CA2744682A1 - Storage tank - Google Patents

Abstract

A sea container for storing liquid, sludge or solid is disclosed. The sea container includes a floor and a roof sealingly joined by opposing side walls and opposing end walls. The floor is made of a rigid material such as steel and the container defines an interior space into which a drain bottom is inserted. The drain bottom includes an open end and a tapered end. Further, a method is disclosed for modifying a sea container for storing liquid, sludge or solid.

Description

STORAGE TANK
TECHNICAL FIELD
[0001] The present disclosure relates to a storage tank, in particular, a storage tank for storing liquids, sludge and solids.

BACKGROUND

[0002] There is often a need to provide temporary storage of liquids, sludge and solids. This is common in various industries including oil and gas exploration, oil and gas production, construction, refining, chemical, manufacturing, and water and sewer. Currently, there are various types of storage tanks that typically range in size between 200 barrels to 450 barrels. Some have axles that allow the tank to be towed to the site requiring storage.

[0003] A commonly used tank in the oil and gas industry is a frac tank. A frac tank is a portable storage tank constructed of steel walls with a single rear axle that can be towed behind a truck or tractor. However, frac tanks are limited to onsite storage of liquids and are limited in transportation options. The same can be said about other types of storage tanks designed for temporarily storing liquids and sludges.

[0004] Sea containers are also well known storage and transportation containers used for transporting goods over land and sea. However, they are unsuitable for storing liquids. While storage tanks having the dimensions of a sea container are known, they are expensive to manufacture and deliver.

[0005] Accordingly, a storage tank that addresses some of these deficiencies remains highly desirable.

SUMMARY

[0006] According to an embodiment of the present technology, a sea container modified for storing liquid, sludge or solid is disclosed. The modified sea container includes a container comprising a floor and a roof sealingly joined by opposing side walls and opposing end walls, the container defining an interior space for storing the liquid, sludge or solid, wherein the floor, roof, opposing side walls and opposing end walls being made of a rigid material, and at least one of the opposing end walls being removably attached; and a drain bottom inserted into the interior space, the drain bottom having an open end for receiving the liquid, sludge or solid and a tapered end connected to a drain hole through a pipe assembly, wherein the drain hole is located on the container.

[0007] According to another embodiment of the present technology, a method of creating a sea container modified for storing liquid, sludge or solid is disclosed. The method includes providing a sea container having a floor made of a rigid material and the sea container being hermetically sealed; inserting a drain bottom into an interior space of the sea container through an access door located at an end of the sea container; connecting a tapered end of the drain bottom to a drain hole through a pipe assembly; and removably attaching an end wall to the end of the sea container having the access door.

[0008] In some embodiments, the container further comprising a flange for removably attaching the at least one of the opposing end walls.

[0009] In some embodiments, the at least one of the opposing end walls is removably attached to the flange using bolts.

[0010] In some embodiments, a gasket is inserted between the at least one of the opposing end walls and the flange.

[0011] In some embodiments, the modified sea container further comprises a manway on at least one of the floor, roof, opposing side walls and opposing end walls.

[0012] In some embodiments, the manway comprises a heating coil, a propeller mixer, or a nozzle mixer, or any combination thereof.

[0013] In some embodiments, the modified sea container further comprising a containment wall inserted into the interior space.

[0014] In some embodiments, a seal is inserted between an edge of the open end of the drain bottom and the containment wall.

[0015] In some embodiments, a seal is inserted between an edge of the open end of the drain bottom and the container.

[0016] In some embodiments, the drain bottom is perforated.

[0017] In some embodiments, the rigid material is steel.

[0018] In some embodiments, the floor, roof, opposing side walls and opposing end walls are sealing joined by continuous weld.

[0019] In some embodiments, the container is configured for vertical orientation.

[0020] In some embodiments, the pipe assembly is installed on the drain hole.

[0021] In some embodiments, a flange is attached to the end of the sea container having the access door.

[0022] In some embodiments, the end wall is removably attached to the flange.

[0023] In some embodiments, a gasket is inserted between the flange and the end wall.

[0024] In some embodiments, a containment wall is inserted into the interior space of the sea container.

