Abstract:
An above ground liquid storage system includes a substantially impermeable liner bounding an interior for receiving a liquid. A plurality of supporting structures and a base support the liner and the liquid when the liquid is received in the interior. The liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures. A temperature controller in communication with the cavity controls a temperature of the cavity to control the temperature of liquid in the interior.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/474,431 filed Apr. 12, 2011, the entire disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates, in general, to storage systems for holding large quantities of various fluids for use in industrial, commercial and energy applications, and more particularly systems for above ground impoundment of water for use in a hydraulic fracturing process. 
       BACKGROUND ART 
       [0003]    Hydraulic Fracturing (i.e., fracking) is a method of extracting natural gas that is trapped in the layers of shale thousands of feet below the surface. The process involves drilling into shale formations (5,000 to 20,000 feet below the surface) and pumping fracturing fluid into the formation at great pressures fracturing the rock creating a conduit for the natural gas to be extracted through. The fracking process requires millions of gallons of water, much of which is extracted from the shale formations and must be stored prior to being treated for any contaminants which they receive during the drilling process. Most “fracking” sites in the Marcellus Shale region located in Pennsylvania, West Virginia, and southern New York are in very remote locations and the pads (drilling sites) have relatively small footprints, thus the storage of massive amounts of water within a small footprint requires a voluminous vessel. Currently there are two methods for large water storage: below ground (lined pit) and above ground (defined storage vessel). 
         [0004]    Thus, a need exists for systems and methods for storing liquids above ground which are intended to be used for, or have been extracted from, drilling sites. These systems and methods may be utilized in remote locations and may protect the environment. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides, in a first aspect, an above ground liquid storage system which includes a substantially impermeable liner bounding an interior for receiving a liquid. A plurality of supporting structures and a base support the liner and the liquid when the liquid is received in the interior. The liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures. A temperature controller in communication with the cavity controls a temperature of the cavity to control the temperature of liquid in the interior. 
         [0006]    The present invention provides, in a second aspect, a method for use in above ground storage of a liquid which includes connecting a plurality of supporting structures to one another such that a base is surrounded by the plurality of supporting structures. A liner is located on the base and the plurality of supporting structures such that the liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures. A liquid is received in a cavity bounded by the liner. A temperature of the cavity is controlled to control the temperature of the liquid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention will be readily understood from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which: 
           [0008]      FIG. 1  is a cutaway view of a portion of a supporting system supporting a basin in accordance with the present invention; 
           [0009]      FIG. 2  is a side cross-sectional view of the basin of  FIG. 1 ; 
           [0010]      FIG. 3  is a perspective view of a backside of the supporting system of the basin of  FIG. 1 ; 
           [0011]      FIG. 4  is a perspective view of the basin of  FIG. 1 ; 
           [0012]      FIG. 5  is a side cross-sectional view of a portion of the basin of  FIG. 1  including an air conditioning mechanism and fluid connection means connected to an underside of the basin; 
           [0013]      FIG. 6  is a side view of a clamp for connecting the supporting structures of the basin of  FIG. 1  to each other; 
           [0014]      FIG. 7  is a front view of the clamp of  FIG. 6  including a cover in accordance with the present invention; and 
           [0015]      FIG. 8  is a perspective view of the basin of  FIG. 1  including a conduit on a support member allowing fluid flow over a top side of the basin. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    In an exemplary embodiment depicted in  FIGS. 1-7  an above ground liquid containment system or basin  51  is shown. Basin  51  may be configured (e.g., shaped and dimensioned) to any shape and various heights. Basin  51  may include a series of interconnected supporting structures or frame units  100  spaced at intervals erected on a prepared surface (e.g., a concrete pad) to form a container skeleton or support structure. Each frame unit includes a support portion  30  and a leg portion  40  facing an interior  50  of the basin. A plurality of leg portions  40  may extend upwardly at an angle (e.g., about 43 degrees) to support basin  51  and any contents of interior  50 . The leg portions may be supported by a plurality of support portions  30 . The support portions and leg portions may be formed of wood, metal or plastic members fastened to each other and configured to carry the weight of a liquid (e.g., water from a fracturing process) in interior  50  of basin  51 . Such support portion and leg portions could also be monolithically formed (e.g., by molding, casting, etc.). As depicted in the figures, such a leg portion (e.g., leg portion  40 ) may have a linear shape extending from base  70  at an angle less than 90 degrees and more than 30 degrees, for example, while the support portion (e.g., support portion  30 ) may be formed of a V shaped structure having a bottom horizontal portion  31  and a side portion extending from an end of horizontal portion  31  (i.e., the end away from base  70 ) to contact leg portion  40 . A frame cavity  60  (e.g., having a triangular shape) may be formed by the connection of one of support portions  30  to one of leg portions  40 . The cavity may be a variety of shapes (e.g., an equilateral triangle) depending on the configuration (e.g., shape and dimension) of the support portions and leg portions. 
