Patent Publication Number: US-2016237789-A1

Title: Flow and pressure balanced frac tank farm

Description:
BACKGROUND 
     This application claims the benefit of U.S. Provisional Application No. 62/117,016, filed Feb. 17, 2015, the entire contents of which is hereby incorporated herein by reference. The complete disclosure of each of the foregoing priority and related applications are hereby fully incorporated herein by reference. 
     One or more fluid storage tanks, such as frac or trailer tanks, may be used to provide storage for fluid at various locations, such as at drilling sites for oil wells, gas wells, manufacturing facilities, warehouses, user facilities (e.g., biodiesel storage for farms), trans loading facilities, municipal and public works locations, etc. In this context, a frac tank may be towed to a temporary location by a tow vehicle. At the drilling site, the frac tank may be unhooked from the tow vehicle and positioned at a suitable location to be filled with fluid. When positioned at the suitable position on stable ground, the frac tank can be filled with fluid for storage and dispensing. Other types of tanks may be stationary, in ground, above ground, round, rectangular or square. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the present disclosure can be better understood with reference to the following drawings. It is noted that the elements in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the embodiments. In the drawings, like reference numerals designate like or corresponding, but not necessarily the same, elements throughout the several views. 
         FIG. 1  illustrates a perspective view of an example flow balanced frac tank farm according to one embodiment of the present disclosure. 
         FIG. 1A  illustrates a perspective view of an example header pipe arrangement according to one embodiment of the present disclosure. 
         FIG. 2  illustrates a top-down view of the flow balanced frac tank farm in  FIG. 1  according to one embodiment of the present disclosure. 
         FIG. 3  illustrates a perspective view of part of a header pipe arrangement in the flow balanced frac tank farm in  FIG. 1  according to one embodiment of the present disclosure. 
         FIG. 4  illustrates a perspective view of an example flow balanced frac tank farm according to another embodiment of the present disclosure. 
         FIG. 5  illustrates a perspective view of part of a header pipe arrangement in the flow balanced frac tank farm in  FIG. 4  according to one embodiment of the present disclosure. 
         FIG. 6  illustrates a top-down view of the flow balanced frac tank farm in  FIG. 4  according to another embodiment of the present disclosure. 
         FIG. 7  illustrates a perspective view of another part of the header pipe arrangement in the flow balanced frac tank farm in  FIG. 4  according to one embodiment of the present disclosure. 
         FIG. 8  illustrates a shield between two frac tank trailers according to one embodiment of the present disclosure. 
         FIG. 9  illustrates a header pipe arrangement including an alternative drain header according to one embodiment of the present disclosure. 
         FIG. 10  illustrates pressure balancing end pipes in a frac tank farm according to one embodiment of the present disclosure. 
         FIG. 11  illustrates a header pipe arrangement for balancing the frac tank farm in  FIG. 10  according to one embodiment of the present disclosure. 
         FIG. 12  illustrates a pressure balancing end pipe according to one embodiment of the present disclosure. 
         FIG. 13  illustrates operation of the flow balanced frac tank farm according to one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     As noted above, frac tanks may be used to provide storage for fluid at various locations, such as drilling sites for oil and gas wells, for example. When located and positioned at a suitable position, a frac tank can be filled with fluid for storage and dispensing. Examples of fluids that may be stored in frac tanks include fracking liquids, drilling mud, fluids from environmental cleanup, water, brine, etc. As used herein, the term “fluid” includes any material or composition of materials of suitable viscosity to flow through pipes or tubes and into and out of a storage tank, with or without pumping. Thus, the term “fluid” is intended to include any flowing mixture, suspension, or slurry, regardless of materials. 
     Depending upon the needs at the site, the volume of fluid held by a single frac tank may be insufficient. For example, the volume of fluid held by a single frac tank trailer, positioned at a suitable location by a tractor, may be insufficient for certain jobs. Further, larger solutions, such as frac pools, may be unsuitable, undesirable, or unavailable for various reasons. In this case, according to the embodiments described herein, a group of frac tank trailers may be arranged together in one or more batteries of frac tanks to form a frac tank farm. 
