Trailer assembly for transport of containers of proppant material

Description

1. RELATED APPLICATIONS

The present application is a continuation which claims priority to and the benefit of U.S. application Ser. No. 13/854,405, filed on Apr. 1, 2013, and titled “Trailer Assembly for Transport of Containers of Proppant Material,” which is incorporated herein by reference in its entirety.

BACKGROUND

2. Field of the Invention

The present invention relates to container trailer assemblies. Additionally, the present invention relates to systems and apparatus for the transport of proppant material. More particularly, the present invention relates to a trailer assembly that is particularly suitable for the transport of containers of proppant material.

3. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98

Hydraulic fracturing is the propagation of fractions in a rock layer caused by the presence of pressurized fluid. Hydraulic fractures may form naturally, in the case of veins or dikes, or may be man-made in order to release petroleum, natural gas, coal seam gas, or other substances for extraction. Fracturing is done from a wellbore drilled into reservoir rock formations. The energy from the injection of a highly-pressurized fracking fluid creates new channels in the rock which can increase the extraction rates and ultimate recovery of fossil fuels. The fracture width is typically maintained after the injection by introducing a proppant into the injected fluid. Proppant is a material, such as grains of sand, ceramic, or other particulates, that prevent the fractures from closing when the injection is stopped.

With the rise of hydraulic fracturing over the past decade, there is a steep climb in proppant demand. Global supplies are currently tight. The number of proppant suppliers worldwide has increased since 2000 from a handful to well over fifty sand, ceramic proppant and resin-coat producers.

By far the dominant proppant is silica sand, made up of ancient weathered quartz, the most common mineral in the Earth's continental crust. Unlike common sand, which often feels gritty when rubbed between the fingers, sand used as a proppant tends to roll to the touch as a result of its round, spherical shape and tightly-graded particle distribution. Sand quality is a function of both deposit and processing. Grain size is critical, as any given proppant must reliably fall within certain mesh ranges, subject to downhole conditions and completion design. Generally, coarser proppant allows the higher flow capacity due to the larger pore spaces between grains. However, it may break down or crush more readily under stress due to the relatively fewer grain-to-grain contact points to bear the stress often incurred in deep oil- and gas-bearing formations.

Typically, in any hydraulic fracturing operation, a large amount of such proppant is required. The transport of proppant presents significant issues and difficulties. Fundamentally, governmental roads requirements establish a limit as to the amount of weight that can be transported over the roads. These weight limits are established so as to avoid damage to the structural integrity of the road and also damage to any bridges, overpasses, or other structures associated with the road. Additionally, there are height requirements on such transport vehicles. Conventionally, all transport vehicles should have a height of less than 13½ feet. As such, the transport vehicle can travel on virtually all roads without issues associated with low overlying bridges and overpasses. Additionally, in the transport of proppant, there are a variety of issues related to the safety of the transport. For example, structures should be provided so as to avoid any shifting of the proppant contents in the container that is being transported. Further, concern should also be directed to the center of gravity associated with the contained proppant on the vehicle. If the center of gravity is too high, then there is an increased likelihood of a potential overturning of the vehicle and a reduction in the handling capability of the vehicle.

Conventionally, a 20 foot ISO container could be utilized so as to transport proppant on a conventional container trailer. Unfortunately, experiments have determined that the transport of sand in such conventional containers is not suitable. If the 20 foot ISO is filled with proppant material, then it would certainly exceed the government weight limits on the road. If the 20 foot ISO container were filled with a lesser amount of proppant material, the material could more easily shift in the container and create a dangerous driving condition. Additionally, if a 20 foot ISO container is minimally filled with proppant, the angle of repose of the proppant in the container would make it extremely difficult to completely empty the proppant material from the container. As such, it would not be possible to empty a conventional 20 foot container. As such, a need has developed so as to avoid the use of a 20 foot container for the transport of proppant material.

Importantly, the weight limits that are imposed by government authorities on the transport of goods on road requires that the weight limit be under 80,000 pounds. This weight limit will include the truck, the trailer and the load that is being transported by the truck and trailer. As such, the weight of the vehicle is of a significant concern when determining the amount of proppant that can be moved by a trailer over the roads. As such, it is desirable to minimize the weight of the truck and trailer while still preserving the structural integrity of the truck and trailer.

