Abstract:
An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured valving member with curved and flat portions that alternatively direct fluid flow through a bore or opening in the valving member or around the periphery of the valving member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable 
   REFERENCE TO A “MICROFICHE APPENDIX” 
   Not applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a method and apparatus that is of particular utility in cementing operations associated with oil and gas well exploration and production. More specifically the present invention provides an improvement to cementing operations and related operations employing a plug or ball dropping head. 
   2. General Background of the Invention 
   Patents have issued that relate generally to the concept of using a plug, dart or a ball that is dispensed or dropped into the well or “down hole” during oil and gas well drilling and production operations, especially when conducting cementing operations. The following possibly relevant patents are incorporated herein by reference. The patents are listed numerically. The order of such listing does not have any significance. 
   
     
       
             
             
             
           
         
             
               TABLE 
             
             
                 
             
             
               PAT. 
                 
                 
             
             
               NO. 
               TITLE 
               ISSUE DATE 
             
             
                 
             
           
           
             
               3,828,852 
               Apparatus for Cementing Well Bore Casing 
               Aug. 13, 1974 
             
             
               4,427,065 
               Cementing Plug Container and Method of 
               Jan. 24, 1984 
             
             
                 
               Use Thereof 
             
             
               4,624,312 
               Remote Cementing Plug Launching System 
               Nov. 25, 1986 
             
             
               4,671,353 
               Apparatus for Releasing a Cementing Plug 
               4,671,353 
             
             
               4,722,389 
               Well Bore Servicing Arrangement 
               Feb. 02, 1988 
             
             
               4,782,894 
               Cementing Plug Container with Remote 
               Nov. 08, 1988 
             
             
                 
               Control System 
             
             
               4,854,383 
               Manifold Arrangement for use with a Top 
               Aug. 08, 1989 
             
             
                 
               Drive Power Unit 
             
             
               4,995,457 
               Lift-Through Head and Swivel 
               Feb. 26, 1991 
             
             
               5,095,988 
               Plug Injection Method and Apparatus 
               Mar. 17, 1992 
             
             
               5,236,035 
               Swivel Cementing Head with Manifold 
               Aug. 17, 1993 
             
             
                 
               Assembly 
             
             
               5,293,933 
               Swivel Cementing Head with Manifold 
               Mar. 15, 1994 
             
             
                 
               Assembly Having Remove Control Valves 
             
             
                 
               and Plug Release Plungers 
             
             
               5,435,390 
               Remote Control for a Plug-Dropping Head 
               Jul. 25, 1995 
             
             
               5,758,726 
               Ball Drop Head With Rotating Rings 
               Jun. 02, 1998 
             
             
               5,833,002 
               Remote Control Plug-Dropping Head 
               Nov. 10, 1998 
             
             
               5,856,790 
               Remote Control for a Plug-Dropping Head 
               Jan. 05, 1999 
             
             
               5,960,881 
               Downhole Surge Pressure Reduction System 
               Oct. 05, 1999 
             
             
                 
               and Method of Use 
             
             
               6,142,226 
               Hydraulic Setting Tool 
               Nov. 07, 2000 
             
             
               6,182,752 
               Multi-Port Cementing Head 
               Feb. 06, 2001 
             
             
               6,390,200 
               Drop Ball Sub and System of Use 
               May 21, 2002 
             
             
               6,575,238 
               Ball and Plug Dropping Head 
               Jun. 10, 2003 
             
             
                 
             
           
        
       
     
   
