Abstract:
A cargo container is modified to carry a fracing proppant such as sand from a quarry or source to the frac site. Openings are cut in the top and bottom of a cargo container and hydraulically operated sliding doors are placed there under. A hopper module with the walls being inclined to approximately the angle of repose for the proppant is installed inside the cargo container. The hopper module is sealed inside the cargo container so that a proppant enters through the top opening at the quarry and flows out through the bottom opening at the fracing site. Once transported to the frac site, the modified cargo container is lifted, emptied and set aside.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This is a continuation patent application claiming priority to and the benefit of U.S. non-provisional patent application Ser. No. 13/370,401, filed Feb. 10, 2012, and entitled “Method and Apparatus for Modifying a Cargo Container to Deliver Sand to a Frac Site,” which is hereby incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to the transportation of a granular substance such as sand and, more particularly, to the modification of cargo containers for the purpose of transporting sand therein to frac sites. 
         [0004]    2. Description of the Prior Art 
         [0005]    Cargo containers (also called intermodal containers, freight containers, ISO containers, shipping containers, Hi-Cube containers, Sea Cans) are standardized, reusable steel boxes used for the safe, efficient and secure storage and movement of materials and products within a global containerized freight transportation system. The container can be moved from one mode of transportation to another without unloading and reloading the contents of the container. All of the containers are 8 ft. wide so they can travel along standard highway systems. The height of the standard container is normally 8 ft. 6 in., but a “high cube” container of 9 ft. 6 in. in height can be used. 
         [0006]    The part of the standard cargo container that may change is the length. The standard length size is either 20 ft. or 40 ft. 
         [0007]    A general purpose cargo container has doors fitted at one end and is constructed of corrugated weathering steel. The cargo containers can be stacked up to seven containers high. At each of the eight corners are castings with openings for twist-lock fasteners to hold the cargo containers in position. It is estimated there are 17 million cargo containers available world-wide. 
         [0008]    In the last two years, hydraulic fracturing (also known as “fracing”) has been used in hydrocarbon wells to create cracks in underground reservoir rock formations to create new channels in the rock, which increases the extraction rate and ultimate recovery of fossil fuels. To keep the fractures from closing, during the fracing process, a proppant is injected with a fluid, which proppant keeps the fractures open once the pressure is released. The most common proppant used is sand, although in recent years other proppants such as resin-coated or ceramic sand have been utilized. 
         [0009]    In reservoirs such as shale rock or coal beds, fracing may be used to cause the production of natural gas or oil from those formations. Otherwise, there is not sufficient viscosity, permeability or reservoir pressure to allow the natural gas or oil to flow from the rock into the well bore at economic rates. Fracturing will provide flow paths connecting a larger area of the reservoir to the well, thereby increasing the area from which natural gas or liquids can be recovered from a formation. In such case, a proppant, such as sand, is necessary to keep the fractures open with the oil and gas flowing there through. 
         [0010]    In the fracturing of a single well, the amount of proppant such as sand that is used can cost five or six million dollars. Most of the cost of the sand is for handling. If the sand can be handled fewer times, the cost can be greatly reduced. 
         [0011]    The type of sand used in fracing is also very critical. The sand should have high quartz content so that it will not crush in the cracks of the formation, but will hold the cracks open. The deeper the well, normally the more quartz content that is required. In order to get the appropriate types of sand, fracing companies are having to purchase it throughout the world. For example, in deep wells in South Texas, the good quality fracing sand comes from such places as the State of Wisconsin, China, or Russia. From other countries, the sand is delivered to the United States by ship and is handled at multiple locations in multiple ways with very inefficient supply chain logistics for the handling of the fracing sand. The more times the fracing sand is handled, the more expensive it is to the individual fracing company and to the well operator. This is passed along to the consumer in the increased price of gasoline. 
         [0012]    Also at the well site if a truck delivers sand and cannot unload when the truck arrives, then the operator is charged the demurrage for waiting. It is common at many frac sites for a number of trucks to be waiting in line to be unloaded, for which the operator is being charged demurrage. It is important that as soon as the sand is delivered to the frac site, that it can be immediately unloaded to eliminate the demurrage. 
