30 container and also during discharge of the particulate material at the material use site, and the road trailer may have a tipping arrangement for tipping the 9 trailer to discharge particulate material from the container while it is mounted on the trailer. The trailer may have a trailer front end which is positioned at a forward end of 5 the trailer when it is travelling along a road and a trailer rear end which is positioned rearmost when the trailer is towed on the road. The tipping arrangement may raise the trailer front end relative to the trailer rear end whereby to discharge particulate material from the end of the container 10 corresponding to the trailer rear end. The tipping arrangement may include a hydraulic lift for lifting the trailer front end. The apparatus may further include a conveyor for mounting on a support surface such as the ground adjacent, to the trailer that receives particulate 15 material discharged from the container through the delivery chute and conveys it to the receiving arrangement. The conveyor may have an upstream end and a downstream end and may incline upwards from the upstream end to the downstream end. In particular 20 the conveyor may be an endless belt conveyor having an upward facing load carrying section and a return section positioned beneath the upward facing leg. The system may include a receiving arrangement for directly or indirectly receiving particulate material that is discharged from the discharge chute. 25 The conveyor may be a portable belt conveyor that is mounted on wheels that can be moved around to position the upstream end next to the delivery chute and the downstream end next to the receiving arrangement. 30 The receiving arrangement may be a storage unit for storing the bulk particulate material and the upstream end of the conveyor may be positioned beneath the 10 outlet opening of the delivery chute, and the downstream end of the conveyor may be positioned above the storage unit for the bulk particulate material for delivering the bulk particulate material into the storage unit. 5 Instead the receiving arrangement may be a blending unit of an apparatus for carrying out hydraulic fracturing of subterranean rocks. According to another aspect of this invention there is provided a delivery chute for discharging a bulk particulate material from a container in a controlled 10 fashion, the delivery chute comprising: a chute body for coupling to a container, the chute body defining a chute inlet through which the bulk particulate material discharged from the container enters the chute body and a chute outlet spaced from the inlet through which particulate material can be discharged from the chute 15 body; and a control arrangement for controlling the rate at which the bulk particulate material is discharged from the chute body through the chute outlet. 20 The control arrangement may comprise a door which extends across the part of the chute outlet and leaves the remainder of the chute outlet open defining a discharge opening through which the bulk particulate material can be discharged. The position of the door can be adjusted to vary the size of the discharge opening and thereby control the rate at which the bulk particulate 25 material is discharged. The door may be capable of substantially translational movement relative to the chute body to adjust the size of the discharge opening. The control arrangement may further include a guide for guiding the substantial 30 translational movement of the door relative to the chute body to adjust the size of the discharge opening. 11 The guide may include two vertical guide channels that are spaced apart from each other and the door may have opposed sides that are received within the vertical guide channels, and the door may slide within the guide channels 5 during the translational movement of the door. The control arrangement may include a control handle operatively connected to the door for enabling an operator to adjust the position of the door, and a control rod extending parallel to the door spaced above the door, which is 10 operatively connected to the door and which is also indirectly connected to the control handle. The control handle can be rotated by an operator in one direction to increase the size of the discharge opening and rotated in another direction to decrease the size of the discharge opening. Further the control may include a link arrangement intermediate the control rod and the door for 15 operatively connecting the control rod to the door. The chute body may define a chute outlet that is configured to complement the width of a conveyor for receiving the particulate material discharged from the chute body so that the particulate material can be discharged efficiently onto 20 the conveyor. The body outlet may be rectangular and the discharge opening through which particulate material may be discharged may also be rectangular. The chute body may have one end that is open that defines the chute inlet and the chute may have an opposite end that is open and that forms