[0025] In some embodiments, the access door is removed.
BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further features and advantages of the present technology will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0027] FIG 1 illustrates a perspective view of a storage tank according an embodiment of the present technology in the horizontal orientation;

[0028] FIG. 2 illustrates a front view of the storage tank of FIG. 1 with an end wall removed;

[0029] FIG. 3 illustrates another embodiment of the storage tank in the vertical orientation;

[0030] FIG. 4A illustrates a top view of the storage tank of FIG. 3;

[0031] FIG. 4B illlustrates a top view of the storage tank in the vertical orientation with a container wall inserted;

[0032] FIG. 5 illustrates variations of manway for the storage tank disclosed in the present disclosure;

[0033] FIG. 6 illustrates a storage tank before conversion to the storage tank for storing liquid, storage and solids;

[0034] FIG. 7 illustrates the storage tank of FIG. 6 with the access doors open;

[0035] FIG. 8 illustrates the storage tank of FIG. 6 in the vertical orientation, with a drain bottom being lowered into the storage tank;

[0036] FIG. 9 illustrates the storage tank of FIG. 8, with the drain bottom positioned onto the pipe assembly;

[0037] FIG. 10 illustrates the storage tank of FIG. 8, with a containment wall being lowered into the storage tank;

[0038] FIG. 11 illustrates the storage tank of FIG. 6 in the horizontal orientation, with a drain bottom being inserted into the storage tank;

[0039] FIG. 12 illustrates the storage tank of FIG. 11 with the drain bottom inserted into the storage tank; and [0040] FIG. 13 illustrates the storage tank of FIG. 6 with the end wall removably attached to the end of the storage tank.

[0041] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

[0042] Embodiments are described below, by way of example only, with reference to FIGs. 1-13.

[0043] The present disclosure generally relates to a storage tank for storing liquids, solids and/or sludge. More specifically, the present disclosure discloses a modified sea container for storing liquids, solids and/or sludge.

[0044] Storage tanks that are designed for onsite storage of liquids and sludge exist. One example of such a tank is a frac tank, which is a portable storage tank typically having a single axle and which is mountable on a transport truck.
However, while frac tanks are designed to store liquids, they typically cannot support the weight of solids for transport. Moreover, frac tanks are designed to be used in one orientation (typically in the horizontal direction).

[0045] There are other known storage and transport tanks, such as sea containers and tanker trailers. Sea containers are often used to ship goods over a great distance, either by land or sea. For example, goods may be manufactured in China and shipped to Canada for resale. Because of its transportability, sea containers have standard dimensions that are approximately 8' wide and 8' 6"
high, and can be 20', 40' or 48' in length. However, while sea containers can support the weight of solids, they are unsuitable for carrying or storing liquids, in part, because of its wooden floors. While storage tanks having the dimensions of a sea container are known, they are typically expensive to manufacture and ship. Also, removal of liquids and accumulated solids from these storage tanks is difficult. Tanker trailers, on the other hand, are used to transport liquids. For example, tanker trailers may be used to transport gasoline to a gas station.

[0046] In this specification and the appended claims, the singular forms "a,"
"an,"
and "the" include plural references unless the context clearly dictates otherwise.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs.

[0047] It will be further understood that the terms "comprises" or "comprising", or both when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0048] In FIG. 1, a storage tank 100 according to an embodiment of the present technology is shown. The storage tank 100 is a modified sea container comprising a floor 102 and a roof 104 (see FIG. 2), joined by opposing side walls 106, 108 and opposing end walls 110, 112. In the present disclosure, the floor 102, the roof 104, the opposing side walls 106, 108, and the opposing end walls 110, 112 may be collectively referred to as "walls".

[0049] As with a typical sea container, the container may include some form of a frame to allow the walls to be joined. For example, the frame may include opposing end frames connected by side rails. In this embodiment, the opposing end walls would be attached to the opposing end frames and the base, roof and opposing side walls would be attached to the side rails. Moreover, the container may further include cross rail members to support additional weight.

