TRANSPORTABLE WATER STORAGE SYSTEM

Abstract

A transportable liquid storage system includes a plurality of silos, each adapted to be transported in a horizontal transport orientation and moved to a vertical operating orientation at the work site. The silos are arranged in at least two adjacent rows, and each silo is releasably and rigidly attached to all silos adjacent thereto such that the plurality of silos forms a rigid silo structure, and an outlet port on each water silo is connected to a conduit, the conduit having a discharge at a selected location. The silos include an overflow chamber at a top end thereof to allow each silo to fill to capacity on uneven ground, and a hollow base which facilitates leak containment and detection.

Description

FIELD OF THE INVENTION

This invention is in the field of water storage and in particular a transportable water storage system with a large capacity.

BACKGROUND OF THE INVENTION

In some industrial applications, very large quantities of liquid are required at temporary work sites. For example in petroleum oil and gas recovery operations, it is common practice to fracture an underground formation by injecting liquid comprising water and various chemicals at high pressure into the formation. Formation fracturing operations, commonly called fracking, can require very large amounts of water, which must be gathered and stored in a temporary tank set up at the work site. Such fracking operations can require on site storage of one or even two million US gallons of water.

It is known to provide large open top tanks by erecting walls and laying a liner membrane over the ground inside the walls and up over the walls. Such open tanks can provide the required storage capacity, however are subject to leaks. A leaking liner may allow a large quantity of the contained liquid to leak into the ground, and since the contained liquid typically contains undesirable materials, significant ground contamination may occur undetected. Emptying these large tanks without spillage is also problematic.

Alternatively large metal tanks are transported to the work site where they are filled with water for use in the fracking operation. The tanks typically have a capacity of about 500 barrels or 21,000 US gallons and at the well site these tanks are placed on the ground either horizontally or vertically. The horizontal tanks typically have wheels mounted on a rear end thereof and are simply towed into position at the well site. About 50 of these tanks are then required to hold the one million US gallons required for a typical fracking operation. The area available at work site for placing these tanks is limited and becomes very crowded.

Horizontal orientation occupies considerably more of the available area, than vertical orientation, however vertical orientation typically requires specialized trailers or cranes to move the tanks, commonly called silos because of their vertical orientation, from the horizontal orientation required for transport, to the vertical orientation. A significant problem with vertical orientation is stability, as a vertical silo rests on a relatively small area provided by the end of the silo. When empty especially, they are susceptible to be being knocked over by high winds or accidental contact with other equipment moving around in the crowded work area.

Periodically such tanks must be cleaned to remove sediment and the like, typically requiring people to enter the tank.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a transportable liquid storage system that overcomes problems in the prior art.

In a first embodiment the present invention provides a transportable liquid storage system comprising a plurality of silos, each silo adapted to be moved on a transport vehicle in a horizontal transport orientation to a work site and moved to a vertical operating orientation at the work site with a silo base resting on the ground. The silos are arranged in at least two adjacent rows, and each silo is releasably and rigidly attached to all silos adjacent thereto such that the plurality of silos forms a substantially rigid silo structure, and an outlet port on each water silo is connected to a conduit, the conduit having a discharge at a selected location.

In a second embodiment the present invention provides a water silo apparatus adapted to be moved on a transport vehicle in a horizontal transport orientation to a work site and moved to a vertical operating orientation at the work site. The apparatus comprises an elongate main chamber with an outlet port in a lower portion thereof. A hollow base is attached to a lower end of the main chamber, wherein an entirety of the lower end of the main chamber rests on the hollow base when in the vertical operating position such that liquid leaking from the lower end of the main chamber collects in the hollow base, and a liquid detector is located in the hollow base and is operative to send a leak signal to a leak indicator when liquid is detected in the hollow base. An overflow chamber extends upward from a top end of the main chamber, the overflow chamber having a cross-sectional area that is less than about 20% of a cross-sectional area of the main chamber, and a vent opening is provided in an upper portion of the overflow chamber.