     It may also be desirable or necessary to heat the fluid stored in a frac tank. For example, in hydraulic fracturing, heated fluid is pumped into wells to stimulate the removal of oil and/or gas deposits. In the case of a frac tank farm, it may be relatively difficult to evenly disperse or diffuse heated fluid throughout the frac tank trailers in the frac tank farm. Thus, according to the embodiments described herein, a header pipe arrangement may be relied upon to help balance the flow of heated fluids among the frac tank trailers in a frac tank farm. Further, it may be relatively difficult to evenly balance fill levels and/or water pressure throughout the frac tank trailers in the frac tank farm. Thus, according to other aspects of the embodiments described herein, pressure balancing end pipes and a balancing header pipe arrangement may be relied upon to help balance fill levels and water pressure among the frac tank trailers in a frac tank farm. 
     In the context outlined above, aspects of flow and pressure balanced frac tank farms are described herein. In one embodiment, a flow and pressure balanced frac tank farm includes at least one battery of frac tanks comprising a plurality of frac tank trailers, a header pipe arrangement, and at least one valve between one or more of the frac tank trailers and the header system. The header pipe arrangement may include a header supply pipe to supply water to individual ones of the plurality of frac tank trailers and a header discharge pipe to discharge water from individual ones of the plurality of frac tank trailers. The header pipe arrangement may be relied upon to help balance the flow of heated fluids among the frac tank trailers in frac tank farm. In various embodiments, the balance of the flow may or may not be augmented by valves, restrictive orifices, pumps, or headers. Also, depending upon the terrain, additional augmentation using valves, restrictive orifices, pumps, or headers may be relied upon. Further, the frac tank farm may include pressure balancing end pipes and an associated balancing header pipe arrangement to help balance fill levels and water pressure in the frac tank farm. 
     Turning now to the drawings, various structural and functional aspects of the embodiments are described in further detail. 
       FIG. 1  illustrates a perspective view of an example flow balanced frac tank farm  100  according to one embodiment of the present disclosure. It should be appreciated that frac tank farm  100  in  FIG. 1  is provided by way of example only. In other words, the embodiments frac tank farms described herein may be arranged in other configurations. 
     As illustrated in  FIG. 1 , the frac tank farm  100  includes four batteries  110  of frac tank trailers  120 , arranged in two rows. In  FIG. 1 , each battery  110  includes ten frac tank trailers  120 , for a total of forty frac tank trailers  120  in the frac tank farm  100 , although any battery  110  may include a lesser or greater number of frac tank trailers  120  among embodiments. The frac tank farm  100  also includes a header pipe arrangement  130 . Among other components, the header pipe arrangement  130  includes at least one header supply pipe to supply water to individual ones of the frac tank trailers  120  and at least one header discharge pipe to discharge water from individual ones of the frac tank trailers  120 . The header pipe arrangement  130  is designed to balance the flow of fluid relatively evenly among the frac tank trailers  120  in the frac tank farm  100 . Particularly when fluid in the frac tank trailers  120  is being heated and exchanged, the header pipe arrangement  130  is designed to balance the flow of heated fluid relatively evenly among the frac tank trailers  120 , so as to achieve a substantially evenly heated temperature of fluid among the frac tank trailers  120 . In the embodiment illustrated in  FIG. 1 , the head ends of the frac tank trailers  120  are facing each other (“head-to-head”) along the central column  136  ( FIG. 2 ) of the header pipe arrangement  130 . The tail ends of the frac tank trailers  120 , having wheels, are further apart from each other. 