       SUMMARY OF THE INVENTION 
       [0013]    It is an object of the present invention to modify standard cargo containers for the delivery of granular material for fracing. 
         [0014]    It is another object of the present invention to provide an insert for cargo containers so the cargo containers are modified to carry sand therein. 
         [0015]    It is still another object of the invention to modify a cargo container so that sand can be inserted from the top and removed from the bottom of a totally self-contained unit. 
         [0016]    It is another object of the present invention to provide cargo containers that can carry sand all the way from the quarry to the ultimate destination of a fracing site without repeated handling of the sand. 
         [0017]    A standard cargo container is 8 ft.×8 ft. 6 in.×20 ft. and can be modified to carry fracing sand. A hole is cut in the top and the bottom. A hopper module is inserted into the cargo container through doors at one end of the cargo container. An upper hatch is located in a hole in the top and used to load sand in the cargo container. A lower hatch is in the opening in the bottom and may be opened to remove the sand therefrom. Hydraulic controls are used to open and close the upper or lower hatches. 
         [0018]    The modified cargo containers may be taken directly to the quarry and loaded with sand. The modified cargo containers can then move through of the normal modes of transportation including ship, barge, rail or by truck, all the way to the frac site. The sand never has to be handled again. All that has to occur is the modified cargo container is moved from one mode of transportation to another (i.e., ship-to-rail-to-truck) as it moves from the quarry to the frac site. 
         [0019]    Also, the modified frac containers may be stacked in any conventional means, either while in transit or at the frac site. This eliminates the demurrage of waiting to unload sand into bulk sand containers at the frac site. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a pictorial illustration of all the ways sand is delivered from the quarry to the frac site. 
           [0021]      FIG. 2  illustrates the present invention being used to deliver sand from the quarry or source to the frac site. 
           [0022]      FIG. 3  is a pictorial illustration of the stackability of modified cargo containers, with or without sand therein. 
           [0023]      FIG. 4  is an illustration showing sand being unloaded from a modified cargo container at the frac site into a bulk sand container. 
           [0024]      FIG. 5  is an elevated sectional side view showing sand flowing through stacked modified cargo containers. 
           [0025]      FIG. 6  is an elevated side view of a trailer that can be used with modified cargo containers filled with frac sand. 
           [0026]      FIG. 7  is an elevated side view of the trailer being used with modified cargo containers thereon which can be filled with frac sand. 
           [0027]      FIG. 8  is a perspective of the trailer shown in  FIG. 7 . 
           [0028]      FIG. 9  is a pictorial view of a cargo container illustrating where openings should be cut. 
           [0029]      FIG. 10  is the cargo container shown in  FIG. 9  with the holes cut and a hopper module being inserted therein. 
           [0030]      FIG. 11  is an exploded perspective view of the equipment that needs to be added to the cargo container illustrated in  FIGS. 9 and 10 . 
           [0031]      FIG. 12  is a perspective view of the hopper module to be inserted in the cargo container of  FIG. 10 . 
           [0032]      FIG. 13  is an elevated end view of a modified cargo container with the end doors opened. 
           [0033]      FIG. 14  is an end view of a modified cargo container illustrating the control panels. 
           [0034]      FIG. 15  is a partial sectional view of a modified cargo container. 
           [0035]      FIG. 16  is an elevated sectional view of one side of the modified cargo container illustrating the upper and lower hatches being closed. 
           [0036]      FIG. 17  is an elevated sectional view of one side of the modified cargo container illustrating the hatches being opened. 
           [0037]      FIG. 18  is a top sectional view of the modified cargo container illustrating flow of the sand therefrom. 
           [0038]      FIG. 19  is an exploded perspective view of a sliding door used at an upper or lower hatch. 
           [0039]      FIG. 20A  is a cross-sectional view of a sliding door for a hatch being closed. 
           [0040]      FIG. 20B  is a cross-sectional view of a sliding door at a hatch being opened. 
           [0041]      FIGS. 21A and 21B  illustrate a spring-loaded cylinder being used to open or close a hatch. 