The transportable liquid storage system provides a plurality of liquid storage silos locked together in a silo structure that has considerable stability, which can be enhanced with folding stabilizer legs. A large quantity of liquid can thus be stored in a relatively small area at the work site. An overflow chamber allows the main chamber of each silo in the silo structure to be filled to capacity when the silos are on uneven ground maximizing the storage capacity of the structure. The overflow chamber also facilitates aeration of the liquid in the silo if necessary. The silos can include a removable hollow base which contains and detects leaks, and facilitates repairs. Scrubbers can facilitate cleaning of the silo interiors.

BRIEF DESCRIPTION OF THE DRAWINGS

While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:

FIG. 1 is a schematic top view of an embodiment of a transportable water storage system of the present disclosure.

FIG. 2 is a schematic side view of the embodiment of FIG. 1.

FIG. 3 is a schematic side view of a silo on a transport vehicle in a horizontal orientation and being moved to a vertical operating orientation at a work site.

FIG. 4 is a schematic cut-away side view of a silo of the embodiment of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 schematically illustrate an embodiment of a transportable water storage system 1 of the present disclosure. The system 1 comprises a plurality of water silos 3, each silo 3, as schematically illustrated in FIG. 3, adapted to be moved on a transport vehicle 5 in a horizontal transport orientation to a work site and moved to a vertical operating orientation at the work site with a silo base 7 resting on the ground 9.

The silos 3 are arranged in at least two adjacent rows, and each silo 3 is releasably and rigidly attached to all silos 3 adjacent thereto by upper and lower releasable locking devices 11 such that the plurality of silos 3 forms a substantially rigid silo structure. In the illustrated system 1 locking device comprises a first lock mechanism 11A on a first silo and a corresponding second lock mechanism 11B on an adjacent second silo, and the first lock mechanism 11A is adapted to releasably engage the second lock mechanism 11B. It is contemplated that the locking devices 11 could be provided by a variety of mechanisms known in the art, as an example FIG. 3 schematically illustrates the first lock mechanism 11A as a hook connected to an over-centering lever that is engageable with the second lock mechanism 11B provided by a loop.

Orienting the silos 3 vertically reduces the area required at the worksite but vertical silos, especially when empty, have significant stability problems. Locking the silos 3 together to form the silo structure greatly increases the stability of the structure compared to a lone silo 3 resting on its base 7. Stability is further increased by providing stabilizer legs 13 movably mounted to the silos 3 such that the stabilizer legs 13 movable from a stored position P1 adjacent to a wall of the silos 3 to an operating position P2 extending outward from the silos 3 and outward from the silo structure and contacting the ground 9.

An outlet port 15 on each water silo 3 is connected through a valve 17 to a conduit 19 and the conduit 19 has a discharge 21 at a selected location where the stored liquid will be used at the work site. An issue that must be dealt with in many situations where the system will be used, such as in formation fracturing operations at well sites, is that the liquid will be drawn out very quickly, and so quite large vent openings are required at the top of each silo 3 to allow air to enter the silo as liquid is drawn off. Often all the valves 17 on the silo structure will be open to allow the liquid to drawn off quickly at the discharge 21. When the silo structure is placed on uneven ground, some silos will be higher than some others such that when the valves are all open, liquid will flow from the higher silo to a lower silo and could spill out the vents.

To avoid this and allow each silo 3 to be filled to capacity each silo 3 comprises a main chamber 23 and an overflow chamber 25 extending upward from a top end of the main chamber 23. The overflow chamber 25 is much smaller than the main chamber 23, with a cross-sectional area that is less than about 20% of the cross-sectional area of the main chamber 23, as seen in the top view of FIG. 1.

FIG. 2 shows the silos 3 located on ground 9 that slopes slightly upward from left to right, such that each silo is higher than the silo 3 to the left thereof. Thus when the outlet ports 15 on first and second silos 3A, 3B are connected through respective valves 17 to the conduit 19 at the same time such that liquid flows between the first and second silos, the first liquid level 27A in the first silo 3A on higher ground is at a top of the main chamber 23A, and the second liquid level 27B in the second silo 3B on lower ground is in the overflow chamber 25B. The main chamber 23 on each silo can thus be filled to capacity. A large vent opening 29 can be provided in an upper portion of the overflow chambers 25 to allow for air movement into and out of the silo 3 when filling and draining the silo.