the chute 25 outlet, and the chute body may define a cross sectional area that reduces in a direction from the chute inlet to the chute outlet. DETAILED DESCRIPTION OF THE INVENTION 30 A system and method for transporting a dry bulk particulate material that is a fracking sand from a source to a material use site and discharging the material 12 in a controlled fashion at the use site in accordance with this invention may manifest itself in a variety of forms. It will therefore be convenient to hereinafter describe several embodiments of the invention in detail with reference to the accompanying drawings. The purpose of providing this detailed description is 5 to instruct persons having an interest in the subject matter of the invention how to carry the invention into practical effect. However it is to be clearly understood that the specific nature of this detailed description does not supersede the generality of the preceding broad description. In the drawings: Fig 1 is a schematic flow sheet showing an overview of a prior art system and 10 method of transporting a dry bulk material that is fracking sand from a point of supply to a well site; Fig 2 is a side view of a system or apparatus including a tipping trailer carrying a container loaded with a bulk particulate material that is fracking sand in 15 accordance with one embodiment of the invention with the trailer shown in a raised tipping orientation; Figures 3 and 4 are upper perspective views of a tipping trailer that is different to the tipping trailer in figure 2; Fig 5 is an upper perspective view of the system of Fig 2 delivering fracking 20 sand into a storage unit at a well site; Fig 6 is a top plan view of the trailer of the system of Fig 2; Fig 7 is a part sectional front view of the container and trailer of Fig 2 shown in a horizontally extending non tipping orientation and showing how the container is loaded with a proppant; 25 Fig 8 is an upper three dimensional view of part of the system of Fig 2 showing the chute in some detail; Fig 9 is an upper three dimensional view of the part of the system shown in Fig 8 showing the trailer in a tipping orientation with particulate fracking sand discharging from the chute onto a conveyor; 30 Fig 10 is an upper three dimensional view of a system that is a variation on the system shown in Fig 8; 13 Fig 11 is an upper perspective view of an intermodal container that is a variation on that shown in Fig 2 for use in carrying out the invention; and Fig 12 is a schematic drawing of a system in accordance with another embodiment of the invention. 5 Fig 1 shows a system or apparatus for delivering a bulk particulate material to a fracking site in accordance with the prior art. It also shows an example bulker bag that is used to carry the fracking sand from a source location to the destination. As the system shown in Figure 1 has been described above in 10 some detail in the background and does not form part of the invention defined in this application, it will not be described further in the specific description below. In Figs 2 to 11, reference numeral 10 refers generally to a system in 15 accordance with one embodiment of the invention for transporting and delivering a bulk particulate material that is fracking sand from a source such as a mine or a manufacturing site to another location that is a fracking site. In this detailed description the term particulate material shall refer to a proppant or fracking sand that is mixed into a fracking fluid and is then pumped into a 20 subterranean rock body in a fracking operation. Broadly the system 10 comprises a container 12 having a container outlet 14, and a delivery chute 16 mounted on the container 12. The container 12 and delivery chute 16 in turn is mounted on a trailer 18. The system 10 for 25 transporting and delivering the fracking sand also includes a conveyor 20 for conveying particulate proppant or fracking sand that is discharged from the chute 16 into a storage unit 22 having an inlet 23. The storage unit 22 forms part of the actual fracking plant and is shown in Figures 2, 3 and 7. Each of these components will now be described in more detail below. 30 14 The container 12 is an elongate rectangular container that is a bulk shipping container having a rear end or rear wall 28. In particular the container is a 20 foot or 40 foot intermodal shipping container 12 that is used to transport or ship a bulk particulate material such as fracking sand or proppant. The container 12 5 is designed to keep the particulate material in a completely dry state during transport and storage thereof and the ability to do this is very important. The container includes mounting formations 29 located in each of the corners of the container for mounting it on the support. In the illustrated embodiment the support is a chassis of a truck used for transporting intermodal shipping 10 containers. One example of the type of shipping container that can be used is shown in Fig 7 which has a cut out section showing a typical load of proppant within the container. The container outlet 14 is in the form of a discharge opening formed in the rear 15 wall 28 of the container 12. A flap closure 30 is mounted over the discharge opening that is pivotally mounted to the rear wall 28 of the container 12 along a top edge of the discharge opening. Consequently when the container 12 is tipped up, the flap closure 30 pivots away from the rear wall 28, opening up the outlet 14 much like a tail gate and permitting the material to discharge. 