           [0042]      FIG. 22  is a schematic illustration of the opening and closing of hatches for a modified cargo container. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0043]    Referring first to  FIG. 1 , fracing sand may be produced in a quarry  30 , which sand is loaded to an elevator  32  into a sand silo  34 . From the sand silo  34 , sand may be loaded by conveyer  36  into bags or is left in bulk by conveyer  38  into a ship or barge  40 , rail car  42 , or truck  44 . 
         [0044]    Referring first to the truck  44 , the truck  44  may be unloaded by conveyer  46  at the site or at the storage  48 . While shown as conveyer  46 , any other type of unloading/loading device can be used, such as a pneumatic pump. From storage  48 , the sand may be reloaded by conveyer  50  onto truck  52  for unloading by conveyer  54  at the site. 
         [0045]    If the fracing sand comes by rail car  42 , rail car  42  may be unloaded by conveyer  56  into storage  58  or truck  60 . If loaded into truck  60 , then the sand would be unloaded by conveyer  62  at the frac site. If the sand goes through storage  58 , it will later have to be loaded by conveyer  59  onto trucks  64  and then unloaded at the frac site by conveyer  66 . 
         [0046]    If the fracing sand comes by ship or barge  40 , the ship or barge  40  will be unloaded by conveyer  68  into truck  70  or sand silo  72 . If loaded into truck  70 , the sand can be taken to the frac site and unloaded by conveyer  74 . For sand traveling by ship or barge  40  that is placed in sand silo  72 , sand from the sand silo  72  may be loaded through conveyer  76  into bags  78 , which bags are moved by conveyer  80  into storage  82 . From storage  82  bags  78  will subsequently be opened and loaded through conveyer  84  onto sand truck  86  for delivery to the site and unloaded by conveyer  88 . 
         [0047]    Bags from conveyer  36  may be located in storage  90 . From the storage  90 , the bags may be emptied onto conveyor  92  and loaded onto either rail car  94  or truck  96 . If loaded onto truck  96 , then the sand will be unloaded on conveyor  98  at the frac site. If the sand is loaded onto rail car  94 , it must later be transferred via conveyer  100  onto truck  102  prior to unloading by conveyer  104  at the frac site. 
         [0048]    Also, the bags of sand from conveyer  36  can be loaded on ship or barge  106 . From the side of the ship or barge  106 , the sand may either be unloaded from the bags or left in the bags. If left in the bags, then bags of sand would be unloaded by conveyer  108  into storage  110 . If unloaded from the bags, the sand then would be loaded by the conveyer  108  into either truck  112  or rail car  114 . If loaded on truck  112 , the sand will be taken and unloaded at the frac site by conveyer  116 . If unloaded into rail car  114 , sand will be unloaded by conveyer  118  into either sand silo  120  or truck  122 . If unloaded into truck  122 , then it could be taken to the frac site and unloaded by conveyer  124 . If unloaded into the sand silo  120 , sand must subsequently be loaded into truck  126  and can be moved to the frac site and unloaded by conveyer  128 . 
         [0049]    If the sand was put into sand storage  110 , the bags then must be opened and emptied into truck  130 , taken to the frac site and unloaded by conveyer  132 . 
         [0050]    As can be seen from  FIG. 1 , there are numerous different ways of moving the sand from the quarry  30  or manufacturing site to the various frac sites. Each time the sand has to be handled through a conveyer, it is an additional expense. Each additional expense means that sand costs more money for the well operator, which goes into additional costs of producing oil, which flows on to the end consumer through higher prices of gasoline, diesel fuel, or natural gas. 
         [0051]    Referring now to  FIG. 9 , a standard 8 ft.×8½ ft.×20 ft. cargo container  130  is shown. The cargo container  130  is made out of corrugated metal and has doors  132  and  134 , on the one end thereof, which doors  132  and  134  are operable by handles  136  and  138 , respectively. Top hole  140  is cut into the top  142  of the cargo container  130 . Bottom hole  144  is cut into bottom  146  of the cargo container  130 . Control panel openings  148  and  150  are cut in doors  132  and  134 , respectively. The cargo container  130  as illustrated in  FIG. 9  has eight corner castings  152  with openings  154  for twist-lock fasteners (not shown). 