FIG. 4 schematically illustrates the water silo 3. In some applications it will be desired to add air to the liquid in the silos 3, such as when storing water returned from a well during fracturing operations. The silos 3 illustrated comprise an aeration conduit 31 extending from a lower portion of the main chamber 23 to an aeration chamber located above the main chamber 23, and conveniently provided by the overflow chamber 25. A pump 33 is operative to pump liquid from the lower portion of the main chamber 23 into the aeration/overflow chamber 25 above a level of liquid 27 in the chamber 25 such that the liquid contacts the air above the liquid, as is desired for aeration purposes. Air can also be pumped into the lower portions of the main chamber 23 and rise to the aeration overflow chamber 25 and escape out through the vent opening 29. The overflow chamber 25 thus conveniently provides an air pocket to allow for aeration through the aeration conduit 31 as well as a surface from which air pumped into liquid can bubble up through to the adjacent vent opening 29.

At times it may be desirable to draw liquid out of the silo 3 at a higher level, such as to avoid sediment that may have formed in the bottom of the silo. The silo 3 in FIG. 4 thus has a lower outlet port 15A and an upper outlet port 15B above the lower outlet port 15A. To facilitate emptying the silo 3 completely, and to facilitate removal of sediment during cleaning, the floor 35 of the main chamber 23 of the silo 3 slopes to the lower outlet port 15A.

A hollow base 7 is attached to a lower end of the main chamber 23. The entire lower end of the main chamber 23 rests on the hollow base 7 when in the vertical operating position such that liquid leaking from the lower end of the main chamber 23 collects in the hollow base 7 where a liquid detector 37 is located and operative to send a leak signal to a leak indicator 39 when liquid is detected in the hollow base 7. The hollow base 7 is fastened to the lower end of the main chamber 23 by bolts or the like so the base is removable to provide access to repair the lower end of the main chamber 23 if a leak is detected.

To facilitate cleaning the silos, lower and upper scrubbers 41A, 41B are operative to direct pressurized streams of liquid on corresponding lower and upper portions of the inner surface of the main chamber 23. Typically such scrubbers 41 will comprises a plurality of rotatable nozzles 43, and a high pressure liquid source 45 connected to the nozzles 43 to rotate the nozzles and provide the pressurized stream of liquid.

The transportable liquid storage system 1 provides a plurality of liquid storage silos locked together in a silo structure that has considerable stability, which can be enhanced with folding stabilizer legs 13. The overflow/aeration chamber 25 allows the main chamber of each silo 3 in the silo structure to be filled to capacity when the silos are on uneven ground and also facilitates aeration of the liquid in the silo if necessary.

The hollow base 7 provides leak detection and containment to prevent undetected contamination of the ground at the work site. Scrubbers 41 can be provided to clean the silo interiors, with a silo floor 35 sloping to the outlet port 15 so sediment and the like will flow to the outlet port 15.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.

Claims

1. A transportable liquid storage system comprising:

a plurality of silos, each silo adapted to be moved on a transport vehicle in a horizontal transport orientation to a work site and moved to a vertical operating orientation at the work site with a silo base resting on the ground;

wherein the silos are arranged in at least two adjacent rows, and each silo is releasably and rigidly attached to all silos adjacent thereto such that the plurality of silos forms a substantially rigid silo structure; and

wherein an outlet port on each water silo is connected to a conduit, the conduit having a discharge at a selected location.

2. The system of claim 1 wherein each silo is releasably and rigidly attached to all silos adjacent thereto by upper and lower releasable locking devices mounted on the silos.

3. The system of claim 2 wherein each locking device comprises a first lock mechanism on a first silo and a corresponding second lock mechanism on an adjacent second silo, and wherein the first lock mechanism is adapted to releasably engage the second lock mechanism.

4. The system of claim 1 further comprising a valve at an outlet port of each silo, and wherein the conduit network is connected to each valve.

5. The system of claim 1 further comprising at least one stabilizer leg movably mounted to at least one silo, the at least one stabilizer leg movable from a stored position adjacent to a wall of the at least one silo to an operating position extending outward from the at least one silo and outward from the silo structure and contacting the ground.

