Abstract:
A method of assembling a dual cylinder positive displacement drill cuttings pump is provided. The method includes providing a hopper including a front end, a generally open rear end with a generally barrel-shaped sidewall extending therebetween to provide a generally barrel-shaped hopper volume, and an inlet port extending through the barrel-shaped sidewall for delivering material into the generally barrel-shaped hopper volume. A rear hopper wall is provided that includes first and second pumping cylinder openings that are spaced apart from each other and at a common elevation from a bottom of the rear hopper wall. An installation configuration for the drill cuttings pump is identified, including a hopper infeed angle. Based upon the identified hopper infeed angle, the hopper is located relative to the rear hopper wall such that an axis of the inlet port of the hopper is positioned substantially at the hopper infeed angle. Then, the hopper is connected to the rear hopper wall.

Description:
TECHNICAL FIELD  
       [0001]     This application relates to a method for moving drill cuttings and a dual cylinder positive displacement pump configured to move drill cuttings or other material.  
       BACKGROUND  
       [0002]     Drill cuttings are the by-product of drilling operations, in particular drilling operations for gas and oil wells. The cuttings include mud, sediment, rock and water as well as various oils, drilling fluids and the like. Because of the hydrocarbon content of drill cuttings, as well as other pollutants, it is desirable to treat the drill cuttings before disposal. Regardless of the mode of treatment and disposal, transport of drill cuttings has presented significant logistical problems, particularly when dealing with drill cuttings produced by offshore oil &amp; gas drilling platforms. Due to the nature of the drill cuttings many types of pumps break down quickly and therefore cannot be used on a commercially viable basis for transporting drill cuttings.  
       SUMMARY  
       [0003]     In an aspect, a method of assembling a dual cylinder positive displacement pump is provided. The method includes providing a hopper including a front end, a generally open rear end with a generally barrel-shaped sidewall extending therebetween to provide a generally barrel-shaped hopper volume, and an inlet port extending through the generally barrel-shaped sidewall for delivering material into the generally barrel-shaped hopper volume. A rear hopper wall is provided that includes first and second pumping cylinder openings that are spaced apart from each other and at a common elevation from a bottom of the rear hopper wall. An installation configuration for the drill cuttings pump is identified, including a hopper infeed angle. Based upon the identified hopper infeed angle, the hopper is located relative to the rear hopper wall such that an axis of the inlet port of the hopper is positioned substantially at the hopper infeed angle. Then, the hopper is connected to the rear hopper wall.  
         [0004]     In another aspect, a dual cylinder positive displacement pump includes a hopper including a front end, a rear end, a generally barrel-shaped sidewall extending therebetween to provide a generally barrel-shaped hopper volume and an inlet port extending through the barrel-shaped sidewall for delivering material into the generally barrel-shaped hopper volume. A rear hopper wall includes first and second pumping cylinder openings that are spaced apart from each other, a front hopper wall with a discharge port that is angularly offset from the inlet port and a swing tube assembly within the hopper. A first pumping cylinder is in communication with the first pumping cylinder opening and a second pumping cylinder is in communication with the second cylinder opening.  
         [0005]     In another aspect, a method of installing a dual cylinder positive displacement drill cuttings pump for moving drill cuttings includes rotating a hopper including a body having a generally barrel-shaped opening extending therethrough and an inlet port in communication with the barrel-shaped opening. The barrel-shaped opening has an elongated, longitudinal axis with the inlet port rotating about the elongated, longitudinal axis to align the inlet port with a drill cuttings infeed conduit. Then, the hopper is connected to a rear hopper wall including first and second pumping cylinder openings that are spaced apart from each other and at a common elevation from a bottom of the rear hopper wall.  
         [0006]     Other advantages and features of the invention will be apparent from the following description of particular embodiments and from the claims. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0007]      FIG. 1  is a side section view of an embodiment of a pump for pumping drill cuttings;  
         [0008]      FIG. 2  is a top section view of the pump of  FIG. 1 ;  
         [0009]      FIGS. 3-5  are side and end views of an embodiment of a hopper for use with the pump of  FIG. 1 ;  
         [0010]      FIG. 6  is a top, partial section view of the hopper along line  6 - 6  of  FIG. 4 ;  
         [0011]      FIG. 7A  is a section view of the hopper along line  7 - 7  of  FIG. 6 ;  
         [0012]      FIG. 7B  is a section view of another embodiment of a hopper along line  7 - 7  of  FIG. 6 ;  
         [0013]      FIG. 8  is an end view of the hopper of  FIGS. 3-5  in a top dead center orientation;  
         [0014]      FIG. 9  is an end, section view of the hopper of  FIGS. 3-5  in a side orientation;  
         [0015]      FIG. 10  is an end, section view of the hopper of  FIGS. 3-5  in a bottom dead center orientation; and  
         [0016]      FIG. 11  illustrates an embodiment of a method of installing the pump of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0017]     Referring to  FIGS. 1 and 2 , a dual cylinder positive displacement pump  12  is hydraulically activated and includes a pumping portion  13  and a hopper portion  15 . The pumping portion  13  includes first and second hydraulic pumping cylinders  18  and  20  each having an associated piston  24 ,  25  positioned for reciprocating movement therein. The pistons  24  and  25  in cylinders  18  and  20  are reciprocated back and forth via a hydraulic control unit  28 , sometimes also referred to as a power pack, (shown diagrammatically). Two cylinder ports  32  and  34  in a rear plate  40  are in communication with cylinders  18  and  20  and are located at a common elevation above a bottom of the rear plate.  