[0050] However, unlike a typical sea container, the walls are joined such that they are watertight. This ensures that contents of the storage tank 100 do not leak.
As it will be further described below, when the storage tank 100 is in a horizontal position (i.e. the floor 102 acting as the base), both end walls 110, 112 may be joined to the floor 102, roof 104 and the opposing side walls 106, 108 to create a hermetic seal. Alternatively, when the storage tank 100 is in a vertical position, the end wall (i.e 112 in FIG. 3) acting as the base may be made watertight against the opposing side walls 106, 108, the floor 102 and roof 104. Furthermore, unlike a typical sea container, the floor 102, roof 104, opposing side walls 106, 108 and opposing end walls 110, 112 are made of rigid materials such as steel.
Together, they define an interior space for storing liquids, solids and/or sludge. In one embodiment, the hermetic seal is created by continuously welding the walls.
The storage tank 100 may also be used to transport goods and solids.

[0051] Because the storage tank 100 has the dimensions of a typical sea container, shipping of the storage tank 100 is easily facilitated using existing transport means. For example, the storage tank 100 may be stacked and loaded with other typical sea containers on a freight carrier. Moreover, the storage tank 100 may be initially used as a sea container to transport goods. Once the goods have been delivered, the storage tank 100 may be further modified (to be described below) to store bulk liquids, solids and/or sludge and transport bulk solids.
This allows another entity to bear the transport cost of the storage tank 100, which may be manufactured overseas. However, it will be understood that other dimensions may be possible depending on the storage and transportation needs.

[0052] Furthermore, one of the opposing end walls 110 may be removably attached to a flange 120 (see FIG. 2) of the storage tank 100. In one embodiment, the removable end wall 110 may be attached to the flange 120 using bolts through bolt holes 122 (see FIG. 2). It will be understood that end wall 110 may be removably attached using other removable means known to the person skilled in the art. While the storage tank 100 typically has one removably attached end wall since typical sea containers have one set of access door, it will be understood that both end walls 110, 112 may be removably attached. When removably attaching the end walls 110, 112, a gasket may be used to ensure a tight seal.

[0053] Now turning to FIG. 2, one embodiment of the storage tank 100 is shown with the removable end wall 110 removed, showing the interior space of the storage tank 100. As it can be seen, the storage tank 100 contains a drain bottom 200 for containing liquid and/or sludge, which can be drained through a pipe assembly provided at the bottom of the drain bottom 200 (see FIG. 11 for another view of the drain bottom 200 and pipe assembly 202 - FIG. 11 depicts drain bottom 1100 and pipe assembly 1102). In this embodiment, the removable end wall 110 may include a drain hole 130 (see FIG. 1) connected to the pipe assembly 202 to facilitate draining of the contents contained in the storage tank 100. The storage tank may further include a manway 210 on the roof 104 to allow contents to be pumped into the interior space of the storage tank 100. Alternatively, or additionally, contents may be pumped into the storage tank 100 by removing the removable end wall 110 or through a manway (not shown in FIG. 1 but shown in FIG. 13 as manway 1302) on the removal end wall 110. It will be understood that various other pipe fittings may be added to accommodate the addition and removal of liquids, sludge and solids.

[0054] The embodiment shown in FIG. 2 depicts the storage tank 100 oriented in the horizontal direction, which is the typical orientation for existing sea containers and frac tanks. However, the storage tank 100 according to the present technology may also be oriented in the vertical direction as shown in FIG. 3. In this embodiment, the end wall (e.g. end wall 112 in FIG. 3) acting as the base may be made of a higher grade corrugated steel. In another embodiment, the end wall acting as the base may further include cross members.

[0055] As with the embodiment shown in FIG. 2, the storage tank 100 in FIG. 3 includes a drain bottom 300 at the bottom of the storage tank 100, connected to a pipe assembly 302 for draining contents contained in the storage tank 100. In the embodiment shown in FIG. 3, "bottom" refers to the end near the end wall 112 acting as the base, while in the embodiment shown in FIG. 2, "bottom" refers to the end near the floor 102, which is acting as the base. Depending on the orientation of the pipe assembly 302, one of the opposing side walls 106, 108 or one of the floor 102 and roof 104 may include a drain hole (not shown) to allow contents stored in the storage tank 100 to be drained.

