Patent Publication Number: US-6213227-B1

Title: Oil and gas well cuttings disposal system with continous vacuum operation for sequentially filling disposal tanks

Description:
This is a continuation-in-part of U.S. patent application Ser. No. 08/950,296, filed Oct. 14, 1997, now U.S. Pat. No. 6,009,959 which is a continuation-in-part of U.S. patent application Ser. No. 08/813,462, filed Mar. 10, 1997 (now U.S. Pat. No. 5,839,521), which is a continuation-in-part of U.S. patent application Ser. No. 08/729,872, filed Oct. 15, 1996 (now U.S. Pat. No. 5,842,529), which is a continuation-in-part of U.S. patent application Ser. No. 08/416,181, filed Apr. 4, 1995 (now U.S. Pat. No. 5,564,509), which is a continuation-in-part of U.S. patent application Ser. No. 08/197,727, filed Feb. 17, 1994 (now U.S. Pat. No. 5,402,857), each of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     In the drilling of oil and gas wells, a drill bit is used to dig thousands of feet into the crust of the earth. Oilrigs typically employ a derrick that extends above the well drilling platform and that can support joints of drill pipe connected end to end during the drilling operation. As the drill bit is pushed into the earth, additional pipe joints are added to the “string” of drill pipes. The drill string pipes each have an internal, longitudinally extending bore for carrying fluid drilling mud from the well drilling platform to a drill bit supported at the lower or distal end of the drill string. 
     Drilling mud lubricates the drill bit and carries away well cuttings generated by the drill bit. The cuttings are carried in a return flow stream of drilling mud through the well annulus and back to the well drilling platform at the earth surface. When the drilling mud reaches the surface, it is contaminated with small pieces of shale and rock known as well cuttings or drill cuttings. 
     In the past, well cuttings have been separated from the reusable drilling mud with commercially available separators that are known as “shale shakers.” Some shale shakers are designed to filter coarse material from the drilling mud while other shale shakers are designed to remove finer particles from the well drilling mud. After separating well cuttings, the drilling mud is returned to a mud pit where it can be supplemented and/or treated prior to transmission back into the well bore via the drill string to repeat the process. 
     The disposal of the separated shale and cuttings is a complex environmental problem. Drill cuttings contain not only the mud product, which would contaminate the surrounding environment, but also can contain environmentally hazardous oil, especially when drilling in a marine environment. 
     In the Gulf of Mexico for example, there are hundreds of drilling platforms that drill for oil and gas by drilling into the sea floor. These drilling platforms can be in many hundreds of feet of water. In such a marine environment, the water is typically crystal clear and filled with marine life that cannot tolerate the disposal of drill cuttings waste containing a combination of shale, drilling mud, and oil. Therefore, there is a need for a simple, yet workable solution to the problem of disposing of oil and gas well cuttings in offshore marine and other fragile environments. Traditional methods of cuttings disposal have been dumping, bucket transport, cumbersome conveyor belts, and washing techniques that require large amounts of water. Adding water creates additional problems of added volume and transport problems. Installing conveyors requires major modification to the rig area and involves many installation hours and very high cost. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved method and apparatus for removing drill cuttings from an oil and gas well drilling platform that uses a drill bit supported with an elongated, hollow drill string. Well drilling fluid (typically referred to as drilling mud) travels through the drill string to the drill bit during a digging of a well bore. 
     The method first includes the step of separating well drilling fluid from the drill cuttings on the drilling platform so that the drilling fluid can be recycled into the well bore during drilling operations. The drill cuttings fall via gravity from solid separators (e.g. shale shakers) into a materials trough. At the materials trough, cuttings are suctioned with an elongated suction line having an intake portion positioned in the materials trough to intake well cuttings as they accumulate. 
     Each suction line has an intake end that is positioned to suction cuttings from the materials trough. Each suction line communicates with a cuttings collection tank. A third tank (i.e. a vacuum tank) is positioned in between the vacuum means and the two collection tanks that communicate with the two materials collection lines. The third tank has dual inlets, each receiving a flow line from a respective collection tank. Each inlet is valved so that either one of the collection tanks can be shut off from the vacuum means. In this fashion, one collection tank can be filled at a time. The two collection tanks can be sequentially filled without having to shut the vacuum source down. 
     The drill cuttings are transmitted via a selected one of the suction lines to a selected one of the collection tanks. 
     A vacuum is formed within the selected collection tank interior using a vacuum means that is in fluid communication with the tank interior. 
     Liquids (drilling mud residue) and solids (well cuttings) are separated from the vacuum line at the selected collection tank before the liquids and solids can enter the vacuum means. 
     The vacuum means is powered with an electric motor drive to reach a vacuum of between about 16 and 25 inches of mercury. Each vacuum line is sized to generate speeds of between about 100 and 300 feet per second. 