         [0018]     The hopper portion  15  includes a hopper  14  having an outlet or discharge port  30  in a front wall  38  and an opening  62  ( FIG. 3 ) in communication with the cylinder ports  32  and  34 . An S-shaped swing tube  36  is used to communicate between the cylinder ports  32  and  34  and the discharge port  30 . The swing tube  36  has an outlet end pivotally connected in communication with the outlet port  30  and an inlet end movable between the cylinder ports  32  and  34  in rear plate  40 . The swing tube  36  may be supported by a swing tube bracket  42  inside the hopper  14 , where movement of the bracket  42  effects movement of the inlet end of the swing tube.  
         [0019]     The bracket  42 , in turn, is pivotally connected to the rear plate  40  on a shaft  44 . The bracket  42  is fixed to the shaft  44  allowing it to swing back and forth and at the same time direct the swing tube  36  back and forth to align with the ports  32  and  34 . On the rearward side of rear plate  40  a collar  46  is keyed to shaft  44 . The collar  46  is rotated back and forth mechanically (for example, by hydraulic pistons attached to the collar  46  by chevises). A single hydraulic piston, or some other mechanism, could also be used to effect movement of the swing tube  36 .  
         [0020]     The outlet port  30  may communicate with a discharge conduit that includes a diversion valve which can be triggered to redirect drill cuttings from the discharge conduit back along a feedback path, as may be defined by one or more conduits leading to a holding bin that communicates with hopper  14 . Selective use of the feedback path can maintain the consistency of the drill cuttings when the flow of the drill cuttings through the discharge conduit is terminated for one reason or another.  
         [0021]     Hopper  14  includes respective mount openings  80  and  82  for receiving an agitator assembly  84 . Agitator assembly  84  includes a driving motor  86  mounted exteriorly of the hopper  14  and associated with a primary agitator shaft  88  on which spaced apart agitator extensions  90  are provided. The opposite end of shaft  88  is associated with a bearing assembly  94  of the opening  80 . Thus, the agitator assembly extends between opposite sides of the hopper  14  to be supported above the swing tube  36  within the hopper. As reflected by the position of opening  82 , the agitator assembly  84  is positioned off-center of the front to rear length of the hopper  14 , and particularly toward the rear. Rotation of the shaft  88  of agitator assembly  84  causes the agitator extensions  90  to work drill cuttings within the hopper  14 .  
         [0022]     Referring now to  FIGS. 3-6 , hopper  14  is shown in isolation and unconnected to the pumping portion  13  (e.g., prior to installation). Hopper  14  includes a body  56  having a round bore  58  therein ( FIG. 6 ), which, in the illustrated embodiment, forms a generally barrel-shaped volume. In some embodiments, round bore  58  is cylindrical having an elongated, longitudinal axis  60  extending therethrough. Opening  62  is in communication with the round bore  58  and is disposed at a rear end  64  of the hopper  14 . Extending outwardly (e.g., at about 90 degrees from the elongated, longitudinal axis) from the body  56  is an inlet port  66  that is in communication with the round bore  58 . Inlet port  66  has a bore  74  that intersects the round bore  58 . Inlet port  66  includes a flange  68  that can be used to connect the hopper  14  to a drill cuttings infeed conduit.  
         [0023]     Outlet port  30  ( FIG. 4 ) is located at the front end  70  of the body  56  opposite the rear end  64 . Outlet port  30  includes a flange  72  that can be used to connect the hopper  14  to the discharge conduit.  
         [0024]     Referring now to  FIG. 7A , in one embodiment, the intersecting bores  58  and  74  form a somewhat T-shaped chamber  76  within the hopper  14  (e.g., having a capacity of about 50 gal. or more such as about 66 gal.). In one embodiment, both bores  58  and  74  are cylindrical, for example, having intersecting axes. Referring to  FIG. 7B , in another embodiment, hopper  14  includes a slanted surface  75  that can urge drill cuttings toward the opening  62  at rear end  64 .  
         [0025]     Referring now to  FIGS. 8-10 , hopper  14  and its chamber  76  are shaped so that the hopper can be positioned at various angular arrangements about axis  60  (e.g., through 360 degrees; see arrow  96 ) to accommodate, for example, various rig or ship installation restrictions. For example,  FIG. 8  shows the hopper  14  in a top dead center (TDC) orientation with the inlet port  66  facing vertically upward for connecting to a drill cuttings infeed conduit  83  (illustrated by dotted lines) disposed thereabove,  FIG. 9  shows the hopper in a side configuration with the inlet port located about 90 degrees from the TDC orientation for connecting to a drill cuttings infeed conduit  83  (illustrated by dotted lines) disposed therebeside and  FIG. 10  shows the hopper in a bottom dead center (BDC) orientation with the inlet port facing vertically downward for connecting to a drill cuttings infeed conduit  83  (illustrated by dotted lines) disposed therebelow. Once the hopper  14  is positioned at the desired angular orientation, for example, in the TDC orientation of  FIG. 8 , the hopper can be connected (e.g., welded) to the plate  40  of the pumping portion  13  as shown in  FIGS. 1 and 2 .  