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides an improved method and apparatus for use in cementing and like operations, employing a plug or ball dropping head of improved configuration. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
       FIGS. 1A ,  1 B,  1 C are partial sectional elevation views of the preferred embodiment of the apparatus of the present invention wherein line A-A of  FIG. 1A  matches line A-A of  FIG. 1B , and line B-B of  FIG. 1B  matches line B-B of  FIG. 1C ; 
       FIG. 2  is a partial, sectional, elevation view of the preferred embodiment of the apparatus of the present invention; 
       FIG. 3  is a partial, sectional, elevation view of the preferred embodiment of the apparatus of the present invention; 
       FIG. 4  is a sectional view taken long lines  4 - 4  of  FIG. 2 ; 
       FIG. 5  is a sectional view taken along lines  5 - 5  of  FIG. 3 ; 
       FIG. 6  is a partial perspective view of the preferred embodiment of the apparatus of the present invention; 
       FIG. 7  is a sectional elevation view of the preferred embodiment of the apparatus of the present invention and illustrating a method step of the present invention; 
       FIG. 8  is a sectional elevation view of the preferred embodiment of the apparatus of the present invention and illustrating a method step of the present invention; 
       FIG. 9  is an elevation view of the preferred embodiment of the apparatus of the present invention and illustrating the method of the present invention; 
       FIG. 10  is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of  FIG. 10  matches line A-A of  FIG. 9 ; 
       FIG. 11  is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of  FIG. 10  matches line A-A of  FIG. 9 ; 
       FIG. 12  is a sectional elevation view illustrating part of the method of the present invention; 
       FIG. 13  is a sectional elevation view illustrating part of the method of the present invention; 
       FIG. 14  is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of  FIG. 10  matches line A-A of  FIG. 9 ; 
       FIG. 15  is a sectional elevation view illustrating part of the method of the present invention and wherein line A-A of  FIG. 10  matches line A-A of  FIG. 9 ; 
       FIG. 16  is a sectional elevation view illustrating part of the method of the present invention; and 
       FIG. 17  is a partial perspective view of the preferred embodiment of the apparatus of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 9  shows generally an oil well drilling structure  10  that can provide a platform  11  such as a marine platform as shown. Such platforms are well known. Platform  11  supports a derrick  12  that can be equipped with a lifting device  21  that supports a top drive unit  13 . Such a derrick  12  and top drive unit  13  are well known. A top drive unit can be seen for example in U.S. Pat. Nos. 4,854,383 and 4,722,389 which are incorporated herein by reference. 
   A flow line  14  can be used for providing a selected fluid such as a fluidized cement or fluidized settable material to be pumped into the well during operations which are known in the industry and are sometimes referred to as cementing operations. Such cementing operations are discussed for example in prior U.S. Pat. Nos. 3,828,852; 4,427,065; 4,671,353; 4,782,894; 4,995,457; 5,236,035; 5,293,933; and 6,182,752, each of which is incorporated herein by reference. 
   A tubular member  22  can be used to support plug dropping head  15  at a position below top drive unit  13  as shown in  FIG. 9 . String  16  is attached to the lower end portion of plug dropping head  15 . 
   In  FIG. 9 , the platform  11  can be any oil and gas well drilling platform such as a marine platform shown in a body of water  18  that provides a seabed or mud line  17  and water surface  19 . Such a platform  11  provides a platform deck  20  that affords space for well personnel to operate and for the storage of necessary equipment and supplies that are needed for the well drilling operation. 
   A well bore  23  extends below mud line  17 . In  FIGS. 10 and 11 , the well bore  23  can be surrounded with a surface casing  24 . The surface casing  24  can be surrounded with cement/concrete  25  that is positioned in between a surrounding formation  26  and the surface casing  24 . Similarly, a liner or production casing  32  extends below surface casing  24 . The production casing  32  has a lower end portion that can be fitted with a casing shoe  27  and float valve  28  as shown in  FIGS. 10-16 . Casing shoe  27  has passageway  30 . Float valve  28  has passageway  29 . 