     In one embodiment, two hoppers are positioned one above the other so that cuttings can be added to the first upper hopper via the suction line that communicates with the trough and then fed by gravity to the second lower hopper. A valving arrangement maintains vacuum within the interior chamber of at least one hopper at all times. The lower hopper discharges onto a shaker where drilling fluids are separated from drill cuttings. The separated drilling fluids are then saved in a storage tank for recycling into the well bore during drilling operations. The separated drill cuttings are then discharged into a holding tank for storage and transportation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals, and wherein: 
     FIG. 1 is a schematic view of the first embodiment of the apparatus of the present invention; 
     FIG. 2 is a schematic view of a second embodiment of the apparatus of the present invention; 
     FIG. 3 is a schematic view of a third embodiment of the apparatus of the present invention; 
     FIG. 4 is a schematic view of the third embodiment of the apparatus of the present invention illustrating the use of a hopper tank in combination with the slurry unit; 
     FIG. 5 is a schematic view of a fourth embodiment of the apparatus of the present invention; 
     FIG. 6 is a fragmentary perspective view of the fourth embodiment of the apparatus of the present invention illustrating the rig vacuum tank portion; 
     FIG. 7 is a fragmentary side, elevational view of the fourth embodiment of the apparatus of the present invention illustrating the rig vacuum tank portion; 
     FIG. 8 is a top fragmentary view of the fourth embodiment of the apparatus of the present invention illustrating the rig vacuum tank portion; 
     FIG. 9 is a perspective view of a fifth embodiment of the apparatus of the present invention; 
     FIGS. 10-12 are fragmentary elevational views of the fifth embodiment of the apparatus of the present invention showing the hoppers and valving member portions; 
     FIG. 13 is a top fragmentary view of the fifth embodiment of the apparatus of the present invention showing the chute movement when filling the two holding tanks; 
     FIG. 14 is perspective view of a sixth embodiment of the apparatus of the present invention; and 
     FIGS. 15-17 are fragmentary elevational views of the sixth embodiment of the apparatus of the present invention showing the hoppers and valving member portions. 
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     The present invention relates to the disposal of oil and gas well cuttings generated during the drilling of an oil and gas well using a drill bit connected to an elongated drill string comprised of a number of pipe sections connected together, wherein a fluid drilling mud carries well cuttings away from the drill bit and upwardly to the well head through a well annulus and to a solids removal area at the well head for separating well cuttings from the drilling mud. Even more particularly, the present invention relates to an improved well cuttings disposal system that collects oil and gas well cuttings in a transportable tank that is subjected to a vacuum and in which collection chambers alternatively and sequentially receive cuttings and separate drilling mud from the cuttings for recycling, and wherein a continuous feed hopper and valve arrangement enables continuous vacuum operation. 
     In FIG. 1, there can be seen a first embodiment of the well cuttings disposal system  10  of the present invention. Well cuttings disposal system  10  is used in combination with a materials trough that collects solids falling via gravity from a plurality of solids separator units. Materials troughs per se are known in the art, typically as a catch basin for cuttings. The materials trough  11  defines an area that is a receptacle for drill cuttings containing some residual drilling mud. The cuttings have been collected from the well bore after the drilling mud has been transmitted through the drill string to the drill bit and then back to the surface via the well annulus. 
     At the material trough, there are a plurality of coarse shakers  12 ,  13  and a plurality of fine shakers  14 ,  15 . The shakers  12 ,  13 , and  14 ,  15  are commercially available. Coarse shakers  12 ,  13  are manufactured under and sold under the mark “BRANDT” and fine shakers are sold under the mark “DERRICK.” Shakers  12 - 15  channel away the desirable drilling mud to a mud pit. The well cuttings fall via gravity into trough  11 . It is known in the prior art to channel away drilling mud that is to be recycled, and to allow well cuttings to fall from shale shakers via gravity into a receptacle. Such as been the case on oil and gas well drilling rigs for many years. 
     Interior  16  of trough  11  catches cuttings that have fallen from shakers  12 ,  15 . The trough  11  thus defines an interior  16  having a plurality of inclined walls  17 ,  18  that communicate with a trough bottom  19 . Walls  17 ,  18  can be Teflon covered to enhance travel of material to bottom  19 . 
     Trough bottom  19  includes a discharge opening  20  that communicates with discharge conduit  21 . The opening  20  is typically sealed during operation with a closure plate (not shown). 
     A first suction line  22  is positioned to communicate with the interior  16  portion of trough  11 . First suction line  22  thus provides an inlet  23  end portion and an opposite end portion  38  that communicates with collection tank  24 . Tank  24  collects solid material and some liquid (e.g., residual drilling mud on the cuttings) as will be described more fully. 
     Collection tank  24  has a bottom  25 , a plurality of generally rectangular sidewalls  27 , and a generally rectangular top  28 . Forklift sockets  26  allow tank  24  to be lifted and transported about the rig floor and to a position adjacent a crane or other lifting device. Openings  32 ,  33  in the top of tank  24  are sealable using hatches  34 ,  35  respectively. 
