Abstract:
Aspects of the present invention generally relates to downhole drilling operations. Particularly, the present invention relates to methods and apparatus to provide remote control of flow communication between inner passage flow and annulus depending on the circumstances where it might be needed. The invention is installed as part of the drilling string comprises of a body, a sleeve, a barrel cam, a restrictor, a ball, a resilient element, and a housing embodying all the elements. The ball is introduced from surface to activate the apparatus.

Description:
FIELD OF THE INVENTION 
       [0001]    Aspects of the present SWiFT Circulating Subgenerally relates to downhole drilling operations. Particularly, the present disclosure relates to methods and apparatus to provide remote control to enable and restrict flow communication between inner passage flow and annulus. 
       BACKGROUND OF THE INVENTION 
       [0002]    The concept of forming subterranean well is referred to; a drill string is typically used to drill a wellbore of a first depth into the formation. The drill string includes a tubular body having a drill bit attached to its lower end for drilling the hole into the formation to form the wellbore. 
         [0003]    While drilling, a drilling fluid (or mud fluid) is circulated down through the drill string, then through the openings in a drill bit which is located at the end of the drill string. Then, the drilling fluid continues the circulation up through the annulus between the outer surface of the drill string and walls of the well. 
       SUMMARY OF THE INVENTION 
       [0004]    Aspects of the present invention generally relates to downhole drilling operations. Particularly, the present invention relates to methods and apparatus to provide remote control of flow communication between inner passage flow and annulus depending on the circumstances where it might be needed. The invention is installed as part of the drilling string comprises of a body, a sleeve, a barrel cam, a restrictor, a ball, a resilient element, and a housing embodying all the elements. The ball is introduced from surface to operate the apparatus. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which: 
           [0006]      FIG. 1  is a prospective section view of a typical drill rig with wellbore, casing and drill bit in directional drilling where the apparatus is part of the drilling string; 
           [0007]      FIG. 2  is a section view of a circulating sub in default drilling mode; 
           [0008]      FIG. 3  is a section view of a circulating sub with actuating ball siting within the restrictor; 
           [0009]      FIG. 4  is a section view of a circulating sub in bypass mode; 
           [0010]      FIG. 5  is a section view of a circulating sub in a position of ready to release ball; 
           [0011]      FIG. 6  is a section view of a circulating sub with ball released from restrictor; 
           [0012]      FIG. 7  is a section view of an alternative example of a circulating sub in default drilling mode; 
           [0013]      FIG. 8  is a section view of an alternative example of a circulating sub with mechanical parts protected from mud; 
           [0014]      FIG. 9  is a section view of an alternative example of a circulating sub with actuating ball siting within the restrictor; 
           [0015]      FIG. 10  is a section view of an alternative example of a circulating sub in bypass mode; 
           [0016]      FIG. 11  is a section view of an alternative example of a circulating sub in a position of ready to release ball; 
           [0017]      FIG. 12  is a section view of an alternative example of a circulating sub with ball released from restrictor; 
           [0018]      FIG. 13  is a perspective view of a barrel cam having first post, a second post, and a ball release post on cam track; 
           [0019]      FIG. 14  is a sketch view of a cam track having a first post, a second post, a ball release post and cam a follower travel direction; 
           [0020]      FIG. 15  is a sketch view of an alternative cam track showing cam follower passage and plurality of first post, plurality of second post and a ball release post; 
           [0021]      FIG. 16  is a section view of an alternative example of circulating sub with energy harvesting for forcing closure of side port; 
           [0022]      FIG. 17  is a section view of a ball catcher sub; 
           [0023]      FIG. 18  is a cross section view of a ball catcher sub; and 
           [0024]      FIG. 19  is a sketch view of a method of changing fluid flow pattern whing a wellbore. 