20 Another example embodiment of the type of shipping container 12 that can form part of the system in accordance with this invention is shown in Fig 10. In this container the outlet or discharge opening 14 is formed by loading doors 32 and 34 that are mounted on the rear end 28 of the container 12. Each loading 25 door 32, 34 is pivotally mounted to one side of the rear end 28 and the loading doors 32, 34 meet in the centre of the rear end 28 when they are closed. As shown in Fig 10 each door 32, 34 can be partially opened to define an outlet 14 through which a particulate material is discharged from the container 12 into the delivery chute 16. 30 15 The operation of the delivery chute 16 is shown in some detail in Figure 9 and comprises a chute body 40 having a chute inlet 42 at one end through which particulate material enters the chute body 40 and a chute outlet 44 at the other end spaced therefrom through which particulate material can be discharged. 5 The chute body 40 when viewed in a plan view comprises an inlet section and an adjacent discharge section. The inlet section is substantially rectangular when viewed in a plan view with sides 46 and 48 extending parallel to each other. By contrast the discharge section has a trapezoidal shape with the two sides 46 and 48 angling towards each other in a direction towards the chute 10 outlet 44. The discharge section enables the chute body 40 to converge to a width that complements a width of the conveyor 20. The chute outlet 44 is specifically dimensioned so that it has a width from one side to the other which complements the width of the conveyor 20 so that particulate material can be discharged directly from the chute 6 directly onto the conveyor 20 without 15 spillage or waste. The chute 14 includes a control arrangement indicated generally by the reference numeral 50 for controlling the rate at which the dry particulate material is discharged through the chute outlet 44 and onto the conveyor 20. 20 The control arrangement 50 includes a door 52 which extends across and closes off part of the other end of the chute body 40 and leaves the remainder of the body end open. The door 52 can be moved to adjust the size of the discharge opening 44, i.e. that part of the end of the chute body 40 which remains open, through which particulate material can be discharged from the 25 chute body 40. This in turn influences the rate of discharge of particulate material from the chute body 40 onto the conveyor 20. The control arrangement 50 also includes a guide having two vertically extending guide channels 54, 56 on either side of the chute body 40 within 30 which the door 52 is received and within which the door 52 can slide. The door 52 is capable of sliding displacement within the guide channels 54, 56 in a 16 substantially vertical direction to adjust the size of the chute outlet 44 through which particulate material can issue. The control arrangement 50 includes a manual control handle 62 which can be used by an operator for adjusting the position of the door 52 and thereby the size of the chute outlet 44. In the 5 illustrated embodiment the manual control handle 62 can be used to rotate a control rod 64 extending parallel to the door 52 spaced above the door 52. The control rod 64 is operatively connected to the door 52 through a link 66 and can be rotated in one direction to raise the door 52 and in another direction to lower the door 52. This way an operator can adjust the control handle 62 to cause a 10 suitable flow rate of particulate material to discharge from the chute outlet 44 onto the conveyor 20. The operator controls the control arrangement 50 so as to have a flow rate that discharges the load of particulate material from the container 12 as soon as possible without depositing too much material on the conveyor 20 at one time to cause it to spill over the edges of the conveyor and 15 be wasted. The trailer 18 comprises a chassis 70 mounted on wheels indicated generally by reference numeral 72. The trailer 18 is mounted to a towing rig (not shown) which is used to tow the trailer 18 and container 12 from one location to 20 another. The trailer 18 includes a front support in the form of one or more legs 74 for supporting a front end of the trailer 18 when it is detached from the rig. The trailer 18 also includes a lifting device 76 for lifting the front end of the trailer 18 to discharge particulate material from the container 12. The trailer 18 is lifted from a horizontally extending non-tipping orientation shown in Fig 7 to a 25 raised tipping orientation shown in