     A plurality of lifting eyes  29 ,  30 , and  31  are provided including eyes  29 ,  30  on the top of tank  24  and lifting eye  31  on the side thereof near bottom  25 . 
     The lifting eyes  29  and  30  are horizontally positioned at end portions of the tank top  28 . This allows the tank to be lifted with a crane, spreader bar, or other lifting means for transferal between a marine vessel and the drilling rig platform. In FIG. 1, the tank  24  is in such a generally horizontal position that is the orientation during use and during transfer between the rig platform and a remote location on shore. 
     The lifting eyes  30 ,  31  are used for emptying the tank  24  after it is filled with cuttings. When the tank is to be emptied, a spreader bar and a plurality of lifting lines are used for attachment to lifting eyes  30 ,  31 . This supports the tank in a position that places lifting eye  29  and lifting eye  30  in a vertical line. In this position, the hatch  34  is removed so that the cuttings can be discharged via gravity from opening  32  and into a disposal site. 
     During a suctioning of well cuttings from materials trough  11 , the suction line  22  intakes cuttings at inlet  23 . These cuttings travel via line  22  to outlet  38 , which communicates with coupling  36  of hatch  35 . Flow takes place from inlet  23  to outlet  38  because a vacuum is formed within the hollow interior of tank  24  after hatches  34 ,  35  are sealed. The vacuum is produced by using second suction line  40  that communicates via separators  43 ,  45  with third suction line  51  and vacuum means  57 . 
     Second suction line  40  connects at discharge  39  to coupling  37  of hatch  35 . The opposite end of suction line  40  connects at end portion  41  via coupling  42  to fine separator  43 . A second fine separator  45  is connected to separator  43  at spool piece  44 . The two separators  43  and  45  are housed on a structural separator skid  46  that includes lifting eyes  47 ,  48  and fork lift sockets  49  for transporting the skid  46  in a manner similar to the transport of tank  24  as previously described. 
     Third suction line  51  connects to effluent line  50  that is the discharge line from separator  45 . End portion  52  of third suction line  51  connects to effluent line  50  at a flanged, removable connection, for example. The three suction lines  22 ,  40 ,  51  are preferably between 3 and 6 inches in internal diameter, and are coupled with vacuum means  57  generating about 300-1500 cubic feet per minute of air flow, to generate desired flow velocities of about 100-300 feet per second that move the shale cuttings through suction line  22 . The suction lines are preferably flexible hoses of oil resistant PVC or can be Teflon coated rubber. Quick connect fittings are used to connect each suction line at its ends. 
     End portion  53  of third section line  51  also connects via a flanged coupling, for example, to vacuum means  57 . Vacuum means  57  and its motor drive  58  are contained on power skid  54 . Power skid  54  also includes a control box  59  for activating and deactivating the motor drive  58  and vacuum means  57 . The power skid  54  provides a plurality of lifting eyes  55 ,  56  to allow the power skid  54  to be transported from a work boat or the like to a well drilling platform using a lifting harness and crane that are typically found on such rigs. 
     Each unit, including tank  24 , separator skid  46 , and power skid  54 , can be lifted from a work boat or the like using a crane and transported to the rig platform deck. 
     In FIG. 2, a second embodiment of the apparatus of the present invention is disclosed, designated generally by the numeral  60 . In FIG. 2, the tank  24  is similarly constructed to that of the preferred embodiment of FIG.  1 . However, in FIG. 2, the well cuttings disposal system  60  includes a support  61  that supports a screw conveyor  62  and its associated trough  63 . The trough  63  and screw conveyor  62  are sealed at opening  70  in trough  63  using hatch  71 . Trough  63  is positioned at an intake end portion of screw conveyor while the opposite end portion of screw conveyor  62  provides a discharged end portion  64  that communicates with discharge shoot  69 . Chute  69  empties into opening  32  when hatch  34  is open during use, as shown in FIG.  2 . 
     The screw conveyor  62  is driven by motor drive  65  that can include a reduction gearbox  66  and a drive belt  67 . Arrow  68  in FIG. 2 shows the flow path of coarse cuttings that are discharged via first suction lines  22  into opening  70  and trough  63 . The sidewall and bottom  74  of trough  63  communicate and form a seal with screw conveyor outer wall  75  so that when a vacuum is applied using second suction line  40 , cuttings can be suctioned from trough  11  at intake  23  as with the preferred embodiment. The conveyor  62  forcibly pushes the drill cuttings toward discharge end  64 . A spring-activated door  76  is placed in chute  69 . When material backs up above door  76 , the door quickly opens under the weight of cuttings in chute  69 . Once the cuttings pass door  76 , the door shuts to maintain the vacuum inside trough  73  and screw conveyor  62 , thus enabling continuous vacuuming. 
     In FIG. 3 there can be seen a third embodiment of the apparatus of the present invention designated generally by the numeral  77 . Well disposal cutting system  77  substitutes a slurry unit  78  for collection tank  24  of FIG.  1 . Slurry unit  78  has a liftable base frame  79  of welded steel, for example. Upon the frame  79  are positioned a pair of vessels  80 ,  81 . Each vessel  80 ,  81  has a top into which well cuttings can be suctioned in a manner similar to the way well cuttings are suctioned into collection tank  24  with the embodiment of FIG.  1 . 