   The present invention provides an improved method and apparatus for dropping balls, plugs, darts or the like as a part of a cementing operation. Such cementing operations are in general known and are employed for example when installing a liner such as liner  32 . In the drawings, arrows  75  indicate generally the flow path of fluid (e.g. cement, fluidized material or the like) through the tool body  34 . In that regard, the present invention provides an improved ball or plug or dart dropping head  15  that is shown in  FIGS. 1-8  and  10 - 17 . In  FIGS. 1A ,  1 B,  1 C and  2 - 8 , ball/plug dropping head  15  has an upper end portion  31  and a lower end portion  33 . Ball/plug dropping head  15  provides a tool body  34  that can be of multiple sections that are connected together, such as with threaded connections. In  FIGS. 1A-1C , the tool body  34  includes sections  35 ,  36 ,  37 ,  38 ,  39 . The section  35  is an upper section. The section  39  is a lower section. 
   Ball/plug dropping head  15  can be pre-loaded with a number of different items to be dropped as part of a cementing operation. For example, in  FIGS. 1A ,  1 B,  1 C there are a number of items that are contained in ball/plug dropping head  15 . These include an upper, larger diameter ball dart  40 ,  41  and smaller diameter ball  42 . 
   The tool body  34  supports a plurality of valving members. The valving members can include first valving member  43  which is an upper valving member. The valving members can include a second valving member  44  which is in between the first valving member  43  and a lower or third valving member  45 . 
   Threaded connections  46 ,  47 ,  48 ,  49  can be used for connecting the various body sections  35 ,  36 ,  37 ,  38 ,  39  together end to end as shown in  FIGS. 1A ,  1 B,  1 C. Tool body  34  upper end  31  is provided with an internally threaded portion  50  for forming a connection with tubular member  22  that depends from top drive unit  13  as shown in  FIG. 9 . A flow bore  51  extends between upper end  31  and lower end  33  of tool body  34 . 
   Sleeve sections  52  are secured to tool body  34  within bore  15  as shown in  FIGS. 1A ,  1 B,  1 C. Sleeves  52  can be generally centered within bore  51  as shown in  FIGS. 1A ,  1 B,  1 C using spacers  67  that extend along radial lines from the sections  35 - 39 . 
   Each valving member  43 ,  44 ,  45  is movable between open and closed positions. In  FIGS. 1A ,  1 B,  1 C each of the valving members  43 ,  44 ,  45  is in a closed position. In that closed position, each valving member  43 ,  44 ,  45  prevents downward movement of a plug, ball, or dart as shown. In  FIG. 1A , the closed position of valving member  43  prevents downward movement of larger diameter ball  40 . Similarly, in  FIG. 1B , a closed position of valving member  44  prevents a downward movement of dart  41 . In  FIG. 1B , a closed position of valving member  45  prevents a downward movement of smaller diameter ball  42 . In each instance, the ball, dart or plug rests upon the outer curved surface  67  of valving member  43 ,  44  or  45  as shown in the drawings. 
   Each valving member  43 ,  44 ,  45  provides a pair of opposed generally flat surfaces  69 ,  70  (see  FIGS. 3 ,  6 ,  17 ).  FIG. 17  shows in more detail the connection that is formed between each of the valving members  43 ,  44 ,  45  and the tool body  34 . The tool body  34  provides opposed openings  90  that are receptive the generally cylindrically shaped valve stems  54 ,  55  that are provided on the flat sections or flat surfaces  69 ,  70  of each valving member  43 ,  44 ,  45 . For example, in  FIGS. 6 and 17 , the flat surface  69  provides valve stem  54 . Openings  90  are receptive of the parts shown in exploded view in  FIG. 17  that enable a connection to be formed between the valving member  43 ,  44  or  45  and the tool body  34 . For the stem  55 , fastener  91  engages an internally threaded opening of stem  55 . Bushing  92  is positioned within opening  90  and the outer surface of stem  55  registers within the central bore  95  of bushing  92 . Bushing  92  is externally threaded at  93  for engaging a correspondingly internally threaded portion of tool body  34  at opening  90 . O-rings  60  can be used to interface between stem  55  and bushing  92 . A slightly different configuration is provided for attaching stem  54  to tool body  34 . Sleeve  94  occupies a position that surrounds stem  54 . Sleeve  54  fits inside of bore  95  of bushing  92 . The externally threaded portion  93  of bushing  92  engages correspondingly shaped threads of opening  90 . Pins  99  form a connection between the stem  54  at openings  98  and the sleeve  94 . Fastener  96  forms a connection between bushing  92  and an internally threaded opening  97  of stem  54 . As assembled, this configuration can be seen in  FIG. 1A  for example. The flat surfaces  69 ,  70  enable fluid to flow in bore  51  in a position radially outwardly or externally of sleeve or sleeve section  52  by passing between the tool body sections  35 ,  36 ,  37 ,  38 ,  39  and sleeve  52 . Thus, bore  51  is divided into two flow channels. These two flow channels  71 ,  72  include a central flow channel  71  within sleeves  52  that is generally cylindrically shaped and that aligns generally with the channel  53  of each valving member  43 ,  44 ,  45 . The second flow channel is an annular outer flow channel  72  that is positioned in between a sleeve  52  and the tool body sections  35 ,  36 ,  37 ,  38 ,  39 . The channels  71 ,  72  can be concentric. The outer channel  72  is open when the valving members  43 ,  44 ,  45  are in the closed positions of  FIGS. 1A ,  1 B and  1 C, wherein central flow channel is closed. 