       
    
    
       [0025]    For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    A complete understanding of the present SWiFT circulating sub  50  may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which: 
         [0027]      FIG. 1  is a section view of an example of a wellbore  10  drilling system wherein a SWiFT circulating sub  50  is disposed within drilling tubular string during well forming operation. Majority of drilling systems used in current days include a tubular string composed of a drill bit having a plurality of perforations located through the drill bit to allow fluid flow there through. Drilling string  30  and bottom hole assembly are normally connected by an end connection  190  commonly in a thread from. A tubular conduit such as drill pipe connects the bottom hole assembly to surface. The wellbore  10  formed into the earth may have a deviated section where the wellbore  10  is not vertical. A cased hole section is the portion of the wellbore  10  having a tubular of large diameter called casing lining the inner side of the wellbore  10  to protect wellbore  10  from damage. While drilling a deeper section into earth formations an open hole section of the wellbore  10  is formed. Surface facilities  20  include mud pumping system is disposed with most drilling operations and includes a drilling fluid tank to store drilling fluid and a pump to force fluid into the inner flow passage  60  defined as the inner space within the tubular string. An annulus  70  is the flow passage defined as the space between the inner wall of the wellbore  10  and the outer wall of the tubular string. When losses are encountered, well control is compromised and drilling operation risks and costs are increased. 
         [0028]      FIG. 2  is a section view of a SWiFT circulating sub  50  in default drilling mode. In this example, the SWIFT circulating sub  50  comprises a sub body  100  having two end connections for connecting the sub body  100  to other drilling component from one end and a ball  200  catcher at the other end. The sub body  100  has at least one side port  110  hydraulically connecting the annulus  70  with the sub body  100  inner surface. An inner flow passage  60  is disposed within the sub body  100  for hydraulically connecting drilling fluid introduced from surface using surface facilities  20  into the drilling string  30 . A sleeve  120  is disposed within the sub body  100 . The sleeve  120  moves within the sub body  100  axially, rotationally or a combination thereof. A barrel cam  170  is disposed on the external surface of the sleeve  120 . In one example the cam track  250  is engraved on the sleeve  120  external surface. In another example, the barrel cam  170  is a separate element inserted around the sleeve  120  and can rotate with respect to the sleeve  120 . A cam follower  180  is disposed within the sub body  100  wall and extending through the sub body  100  internal surface to engage the barrel cam  170 . Specifically, the cam follower  180  travels the cam track  250  in a specific direction controlled by the cam track  250  shape. The sleeve  120  further comprises an orifice  130 . The orifice  130  in this example is in a form of lateral perforation near one end of the sleeve  120 . When the orifice  130  is aligned with the port  110 , the annulus  70  is in fluid communication with the inner flow passage  60 . When the orifice  130  is not aligned with the port  110 , fluid communication between annulus  70  and inner flow passage  60  is restricted. A restrictor  140  is disposed within the sleeve  120 . This restrictor  140  is configured and arranged to receive the activation ball  200  and restrict the activation ball  200  from passing through from one end of the sub body  100  to the other end of the sub body  100 . A resilient element such as a form of a spring  150  is disposed laterally between the sleeve  120  external surface and the sub body  100  inner surface. One end of the spring  150  is engaged with a shoulder  155  arranged on the external surface of the sleeve  120 , and the other end of the spring  150  is engaged with a stopper  160  that is fixed to the sub body  100  inner surface. In this figure, the spring  150  is extended pushing and biasing the sleeve  120  towards one end of the sub body  100 . The sleeve  120  is restricted and its travel is controlled by the cam follower  180  engaged with the cam track  250 . In this figure the cam follower  180  is engaged with the track at a first post  260  and the SWiFT circulating sub  50  is said to be in default mode. When drilling fluid is introduced from surface, it will flow through the drilling string  30  and through the inner flow passage  60  of the SWiFT circulating sub  50  then through other drilling bottom hole assembly component on the other end of the SWIFT circulating sub  50  until it reaches the drill bit at the deepest end of the drilling string  30 . 
         [0029]      FIG. 3  is a section view of one example of the SWiFT circulating sub  50  explained in  FIG. 2  where a ball  200  introduced from surface into the inner flow passage  60  is engaged with the restrictor  140 . The ball  200  is designed such that the ball  200  outside diameter is slightly larger than the inner diameter of the restrictor  140 . In another example the ball  200  may have a protruding part to prevent the ball  200  from passing through the restrictor  140 . In another example the restrictor  140  is having a geometry that is not matching with the ball  200  and prevent the ball  200  from passing through the restrictor  140 . The ball  200  restrict fluid flow through the SWiFT circulating sub  50  inner flow passage  60 . Any attempt to pump fluid from surface into the inner flow passage  60  will be restricted by the ball  200  sitting in the restrictor  140  and the pressure will increase on surface and at the one side of the ball  200  in contact with the fluid introduced from surface. 