     The vessel tops  82 ,  83  respectively can be provided with openings for connecting the flow lines  22 ,  40  as with the embodiments of FIGS. 1 and 2. The slurry unit  78  provides pumps  84 ,  85  with impellers (e.g., Mission Magnum fluid centrifugal pump with 75 hp electric motor—5″ discharge, 6″ suction) for continuously breaking up the cuttings until they form a slurry with a liquid such as water. Pumps  84 ,  85  have suction flow lines  86 ,  87  respectively and discharge lines  88 ,  89  respectively. The discharge lines  88 ,  89  communicate with the upper end portion of each of the vessels  80 ,  81  respectively. Likewise, the suction lines  86 ,  87  communicate with the lower end portion of each of the vessels  80 ,  81  respectively. 
     Using the method and apparatus of FIG. 3, a desired volume of cuttings can be suctioned into either one or both of the vessels  80 ,  81 . The pumps  84 ,  85  are equipped with impellers that can chop up the cuttings into even finer pieces. For example, the pump impellers can have carbide tips that are effective in chopping up and pulverizing the cuttings until a slurry is formed. Each pump  84 ,  85  continuously recirculates the slurry of cuttings and water between the pump  84 ,  85  and its respective vessel  80 ,  81  until a thick viscous slurry is created. A triplex pump (e.g., Gardner Denver) and piping (not shown) can then be used for transmitting the slurried cuttings from the respective vessels  80 ,  81  downhole into the well annulus, usually between 2000 and 5000 feet, to a porous zone such as a sand zone. In this fashion, the cuttings are disposed of by deep well disposal at the drill site rather than transporting the cuttings to a remote site such as on shore in the case of a marine based platform. 
     In FIG. 4, a hopper tank  90  is shown in combination with the slurry unit  78 . Hopper  90  is an optional unit that can be used to receive cuttings from first suction line  22  and to collect the cuttings for batch discharge into slurry unit  78  at intervals. As with the embodiment of FIG. 1, the hopper tank  90  provides a rectangular or circular lid  93  with openings  94 ,  95  that communicate with vacuum lines  22  and  40  respectively. 
     Hopper tank  90  is preferably supported with a structural liftable frame  91 . The tank  90  has a conical wall  92 . The upper end portion of tank  90  provides the circular lid  93  while the lower end portion of tank  90  has a discharge outlet  96  controlled by valve  98 . Air vibrators  97  can be attached to the conical wall  92  for insuring a complete and smooth discharge of cuttings from within the interior of the hollow hopper tank  90 . 
     In FIGS. 5-8, the fourth embodiment of the apparatus of the present invention is designated generally by numeral  133 . Well cuttings disposal system  133  employs two suction lines  134 ,  135  in the embodiment of FIGS. 5-8. The two suction lines  134 ,  135  each provide respective inlet portions  136 ,  137  for intaking well cuttings and associated material that fall into trough  11 . Trough  11  would be constructed in accordance with the description of FIG.  1 . Thus, trough  11  can include material separation equipment such as coarse or fine shakers that channel away desirable drilling mud to a mud pit and allow well cuttings fall via gravity, for example, into trough  11 . 
     As with the embodiment of FIG. 1, it is known in prior art to channel away drilling mud that is to be recycled and to allow well cuttings to fall from shale shakers and like separating equipment via gravity into the interior of a receptacle such as trough  11 . 
     In FIG. 5, the inlet portions  136 ,  137  are positioned in the interior of trough  11  to enable either inlet portion  136  or  137  to vacuum cuttings. The embodiment of FIG. 1 uses a single suction line to remove cuttings from the interior of trough  11 , but in FIG. 5, two suction lines are used, each with its own collection tank  138  or  139 . 
     In FIG. 5, each collection tank  138 ,  139  receives well cuttings suctioned from suction lines  134 ,  135  respectively. Each collection tank  138 ,  139  provides fittings for forming connections with end portions of the primary suction lines  134 ,  135  and with end portions of secondary suction lines  148 ,  149 . 
     An end portion  145  of suction line  134  forms a connection at inlet fitting  141 . Similarly, inlet fitting  142  forms a connection with end portion  146  of primary suction line  135 . Secondary suction line  148  forms a connection at its end portion  144  with outlet fitting  140 . Similarly, secondary suction line  149  forms a connection at its end portion  147  with outlet fitting  143 . The secondary suction lines  148 ,  149  form connections at their respective end portions  153 ,  154  with inlet fittings  151 ,  152  of rig vacuum tank  150 . 
     In FIGS. 5-8, rig vacuum tank  150  provides an outlet fitting  161  for connection of tertiary suction line  160 . Line  160  conveys air to vacuum skid  162  as shown by the arrow  159  in FIG.  5 . The vacuum skid  162  is constructed in accordance with the embodiment of FIGS. 1-4, including a vacuum means that is powered with an electric motor to reach a vacuum of between 16 and 25 inches of mercury. In FIG. 1, power skid unit  54  includes a control box  59  for activating and deactivating the motor drive  58  and vacuum means  57 . Vacuum skid  162  can thus be constructed in accordance with power skid unit  54  in the embodiment of FIG.  1 . 