[0056] One of the advantages realized in vertically orienting the storage tank is the easier liquid and solid separation. When the storage tank 100 contains fluid that consists of liquid and particles or solids, depending on the properties of the particles or solids, they may settle to the bottom of the liquid over time due to gravity. With a vertically oriented storage tank 100, it is easier to differentiate between the settled particles or solids and liquid. Moreover, the drain bottom 200, 300 facilitates easier removal of solids because of its generally tapered shaped.
Another advantage realized by the vertical orientation is the smaller footprint of the storage tank 100 at the temporary storage site.

[0057] In both the embodiments shown in FIGs. 2 and 3, the drain bottom 200, 300 is shown in the shape of an inverted pyramid. Because the storage tank 100 shown in FIGs. 2 and 3 is generally in the shape of a rectangular prism, the drain bottom 200, 300 has an open end that is four sided and a tapered bottom that is connected to the pipe assembly 202, 302. To ensure that the drain bottom 200, maintains its orientation, the open end of the drain bottom (i.e. the end not connected to the pipe assembly 202, 302) is dimensioned to be against the walls of the storage tank 100. Referring to FIG. 4A, which is a top view of the storage tank 100 in FIG. 3, the drain bottom 200, 300 has four edges 400A, 400B, 400C, and 400D against the walls of the storage tank 100. When the storage tank 100 is in the horizontal position, the edges of the open end of the drain bottom 200 may be against the opposing side walls 106, 108 and opposing end walls 110, 112. When the storage tank 100 is in the vertical position, the edges of the open end of the drain bottom 300 may be against the opposing side walls 106, 108, the floor and the roof 104. Alternatively, or additionally, the drain bottom 200, 300 may be coupled to the storage tank 100 to further ensure that the orientation of the drain bottom 200, 300 is maintained. Furthermore, the drain bottom 200, 300 may incorporate a seal 410 around the edges of the open end of the drain bottom 200, 300 to ensure a tight seal between the drain bottom 200, 300 and the walls of the storage tank 100. FIG. 4A also shows opening 402 at the bottom of the drain bottom 300 for draining contents in the storage tank 100 through the pipe assembly 202, 302. In a further embodiment, the drain bottom 200, 300 may be made of a perforated material to allow the filtering of the contents in the storage tank 100. For example, liquids contaminated with foreign particles may be filtered using a perforated drain bottom 200, 300. In this embodiment, liquid would pass through the perforated drain bottom 200, 300 while preventing foreign particles from passing through.

[0058] While the drain bottom 200, 300 has been described as being pyramid-like in shape, it will be understood that the drain bottom 200, 300 may be a different shape. For example, as it will described below with FIG. 10, a cylindrical wall 1000 may be inserted into the storage tank 100 to provide a double wall containment system. In that embodiment, the drain bottom 200, 300 may be conical in shape.
Referring to FIG. 4B, which is a top view of a storage tank 100 of FIG. 3 when a cylindrical wall 1000 is inserted into the storage tank 100, the edge 400E of the open end of the drain bottom 200, 300 may follow the perimeter of the cylindrical wall 1000. As shown in FIG. 4B, the edge 400E may be circular or elliptical in shape depending on the shape of the cylindrical wall 1000. As the drain bottom 200, 300 shown in FIG. 4A, the drain bottom 200, 300 may be coupled to the storage tank 100 and may further include a seal (e.g. 410) to ensure a tight seal between the drain bottom 200, 300 and the walls of the storage tank 100. The drain bottom 200, 300 of FIG. 4B may also be perforated. It will also be understood that even if there is no cylindrical wall 1000, the drain bottom 200, 300 may be a shape other than a pyramid or cone such as a shape that is generally tapered at the bottom to allow connection with the pipe assembly 202, 302. In an embodiment where the edges of the open end of the drain bottom 200, 300 do not follow the contour of the storage tank 100 or the containment wall (e.g. cylindrical wall 1000), a seal may be used to ensure a tight seal. However, a tight seal between the drain bottom 200, 300 and the walls of the storage tank 100 is not necessary. Liquid at the bottom of the storage tank 100 (i.e. under the drain bottom 200, 300) may be beneficial in providing support for the drain bottom 200, 300.