     To heat the fluid in the frac tank farm  100 , a heater truck  140  may be relied upon. The header pipe arrangement  130  may be installed or otherwise connected for fluid communication between the frac tank trailers  120  in the frac tank farm  100  and the heater truck  140 . In this configuration, fluid may be discharged from the frac tank trailers  120 , routed to the heater truck  140  for heating by the header pipe arrangement  130 , and returned to the frac tank trailers  120  by the header pipe arrangement  130 . Thus, in one configuration, the header pipe arrangement  130  provides a closed fluid loop between the frac tank trailers  120  in the frac tank farm  100  and the heater truck  140 . The heater truck  140  may be capable of generating an amount of energy, measured in British Thermal Units (BTUs), for example, to heat the fluid from the frac tank trailers  120 . Depending upon the desired temperature and other factors, the heater truck  140  may be selected to provide ten or more million BTUs for each battery  110  of ten frac tank trailers  120 , although other suitable ratios of BTUs to tanks may be relied upon. 
     Each frac tank trailer  120  includes a storage tank and wheels. A frac tank trailer  120  may be formed from steel or any other material suitable for the application. The walls of the frac tank trailer  120  may be formed from corrugated steel plate, pig iron, plastic or other materials, formed into a rectangular tank structure, and welded along one edge to the tank base. Inside the walls, a liner for the storage tank may or may not be relied upon to separate or insulate the storage tank from the walls, as some tanks are single walled. Generally, the wheels of the frac tank trailer  120  may be relied upon to transport and position the frac tank trailer  120  to any suitable location using a tractor, for example. 
     In some embodiments, one or more of the frac tank trailers  120  may include an exchanger to help disperse fluid relatively evenly over its storage tank. One example of such an exchanger is described in U.S. Non-provisional patent application Ser. No. 14/526,204, filed Oct. 28, 2014, and titled “Frac and Storage Tank Exchanger.” 
       FIG. 1A  illustrates a perspective view of the header pipe arrangement  130  in  FIG. 1 . As shown in  FIG. 1A , the header pipe arrangement  130  includes a header supply pipe  132  to supply water to individual ones of the plurality of frac tank trailers  120  ( FIG. 1 ) and a header discharge pipe  134  to discharge water from individual ones of the plurality of frac tank trailers  120  ( FIG. 1 ). The header supply pipe  132  and header discharge pipe  134  provide a closed fluid loop between the frac tank trailers  120  in the frac tank farm  100  and the heater truck  140  ( FIG. 1 ), for example. Specifically, fluid may be routed from the frac tank trailers  120  to the heater truck  140  for heating through the header discharge pipe  134  and returned to the frac tank trailers  120  through the header supply pipe  132 . 
     Header supply tubes  132 A branch off the header supply pipe  132  and supply water to individual ones of the frac tank trailers  120 . Similarly, discharge supply tubes  134 A branch off the header discharge pipe  134  to discharge water from individual ones of the frac tank trailers  120 . In one embodiment, the lengths of the header supply tubes  132 A are similar to (e.g., the same or nearly the same as) those of the discharge supply tubes  134 A, although different lengths may be relied upon. In some embodiments, valves may be placed in one or more of the header supply tubes  132 A or the discharge supply tubes  134 A to control the flow of fluids into or out of the individual ones of the frac tank trailers  120 . 
     The header supply tubes  132 A may be evenly spaced and connected along the central column  136  ( FIG. 2 ) of the header supply pipe  132  in one embodiment, although any suitable spacing may be used, as needed, depending upon the positions of the frac tank trailers  120 , for example. First ends of the header supply tubes  132 A may be connected with the header supply pipe  132  using tee joints or other suitable fittings or attachment means. Second ends of the header supply tubes  132 A may be connected to one or more fluid input or intake ports or manifolds at the head of the frac tank trailers  120  (see also, e.g.,  FIG. 3 ). In some embodiments, the volume of fluid provided through the header supply tubes  132 A may be pressure and/or volume balanced along the central column  136  of the header supply pipe  132  to allow balanced flow to the frac tank trailers  120 . Connections to the header supply pipe  132  may be calculated or determined empirically for balanced or desired flow among each of the header supply tubes  132 A. Also, the positions and inclination/declination of each connection to the header supply pipe  132  may be relied upon as a restrictive orifice. In this context, smaller or larger openings and hoses may be relied upon to augment the balance of the flow. 