     During use, the vacuum skid  162  generates a vacuum that communicates with flow line  160  and thus the interior of tank  150 . The presence of a vacuum in tank  150  also produces a vacuum in the primary suction lines  134 ,  135 , collection tanks  138 ,  139 , and in the secondary vacuum lines  148 ,  149 . This vacuum produces suction at inlets  136 ,  137  for transmitting cuttings and like material contained in trough  11  to collection tanks  138 ,  139  via primary suction lines  134 ,  135  respectively. This travel of well cuttings and like material from trough  11  to collection tanks  138  and  139  is indicated by the arrows  155 ,  156  in FIG.  5 . 
     Material traveling from trough  11  to collection tank  138  travels in primary suction line  134  and enters collection tank  138  at inlet fitting  141 . The collection tank  138  communicates with its outlet fitting  140  with secondary suction line  148  and inlet fitting  151  of vacuum tank  150 . When tank  138  fills, some material may flow in the direction of arrow  157  from tank  138  into vacuum tank  150 . However, the vacuum tank  150  has a level sensor  172  that shuts off vacuum skid  162  should the level of material in tank  150  reach the sensor  172  which is positioned at a level just below inlets  151 ,  152 . In this fashion, neither liquid nor solid material can reach vacuum skid  162 . 
     In practice, the collection tanks  138 ,  139  are filled in an alternating, sequential fashion. This is made possible by valves  151 A,  152 A that are placed at fittings  151 ,  152  respectively. The operator simply closes the valve at fitting  152  when the valve at  151  is open and tank  138  is being filled. This closure of valve  152 A shuts off any vacuum from secondary flow line  149  and primary flow line  135  to tank  139 . Thus, tank  138  preliminarily fills until the valve  152 A at fitting  152  is opened and the valve  151 A at fitting  151  is closed. 
     In this manner, an operator can continuously suction cuttings from trough  11 . This is important when well drilling activity is at a peak and the trough  11  is receiving a continuous flow of cuttings from shale shakers and like equipment. By alternating the vacuum to tank  138  or tank  139 , the well cuttings disposal system  133  of the present invention can function continuously. When a tank  138  or  139  is filled, suctioning switches to the other tank so that the filled tank  138  or  139  can be removed and a new tank can be put in its place. If fluid or other material in tank  150  reaches sensor  172 , the vacuum skid  162  can be automatically shut off. However, the sensor  172  can also operate a diaphragm discharge pump  174  for emptying the contents of vacuum tank  150 . 
     FIGS. 6-8 show more particularly the construction of rig vacuum tank  150 . Tank  150  has a base  164  with a pair of sockets  165  for receiving forklift tines that can lift and transport tank  150 . The tank  150  has a cylindrical wall  166  with a hollow tank interior  167 . Screen  168  is placed on the inside  167  of tank  150  and functions to prevent debris from getting into diaphragm discharge pump  174 . Tank  150  has a removable lid  169  that carries an inspection hatch  170  and a separator  173 . The entire lid  169  is removable for easy cleaning of tank  150  should such cleaning be required. 
     Separator  173  removes any fluids in the air stream that flows through lines  160  to vacuum skid  162 . Deflector plate  171  is positioned on the inside  167  of tank  150  for deflecting material that enters tank interior  167  via inlet fittings  151 ,  152 . Discharge pump  174  communicates with tank interior via flow line  175 . 
     FIGS. 9-13 show a fifth embodiment of the apparatus of the present invention designated generally by the numeral  200 . The embodiment of the FIGS. 9 and 10 is similar in overall layout to the embodiment of FIG.  1 . The difference is that instead of the collection tank  24  of FIG. 1, the first suction line  22  communicates with an upper hopper  201  so that cuttings flowing in the first suction line  22  enter hopper  201  at inlet  203 . Arrow  202  in FIG. 9 indicates the flow direction of the cuttings. Upper hopper  201  is also positioned above a lower hopper  205 . Thus, the embodiment of FIGS. 9 and 10 represents a double hopper  201 ,  205  arrangement that replaces the tank  24  of FIG.  1 . The upper hopper interior chamber  204  is subjected to a vacuum applied by vacuum means  57  and second suction line  40  and arrow  206  in FIG. 9 indicates the direction of the air flow. Outlet fitting  207  can be used to form a connection between upper hopper  201  and second suction line  40  as shown in FIG.  9 . 
     As shown in FIGS. 9 and 10, a valving arrangement is used to control the flow of cuttings between upper hopper  201  and lower hopper  205 . Similarly, this valving arrangement controls the flow of cuttings from the lower hopper  205  to discharge conduit  208  and then to holding tanks  209 ,  210 . The holding or collection tanks  209 ,  210  can be constructed as shown in FIGS. 1 and 2 with respect to tank  24 . During use, multiple holding tanks  209 ,  210  can be used for collecting cuttings that are discharged by conduit  209  from lower hopper  205 . A user controls the valve members  211 ,  212  using a control panel  213  and pneumatic or hydraulic controllers (commercially available) to direct flow from holding tank  209  that has become filled to holding tank  210  that is empty, Valves  211 ,  212  can be pneumatic actuated flex-gate knife valves, for example, manufactured by Red Valve Company, Inc. of Pittsburgh, Pa., USA. 