Fig 9. The lifting device 76 comprises a hydraulic lift 78 and a pivot member 79 extending between the towing rig and the chassis 70 of the trailer 18. The conveyor 20 is shown in some detail in Figures 2, 5 and 6. The conveyor 30 20 has an upstream end 80 and a downstream end 82 and inclines upwards from the upstream end 80 to the downstream end 82. The conveyor 20 is an 17 endless belt conveyor having an upward facing load carrying section 84 and a return section (not shown) positioned beneath the upward facing section 84. The conveyor 20 is a portable belt conveyor that is mounted on a stand having wheels 88 which enable it to run on the ground. This enables it to be moved 5 into position for use on any given trailer 18 and also enables it to be positioned to deliver the particulate material into the storage unit 22. The upstream end 80 of the conveyor 20 is positioned beneath the outlet 44 of the delivery chute 16. Correspondingly the downstream end 82 of the conveyor 10 20 is positioned above the inlet 23 to the storage unit 22 for the bulk particulate material. The storage unit 23 comprises at least one storage compartment 90 which receives the particulate material and holds it prior to use. When the material is required for use, it can be discharged through a hopper outlet at the bottom of the hopper 90. Material that is discharged through the hopper outlet 15 can be conveyed directly into a blending unit of the fracking system, e.g. by mean of a further conveyor. While the hopper outlet is not shown in the drawings its structure and function would be well known to a person skilled in the art. The example storage unit 23 shown in the drawings has a plurality of storage compartments or hoppers 90 and is in the form of a vehicle mounted on 20 wheels 92 that can be moved around. Conveniently the storage unit may be a vehicular unit 92 sold under the trade mark SAND CHIEF by the company CONVEY ALL INDUSTRIES PTY LTD. In use, particulate material that is fracking sand or proppant is loaded onto the 25 trailer 18 at a source location such as a mine site. Typically this might be a mine where the fracking sand is produced or an industrial plant where the fracking sand is produced. The trailer 18 is then hauled by road haulage to a material use site which is a well site where fracking is to be carried out. At the well site the conveyor 20 is moved into position so that it receives particulate 30 material from the chute 16 and delivers the material into the appropriate hopper of the storage unit 22. Thereafter the trailer 18 is tipped so that the front end of 18 the trailer 18 is raised relative to the rear end as shown in Figures 2, 5 and 9. This is accomplished by the tipping arrangement 76 on the trailer 18. This flap closure 30 extends across the discharge opening 26 is allowed to open and this causes particulate material to be discharged through the container opening 26 5 through the chute inlet 42 and into the chute body 40. The particulate material is discharged through the chute outlet 44 onto the conveyor 20 from where it is conveyed to the hopper 90 of the storage unit 22 and in through the inlet 23 thereof. 10 The control 60 is controlled by an operator who uses the handle 62 to raise or lower the door 42 and adjust the size of the discharge opening forming the chute outlet 44 through which particulate material can be discharged. This way the flow rate of particulate material discharging through the outlet 44 onto the conveyor 18 can be controlled. Thus if the rate of discharge of particulate 15 material through the chute outlet 44 reduces over time the operator can increase the size of the outlet 44 so that the overall amount of material being discharged per unit time is maintained. Further if the rate of discharge of material onto the conveyor 20 is too high, the operator can lower the door 52 and reduce the size of the discharge opening. 20 In addition the operator can influence the rate at which particulate material is discharged from the container 12 and the chute 16 by adjusting the tipping height of the trailer 18. The higher the height to which the front of the trailer 18 is lifted (hereinafter referred to as the tipping height) the greater is the flow rate 25 of material discharged from the container 12. While the chute 16 has a holding zone having some capacity to receive more particulate material than is being discharged through the chute outlet 44, the operator is required to control the tipping height of the trailer 18, and thereby the rate of discharge of material from the container 12, so that the chute body 40 does not fill up completely and 30 overflow. 