In the earlier patent applications by the present inventor (for example, U.S. patent application Ser. No. 13/628,702) a 10 foot ISO container was proposed. In this earlier application, it is found that the 10 foot ISO container has a height of 8.5 feet. As such, such a container would contain less than an optimal amount of proppant. In order to deliver the desired 46,500 pounds of proppant to the site, and in order to provide a proper angle of repose of the proppant material within the container, it was found that an ISO container with a height of 9.5 feet was necessary. If such a container of an increased height were actually used on a conventional container trailer, it would exceed the height requirements for the vehicle. If the conventional container trailer were used, the total weight of the vehicle would be in excess of the 80,000 pound limit. Additionally, the placement of the container on the top of a conventional container trailer would increase the center of gravity to the trailer and, as such, increase the potential for vehicle overturns and reduce the handling capability of the truck. Additionally, a standard container trailer could cause the operator to place the sand container in an improper location along the length of the trailer such that the weight is not properly centered for proper transport.

In the past, various patents have issued relating to container trailers. For example, U.S. Pat. No. 3,958,707, issued on May 25, 1976 to D. L. Deppe, discloses a container transport trailer having a bottomless U-shaped support frame including a cross member and a pair of side members. A lift member is connected to the forward end of the trailer and cooperates with a pair of support arms pivotally connected to the rear ends of the side members of the U-shaped frame to engage against the rear portion of the article.

U.S. Pat. No. 5,839,864, issued on Nov. 24, 1998 to S. K Reynard, teaches a locking system for a container-carrying trailer having a loading platform on which a container can be mounted. The locking system comprises a forward pair of locking devices and a rearward pair of locking devices mounted at forward and rear ends of the loading platform. The locking device is cooperative with respective corner fittings of the container in order to clamp the container to the loading platform.

U.S. Pat. No. 6,109,684, issued on Aug. 29, 2000 to M. A. Reitnouer, discloses a flatbed trailer design that unitizes the three main components of a trailer bed, i.e. the main rails, the cross members and the floor, to create a lightweight and stronger trailer. The trailer design comprises two main rails having dual webs and a plurality of shouldered cross members. These dual web main rails and shouldered cross members have top flanges that are formed by the upper plane of the flooring members. In addition, intermediate flooring supports are used between cross members.

U.S. Pat. No. 7,866,933, issued on Jan. 11, 2011 to Welch et al., teaches a container trailer that includes a coupling to attach the trailer to a tractor, and a frame attached to the coupling. The frame is positioned as a single unit about a container such that the frame can be attached to the container in four regions of the container to lift the container. The trailer has road wheels for long-haul transportation. The trailer frame can be positioned about the container by laterally expanding and retracting, pivoting about a horizontal axis, and pivoting about a vertical axis.

U.S. Pat. No. 8,182,193, issued on May 22, 2012 to Gaudet et al., shows a trailer for transporting freight a container. The trailer has a frame with a front frame section which is adapted to be coupled to a suitable road vehicle. A pair of displaceable horizontal side beams are secured to the front frame section and are provided with a hingeable rear gate formed by a pair of hinge arms. Each of the side beams has a suspension assembly to support a tandem wheel arrangement. Retractable vertical lifting piston cylinders are secured to a portion of the front frame and to the pair of hinge arms and are actuable to lift the pair of horizontal side beams and its wheels above a ground surface. Laterally extendable piston cylinders are also secured to the front frame and the hinge arms to displace the horizontal side beams outwardly and inwardly with respect to one another when lifted off the ground surface. Container lifting posts are secured to opposed ends of the front frame section and the hinge arms for removable connection to a container positioned between the side beams to lift and lower the container therebetween. Container connectors are secured to each of the side beams for securing a container thereto for transportation.