[0059] Turning to FIG. 5, variations of manway 500-504 are shown. The different configurations of manway may be on one or more of the walls of the storage tank 100. For example, manway 500-504 may be on the removable end wall 110 as shown in FIG. 13 (in FIG. 13, removable end wall is shown as 1300 and manway is shown as 1302). In other embodiments, the manway 500-504 may be on the roof 104 of the storage tank 100 as shown in FIG. 2 as manway 210. The manway 500-504 may have different configurations as required by the storage tank 100. For example, a mixer 510 may be mounted on the manway, as shown in manway 502. This allows the contents inside the storage tank 100 to be mixed (e.g.
sludge). While the mixer 510 is shown as a propeller-based mixer, it will be understood that a nozzle-based mixer may also be attached. In another embodiment, a heating coil 512 may be provided on the manway, as shown in manway 504. The heating coil 512 may be a steam-based heating coil with the heating steam going into input 512A and coming out of output 512B.

[0060] Now referring to FIGs. 6-13, a method for creating a storage tank according to an embodiment of the present technology will be described. FIG. 6 shows a sea container 600 having the typical dimension of a sea container as described above. Similarly to a typical sea container, the sea container 600 has access doors 602 that can be opened to load the sea container 600 with goods.
In FIG. 6, the sea container 600 has one set of access doors 602 on one end of the container and a fixed wall on the other end of the container. However, it will be understood that the sea container 600 may have two sets of access doors depending on the required configuration.

[0061] The sea container 600, unlike a typical sea container, has floor 604 made of a rigid material such as steel. Moreover, the walls of the sea container except the access doors 602 are joined together with a tight seal. For example, the walls may be joined using continuous weld.

[0062] Using the sea container 600, goods are sent to the destination using typical transporation means. For example, the sea container 600 containing products made abroad may be loaded onto a freight carrier and shipped across the ocean. Once the sea container 600 reaches the destination, the products contained in the container may be unloaded by opening access doors 602 as shown in FIG.
7.
Typically at this time, the unloaded sea container remains at that location until it is reloaded with other goods that require transportation. However, using the modified sea container 600, the sea container 600 may be used for transporting or storing not only goods but also for storing liquids, sludge and solids.

[0063] After unloading the goods from the sea container 600, a flange 700 may be attached to the sea container 600 at the end having the access doors 602.
For example, the flange 700 may be welded to the end having the access doors 602.
Alternatively, the flange 700 may be one of the modification made during the fabrication of the sea container 600, similarly to the base 604. If the sea container 600 is provided with two sets of access doors, a flange may be attached to each end having the access doors. In one embodiment, the flange 700 may have bolt holes (like bolt holes 122 shown in FIG. 2).

[0064] The sea container 600 is further modified to include a drain bottom 800.
In FIG. 8, a sea container 600 in the vertical orientation is shown. In the vertical orientation, the sea container 600 is positioned such that the end having the access door faces upward so that the drain bottom 800 may be lowered into the sea container 600. At the bottom of the sea container 600, a pipe assembly (e.g.
900 in FIG. 9) is installed. The drain bottom 800 is lowered until the opening 802 (see 402 of FIGs. 4A and 4B) is placed over the pipe assembly 900 as shown in the blow up section 910 in FIG. 9. Thus, contents in the modified sea container 600 can be drained out using the drain bottom 800 and the pipe assembly 900.

[0065] Additionally, a double wall containment system may be required. Double wall containment (also referred to as secondary containment system) is a typical regulatory requirement for containment of petroleum products. To provide a double wall containment system, a containment wall such as a cylindrical wall 1000 as shown in FIG. 10 may be inserted into the sea container 600. In this embodiment, the drain bottom to be inserted into the modified sea container 600 may be conical in shape so that the edge of the open end is against the cylindrical wall 1000 (see FIG. 4B). A seal may be further included to ensure a tight seal against the cylindrical wall 1000. In another embodiment, the drain bottom may be a different shape having the edge of the open end not entirely against the cylindrical wall 1000.
In this embodiment, a seal may be included to close the gap between the edges of the open end of the drain bottom and the cylindrical wall 1000. While the containment wall has been described using a cylindrical wall 1000, it will be understood that walls of other shapes may be contemplated.