19 Figures 3 and 4 illustrate a tipping trailer that is different to the tipping trailer illustrated in Figure 2 and described above. This type of trailer is known as a Ripping Skel trailer. It has a sub-frame mounted on the chassis on which the container is mounted. The sub-frame has a hydraulic lift that lifts the sub-frame 5 up on the chassis during a tipping operation. During this operation the primary chassis and the wheels of the trailer 18 remain firmly planted on the ground. Applicant believes that this type of trailer may offer more stability when tipping material than the trailer shown in Figure 2. Applicant believes that this may be a factor that favours its use on a well site where other apparatus is positioned in 10 close proximity to the tipping trailer. Fig 11 illustrates a container that is different to the container in the earlier drawings. In essence the container has half the height of the container shown in Fig 7. As road regulations impose limits on the weight of a load transported 15 on the road the container shown in Fig 7 will never be loaded more than half full because of these constraints. Therefore the container shown in Fig 11 which is half the height of the Fig 7 container will be able to carry the same load of particulate material as the Fig 7 20 container. While the use of the Fig 11 container does not confer advantages when a loaded container is being transported to the fracking site it does confer advantages in other parts of the logistical chain. For example some modes of freight such as shipping and rail are volume based rather than being weight based. In these scenarios the Fig 11 container can be more efficient because 25 two containers can be stacked on top of each other. Further when travelling spare two Fig 11 containers that are empty can be stacked on a truck and transported back to the source after the particulate material has been discharged at the fracking site. 30 Fig 12 illustrates a system and a method in accordance with another embodiment of the invention. 20 As the system shown in the Fig 12 embodiment has many similarities to the system in the embodiment illustrated above with reference to Figs 2 to 11 the same reference numerals will be used to describe the same components as in 5 the earlier embodiment unless otherwise illustrated. The following description will focus on the difference between this embodiment and the earlier embodiment. In Fig 12 the system comprises a container 12 and a discharge chute 14 10 mounted on a trailer 18. However the trailer 18 discharges the particulate material from the container 12 through the chute 16 directly into a receiving vessel 93 that forms part of a blender 94 of the apparatus used for hydraulic fracking. The particulate material is mixed with other components of the fracking liquid in the blender 94 and is then pumped at high pressure into a well 15 bore and into the rocks in the ground. Thus the system 10 shown in Fig 12 does not require either a storage unit 22 within which the particulate material is temporarily stored. Further in some forms the system does not require a conveyor for conveying particulate material that is discharged from the chute 16 into the blender. The system discharges particulate material from the container 20 12 through the chute 16 directly into the blender 94 without any intervening handling apparatus. An advantage of this embodiment of the invention is that it discharges the proppant or fracking sand directly into the fracking process and obviates the 25 need to send it to an intermediate storage unit. This helps to reduce the cost of supplying the fracking sand into the process because it is more direct and cuts out one step in the process. It also reduces the capital cost of the equipment because a storage unit is not required. Further it confers significant operational advantages because a well site has a very small confined and compact area 30 and the streamlined process which requires less equipment occupies less space on the confined and limited well site. 21 An advantage of the system described above with reference to all the drawings is that it is able to efficiently and expeditiously discharge particulate proppant material from a container into a well site storage device or a blender of a 5 fracking apparatus in a controlled fashion. The flow of material out of the container is regulated by the chute and the material is discharged directly onto a conveyor which delivers the particulate material into the storage unit. The system and method described above with reference to the drawings is that it does not rely on a human operator to position themselves in a dangerous 10 position beneath a suspended bulker bag and then to split the bag open. Rather the operator stands on one side of the trailer 18 well out of the way of the discharging particulate material and operates the control arrangement by means of handle 62 which projects from the side of the chute 16. 15 The proppant or fracking sand needs to be transported in a closed environment where it is not contaminated with foreign matter including water. The method and system described above provides an elegant and efficient manner of transporting and delivering this material to a fracking site in a way that safeguards it against contamination by moisture or other foreign bodies. 20 It will of course be realized that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of the invention as is herein 25 set forth. 22