     As will be described more fully below, the upper valve  211  is initially closed so that suction lines  22 ,  40  begin filling upper hopper  201  (FIG.  9 ). As the interior chamber  204  of upper hopper  201  becomes almost filled, valve operator  216  opens valve  211  while lower valve  212  remains closed (FIG.  10 ). In FIG. 10, both hoppers  201  and  205  are subjected to a vacuum. However, the vacuum does not prevent cuttings  215  collected in upper hopper interior chamber  204  from falling through upper valve  211  and into the interior chamber  214  of lower hopper  205 . This transfer of cuttings from upper hopper  201  to lower hopper  205  is shown in FIG.  10 . Closure of lower valve  212  maintains the vacuum on interior chambers  204  and  214  of both hoppers  201  and  205 . Otherwise, if valve  212  were opened the vacuum would be lost. 
     Holding tank  209  cannot receive cuttings  215  when lower valve  212  is closed as shown in FIG.  10 . Once the contents of upper hopper  201  have been emptied to the lower hopper  205 , valve operator  216  closes valve  211  (FIG.  11 ). With the vacuum preserved within interior chamber  204  of hopper  201  (FIG.  11 ), valve operator  218  then is opens valve  212  (FIG.  12 ). Opening valve  212  discharges the contents (cuttings  215 ) within the interior chamber  214  of lower hopper  205  into conduit chute  208  and then into the selected cuttings disposal tank  209 ,  210  (FIG.  12 ). Conduit chute  208  can be rotated at rotary coupling  219  from one holding tank  209  to the other holding tank  210  and then back to tank  209  as each tank  209 ,  210  is filled, emptied, and then placed back under conduit chute  208  as shown by arrow  220  in FIG.  13 . 
     FIGS. 14-17 show a sixth embodiment of the apparatus of the present invention designated generally by the numeral  300 . The embodiment of FIGS. 14 and 15 is similar in overall layout to the embodiment of FIG.  1 . The difference is that instead of the collection tank  24  of FIG. 1, the first suction line  22  communicates with an upper hopper  201  so that cuttings flowing in the first suction line  22  enter hopper  201  at inlet  203 . Arrow  202  in FIG. 14 indicates the flow direction of the cuttings. The upper hopper interior chamber  204  is subjected to a vacuum applied by vacuum means  57  and second suction line  40 . Arrow  206  in FIG. 9 indicates the direction of the air flow. Outlet fitting  207  can be used to form a connection between upper hopper  201  and second suction line  40  as shown in FIG.  14 . Upper hopper  201  is also positioned above a lower hopper  205 . Thus, the embodiment of FIGS. 9 and 10 represents a double hopper  201 ,  205  arrangement that replaces the tank  24  of FIG.  1 . 
     As shown in FIGS. 14 and 15, a valving arrangement is used to control the flow of cuttings between upper hopper  201  and lower hopper  205 . Similarly, this valving arrangement controls the flow of cuttings from the lower hopper  205  to a shaker  221  and then to cuttings storage tank  230 . The holding or collection tank  230  can be constructed as shown in FIGS. 1 and 2 with respect to tank  24 . A user controls valves  211 ,  212  using a control panel  213  and pneumatic or hydraulic controllers (commercially available) to direct flow of cuttings to shaker  221 . Valves  211 ,  212  can be pneumatic actuated flex-gate knife valves, for example, manufactured by Red Valve Company, Inc. of Pittsburgh, Pa., USA. 
     As will be described more fully below, the upper valve  211  is initially closed (FIG. 14) so that suction lines  22 ,  40  begin filling upper hopper  201  (FIG.  14 ). As the interior chamber  204  of upper hopper  201  becomes almost filled, valve operator  216  opens valve  211  while lower valve  212  remains closed (FIG.  15 ). In FIG. 15, both hoppers  201  and  205  are subjected to a vacuum. However, the vacuum does not prevent cuttings  215  collected in upper hopper  201  from falling through upper valve  211  and into the interior chamber  214  of lower hopper  205 . This transfer of cuttings from upper hopper  201  to lower hopper  205  is shown in FIG.  15 . Closure of lower valve  212  maintains the vacuum on the interior chambers  204  and  214  of both hoppers  201  and  205 . Otherwise, if valve  212  were opened the vacuum would be lost. 
     Shaker  221  cannot receive cuttings  215  when the lower valve  212  is closed as shown in FIG.  15 . Once the contents of upper hopper  201  have been emptied to the lower hopper  205 , valve operator  216  closes valve  211  (FIG.  16 ). With the vacuum preserved within interior chamber  204  of hopper  201 , valve operator  218  then opens valve  212  (FIG.  17 ). Opening valve  212  discharges the contents (cuttings  215 ) within the interior chamber  214  of lower hopper  205  onto a shaker  221  (FIG.  17 ). 
     Shaker  221  has a vibrating shaker screen  222  that separates the contents of lower hopper  205  into cuttings  215  and drilling fluids  237 . Drilling fluids  237  fall through vibrating shaker screen  222  into recycled drilling fluids trough  224  (FIG.  17 ). Drilling fluids  237  then drain from recycled drilling fluids trough  224  through drilling fluids discharge openings  226  into a drilling fluids storage tank  231 . Arrows  228  in FIG. 17 show the flow direction of drilling fluids  237  as they drain from recycled drilling fluids trough  224 . 
     Cuttinos  215  travel across the vibrating shaker screen  222  in the direction of arrow  225 . Cuttings  215  then discharge into holding tank  230  for storage and transportation. Arrow  217  indicates the discharge direction of drill cuttings  215  as they are discharged into holding tank  230 . 
     From the drilling fluids storage tank  231 , drilling fluids pump  234  pumps drilling fluids  237  through a drilling fluids line  233  in the direction of arrow  232  (FIG.  17 ). Pump  234  then pumps drilling fluids  237  through drilling fluids discharge line  236  in the direction of arrow  235 . Drilling fluids  237  are then recycled into the well bore during drilling operations. The following table lists the parts numbers and parts descriptions as used herein and in the drawings attached hereto. 
     