         [0030]      FIG. 4  is a section view of one example of the SWIFT circulating sub  50  explained in  FIG. 3  where fluid introduced from surface is pushed with higher pressure resulted in sufficient force that overcome the spring  150  bias force. The fluid pressure cased the spring  150  to collapse and the sleeve  120  moves controlled by the cam follower  180  travelling the cam track  250  until the cam follower  180  reach a second post  270  where the orifice  130  is aligned with the port  110 . In this position, inner fluid passage is in fluid communication with the annulus  70  and the SWiFT circulating sub  50  is in bypass mode. When pump is stopped at surface and pressure is released, the energy stored in the spring  150  at the collapse position will be released pushing and biasing the sleeve  120  towards the position of  FIG. 3 . The cam follower  180  engaged with the cam track  250  controls the sleeve  120  travel until. The barrel cam  170  tract is arranged such that when fluid flow stops and pressure is released, the cam follower  180  will go to another first post  260  position. At this position the orifice  130  will not be aligned with the port  110  and fluid communication between the inner flow passage  60  and the annulus  70  will be restricted. 
         [0031]      FIG. 5  is the section view of the SWiFT circulating sub  50  explained in  FIGS. 2, 3, and 4 . In this view the fluid introduced from surface pushing the ball  200  and the sleeve  120  towards the lower end of the sub body  100 . In this figure the cam follower  180  traveling the cam track  250  will be engaged the track at the ball release post  280 . In this position the sleeve  120  will travel partially and the travel will be restricted by the engagement of the cam follower  180  at the ball release post  280 . This partial travel of sleeve  120  will force the spring  150  to be partially collapsed and energized. In this position, the orifice  130  is not aligned with the port  110  and fluid within the inner flow passage  60  is in restricted communication with the annulus  70  through the port  110 . Any additional fluid introduced from surface will result in building pressure at the one side of the ball  200  in contact with the fluid introduced from surface. When sufficient pressure is applied, the force exerted on the ball  200  will exceed the restriction force preventing the ball  200  from moving through the restrictor  140 . In this case, the ball  200  will be released from the restrictor  140  and will flow through the inner flow passage  60  through the sub body  100  end connection  190 . However, if the pressure applied on the ball  200  was not high enough to release the ball  200  from the restrictor  140 , the ball  200  will stay in its position. In this case when pump is stopped at surface and pressure is released, the energy stored in the spring  150  at this partial collapse position will be released pushing and biasing the sleeve  120  towards the position of  FIG. 3 . The cam follower  180  engaged with the cam track  250  controls the sleeve  120  travel until. The cam track  250  is arranged such that when fluid flow stops and pressure is released, the cam follower  180  will go to another first post  260  position. At this position the orifice  130  will not be aligned with the port  110  and fluid communication between the inner flow passage  60  and the annulus  70  will be restricted. In this example explained the cam follower  180  can travel the cam track  250  infinitely and the SWiFT circulating sub  50  can be activated into bypass mode infinite number of time if the pressure applied from surface did not exceed ball  200  release pressure. 
         [0032]    On the other hand, when the pressure introduced from surface force the ball  200  with a much higher force that overcome the restrictor  140  force, the ball  200  will squeeze into the restrictor  140  and overcome the friction. The sleeve  120  will move to home position and the SWiFT circulating sub  50  will be in default mode. 
         [0033]    In another example the ball  200  is designed and arranged to shear the overlapping geometry with the restrictor  140  by the force exerted on the ball  200  by the pressure introduced from surface. 