         [0052]    Referring now to  FIG. 10 , modification of the cargo container  130  is shown. The top hole  140  and bottom hole  144  have been cut as well as the control panel openings  148  and  150 . The control panel opening  150  is illustrated because door  132  has been removed so the hopper module  156  can be seen as it is being inserted inside of cargo container  130 . Alternatively, the hopper module  156  may be constructed inside of the cargo container  130 . 
         [0053]    Referring now to  FIGS. 10 and 12 , the hopper module  156  will be explained in more detail. Hopper module  156  has a width so that it will fit just inside of the fully opened doors  132  and  134 . Hopper module  156  has a base  158  made out of tubular steel. Towards the front of the base  158  is front module wall  160  and towards the rear is rear module wall  162 . Behind the front module wall  160  are L-beams  164  with I-beams  166  (see  FIG. 17 ) providing cross support there between. To hold the front module wall at or near the angle of repose of sand or similar granular material, front braces  168  are located between the L-beams  164  and the base  158 . 
         [0054]    Just as the front module wall  160  is supported, rear module wall  162  is also supported by L-beams  170  and I-beams  172 . The rear module wall  162  is held at or near the angle of repose by rear braces  174 , extending between L-beams  170  and base  158 . 
         [0055]    On each side of the hopper module  156  is located left side wall  176  and right side wall  178 . Both the left side wall  176  and the right side wall  178  have a ridge  180  formed therein to give additional strength to either the left side wall  176  or the right side wall  178 . 
         [0056]    As can be seen in  FIG. 10 , the front module wall  160  has numerous weld spots  182  therein, which is where the front module wall  160  is electrically welded to the I-beams  166  located there behind. The weld spots are only illustrated in  FIG. 10 . The hopper module  156  is wide enough so that it barely fits inside of cargo container  130 . 
         [0057]    The component parts needed to retrofit the cargo container  130  are illustrated in the exploded perspective view of  FIG. 11 . The hopper module  156  has already been explained in conjunction with  FIGS. 10 and 12 . At the top hole  140  (see  FIG. 10 ) is located an upper hatch  184 , which upper hatch  184  has an upper opening  186  therein. Upper hatch  184  has a wedge-shaped slot  188  there below with an upper sliding door  190  (as will be explained in more detail subsequently) that slides back and forth into wedge-shaped slot  188  to open and close the upper opening  186  in the upper hatch  184 . An upper hydraulic cylinder  192  moves the upper sliding door  190  from the open to closed position and vice versa. Hydraulic lines  194  and  196  connect via elbow  198  to upper hydraulic control panel  200  inside of the upper hydraulic control panel  200 . The hydraulic lines connect via pressure gauge  202  to either a hand-operated hydraulic pump  204  or a remote hydraulic connection  206 . If hydraulic pressure needs to be relieved from the upper hydraulic cylinder  192 , the pressure may be relieved by pressure relief valve  208 . The upper hydraulic control panel  200  may be closed and locked by closing the upper hydraulic panel control door  210  and locked by turning the lock  212 . 
         [0058]    The bottom hole  144  (see  FIG. 10 ) is operated the same way with a lower hatch  214  having a wedge-shaped slot  216  therein in which the lower sliding door  218  opens and closes the lower opening  220 , operation of the lower sliding door  218  being controlled by lower hydraulic cylinder  222 . The lower hydraulic cylinder  222  is connected by hydraulic line  224  to the lower hydraulic control panel  226 . The lower hydraulic control panel  226  works in the same manner as the upper hydraulic control panel  200 . Therefore, the internal workings will not be explained again. 
         [0059]    Referring to  FIGS. 13 and 14  in combination, the elevated end view of a modified cargo container  130  is shown, first with the doors  132  and  134  being opened in  FIG. 13 , then closed in  FIG. 14 . Referring first to door  132 , lower hydraulic control panel  226  is shown. The hydraulic line  224  connects to the lower hydraulic cylinder  222  to open the lower hatch (not shown in  FIG. 13 ). 
         [0060]    On the other door  134  is located upper hydraulic control panel  200  which connects through hydraulic lines  196  and  194  to upper hydraulic cylinder  192  to open the upper hatch (not shown in  FIG. 13 ). 