         [0026]     In some orientations such as those shown by  FIGS. 9 and 10 , the agitator assembly  84  may be replaced by a different agitator configuration, such as two separate hydraulic motors  92  driving a remixer propeller  98  mounted through the hopper  14  wall. The hydraulic motors  92  may be capable of driving the propellers  98  in both clockwise and counterclockwise directions. The agitator along with the round-shaped volumes forming chamber  76  will facilitate flow of the drill cuttings during operation. A suitable hydraulic motor for driving the remixer propeller is commercially available from Eaton Corp.  
         [0027]      FIG. 11  shows an exemplary method  100  for installing the pump  12 . The pumping portion  13  and hopper portion  15  are transported to, for example, an oil drilling rig, ship or barge at step  102 . At step  104 , the hopper  14  is rotated about its longitudinal axis  60  to align the inlet port  66  and flange  68  with an infeed conduit for attachment thereto (e.g., by welding and/or fastening). It should be noted that only the body  56  of the hopper  14  is rotated, in some embodiments, with the remaining components of the pump  12  remaining stationary or not rotating with the body of the hopper. The pumping portion  13  may already installed prior to step  104 , or the pumping portion may be installed thereafter. Once the hopper  14  is oriented, the hopper and plate  40  of the pumping portion  13  are connected (e.g., welded) together at step  106  and the outlet port  30  is connected (e.g., welded and/or fastened) to the discharge conduit.  
         [0028]     Once the pump  12  is installed, referring back to  FIGS. 1 and 2 , drill cuttings and muds are placed in hopper  14 . The pistons  24  and  25  in cylinders  18  and  20  will reciprocate back and forth. When the piston  24  is moving rearwardly, the swing tube is in alignment with the cylinder  20  leaving the opening  32  in communication with the interior of the hopper  14 . Thus, the drill cuttings are drawn into the cylinder  18  as the piston  24  is pulled backwards. At the same time the piston  25  in cylinder  20  is moving forward. The swing tube  36  is aligned with the port  34  and the drill cuttings are pushed by the piston  25  through the swing tube  36 . Once the right piston  25  has completed its stroke, the hydraulic cylinders  48  and  50  attached to the collar  46  cause the swing tube  36  to swing in the opposite direction as indicated by arrow  68  aligning the swing tube  36  with the cylinder  18 . During movement of the inlet end of the swing tube  36  movement of the pistons  24  and  25  is temporarily paused. Once the movement of the swing tube  36  is completed, the piston  24  in cylinder  18  then moves forward forcing the drill cuttings in the cylinder  18  through the swing tube  36 . At the same time the piston  25  in the right cylinder  20  moves backwards drawing in drill cuttings. This action continues repeatedly so that drill cuttings continue to be drawn from the hopper into the pumping cylinders and then moved from the pumping cylinders along the swing tube to the discharge port  30  and into a discharge tube.  
         [0029]     Various features useful for incorporation into pump 12 are described in U.S. patent application Ser. No. 11/191,246, entitled Method of Pumping Drill Cuttings and Dual Cylinder Positive Displacement Pump for Moving Drill Cuttings, filed Jul. 27, 2005, the content of which is hereby incorporated by reference as if fully set forth herein.  
         [0030]     The pumping capacity of a dual cylinder positive displacement pump for pumping drill cuttings will tend to vary with the size of the pump and the application to which the pump is applied (e.g., whether the pump is simply transferring drill cuttings from one storage location to another or whether the pump is being used to feed drill cuttings to a processing system having a limited capacity).  
         [0031]     In one application a dual cylinder positive displacement pump  12  is used on an offshore drilling platform to move drill cuttings into a unit for processing of the drill cuttings. In another application the pump is used to pump the drill cuttings off of an offshore platform onto a seagoing vessel such as a barge so that the drill cuttings can be transported to a land-based processing facility. In the latter case, the pump may be associated with a movable discharge tube, such as a high pressure hose or conduit, that can be aligned with a hatch or other opening on the vessel. The hopper  14  may be formed of any suitable material such as heavy duty steel.  
         [0032]     The above-described hopper  14  can allow for installation at a location where available space is limited, for example, on board oil drilling rigs or below the decks of ships or barges.  
         [0033]     Depending on the orientation of the hopper  14  and infeed conduit, pump  12  can be fed from the top, bottom, either side or from any angle through 360 degrees about the longitudinal axis  60 . The shape of the chamber  76  can allow for self-cleaning during a pumping cycle.  
         [0034]     It is to be clearly understood that the above description is intended by way of illustration and example only and is not intended to be taken by way of limitation, and that changes and modifications are possible. Accordingly, other embodiments are contemplated and modifications and changes could be made without departing from the scope of this application as expressed by any claims now included or hereafter added.