6. The system of claim 1 wherein each silo comprises a main chamber and an overflow chamber extending upward from a top end of the main chamber, the overflow chamber having a cross-sectional area that is less than a cross-sectional area of the main chamber, and wherein the outlet ports on first and second silos are connected to the conduit at the same time such that liquid flows between the first and second silos, and such that a first liquid level in the first silo on higher ground is at a top of the main chamber, and such that a second liquid level in the second silo on lower ground is in the overflow chamber.

7. The system of claim 6 wherein the cross-sectional area of the overflow chamber is less than about 20% of the cross-sectional area of the main chamber.

8. The system of claim 6 comprising a vent opening in an upper portion of the overflow chamber.

9. The system of claim 6 wherein each silo comprises an aeration conduit extending from a lower portion of the main chamber to an aeration chamber located above the main chamber, and a pump operative to pump liquid from the lower portion of the main chamber into the aeration chamber above a level of liquid in the aeration chamber.

10. The system of claim 9 wherein the aeration chamber is provided by the overflow chamber.

11. The system of claim 1 wherein at least one silo comprises a main chamber and a hollow base attached to a lower end of the main chamber, and wherein an entirety of the lower end of the main chamber rests on the hollow base when in the vertical operating orientation such that liquid leaking from the lower end of the main chamber collects in the hollow base, and a liquid detector located in the hollow base and operative to send a leak signal to a leak indicator when liquid is detected in the hollow base.

12. The system of claim 11 wherein the hollow base is removable to provide access to repair leaks in the lower end of the main chamber.

13. The system of claim 1 wherein a floor of each silo slopes to the outlet port.

14. The system of claim 13 wherein each silo has a lower outlet port and an upper outlet port above the lower outlet port and wherein a floor of each silo slopes to the lower outlet port.

15. The system of claim 1 comprising a lower scrubber operative to direct a pressurized stream of liquid on lower portions of an inner surface of the main chamber.

16. The system of claim 1 comprising an upper scrubber operative to direct a pressurized stream of liquid on upper portions of an inner surface of the main chamber.

17. The system of claim 15 wherein at least one of the upper and lower scrubbers comprises a plurality of rotating nozzles, and a high pressure liquid source connected to the nozzles to rotate the nozzles and provide the pressurized stream of liquid.

18. A water silo apparatus adapted to be moved on a transport vehicle in a horizontal transport orientation to a work site and moved to a vertical operating orientation at the work site, the apparatus comprising:

an elongate main chamber with an outlet port in a lower portion thereof;

a hollow base attached to a lower end of the main chamber, wherein an entirety of the lower end of the main chamber rests on the hollow base when in the vertical operating position such that liquid leaking from the lower end of the main chamber collects in the hollow base;

a liquid detector located in the hollow base and operative to send a leak signal to a leak indicator when liquid is detected in the hollow base;

an overflow chamber extending upward from a top end of the main chamber, the overflow chamber having a cross-sectional area that is less than about 20% of a cross-sectional area of the main chamber; and

a vent opening in an upper portion of the overflow chamber.

19. The apparatus of claim 18 wherein the hollow base is removable to provide access to repair the lower end of the main chamber.

20. The apparatus of claim 18 further comprising an aeration conduit extending from a lower portion of the main chamber to an aeration chamber located above the main chamber, and a pump operative to pump liquid from the lower portion of the main chamber into the aeration chamber above a level of liquid in the aeration chamber.

21. The apparatus of claim 20 wherein the aeration chamber is provided by the overflow chamber.

22. The apparatus of claim 18 wherein a floor of the silo slopes to the outlet port.

23. The apparatus of claim 22 wherein the silo has a lower outlet port and an upper outlet port above the lower outlet port and wherein the floor slopes to the lower outlet port.

24. The apparatus of claim 18 comprising a lower scrubber operative to direct a pressurized stream of liquid on lower portions of an inner surface of the main chamber.

25. The apparatus of claim 24 comprising an upper scrubber operative to direct a pressurized stream of liquid on upper portions of an inner surface of the main chamber.

26. The apparatus of claim 25 wherein at least one of the upper and lower scrubbers comprises a plurality of rotating nozzles, and a high pressure liquid source connected to the nozzles to rotate the nozzles and provide the pressurized stream of liquid.