         [0061]    The end of rear module wall  162  can be seen along with the L-beams  170  and the I-beams  172 . Likewise, the left and right side walls  176  and  178 , respectively, can be seen in broken lines. 
         [0062]    Referring to  FIG. 14 , doors  132  and  134  are closed with the lower hydraulic control panel  226  being opened and the upper hydraulic control panel door  210  being closed. The door  228  of the lower hydraulic control panel  226  can be closed and locked via lock  230 . 
         [0063]    Referring now to  FIG. 15 , a partial exploded view of the cargo container  130  having a hopper module  156  therein is shown. The inside of the hopper module  156  is covered with a liner material  232 . The types of the liner material  232  may vary, but the type that is found to work well by Applicant is a “Greased Lightning Liner” made by RRR Supply, Inc. The inside of the cargo container  130 , and more particularly, the inside of the hopper module  156 , are coated with the liner material  232 , which liner material  232  is very slick. This greatly reduces the angle of repose (the angle at which the granular material will flow) inside of cargo container  130 . 
         [0064]    Referring to  FIGS. 10 and 15 , the hopper module  156  is held into position by bolts  234  connecting through the bottom  146  of the cargo container  130  to nut  236 . While only one bolt  234  and nut  236  are illustrated, several would be used. 
         [0065]    Referring to  FIGS. 16 and 17 , the operation of the upper hatch  184  and lower hatch  214  is explained in detail. The top hole  140  and the bottom hole  144  can be seen in both  FIGS. 16 and 17 . However, in  FIG. 17 , upper hatch  184  is opened because upper sliding door  190  is retracted by upper hydraulic cylinder  192 . Also in  FIG. 17 , bottom hole  144  is open because lower hatch  214  has lower sliding door  218  retracted by lower hydraulic cylinder  222 . The lower hydraulic cylinder  222  connects through hydraulic line  224  to the lower hydraulic control panel  226  (not shown in  FIGS. 16 and 17 ). The upper hydraulic cylinder  192  will connect through hydraulic lines  194  and  196  to upper hydraulic control panel  200 . 
         [0066]      FIG. 16  is the same as  FIG. 17 , except the upper sliding door  190  and lower sliding door  218  are both closed. This occurs via upper hydraulic cylinder  192  and lower hydraulic cylinder  222 , respectively. Otherwise, everything is the same. 
         [0067]    Referring now to  FIG. 18 , a top view of the cargo container  130  as modified is shown, but with the top  142  removed. The lower hydraulic cylinder  222  has moved the lower sliding door  218  so that the bottom hole  144  is now open. Any sand or granular material contained inside of modified cargo container  130  flows down towards the bottom hole  144  in the direction indicated by the arrows. 
         [0068]    If there is any space between left side wall  176  and right side wall  178 , it is filled in with a spray on material sold under the mark LINE-X. The LINE-X makes sure there is no space between the Greased Lightning sheets of material and the edges. The inside of the modified cargo container  130  will have a slick container hopper area. 
         [0069]    Referring now to  FIGS. 19, 20A and 20B  in combination, the operation of either the upper hatch  184  or lower hatch  214  is illustrated. For the purposes of consistency and numbers,  FIGS. 19, 20A and 20B  are being explained as operation of the upper hatch  184 . The upper hatch  184  has a top plate  238  through which the upper opening  186  is cut. The top plate  238  connects to a wedge-shaped trough  240 . The wedge-shaped trough  240 , in combination with the top plate  238 , makes up the upper hatch  184 . The wedge-shaped trough  240  has a lower opening  242  therein. A resilient flap  244  made from a flexible material such as rubber hangs down from top plate  238  as is illustrated in  FIG. 19 . 
         [0070]    The upper sliding door  190  has a wedge-shape front end  246  and a pivot point  248  on the rear thereof for connection to the clevis  250  on the front of the upper hydraulic cylinder  192 . 
         [0071]    In  FIG. 20A , the upper hatch  184  is shown in a closed position. The upper sliding door  190  is moved all the way forward by the piston rod  252  of the upper hydraulic cylinder  192 . The wedge shape  246  on the front of the upper sliding door  190  moves the resilient flap  244  upward and out of the way. The wedge-shaped trough  240  presses against the bottom shoulder  254  of the sliding door  190 . Likewise, the front part of the wedge-shaped trough  240  presses against the front lower edge  256  of upper sliding door  190 . The upward force on the bottom shoulder  254  and the front lower edge  256  by the wedges-shaped trough  240  causes a complete sealing of the top hole  140  and the upper opening  186  in the upper hatch  184 . 