U.S. Patent Publication No. 2013/0004272, published on Jan. 3, 2013 to M. Mintz, provides an apparatus for transporting proppant for use in standard ISO intermodal container and for delivering the proppant to well sites. The apparatus is configured for being inserted into a standard 20 foot container and adapted for transporting frac sand and proppant from a quarry to a well site. A plurality of inlet ports are disposed atop the roof, with the inlet ports receiving the proppant from a proppant supply source into a funnel/hopper. A plurality of outlet ports received the proppant within the funnel/hopper and deliver the proppant to the well site. An in situ valve is disposed within the hopper assembly for effectuating industry standard continuous pressurized discharge of stored proppant material into a discharge pipe for delivery downhole.

It is an object of the present invention to provide a trailer assembly that is able to effectively transport a 10 foot ISO container.

It is another object of the present invention to provide a trailer assembly that facilitates the transport of proppant in containers positioned thereon.

It is another object of the present invention to provide a trailer assembly which is of minimal of weight so as to facilitate the delivery of a maximum amount of proppant within the container positioned thereon.

It is still another object of the present invention to provide a trailer assembly which minimizes the center of gravity of the proppant containing container positioned thereon.

It is still another object of the present invention to provide a trailer assembly which allows multiple empty proppant containers to be positioned thereon.

It is still a further object of the present invention to provide a trailer assembly which allows the proppant-containing container to meet height and weight requirements during the transport of proppant.

It is still another object of the present invention to provide a trailer assembly which is easy to use, relatively inexpensive and easy to manufacture.

These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.

BRIEF SUMMARY OF THE INVENTION

The present invention is a trailer assembly which comprises a frame having a first section and a second section, and a plurality of wheels rotatably mounted below the first section so as to allow the frame to move along an underlying surface. The first section is positioned at a higher level than the second section. Each of the first and second sections has length of at least 10 feet. The first section is suitable for receiving a first sand container thereon. The second section is also suitable for receiving a second sand container thereon. The frame has a connector section suitable for connection to a towing vehicle.

The first section has a planar top surface. The second section has a planar top surface. The first section has a top surface extending in a plane approximate 1 foot 9 inches above a plane in which a top surface of the second section extends.

The frame has a first side rail and a second side rail extending in spaced parallel relation to each other. The frame also has a plurality of cross members extending between the first side rail and the second side rail. The first section has a first outrigger extending across the first and second side rails so as to have a first end extending outwardly of the first side rail and a second end extending outwardly of the second side rail. The first section has a second outrigger extending across the first and second side rails so as to have a first end extending outwardly of the first side rail and a second end extending outwardly of the second side rail. The first and second outriggers are suitable for attachment to an underside of the first container.

The second section has a first outrigger extending across the first and second side rails so as to have a first end extending outwardly of the first side rail and a second end extending outwardly of the second side rail. The second section also has a second outrigger extending across the first and second side rails so as to have a first end extending outwardly of the first side rail and a second end extending outwardly of the second side rail. The first and second outriggers of the second section are suitable for attachment to the underside of the second container. The first outrigger is positioned in transverse relationship to the first and second side rails. The second outrigger is positioned in transverse relation to the first and second side rails. The first outrigger of the first section is positioned at an end of the frame. The second outrigger of the first section is positioned adjacent the second section.

The plurality of wheels are positioned below and between the first and second outriggers of the first section. The connector section is a gooseneck connector having a portion extending upwardly from an end of the second section opposite the first section. The connector section has another portion extending away from the second section.

In the present invention, the first container would be an empty container. The empty container would be positioned directly above the wheels. In the present invention, the second container would be a container that is filled with proppant material. When the second container is filled with proppant material, it is placed on the second section of the trailer. Under these circumstances, there would be no first container placed on the first section. When the second container is empty, a pair of containers, i.e. the first container and the second container, can be respectfully placed on the first section and the second section. As such, when the trailer is used to transport proppant to a well site, the second container (filled with proppant) is placed on the second section of the trailer and the truck can serve to tow the trailer to the well site. At the well site, an empty container can he placed on the second section and another empty container can he placed on the first section. As such, a pair of empty containers can be transported from the well site.

The foregoing Section is intended to describe, in generality, the preferred embodiment of the present invention. It is understood that modifications to this preferred embodiment can be made within the scope of the present invention. As such, this Section should not be construed, in any way as limiting of the broad scope of the present invention. The present invention should only be limited by the following claims and their legal equivalents.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a side elevational view of a trailer assembly in accordance with the preferred embodiment of the present invention.