       
         
           
               
            
               
                   
               
               
                 PARTS LIST 
               
            
           
           
               
               
            
               
                 Part Number 
                 Description 
               
               
                   
               
            
           
           
               
               
            
               
                 10 
                 well cuttings disposal system 
               
               
                 11 
                 materials trough 
               
               
                 12 
                 coarse shaker 
               
               
                 13 
                 coarse shaker 
               
               
                 14 
                 fine shaker 
               
               
                 15 
                 fine shaker 
               
               
                 16 
                 reservoir 
               
               
                 17 
                 inclined wall 
               
               
                 18 
                 inclined wall 
               
               
                 19 
                 trough bottom 
               
               
                 20 
                 discharge opening 
               
               
                 21 
                 conduit 
               
               
                 22 
                 first suction line 
               
               
                 23 
                 inlet 
               
               
                 24 
                 collection tank 
               
               
                 25 
                 bottom 
               
               
                 26 
                 fork lift socket 
               
               
                 27 
                 side wall 
               
               
                 28 
                 top 
               
               
                 29 
                 lifting eye 
               
               
                 30 
                 lifting eye 
               
               
                 31 
                 lifting eye 
               
               
                 32 
                 opening 
               
               
                 33 
                 opening 
               
               
                 34 
                 hatch 
               
               
                 35 
                 hatch 
               
               
                 36 
                 coupling 
               
               
                 37 
                 coupling 
               
               
                 38 
                 outlet 
               
               
                 39 
                 discharge 
               
               
                 40 
                 second suction line 
               
               
                 41 
                 end 
               
               
                 42 
                 coupling 
               
               
                 43 
                 separator 
               
               
                 44 
                 spool piece 
               
               
                 45 
                 separator 
               
               
                 46 
                 separator skid 
               
               
                 47 
                 lifting eye 
               
               
                 48 
                 lifting eye 
               
               
                 49 
                 fork lift socket 
               
               
                 50 
                 effluent line 
               
               
                 51 
                 third suction line 
               
               
                 52 
                 end 
               
               
                 53 
                 end 
               
               
                 54 
                 power skid 
               
               
                 55 
                 lifting eye 
               
               
                 56 
                 lifting eye 
               
               
                 57 
                 vacuum means 
               
               
                 58 
                 motor drive 
               
               
                 59 
                 control box 
               
               
                 60 
                 well cuttings disposal system 
               
               
                 61 
                 support 
               
               
                 62 
                 screw conveyor 
               
               
                 63 
                 trough 
               
               
                 64 
                 discharge end portion 
               
               
                 65 
                 motor drive 
               
               
                 66 
                 gearbox 
               
               
                 67 
                 drive belt 
               
               
                 68 
                 arrow 
               
               
                 69 
                 discharge chute 
               
               
                 70 
                 opening 
               
               
                 71 
                 hatch 
               
               
                 72 
                 top 
               
               
                 73 
                 side wall 
               
               
                 74 
                 bottom 
               
               
                 75 
                 screw conveyor outer wall 
               
               
                 76 
                 spring loaded door 
               
               
                 77 
                 well cuttings disposal unit 
               
               
                 78 
                 slurry unit 
               
               
                 79 
                 frame 
               
               
                 80 
                 vessel 
               
               
                 81 
                 vessel 
               
               
                 82 
                 top 
               
               
                 83 
                 top 
               
               
                 84 
                 pump 
               
               
                 85 
                 pump 
               
               
                 86 
                 flow line 
               
               
                 87 
                 flow line 
               
               
                 88 
                 flow line 
               
               
                 89 
                 flow line 
               
               
                 90 
                 hopper tank 
               
               
                 91 
                 liftable frame 
               
               
                 92 
                 conical wall 
               
               
                 93 
                 circular lid 
               
               
                 94 
                 opening 
               
               
                 95 
                 opening 
               
               
                 96 
                 outlet 
               
               
                 97 
                 air vibrator 
               
               
                 98 
                 valve 
               
               
                 133 
                 well cuttings disposal system 
               
               