   When the valving members  43 ,  44 ,  45  are rotated to a closed position, fins  73  become transversely positioned with respect to the flow path of fluid flowing in channel  72  thus closing outer flow channel  72  (see  FIG. 5 ). This occurs when a valving member  43 ,  44 ,  45  is opened for releasing a ball  40  or  42  or for releasing dart  41 .  FIG. 4  illustrates a closed position ( FIG. 4 ) of the valving member  45  just before releasing smaller diameter ball  42 . Fins  73  are generally aligned with bore  15  and with flow channels  71 ,  72  when flow in channel  72  is desired ( FIG. 4 ). In  FIG. 4 , valving member  45  is closed and outer flow channel  72  is open. 
   In  FIGS. 2-3 ,  5  and  7 , a tool  74  has been used to rotate valving member  45  to an open position that aligns its channel  53  with central flow channel  71  enabling smaller diameter ball  42  to fall downwardly via central flow channel  71 . In  FIG. 5 , outer flow channel  72  has been closed by fins  73  that have now rotated about 90 degrees from the open position of  FIG. 4  to the closed position. Fins  73  close channel  72  in  FIG. 5 . It should be understood that tool  74  can also be used to rotate valving member  44  from an open position of  FIG. 1B  to a closed position such as is shown in  FIG. 5  when it is desired that dart  41  should drop. Similarly, tool  74  can be used to rotate upper valving member  43  from the closed position of  FIG. 1A  to an open position such as is shown in  FIG. 5  when it is desired to drop larger diameter ball  40 . 
     FIGS. 10-16  illustrate further the method and apparatus of the present invention. In  FIG. 10 , lower or third valving member  45  has been opened as shown in  FIG. 5  releasing smaller diameter ball  42 . In  FIG. 10 , smaller diameter ball  42  is shown dropping wherein it is in phantom lines, its path indicated schematically by arrows  75 . 
     FIG. 10  shows a pair of commercially available, known plugs  76 ,  77 . These plugs  76 ,  77  include upper plug  76  and lower plug  77 . Each of the plugs  76 ,  77  can be provided with a flow passage  79 ,  81  respectively that enables fluid to circulate through it before ball  42  forms a seal upon the flow passage  81 . Smaller diameter ball  42  has seated upon the lower plug  77  in  FIG. 10  so that it can now be pumped downwardly, pushing cement  80  ahead of it. In  FIG. 11 , arrows  78  schematically illustrate the downward movement of lower plug  77  when urged downwardly by a pumped substance such as a pumpable cement or like material  80 . Each of the plugs  76 ,  77  can be provided with a flow passage  79 ,  81  respectively that enables fluid to circulate through it before ball  42  forms a seal upon the flow passage  81  (see  FIG. 11 ). When plug  77  reaches float valve  28 , pressure can be increased to push ball  42  through plug  77 , float valve  28  and casing shoe  27  so that the cement flows (see arrows  100 ,  FIG. 11 ) into the space  101  between formation  26  and casing  32 . 
   In  FIG. 12 , second valving member  44  is opened releasing dart  41 . Dart  41  can be used to push the cement  80  downwardly in the direction of arrows  82 . A completion fluid or other fluid  83  can be used to pump dart  41  downwardly, pushing cement  80  ahead of it. Once valves  44  and  45  are opened, fluid  83  can flow through openings  84  provided in sleeves  52  below the opened valving member (see  FIG. 7 ) as illustrated in  FIGS. 7 and 12 . Thus, as each valving member  43  or  44  or  45  is opened, fluid moves through the openings  84  into central flow channel  71 . 
   When valve  44  is opened, dart  41  can be pumped downwardly to engage upper plug  76 , registering upon it and closing its flow passage  79 , pushing it downwardly as illustrated in  FIGS. 14 and 15 . Upper plug  79  and dart  41  are pumped downwardly using fluid  83  as illustrated in  FIGS. 14 and 15 . In  FIG. 16 , first valving member  43  is opened so that larger diameter ball  40  can move downwardly, pushing any remaining cement downwardly. 
   The ball  40  can be deformable, so that it can enter the smaller diameter section  86  at the lower end portion of tool body  34 . During this process, cement or like mixture  80  is forced downwardly through float collar  28  and casing shoe  27  into the space that is in between production casing  32  and formation  26 . This operation helps stabilize production casing  32  and prevents erosion of the surrounding formation  26  during drilling operations. 
   During drilling operations, a drill bit is lowered on a drill string using derrick  12 , wherein the drill bit simply drills through the production casing  32  as it expands the well downwardly in search of oil. 
   The following is a list of parts and materials suitable for use in the present invention. 
   