FIG. 2 is a plan view of a trailer assembly of the preferred embodiment of the present invention.

FIG. 3 is a side elevational view of the trailer assembly of the present invention as used in the transport of proppant containers.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there is shown the trailer assembly 10 in accordance with the preferred embodiment of the present invention. The trailer assembly 10 includes a frame 12 that has a first section 14 and a second section 16. The first section 14 is located at a higher level than the level of the second section 16. The first section 14 has a planar top surface 18. The second section 16 has a planar top surface 20. The planar top surface 18 of the first section 14 is in spaced parallel planar relationship to the planar top surface 20 of the second section 16. Each of the sections 14 and 16 will have a length of at least ten feet. The first section 14 is suitable for receiving a sand container thereon. The second section 16 is also suitable for receiving a sand container thereon. The frame 12 has a connector section 22 at the forward end thereof suitable for connection to a towing vehicle. A plurality of wheels 24 are rotatably mounted below the first section 14 so as to allow the frame 12 to move along an underlying surface.

The first section 14 is located directly above the wheels 24. A first section 14 has its planar surface 18 located about one foot nine inches above the planar top surface 20 of the second section 16. The first section 14 has an end 26 adjacent a rear of the trailer 12. The opposite end 28 is located adjacent to the second section 16.

The second section 16 has the planar top surface 20 extending from the end 28 of the first section 14 to an end 30 adjacent the connector section 22. The second section 16 is suitably welded, bolted, or otherwise connected to the underside of the first section 14 adjacent to the wheels 24. As such, this underslung configuration will minimize the height of the second section 16 so as to allow the heavy weights of a loaded proppant container to be placed thereon in an easy and convenient manner and also to minimize the center of gravity of the trailer 10 while traveling along a road surface.

The connector section 22 is a gooseneck connector having an end adjacent to the end 30 of the second section 16, a portion 32 extending upwardly therefrom, and a generally horizontal portion 34 extending to a coupling 36. Coupling 36 allows the trailer 10 to be suitably joined to a towing vehicle.

FIG. 2 illustrates the frame 10 a plane view. The frame 10 has a first side rail 40 and a second side rail 42 extending in parallel planar relationship to each other. A plurality of cross members 44 extend between the first side rail 40 and the second side rail 42. As such, cross members 44 enhance the structural integrity of the frame 12. These cross members 44, in combination with the side rails 40 and 42 also serve to minimize the weight of the trailer 10.

In FIG. 2, the first section 14 is illustrated as positioned above the wheels 24. In the present invention, the wheels 24 are arranged in tandem. Each of the tires associated with the wheels 24 can be of an expanded form so that the weight of each of the wheels 24 is minimized. In other words, the tires associated with each of the wheels 24 will have a width that is substantially greater than conventional trailer tires. It can be seen that a container placed upon the side rails 40 and 42 in the area of first section 14 will be located above the wheels 24 and between the wheels 24. As such, the wheels 24 will provide substantial support, in combination with the frame 12, for the transport of an empty container on the first section 14.

The second section 16 extends from the first section 14 to the connector section 22. Cross members 44 also extend between the side rails 40 and 42 in the second section 16. The use of the cross members 44, in combination with the side rails 40 and 42, further serve to minimize the weight of the trailer 10 for the transport of substantial quantities of proppant material. As such, the cross members 44, in combination with the side rails 40 and 42, maintain the structural integrity of the trailer 10 while, at the same time, reducing the weight of the trailer such that the loaded container can be transported within the weight limits imposed by governments on roads.

The connector section 22 also has cross members 44 extending between the side rails 40 and 42. The coupling 36 is illustrated adjacent to the forward end 46 of the frame 12.

Importantly, in FIG. 2, the first section 14 has a first outrigger 50 and a second outrigger 52. The first outrigger 50 extends across the first side rail 40 and the second side rail 42 so as to have one end 54 extending outwardly of the first side rail 40 and an opposite end 56 extending outwardly of the second side rail 42. Similarly, the second outrigger 52 extends across the side rails 40 and 42 so as to have an end 58 extending outwardly of the first side rail 40 and an end 60 extending outwardly of the second side rail 42. As such, the outriggers 50 and 52 are suitably configured so as to receive a ten foot ISO container thereon. Suitable connector mechanisms are provided on the outwardly extending portions of the outriggers 50 and 52 so as to secure, in a conventional fashion, with the connectors at the bottom of the container.