     The discharge supply tubes  134 A may also be evenly spaced and connected along the central column of the discharge supply pipe  134  in one embodiment, although any suitable spacing may be used, as needed, depending upon the positions of the frac tank trailers  120 , for example. First ends of the discharge supply tubes  134 A may be connected with the discharge supply pipe  134  using tee joints or other suitable fittings or attachment means. Second ends of the discharge supply tubes  134 A may be connected to one or more fluid output ports or manifolds at the head of the frac tank trailers  120 . In some embodiments, the volume of fluid provided through the discharge supply tubes  134 A may be pressure and/or volume balanced along the central column  136  of the discharge supply pipe  134  to allow even flow from the frac tank trailers  120 . In some embodiments, valves may be placed in one or more of the discharge supply tubes  134 A to control the flow of fluids out of the individual ones of the frac tank trailers  120 . Connections to the discharge supply pipe  134  may be calculated or determined empirically for balanced or desired flow among each of the discharge supply tubes  134 A. Also, the positions and inclination/declination of each connection to the discharge supply pipe  134  may be relied upon as a restrictive orifice. In this context, smaller or larger openings and hoses may be relied upon to augment the balance of the flow. 
     As also shown in  FIG. 1A , the header pipe arrangement  130  includes a drain pipe  138  and drain supply tubes  138 A which branch off the drain pipe  138 . The drain pipe  138  may be relied upon as an alternative way to discharge or drain fluid from the frac tank trailers  120 . The drain supply tubes  138 A may be connected to one or more fluid output ports or manifolds at a tail of the frac tank trailers  120 . 
     It is noted that, in various embodiments, the header pipe arrangement  130  may be embodied by any suitable type or types of pipes or tubes formed from any suitable material, such as metal, metal alloys, plastic, etc. The header pipe arrangement  130  may be constructed using several different parts, pieces, and/or lengths of pipes or tubes, and associated fittings, as needed, based on the configuration and size of the frac tank farm  100 . In some embodiments, the header pipe arrangement  130  may be insulated, at least in part, to help prevent the loss of heat from the fluid in the header pipe arrangement  130 . 
       FIG. 2  illustrates a top-down view of the flow balanced frac tank farm  100  in  FIG. 1  according to one embodiment of the present disclosure. In the view provided in  FIG. 2 , it is clear how the header supply pipe  132  and the header discharge pipe  134  are routed from the heater truck  140  and centrally between two of the batteries  110  in one row before branching off to the central column  136  of the header pipe arrangement  130 . By centrally positioning parts of the header pipe arrangement  130  among the frac tank trailers  120  in the frac tank farm  100 , a more balanced and/or even supply of heated fluids may be exchanged among the frac tank trailers  120 . Similarly, a balanced and/or even supply of heated fluids may be drained from the frac tank trailers  120  using drain pipe  138 . 
       FIG. 3  illustrates a perspective view of part of a header pipe arrangement  130  in the flow balanced frac tank farm in  FIG. 1  according to one embodiment of the present disclosure. In  FIG. 3 , the header supply tubes  132 A and the discharge supply tubes  134 A can be more easily seen extending from the header supply pipe  132  and the discharge supply pipe  134 , respectively, to the individual ones of the frac tank trailers  120 . As shown, the header supply tubes  132 A may be evenly spaced and connected along the header supply pipe  132 . First ends of the header supply tubes  132 A may be connected with the header supply pipe  132  using tee joints or other suitable fittings or attachment means. Second ends of the header supply tubes  132 A may be connected to one or more fluid input or intake ports or manifolds  1326  at the head of the frac tank trailers  120 . 
     The discharge supply tubes  134 A may also be evenly spaced and connected along the discharge supply pipe  134 , as illustrated. First ends of the discharge supply tubes  134 A may be connected with the discharge supply pipe  134  using tee joints or other suitable fittings or attachment means. Second ends of the discharge supply tubes  134 A may be connected to one or more fluid output ports or manifolds  134 B at the head of the frac tank trailers  120 . In some embodiments, valves may be placed in one or more of the discharge supply tubes  134 A to control the flow of fluids out of the individual ones of the frac tank trailers  120 . 