         [0072]    Referring now to  FIG. 20B , the upper sliding door  190  has been retracted by the upper hydraulic cylinder  192  so that now the top hole  140  and the upper opening  186  in hatch  184  are open and in alignment with lower opening  242  so that any sand there above will flow there through. The resilient flap  244  drops down as illustrated in  FIG. 20B . 
         [0073]    The lower hatch  214  operates in the same manner as the upper hatch  184  as previously described in conjunction with  FIGS. 19, 20A and 20B . 
         [0074]    Operation of the upper hydraulic cylinder  192  is explained in conjunction with  FIGS. 21A and 21B . The upper hydraulic cylinder  192  has a cylinder  258  with a piston  260  located in one end thereof. Typically, pressure is applied to the piston  260  through pressure connection  262 . In the unpressurized state, spring  264  forces piston  260  out, which in turn pushes piston rod  252  with the clevis  250  outward, which in turn will close upper sliding door  190  as shown in  FIG. 20A . The upper hydraulic cylinder  192  is held in position by pivot connection  266 . 
         [0075]    Alternatively, hydraulic pressure may be used to extend and retract the upper hydraulic cylinder  192  or lower hydraulic cylinder  222 . 
         [0076]    When pressure is applied to the upper hydraulic cylinder  192  as previously explained in  FIG. 21A , the piston  260  is moved in the opposite direction and the spring  264  compressed. This causes the piston rod  252  to be retracted inside of cylinder  258 . As long as pressure is applied through pressure connection  262 , spring  264  will remain compressed and the upper sliding door  190  retracted as shown in  FIG. 20B . 
         [0077]    The sequence of operation is explained in the schematic of  FIG. 22 , which is for opening the upper hatch  184 , but can equally apply to lower hatch  214 . Upper hydraulic cylinder  192  can receive pressurized hydraulic fluid from either hand-operated hydraulic pump  204  or remote hydraulic connection  206 . Remote hydraulic connection  206  may connect through hydraulic plug  205  to a remote hydraulic fluid source  207 . Pressure gauge  202  monitors pressure being delivered to upper hydraulic cylinder  192 . Pressure relief valve  208  may relieve the pressure if excessive, or to return upper hydraulic cylinder  192  to its normally extended position, i.e., hatch  184  closed. 
         [0078]    The various supply chains and the numerous handling of sand was explained in conjunction with  FIG. 1 . The supply chain can be greatly reduced by use of a modified cargo container  130  as previously described in conjunction with  FIGS. 9 through 22 . 
         [0079]    Turning to  FIG. 2 , sand from the sand quarry  30  or source can now be loaded by a conveyer  268  to a modified cargo container which hereinafter will be referred to by reference numeral  270 . Modified cargo containers  270  can be loaded on a ship  272 , barge  274 , rail  276  or a flatbed truck trailer  278 . Obviously, multiple modified cargo containers  270  may be loaded on each of these alternative modes of transportation. 
         [0080]    If the modified cargo containers  270  are loaded on flatbed truck trailer  278  or container chassis, the modified cargo containers  270  can be taken directly to the fracing site  280  or placed in storage  282  at the fracing site  280 . 
         [0081]    Concerning sand being hauled by rail  276 , the modified cargo containers  270  will have to be off-loaded onto flatbed truck trailer  284 , which flatbed truck trailer  284  can then take the modified cargo containers  270  filled with fracing sand either to storage  286  or to the fracing site  288 . 
         [0082]    Concerning the modified cargo containers  270  being hauled by ship  272  or barge  274 , the modified cargo containers  270  will have to be off-loaded onto either a flatbed truck trailer  290  or a rail car  292 . If being hauled by the flatbed truck trailer  290 , the modified cargo container  270  can be taken directly to the fracing site  294 . However, if modified cargo containers  270  are being transported by rail car  292 , they must be off-loaded onto flatbed truck trailer  296  prior to be taken to the fracing site  294 . 