Claims (34)

1. A method of transporting a bulk particulate material from a source to a material use site and discharging the bulk particulate material in a controlled 5 fashion at the material use site, the method including: transporting the bulk particulate material in a container; discharging the bulk particulate material from the container into a delivery chute; and controlling the rate at which the bulk particulate material is discharged 10 from the delivery chute.

2. A method of transporting a bulk particulate material according to claim 1, wherein transporting the bulk particulate material in a container includes transporting the material in a container that resists the ingress of moisture, and 15 other components from the environment, into the container.

3. A method of transporting a bulk particulate material according to claim 1 or claim 2, wherein discharging the bulk particulate material from the container includes tipping the container to cause the particulate material to flow out of an 20 opening in the container under the influence of gravity.

4. A method of transporting a bulk particulate material according to claim 3, wherein the container is a substantially rectangular container having two ends, and discharging the bulk particulate material from the container includes tipping 25 the container such that the bulk particulate material is discharged through the opening which is positioned in an end of the container.

5. A method of transporting a bulk particulate material according to any one of claims 1 to 4, wherein transporting the bulk particulate material includes 30 transporting the container on a vehicle by road and/or rail and the container is an intermodal shipping container that is removably mounted on the vehicle. 23

6. A method of transporting a bulk particulate material according to claim 5, wherein transporting the bulk particulate material includes transporting the bulk particulate material on a road trailer that can be tipped to discharge bulk 5 particulate material from the trailer.

7. A method of transporting a bulk particulate material according to any one of claims 1 to 6, wherein the method further includes an initial step of loading the bulk particulate material into the container at the source prior to transporting 10 the bulk particulate material.

8. A method of transporting a bulk particulate material according to any one of claims 1 to 7, wherein controlling the rate at which the bulk particulate material is discharged from the delivery chute includes adjusting the size of an 15 outlet opening in the delivery chute through which particulate material is discharged.

9. A method of transporting a bulk particulate material according to any one of claims 1 to 8, wherein the method includes discharging the bulk particulate 20 material through the delivery chute onto a conveyor and conveying the bulk particulate material away from the delivery chute on the conveyor to a receiving arrangement.

10. A method of transporting a bulk particulate material according to claim 9, 25 wherein conveying the bulk particulate material away from the delivery chute includes conveying the discharged bulk particulate material to a receiving arrangement that is a storage unit and then delivering the bulk particulate material into the storage unit. 30

11. A method of transporting a bulk particulate material according to any one of claims 1 to 10, wherein the method is used for transferring a bulk particulate 24 material that is suitable for use as a proppant in a fracking operation, from a source of the bulk particulate material to a material use site that is well site used for recovering hydrocarbon fuels. 5

12. A system for transporting a bulk particulate material from a source to a material use location, the system including: a container for receiving a bulk particulate material defining a container outlet; and a delivery chute mounted on the container including a chute body 10 defining an inlet through which the bulk particulate material discharged from the container enters the chute and an outlet spaced from the inlet through which particulate material can be discharged from the chute body, the outlet of the container opens into the inlet of the delivery chute whereby to permit particulate material discharging from the container to 15 enter the delivery chute, the delivery chute including a control arrangement for controlling the rate at which the bulk particulate material is discharged through the outlet.

13. A system for transporting a bulk particulate material from a source to a 20 material use location according to claim 12, wherein the container is capable of being sealed off from the outside environment so that elements in the outside environment cannot come into contact with the bulk particulate material in the container. 25

14. A system for transporting a bulk particulate material from a source to a material use location according to claim 12 or claim 13, wherein the container is an elongate rectangular box shaped container having two end walls and the container outlet is formed in one end wall of the container. 30

15. A system for transporting a bulk particulate material from a source to a material use location according to claim 14, wherein the container outlet is in 25 the form of a discharge opening defined in said one end wall having a flap closure mounted over the discharge opening that swings open when the container is tipped up to permit the bulk particulate material to discharge from the container. 5

16. A system for transporting a bulk particulate material from a source to a material use location according to claim 15, wherein the container is an intermodal shipping container for the transport of a bulk particulate material. 10

17. A system for transporting a bulk particulate material from a source to a material use location according to claim 14, wherein the container has two loading doors on said one end wall of the container and the loading doors are partially opened to define the container outlet though which particulate material can flow. 15

18. A system for transporting a bulk particulate material from a source to a material use location according to any one of claims 12 to 17, wherein the delivery chute comprises a chute body for coupling to a container, the chute body defining a body inlet through which the bulk particulate material 20 discharged from the container enters the chute body and a body outlet spaced from the inlet through which particulate material can be discharged from the chute body; and a control arrangement for controlling the rate at which the bulk particulate material is discharged from the chute body through the outlet. 25

19. A system for transporting a bulk particulate material from a source to a material use location according to claim 18, wherein the control arrangement comprises a door which extends across the part of the body outlet and leaves the remainder of the body outlet open defining a discharge opening through which the bulk particulate material can be discharged, wherein the position of 30 the door can be adjusted to vary the size of the discharge opening and thereby control the rate at which the bulk particulate material is discharged. 26

20. A system for transporting a bulk particulate material from a source to a material use location according to any one of claims 12 to 19, wherein the apparatus further includes a vehicle on which the container is removably 5 mounted for transporting the container by road or rail.