       FIG. 4  illustrates a perspective view of an example flow balanced frac tank farm  400  according to another embodiment of the present disclosure. In the embodiment illustrated in  FIG. 4 , the head ends of the first row  410  of the frac tank trailers  120  are facing the tail ends of the second row  420  of the frac tank trailers  120  (“head-to-tail”). This configuration may be easier to arrange, especially if the frac tank trailers  120  are delivered and positioned by semi tractors. As compared to the arrangement of the header supply pipe  132  and the header discharge pipe  134  in  FIGS. 1, 1A, 2, and 3 , the header supply pipe  432  and the header discharge pipe  434  in  FIG. 4  run in two columns rather than one, due to the “head-to-tail” arrangement of the frac tank trailers  120 . Similarly, as compared to the drain pipe  138  ( FIG. 1 ), the drain pipe  438  is arranged in an alternative way due to the “head-to-tail” arrangement of the frac tank trailers  120 . 
       FIG. 5  illustrates a perspective view of part of the flow balanced frac tank farm  400  in  FIG. 4  according to one embodiment of the present disclosure. In addition to the header supply pipe  432 , the header discharge pipe  434 , and the drain pipe  438 ,  FIG. 4  illustrates a pump  500  between the header supply pipe  432  and the header discharge pipe  434 . The pump  500  may be relied upon to assist with the flow of fluid between the frac tank trailers  120  and the heater truck  140 . The pump  500  may be embodied as any suitable size or style pump, depending upon the viscosity of the fluid in the frac tank trailers  120  and other factors. In  FIG. 5 , valves  420  are also shown between the frac tank trailers  120  and the drain pipe  438 . It should be appreciated that valves, similar to valve  420 , may be relied upon in various locations between any header pipes and the frac tank trailers  120  or in the header pipes themselves. 
       FIG. 6  illustrates a top-down view of the flow balanced frac tank farm  400  in  FIG. 4  according to another embodiment of the present disclosure. In the view provided in  FIG. 6 , it is clear how the header supply pipe  432 , the header discharge pipe  434 , and the drain pipe  438  are routed from the heater truck  140  to the frac tank trailers  120 . 
       FIG. 7  illustrates a perspective view of the flow balanced frac tank farm  400  in  FIG. 4  according to one embodiment of the present disclosure. In  FIG. 7 , the header supply pipe  432  and the header discharge pipe  434  run from the heater truck  140  to a center split  700 , before being routed along the head ends of the frac tank trailers  120 . By making the center split  700  substantially in the middle of the header pipes, the temperature of the fluid that flows among the frac tank trailers  120  may be substantially uniform. 
       FIG. 8  illustrates a shield  800  between two frac tank trailers  120  according to one embodiment of the present disclosure. The shield  800  may help prevent heat from radiating from the frac tank trailers  120 , by preventing or reducing wind from circulating around the frac tank trailers  120 . Shields similar to the shield  800  may be arranged and mounted between one or more pairs of the frac tank trailers  120 , among embodiments, as desired. The shield  800  may be formed from metal, wood, plastic or any other suitable material and may be secured to the frac tank trailers  120  using magnets, mechanical fastening means (e.g., screws, bolts, etc.), hooks, or any other suitable fastening or affixing means. In other aspects of the embodiments, the frac tank trailers  120  may be insulated in other ways, including insulation wraps, jackets, and other coverings. 
       FIG. 9  illustrates a header pipe arrangement including an alternative drain header  900  according to one embodiment of the present disclosure. As illustrated in  FIG. 9 , the alternative drain header  900  is connected in fluid communication with an alternate drain, orifice, or opening of the frac tank trailers  120 . In this context, it should be appreciated that the frac tank trailers  120  may be drained using one or more drain headers. 