         [0017]    A thick geogrid material  20  may extend from a top  41  of each leg portion  40  downwardly on the leg portion and continue a short distance out onto a base  70  as depicted in  FIG. 1 , for example. Geogrid material  20  has the ability to restrict a liner  80  from forming pockets within frame units  100  due to the added rigidity it provides, thus keeping a surface of the liner facing the liquid as a smooth sided container. Geogrid material  20  is attached at intervals to one or more of support portions  30  and/or leg portions  40  of the frame unit with zip ties or other connection mechanism(s). Geo-grid material  20  may be a material configured for use as a base course for reinforcement and soil stabilization such as MARAFI BXG GEOGRID. Such a geo-grid material may have a tensile strength of 2,500 pounds per foot in a machine direction and 2,500 pounds per foot in a cross direction. 
         [0018]    Base  70  (i.e., horizontal portion surrounded by the frame units) of basin  51  may be a portion of a concrete pad or other material capable of supporting the weight of liquid thereon in conjunction with the frames (e.g., frames  100 ) which surround such base. Further, basin  51  may be lined with a thick felt material  22  which overlaps geogrid material  20  a short distance and is attached to one or more of support portions  30  and/or leg portions  40  by means of zip ties or other connection mechanism(s). For example, the felt may be a needle punched non-woven geo-textile composed of polypropylene fibers formed with a stable network such that the fibers retain their relative position, such as MIRAFI 180N. Such a geo-textile may be inert to biological degradation and resist naturally encountered chemicals, alkalis and acids. The felt material  20  may have a weight of 271 grams per meter squared and a thickness of 1.8 mm, for example. 
         [0019]    Liner  80  may be a continuous liner impermeable to liquids (e.g., water) installed on the container skeleton (i.e., frame units  100 , geogrid material  20 , base  70 ). Liner  80  may be tailored (e.g., shaped and dimensioned) to fit the inside measurements of basin  51  (e.g., the inside surface of the plurality of leg portions  40  and base  70 ) and extend over the top (e.g., top  41 ) of frame units  100  and vertically down to the ground on the outside of the container, where it may be anchored to the ground by weight.  FIGS. 4 and 5  depict the liner pulled over the frame to the ground. Further, the liner may be any type of liner which may support the weight of water or another liquid when connected to frame units  100  and may be substantially impermeable. Also, liner  80  may be formed of a plurality of liner portions welded or otherwise connected to one another such that the seams are substantially impermeable. Further, liner  80  could be formed of a scrim reinforced polyethylene, such as DUR SKRIM. Such a liner could have an average thickness of about 30 mil, a weight of about 144 pounds per thousand square feet. The liner may also have a tensile strength of 160 foot pounds per square inch in a machine direction and 150 foot pounds per square inch in a transverse direction. The liner may be a reinforced laminate manufactured using high strength virgin grade polyethylene resins and stabilizers. 
         [0020]    When liner  80  extends from top  41  to the ground, a liner cavity or area  81  under liner  80  and under leg portions  40 , including cavities  60 , may be heated, cooled or otherwise conditioned. For example, warmed air may be pumped into area  81  to maintain the area under leg portions  40  at a desired temperature such that any liquid held in interior  50  is held at a desired temperature due to the convection and conduction occurring in the area under leg portions  40  relative to leg portions  40 , geogrid  20 , any felt and liner  80 . For example, area  81  under leg portions and under liner  80  (e.g., including cavities  60 ) may be heated (e.g., a heater  3  may be connected to a tube  4  to provide heated air as depicted in  FIG. 7 ) to avoid any liquid in interior  50  from freezing thereby avoiding any damage that could occur to liner  80  resulting from freezing and/or thawing of the liquid. Also, a bubbling mechanism  11  may be utilized to inhibit freezing of the liquid in basin  50  to minimize any such damage to liner  80  as depicted in  FIG. 7 . Such a bubbling mechanism could be any type of air generating mechanism which provides air to a liquid held in interior  50  to inhibit freezing of the liquid and thereby avoid any damage to basin  51 , including liner  80 , due to such freezing. 
         [0021]    Basin  51  could also be configured to include under-floor or over-top piping to accommodate inflow/outflow requirements into and/or out of interior  50 . Over the top piping may be utilized where under-floor piping is not feasible, for example. Basin  51  could also be configured to allow the liquid/slurry to weir over in a particular location at a desired elevation. As depicted in  FIG. 5 , a drain/inlet may be provided in base  70  and liner  80  to allow fluid communication therethrough. As depicted in the figures, fluid communication may be provided through an underside (e.g., base  70 ) of basin  51 . A manhole casting  5  may connect to an underside of basin  51  opposite interior  50  and seals  6  may be utilized on opposite sides of liner  80 . A manhole riser  7  may be coupled to casting  5  and the seals. A conduit  8  may connect riser  7  to a manifold system  10  to allow the introduction and/or removal of liquids relative to interior  50  therethrough. A shutoff valve  9  may be utilized to allow or prevent such fluid communication. 