     
       
             
           
             
             
           
             
             
           
         
             
                 
             
             
               PARTS LIST 
             
           
        
         
             
               Part Number 
               Description 
             
             
                 
             
           
        
         
             
               10 
               oil well drilling structure 
             
             
               11 
               platform 
             
             
               12 
               derrick 
             
             
               13 
               top drive unit 
             
             
               14 
               flow line 
             
             
               15 
               ball/plug dropping head 
             
             
               16 
               string 
             
             
               17 
               sea bed/mud line 
             
             
               18 
               body of water 
             
             
               19 
               water surface 
             
             
               20 
               platform deck 
             
             
               21 
               lifting device 
             
             
               22 
               tubular member 
             
             
               23 
               well bore 
             
             
               24 
               surface casing 
             
             
               25 
               cement/concrete 
             
             
               26 
               formation 
             
             
               27 
               casing shoe 
             
             
               28 
               float valve 
             
             
               29 
               passageway 
             
             
               30 
               passageway 
             
             
               31 
               upper end 
             
             
               32 
               liner/production casing 
             
             
               33 
               lower end portion 
             
             
               34 
               tool body 
             
             
               35 
               section 
             
             
               36 
               section 
             
             
               37 
               section 
             
             
               38 
               section 
             
             
               39 
               section 
             
             
               40 
               larger diameter ball 
             
             
               41 
               dart 
             
             
               42 
               smaller diameter ball 
             
             
               43 
               first valving member 
             
             
               44 
               second valving member 
             
             
               45 
               third valving member 
             
             
               46 
               threaded connection 
             
             
               47 
               threaded connection 
             
             
               48 
               threaded connection 
             
             
               49 
               threaded connection 
             
             
               50 
               threaded portion 
             
             
               51 
               flow bore 
             
             
               52 
               sleeve 
             
             
               53 
               channel 
             
             
               54 
               stem 
             
             
               55 
               stem 
             
             
               56 
               sleeve 
             
             
               57 
               sleeve 
             
             
               58 
               plug 
             
             
               59 
               plug 
             
             
               60 
               o-ring 
             
             
               61 
               opening 
             
             
               62 
               opening 
             
             
               63 
               opening 
             
             
               64 
               opening 
             
             
               65 
               opening 
             
             
               66 
               opening 
             
             
               67 
               spacer 
             
             
               68 
               outer curved surface 
             
             
               69 
               flat surface 
             
             
               70 
               flat surface 
             
             
               71 
               central flow channel 
             
             
               72 
               outer flow channel 
             
             
               73 
               fin 
             
             
               74 
               tool 
             
             
               75 
               arrow 
             
             
               76 
               upper plug 
             
             
               77 
               lower plug 
             
             
               78 
               arrows 
             
             
               79 
               flow passage 
             
             
               80 
               cement 
             
             
               81 
               flow passage 
             
             
               82 
               arrow 
             
             
               83 
               fluid 
             
             
               84 
               opening 
             
             
               85 
               opening 
             
             
               86 
               smaller diameter section 
             
             
               87 
               arrow - fluid flow path 
             
             
               88 
               fastener 
             
             
               89 
               internally threaded opening 
             
             
               90 
               opening 
             
             
               91 
               fastener 
             
             
               92 
               bushing 
             
             
               93 
               external threads 
             
             
               94 
               sleeve 
             
             
               95 
               passageway/bore 
             
             
               96 
               fastener 
             
             
               97 
               internally threaded opening 
             
             
               98 
               opening 
             
             
               99 
               pin 
             
             
               100 
               arrows 
             
             
               101 
               space 
             
             
                 
             
           
        
       
     
   
   All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise. 
   The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.