       FIG. 10  illustrates pressure balancing end pipes  1002  in a frac tank farm according to one embodiment of the present disclosure, and  FIG. 11  illustrates a header pipe arrangement including pipes  1004 ,  1006 , and  1008  for pressure balancing the frac tank farm in  FIG. 10  according to one embodiment of the present disclosure. As shown in  FIG. 10 , a pressure balancing end pipe  1002 , formed in a “J” shape, is included within each frac tank trailer  120 . In the illustrated embodiment, the pressure balancing end pipes  1002  include slots or holes, as described in further detail below with reference to  FIG. 12 , although the slots or holes may be omitted in alternate embodiments. Further, the pipes  1002  may be formed into other shapes in alternate embodiments. The pressure balancing end pipe(s)  1002  and header pipes  1004 ,  1006 , and  1008  are not required in frac tank farms. That is, the pressure balancing end pipe(s)  1002  and header pipes  1004 ,  1006 , and  1008  may be omitted in certain embodiments. 
     Referring to  FIG. 11 , it can be seen that each pressure balancing end pipe  1002  is in fluid communication with a header pipe  1004  which is, in turn, in fluid communication with a bay header pipe  1006 . Further, each bay header pipe  1006  is in fluid communication with a farm header pipe  1008 . The farm header pipe  1008  includes values  1010 . The valves  1010  may be relied upon to isolate a bay header pipe  1006  for a bay  1020  of frac tank trailers  120 . The frac tank trailers  120  in  FIG. 11  are arranged in bays  1020  of five, although other numbers of frac tank trailers  120  may be arranged in a bay  1020 . 
     When the valves  1010  are closed, the pressure balancing end pipes  1002 , header pipes  1004 , and bay header pipes  1006  permit water to pressure balance between the frac tank trailers  120  in a bay  1020 . Particularly, the pressure balancing end pipes  1002  operate in a way similar to a manometer, by permitting an overage of pressure (e.g., from water or fluid) in one frac tank trailer  120  to push excess fluid into other frac tank trailers  120  in the bay  1020 . It is noted that, when being filled, individual ones of the frac tank trailers  120  may fill at respective, different rates. In that case, certain frac tank trailers  120  may hold more fluid than others. That difference in fill level may be compensated for, at least in part, by the pressure balancing end pipes  1002 , header pipes  1004 , and bay header pipes  1006  for any given bay  1020 . The differences in fill levels among two bays  1020  may additionally be compensated for by opening the valves  1010 , so that pressure may be balanced between two bays  1020  using the farm header pipe  1008 . 
       FIG. 12  illustrates a pressure balancing end pipe  1002  according to one embodiment of the present disclosure. As shown, the pressure balancing end pipe  1002  includes slots or holes  1030  and a “J” hooked end  1040 . The slots or holes  1030  permit fluid pressure to be transferred or translated among the header pipes  1004  and bay header pipes  1006  ( FIG. 11 ), as the level of fluid rises in a frac tank trailer ( FIG. 10 ). While the pressure balancing end pipe  1002  is shown to have a “J” hooked shape, other types or shapes of pipes may be relied upon, including inverted “L” or “T” shaped pipes, for example. The slots or holes  1030  may be omitted from some embodiments. 
       FIG. 13  illustrates operation of a flow balanced frac tank farm  1300  according to one embodiment of the present disclosure. As illustrated, water is being pumped out from the batteries  1310 , the battery  1320  is on standby, and fluid is being circulated in the battery  1330  for heating. This process may be rotated over time, so that combinations of all of the batteries  1310 ,  1320 , and  1330  may rotate through pumpout, circulation heating, and standby. The rotation may be achieved using valves as illustrated in  FIG. 13  and described herein. 
     Although embodiments have been described herein in detail, the descriptions are by way of example. The features of the embodiments described herein are representative and, in alternative embodiments, certain features and elements may be added or omitted. Additionally, modifications to aspects of the embodiments described herein may be made by those skilled in the art without departing from the spirit and scope of the present invention defined in the following claims, the scope of which are to be accorded the broadest interpretation so as to encompass modifications and equivalent structures.