         [0034]      FIG. 6  is a section view of the SWiFT circulating sub  50  explained in  FIG. 5  when the pressure applied from surface exceed resulted in force exerted on the ball  200  that exceed the restrictor  140  force by the restrictor  140 . The ball  200  is designed to deform and squeeze into the restrictor  140 . In another example the ball  200  is designed to shear the outer shell and flow through the restrictor  140 . In one example the restrictor  140  is designed to deform such that it allows the ball  200  to pass through under release pressure. In another example the restrictor  140  is designed to shear under release pressure and allow the ball  200  to pass through the restrictor  140 . In another example both the ball  200  and restrictor  140  may have any combination of deformation or shearing to allow the ball  200  to pass through the restrictor  140 . In another example the ball  200  may dissolve and disappear allowing the fluid introduced from surface to pass through the inner flow passage  60  with no restriction. In another example the ball  200  is designed to react to specific fluid introduced from surface and changes its geometry and partially dissolve allowing the ball  200  to pass through the restrictor  140 . 
         [0035]      FIG. 7  is a section view of another example of the SWIFT circulating sub  50  explained in  FIG. 2  where the orifice  130  is arranged to be at the top of the sleeve  120  instead of a side perforation in the sleeve  120 . In this example a nozzle  210  is inserted in the side port  110  to change the geometry and flow area of the port  110 . 
         [0036]      FIG. 8  is a section view of another example of the SWIFT circulating sub  50  explained in  FIG. 7  and  FIG. 2  with the protection system to isolate the mechanical parts from mud. An isolation piston  220  is placed near one end of the sleeve  120  isolating the component compartment  230  on one side from mud in the inner flow passage  60  on the other side of the isolation piston  220 . The component compartment  230  is defined as the space between the sub body  100  inner surface and the sleeve  120  outer surface laterally and axially between one side of the isolation piston  220  at one end and the compartment limit  240  at the other end. The compartment limit  240  is defined as the space just before the side port  110  and hydraulically restrict fluid communication between the component compartment  230  and the port  110 . Barrel cam  170 , cam track  250  and the portion of the cam follower  180  traveling the cam track  250  are all disposed within the component compartment  230 . In another example the component compartment  230  is filled with a clean fluid such as hydraulic oil. In another example the isolation piston  220  is a floating piston equalize the hydraulic pressure of fluid within the component compartment  230  and the pressure of the inner flow passage  60 . This hydraulic compensation is valuable for reducing friction of sleeve  120  movement. Hydraulic fluid within the component compartment  230  insure lubricity of cam follower  180  traveling cam track  250  and reliable performance during operation of the sleeve  120  traveling from default position and bypass position. 
         [0037]      FIG. 9  is a section view of the SWiFT circulating sub  50  explained in  FIG. 3  having an orifice  130  explained in  FIG. 7 . 
         [0038]      FIG. 10  is a section view of the SWIFT circulating sub  50  explained in  FIG. 4  with an orifice  130  similar to the orifice  130  explained in  FIG. 7   
         [0039]      FIG. 11  is a section view of the SWiFT circulating sub  50  explained in  FIG. 5  with an orifice  130  similar to the orifice  130  explained in  FIG. 7   
         [0040]      FIG. 12  is a section view of the SWIFT circulating sub  50  explained in  FIG. 7  with an orifice  130  similar to the orifice  130  explained in  FIG. 7   
         [0041]      FIG. 13  is a perspective view of a barrel cam  170  having a cam track  250  engraved on its surface. Cam track  250  can be protruding in a different example (not shown). The cam track  250  having end points to limit the axial travel of the barrel cam  170 . Those end posts include a first post  260  where the cam follower  180  travel the cam track  250  to one end when the sleeve  120  is in home position, alternatively called default position where fluid communication between orifice  130  and port  110  is restricted. A second post  270  is the position where the cam follower  180  travel to at the effect of axial movement of the barrel cam  170  such that the orifice  130  and port  110  are in fluid communication. The ball release post  280  is the position on the cam track  250  where the cam follower  180  travel to at the axial movement of the barrel cam  170  such that the fluid communication between the orifice  130  and the port  110  is restricted and the cam axial travel is where the sleeve  120  is between the bypass position and the home default position. The cam track  250  is arranged such that the cam follower  180  travel the cam track  250  in one rotational direction all the time at any axial movement direction. This arrangement force the cam follower  180  to go in the same sequence all the time. 