[0066] Alternatively, the modified sea container 600 may be positioned horizontally as shown in FIG. 11. In this embodiment, the drain bottom 1100 is shown to have multiple tapered bottoms connected to the pipe assembly 1102;
however, it will be understood that the drain bottom 1100 may be a single tapered bottom configuration as shown in FIG. 9. Moreover, the drain bottom 800 as shown in FIG. 9 may have multiple tapered bottoms as shown in FIG. 11. FIG. 12 shows the drain bottom 1100 installed into the modified sea container 600 in the horizontal orientation.

[0067] After installation of the drain bottom 800, 1100, end wall 1300 is installed, for example, by using the flange 700 in FIG. 7. In one embodiment, the end wall 1300 may be bolted to the flange 700 as shown in FIG. 7. Additionally, a gasket (not shown) may be inserted between the end wall 1300 and the flange 700 to ensure a tight seal. Where the modified sea container 600 includes two sets of access doors (see 602 in FIG. 6), end wall 1300 may be installed on both ends of the modified sea container 600. Additionally, the access doors 602 may be removed. The end wall 1300 may also include manway 1302, such as those shown in FIG. 5.

[0068] Therefore, the modified sea container 600, having the dimensions of a typical sea container but having unique features unlike a typical sea container, may be initially used as a sea container to transport goods. The modified sea container 600 is then further modified to store liquid, solids and/or sludge as explained in this disclosure.

[0069] While the present technology has been described in terms of specific implementations and configurations, further modifications, variations, modifications and refinements may be made without departing from the inventive concepts presented herein. The scope of the exclusive right sought by the Applicant(s) is therefore intended to be limited solely by the appended claims.

Claims (20)

1. A sea container modified for storing liquid, sludge or solid, the modified sea container comprising:

a container comprising a floor and a roof sealingly joined by opposing side walls and opposing end walls, the container defining an interior space for storing the liquid, sludge or solid, wherein the floor, roof, opposing side walls and opposing end walls being made of a rigid material, and at least one of the opposing end walls being removably attached; and a drain bottom inserted into the interior space, the drain bottom having an open end for receiving the liquid, sludge or solid and a tapered end connected to a drain hole through a pipe assembly, wherein the drain hole is located on the container.

2. The sea container according to claim 1, wherein the container further comprising a flange for removably attaching the at least one of the opposing end walls.

3. The sea container according to claim 2, wherein the at least one of the opposing end walls is removably attached to the flange using bolts.

4. The sea container according to claim 2, wherein a gasket is inserted between the at least one of the opposing end walls and the flange.

5. The sea container according to claim 1, further comprising a manway on at least one of the floor, roof, opposing side walls and opposing end walls.

6. The sea container according to claim 5, wherein the manway comprises a heating coil, a propeller mixer, or a nozzle mixer, or any combination thereof.

7. The sea container according to claim 1, further comprising a containment wall inserted into the interior space.

8. The sea container according to claim 7, wherein a seal is inserted between an edge of the open end of the drain bottom and the containment wall.

9. The sea container according to claim 1, wherein a seal is inserted between an edge of the open end of the drain bottom and the container.

10. The sea container according to claim 1, wherein the drain bottom is perforated.

11. The sea container according to claim 1, wherein the rigid material is steel.

12. The sea container according to claim 1, wherein the floor, roof, opposing side walls and opposing end walls are sealing joined by continuous weld.

13. The sea container according to claim 1, wherein the container being configured for vertical orientation.

14. A method of creating a sea container modified for storing liquid, sludge or solid, the method comprising:

providing a sea container having a floor made of a rigid material and the sea container being hermetically sealed;

inserting a drain bottom into an interior space of the sea container through an access door located at an end of the sea container;

connecting a tapered end of the drain bottom to a drain hole through a pipe assembly; and removably attaching an end wall to the end of the sea container having the access door.

15. The method according to claim 14, further comprising installing the pipe assembly to the drain hole.

16. The method according to claim 14, further comprising attaching a flange to the end of the sea container having the access door.

17. The method according to claim 16, wherein the end wall is removably attached to the flange.

18. The method according to claim 17, further comprising inserting a gasket between the flange and the end wall.

19. The method according to claim 14, further comprising inserting a containment wall into the interior space of the sea container.

20. The method according to claim 14, further comprising removing the access door.