The second section 16 includes a first outrigger 62 and a second outrigger 64. The first outrigger 62 has an end 66 which extends outwardly of the first side rail 40 and another end 68 extending outwardly of the second side rail 42. The second outrigger 64 of the second section 16 has an end 70 which extends outwardly of the first side rail 40 and an end 72 which extends outwardly of the second side rail 42. As such, the outriggers 60 and 62 are suitably positioned so as to receive the second container thereon. The location of the loaded container placed upon the outriggers 62 and 64 will centralize the loaded container on the trailer 10 so as to enhance the transport capability of such a container. Suitable locking mechanisms can be provided on the outriggers 62 and 64 so as to secure the underside of the second container.

FIG. 3 illustrates the manner in which a first container 90 is secured to the first section 14 of the frame 12 of the trailer 10 and the manner in which the second container 92 is secured to the second section 16 of the frame 12 of the trailer 10. In normal use, the first container 90 would be an empty container. This empty container is positioned on the first section 14 directly above the wheels 24 such that the empty container 90 can be transported from the well site. As illustrated in FIG. 3, the second container 92 is also an empty container. The empty container 92 is placed upon the outriggers 62 and 64 of the second section 16 so as to be transported from the well site. In this manner, the trailer 10 is suitable for transporting a plurality of empty containers from the well site.

Dimensional indications are provided on FIG. 3. As can be seen, the first container 90 will extend upwardly so as to have a height of thirteen feet three inches above the road surface. The container 90 has a height of nine feet six inches. As such, the total height of the first container 90 above the road will be three inches less than the height requirement of 13.5 feet Since the second container 92 is positioned at a lower level than that of the first container 90, the height of the second container 92 will have no effect during its transport along the road surface. Each of the containers 90 and 92 are suitably positioned on the trailer 10 in an optimal manner so as to enhance the handling capability of the truck during the transport of the containers 90 and 92 from the well site.

Importantly, in the present invention, when it is desired to transport proppant to the well site, only a single container can be used. The single container can be filled with 46,500 pounds of proppant. This 9.5 foot tall container will provide a proper angle of repose of the proppant within the container such that the proppant can be properly discharged from the container through an outlet at the bottom of the container.

In view of the great weight of the filled container, a single container can be used on the trailer 10 during transport to the well site. This single container would be in the nature of container 92. Container 92 is properly filled with proppant and placed upon the second section 16 of the frame 12. It can be seen that the weight of the proppant in the container 92 is properly centralized on the trailer 12 by being positioned on the lower second section 16. Additionally, the use of the lower second section 16 will create a lower center-of-gravity of the load on the trailer 10. As such, the handling characteristics of the trailer 10 are greatly improved and the possibilities of an overturn are avoided. The load in the container 92 is properly supported by the truck and by the wheels 24 so as to distribute the load of the container over a relatively wide and long area. As such, shifting of the load is effectively avoided. The unique structure of the trailer 10 creates a minimal weight trailer for this intended purpose so that the load can be safely and easily transported within the weight limits imposed upon roads.

In the configuration shown in FIG. 3, when a loaded container is transported, the first container 90 should not be placed on the first section 14. The placement of the container 90 on the first section 14 during the transport of the loaded container 92 could exceed the weight limits of the road.

Once the loaded container 92 reaches the well site, the container 92 can be released from the locking mechanisms associated with the outriggers 62 and 64 and the load can be lifted and delivered for proper discharge. Subsequently, empty containers, such as containers 90 and 92, can be put on the trailer 10 for transport back to the proppant supplying location.

The present application is a continuation which claims priority to and the benefit of U.S. application Ser. No. 13/854,405, filed on Apr. 1, 2013, and titled “Trailer Assembly for Transport of Containers of Proppant Material,” which is incorporated herein by reference in its entirety.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.