21. A system for transporting a bulk particulate material from a source to a material use location according to claim 20, wherein the vehicle is a road trailer mounted on wheels, and the container may be mounted on the trailer during 10 transport of the container and also during discharge of the particulate material at the material use site, and the road trailer has a tipping arrangement for tipping the trailer to discharge particulate material from the container while it is mounted on the trailer. 15

22. A system for transporting a bulk particulate material from a source to a material use location according to any one of claims 12 to 21, wherein the apparatus further includes a conveyor for mounting on a support surface such as the ground adjacent, to the trailer that receives particulate material discharged from the container through the delivery chute and conveys it to the 20 receiving arrangement.

23. A system for transporting a bulk particulate material from a source to a material use location according to claim 22, wherein the conveyor has an upstream end and a downstream end and inclines upwards from the upstream 25 end to the downstream end.

24. A system for transporting a bulk particulate material from a source to a material use location according to claim 23, wherein the system includes a receiving arrangement for receiving particulate material that is discharged from 30 the discharge chute. 27

25. A system for transporting a bulk particulate material from a source to a material use location according to claim 24, wherein the conveyor is a portable belt conveyor that is mounted on wheels that can be moved around to position the upstream end next to the delivery chute and the downstream end next to 5 the receiving arrangement.

26. system for transporting a bulk particulate material from a source to a material use location according to claim 24 or claim 25, wherein the receiving arrangement is a storage unit for storing the bulk particulate material and the 10 upstream end of the conveyor is positioned beneath the outlet opening of the delivery chute, and the downstream end of the conveyor is positioned above the storage unit for the bulk particulate material for delivering the bulk particulate material into the storage unit. 15

27. A system for transporting a bulk particulate material from a source to a material use location according to claim 24 or claim 25, wherein the receiving arrangement is a blender of a hydraulic fracturing apparatus.

28. A delivery chute for discharging a bulk particulate material from a 20 container in a controlled fashion, the delivery chute comprising: a chute body for coupling to a container, the chute body defining a body inlet through which the bulk particulate material discharged from the container enters the chute body and a body outlet spaced from the inlet through which particulate material can be discharged from the chute 25 body; and a control arrangement for controlling the rate at which the bulk particulate material is discharged from the chute body through the outlet.

29. A delivery chute for discharging a bulk particulate material from a 30 container in a controlled fashion according to claim 28, wherein the control arrangement comprises a door which extends across the part of the body outlet 28 and leaves the remainder of the body outlet open defining a discharge opening through which the bulk particulate material can be discharged, wherein the position of the door can be adjusted to vary the size of the discharge opening and thereby control the rate at which the bulk particulate material is discharged. 5

30. A delivery chute for discharging a bulk particulate material from a container in a controlled fashion according to claim 28, wherein the control arrangement further includes a guide for guiding the substantial translational movement of the door relative to the chute body to adjust the size of the 10 discharge opening.

31. A delivery chute for discharging a bulk particulate material from a container in a controlled fashion according to claim 29 or claim 30, wherein the control arrangement includes a control handle operatively connected to the 15 door for enabling an operator to adjust the position of the door, and a control rod extending parallel to the door spaced above the door, which is operatively connected to the door and which is also indirectly connected to the control handle, and which can be rotated by an operator in one direction to increase the size of the discharge opening and rotated in another direction to decrease 20 the size of the discharge opening.

32. A delivery chute for discharging a bulk particulate material from a container in a controlled fashion according to any one of claims 28 to 31, wherein the chute body defines a body outlet that is configured to complement 25 the width of a receiving arrangement for receiving the particulate material discharged from the chute body so that the particulate material can be discharged efficiently onto the receiving arrangement.

33. A method of transporting a bulk particulate material from a source to a 30 material use site and discharging the bulk particulate material in a controlled 29 fashion at the material use site substantially as herein described in the detailed description of the invention with reference to the drawings

34. A delivery chute for discharging a bulk particulate material from a 5 container in a controlled fashion substantially as herein described in the detailed description of the invention with reference to the drawings. 30