         [0022]    In one example, manhole casting  5  may be 6″ to 8″ in height. The drain may be 24″ in diameter on top (for the opening) and then 36″ at the base which is between 5′ and 7′ below the top surface of the drain. These dimensions may be adjusted as desired, e.g., to adjust an amount of flow to fill and discharge the system. 
         [0023]    As depicted in  FIGS. 6 and 7 , a clamp cover  150  may protect the liner material (i.e., liner  80 ) from a clamp. The cover may be formed of a foam material (e.g., 1.7# low density form fit polyethylene foam or any other material which would properly act as a cushion/buffer to minimize risk of damage from impact, chaffing, puncturing or tearing) which fits over a clamp  160  which then rests against the geogrid material (e.g., geogrid material  20 ), which contacts the liner material. The cover may be connected to the clamp by twine or zip ties, for example. Multiple clamps  160  may be utilized to connect individual frame units (e.g., units  100 ) to each other as depicted in the figures. For example, a top portion  153  and a bottom portion  154  may receive multiple leg portions  40  therebetween to connect such leg portions to one another. The top portion and bottom portion could be connected to each other by a fastening mechanism, such as a bolt  155 , for example. Clamp  160  could be shaped and dimensioned in any way to allow adjacent frame units  100  (e.g., leg portions  40  thereof) to be connected to one another. 
         [0024]    Further, basin  51  may include a portion thereof having a top end lower than a remaining portion of such basin. For example, several of frame units  100  may include leg portion  40  of reduced length such that a top end in the local area of such reduced dimensioned leg portions are lower than the top ends of other leg portions adjacent such reduced dimension leg portions. This reduced height may form a weir to allow liquid in interior  50  to flow out of basin  51  when such liquid reaches a top end of the reduced height portion. Such a “weir over” arrangement may be useful in the case of the subsurface conditions don&#39;t allow for a underground method or when such an underground method is not cost effective. 
         [0025]    In another example, basin  51  may include a conduit  200  which extends from liner  80  in the vicinity of top end  41  into interior  50  and rests on a supporting surface, such as concrete blocks  210 , as depicted in  FIG. 8 . Such blocks may act as an anchoring point for the conduit and also may act as a diffusion device when fluid flows at high velocity through conduit  200 . Liquid may flow into and/or out of basin  51  through conduit  200  (e.g., via pump(s)). A support  220  may extend from one of blocks  210  to a position at/or near top end  41  to support conduit  200  as depicted in  FIG. 8 . 
         [0026]    Further, in another example, through-wall piping for filling/evacuating fluid materials may be used when sub-surface conditions don&#39;t permit installation of an in-floor system (e.g., conduit  8 ) or an over-the-top system cannot be properly stabilized (e.g., secured to dead-men inside basin) to minimize the risk of liner damage by pipe thrashing. Such a through-wall piping system would extend through leg  40 , liner  80 , and geo-grid  20 , for example, such that a conduit extending through leg  40 , and liner  80  is sealed to inhibit leakage through liner  80  and leg  40  other than that flowing through such conduit. 
         [0027]    The above described system (e.g., basin  51 ) may be used for the temporary short or long term storage of any form of liquid or slurry where in-ground impoundments or frack tanks are either not permitted or not viable. Such systems are intended to be used above ground and are portable; the frame units and separate hardware can be individually stacked and transported by truck to any location including very remote locations. The systems may be easily assembled, broken down and re-assembled at different locations. For example, each of frames  100  may be releasably connected to adjacent frames of frames  100  to form the structure of basin  51  by a plurality of clamps (e.g., clamp  150 ) and/or other connecting mechanism (e.g., cables) thereby allowing a basin to be constructed in various sizes and shapes (e.g., by using different number of frames  100  in different configurations) and allowing the easy deconstruction and movement of such a basin from one place to another due to the releasable nature of the connections. The frames may also be separated from each other and re-used after a basin has achieved a particular purpose, for example. The assembly and re-assembly may be done by hand with the assistance of lifting machinery. The system (e.g., basin  51 ) may be used for central frack water storage in the Marcellus shale industry in Pennsylvania where limited access is available, for example. It may also be used for many other types of storage requirements. Basin  51  would not affect the existing water table and has a minimal impact on the ground and surrounding area where it is being used due to its above ground construction. 
         [0028]    Further, basin  51  may permit temporary storage of millions of gallons of fresh water used in industrial, commercial and energy applications. Basin  51  may be ten feet high, for example, providing a larger storage capacity when compared to similar above ground systems. The described systems may be portable and may be assembled, broken down re-located and re-assembled in a minimal time-frame as compared to similar above ground systems as described above. 
         [0029]    Basin  51  may be completely modular and can be constructed into any shape or size configuration based on needs (e.g., maximizing the drill pad footprint) of a user. The system described (e.g., basin  51 ) may have in-floor or thru-wall piping capabilities for quick fill and discharge requirements. The system described (e.g., basin  51 ) may have minimal labor and equipment requirements for assembly/disassembly. Further, the system described (e.g., basin  51 ) is environmentally friendly and requires minimal disturbance/impact to terrain. 
         [0030]    While the invention has been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.