         [0083]    By just comparing  FIGS. 1 and 2 , it can be easily seen that the sand is being handled fewer times by the use of the modified cargo container  270 . This results in considerably less expense, which reduces the price of fracing sand or other proppants to the well operator. The reduction in price can be in the millions of dollars per well. 
         [0084]    At the well site to be fraced, modified cargo containers  270  can be stacked as shown in  FIG. 3 . Since well sites have a tendency to be rough, the Rough Terrain Container Handler (RTCH) as made by Kalmar from Cibolo, Tex. may be used to pick up and stack the modified cargo containers  270  as illustrated in  FIG. 3 . The Rough Terrain Cargo Handler  298  can pick up one of the modified cargo containers  270  full of sand and unload the modified cargo container  270  to a bulk sand container  300  at the frac site (see  FIG. 4 ). The bulk sand container  300  may be the Frac Sander as is made by NOV-HPCO, located at 492 N. W.W. White Road, San Antonio, Tex. 78219. From the bulk sand container  300 , sand travels on a conveyer in the bottom thereof to the blender (not shown) at the frac site. 
         [0085]    Also, one modified cargo container, while stacked, can feed directly into another modified cargo container located there below. For example, in  FIG. 5 , modified cargo container  302  receives sand  306  from auger  303  through upper hatch  305 . Modified cargo containers  302  may feed sand  306  or any other granular proppant therein through lower hatch  308  in modified cargo container  302  and upper hatch  310  into modified cargo container  304  located immediately there below. This was accomplished by opening the lower sliding door  312  in modified cargo container  302  and the upper sliding door  314  in modified cargo container  304 . The sand  306  may either be transferred from the modified cargo container  302  into the modified cargo container  304  located immediately there below or delivered to a conveyer (not shown) located below the lower modified cargo container  304  by opening the lower sliding door  316  in the modified cargo container  304  to open lower hatch  318 . The sand flowing from the lower hatch  318  may be dumped on a belt (not shown), which will feed the sand to the blenders (not shown). In the blenders, the sand is mixed with the fracing fluid that will contain other chemicals therein prior to injection under pressure into the well being fraced at the frac site. 
         [0086]    However, rather than being located over a belt,  FIG. 5  illustrates the loading of multiple modified cargo containers  302 ,  304 ,  309  and  311  while sitting on rail car  313 . 
         [0087]    Referring to  FIGS. 6, 7 and 8  in combination, a flatbed trailer  320  is used to create a super T-belt design. A control tower  322  is located on the back end of the flatbed trailer  320 . In  FIG. 6 , the control tower  322  is laying down on the flatbed trailer  320  for movement to the frac site. Also, in  FIG. 6 , flat racks  324  are being transported to the frac site. Flat racks  324  may be used to the set the modified cargo containers thereon rather than setting them directly on the ground. 
         [0088]    Upon arriving at the frac site with the flatbed trailer  320  as shown in  FIG. 6 , the control tower  322  is deployed as shown in  FIG. 7  and the flat racks  324  removed. Also, the wheels  326  and axles (not shown) can be removed so that the flatbed trailer  320  sets directly on the ground as is illustrated in  FIG. 7 . 
         [0089]    Also as illustrated in  FIG. 7 , modified cargo containers  328  are stacked one on top of the other with the lowermost modified cargo containers fitting directly on a belt system  330  located there below. 
         [0090]    In  FIG. 7 , only the outside view of the belt system  330  is shown. However, fracing sand will be delivered through the dispensing end  332  of the belt system  330  to deliver the fracing sand to the blender. Hydraulic connections  334  may be used to control the operation of any of the sliding doors as previously described herein above. The hydraulic connections  334  may be controlled locally or remotely. 
         [0091]    In the alternative, the above trailer  320  can be disconnected with front legs  336  being deployed. Thereafter, the modified cargo containers  338  may be simply stored on the flatbed trailer  320 . 
         [0092]    By use of the modified cargo containers as described herein above, the number of times the fracing proppant, such as sand, is handled is greatly reduced. The reduction in the number of times the fracing proppant is handled greatly reduces the cost of completion of a single hydrocarbon well.