                 134 
                 primary suction line 
               
               
                 135 
                 primary suction line 
               
               
                 136 
                 inlet portion 
               
               
                 137 
                 inlet portion 
               
               
                 138 
                 collection tank 
               
               
                 139 
                 collection tank 
               
               
                 140 
                 outlet fitting 
               
               
                 141 
                 inlet fitting 
               
               
                 142 
                 inlet fitting 
               
               
                 143 
                 outlet fitting 
               
               
                 144 
                 end portion 
               
               
                 145 
                 end portion 
               
               
                 146 
                 end portion 
               
               
                 147 
                 end portion 
               
               
                 148 
                 secondary suction line 
               
               
                 149 
                 secondary suction line 
               
               
                 150 
                 rig vacuum tank 
               
               
                 151 
                 inlet 
               
               
                 151A 
                 valve 
               
               
                 152 
                 inlet 
               
               
                 152A 
                 valve 
               
               
                 153 
                 end portion 
               
               
                 154 
                 end portion 
               
               
                 155 
                 arrow 
               
               
                 156 
                 arrow 
               
               
                 157 
                 arrow 
               
               
                 158 
                 arrow 
               
               
                 159 
                 arrow 
               
               
                 160 
                 flow line 
               
               
                 161 
                 outlet fitting 
               
               
                 162 
                 vacuum skid 
               
               
                 163 
                 inlet fitting 
               
               
                 164 
                 base 
               
               
                 165 
                 socket 
               
               
                 166 
                 cylindrical wall 
               
               
                 167 
                 tank interior 
               
               
                 168 
                 screen 
               
               
                 169 
                 lid 
               
               
                 170 
                 inspection hatch 
               
               
                 171 
                 deflector plate 
               
               
                 172 
                 fluid level sensor 
               
               
                 173 
                 separator 
               
               
                 174 
                 discharge pump 
               
               
                 175 
                 flow line 
               
               
                 176 
                 lifting eye 
               
               
                 200 
                 continuous feed well cuttings 
               
               
                   
                 disposal system 
               
               
                 201 
                 upper hopper 
               
               
                 202 
                 arrow 
               
               
                 203 
                 inlet fitting 
               
               
                 204 
                 interior chamber 
               
               
                 205 
                 lower hopper 
               
               
                 206 
                 arrow 
               
               
                 207 
                 outlet fitting 
               
               
                 208 
                 discharge conduit 
               
               
                 209 
                 holding tank 
               
               
                 210 
                 holding tank 
               
               
                 211 
                 valving member 
               
               
                 212 
                 valving member 
               
               
                 213 
                 control panel 
               
               
                 214 
                 interior chamber 
               
               
                 215 
                 cuttings 
               
               
                 216 
                 operator 
               
               
                 217 
                 arrow 
               
               
                 218 
                 operator 
               
               
                 219 
                 rotary coupling 
               
               
                 220 
                 arrow 
               
               
                 300 
                 continuous feed well cuttings 
               
               
                   
                 disposal system 
               
               
                 221 
                 drill cuttings shaker 
               
               
                 222 
                 vibrating shaker screen 
               
               
                 223 
                 arrow 
               
               
                 224 
                 recycled drilling fluids trough 
               
               
                 225 
                 drill cuttings discharge opening 
               
               
                 226 
                 drilling fluids discharge opening 
               
               
                 227 
                 arrow 
               
               
                 228 
                 arrow 
               
               
                 229 
                 cuttings storage tank opening 
               
               
                 230 
                 cuttings storage tank 
               
               
                 231 
                 drilling fluids storage tank 
               
               
                 232 
                 arrow 
               
               
                 233 
                 drilling fluids line 
               
               
                 234 
                 drilling fluids pump 
               
               
                 235 
                 arrow 
               
               
                 236 
                 drilling fluids discharge line 
               
               
                 237 
                 drilling fluids 
               
               
                   
               
            
           
         
       
     
     Because varying and different embodiments may be made within the scope of the inventive concept taught, and because modifications may be made in the embodiments detailed in accordance with the descriptive requirement of the law, it is to be understood that the disclosed details are to be interpreted as illustrative and not in a limiting sense.