         [0042]      FIG. 14  is a sketch demonstrating the cam follower passage  290  and cam follower  180  travel direction  292 . In this example the cam follower  180  travel from a second post  270  to first post  260  by effect of a first axial movement direction of the barrel cam  170 . The cam follower  180  travel from the first post  260  to a ball release post  280  under the effect of a second axial movement direction of the barrel cam  170  wherein the first axial movement direction of the barrel cam  170  is in opposite direction to the second axial movement direction of the barrel cam  170 . The cam follower  180  travel from the ball release post  280  to a first post  260  under the effect of another first axial movement direction of the barrel cam  170  and so on. With the cam track  250  connected laterally around the barrel cam  170 , the sequence of cam follower  180  traveling the cam track  250  is infinite. 
         [0043]      FIG. 15  is a sketch demonstrating the cam follower passage  290  traveling the cam track  250  where there are plurality of first post  260  and plurality of a second post  270  and one ball release post  280 . This is an example of possible combination of a cam track  250  and cam track  250  post arrangements. Other cam track  250  configuration with plurality of ball release post  280  can be demonstrated with the same method and considered understood and not presented in a separate graph. 
         [0044]      FIG. 16  is a section view of another example of the SWiFT circulating sub  50  explained in  FIG. 8  with an energy harvesting positive closure system explained. An annulus pressure compartment  330  is in fluid communication with the annulus  70  through the port  110 . The annuls pressure compartment is pressure isolated from the inner flow passage  60  pressure by an upper seal  300 . The annulus pressure compartment  330  is pressure isolated from the inner pressure compartment  340  by the lower seal  310 . The upper seal  300  is of a smaller diameter when compared to the lower seal  310 . The pressure of the inner flow passage  60  is in pressure communication with the inner pressure compartment  340  through the floating isolation piston  220 . This means that the pressure at one side of the lower seal  310  is almost equivalent to the pressure of at one side of the upper seal  300  and almost equivalent to the inner flow passage  60  pressure. 
         [0045]    In operation, when there is no flow within the tubular string, the inner flow passage  60  pressure is equalized to the annulus  70  pressure through perforation at the drill bit. On the other hand, during drilling operation and during fluid circulation, the inner flow passage  60  pressure is much higher than the annulus  70  pressure to force fluid to go through perforation at drill bit and push the fluid in the annulus  70  to return to surface. 
         [0046]    This means that the pressure in the inner pressure compartment  340  which is almost equal to the inner flow passage  60  pressure, much higher than the annulus  70  pressure. An energy harvesting area  320  equivalent to the difference in area of the upper seal  300  and lower seal  310  is disposed on the sleeve  120 . At circulation a force will be exerted over the energy harvesting area  320  in proportion to the multiplier of the energy harvesting area  320  times the pressure difference between the inner flow passage  60  and the annulus  70 . This energy harvesting system insure the sleeve  120  is pushed towards the home default position closing the side port  110  with a force generated more and above the force generated by the energy stored in the compressed spring  150 . This system enables the side port  110  to be closed even when some debris are deposited on the restrictor  140  and the inner surface of the sleeve  120 . 
         [0047]      FIG. 17  is a section view of a ball  200  catcher sub  400  comprising a catcher body  405  having two end connection  190  and is connected to the lower end connection  190  of the sub body  100 . an access passage  430  of a width smaller than the ball  200  diameter is disposed within the catcher body  405 . A ball trap  410  is disposed within the catcher body  405  having a dimension larger than the ball  200  diameter from one side and smaller than the ball  200  diameter on another side. The ball trap  410  has a ball guide  420  at one end to allow the ball  200  to slide towards the ball  200  travel and prevent it from being stuck at the access passage  430 . A ball stopper  440  is attached to the other end of the ball trap  410  to prevent a ball  200  collected into the ball trap  410  from traveling beyond the ball  200  catcher sub  400 . 
         [0048]      FIG. 18  is an example of cross section of the ball  200  catcher sub  400  where the passage within the catcher body  405  is in a form of a key seat. The access passage  430  is of shown of a smaller width than the ball  200  diameter preventing the ball  200  from passing through the ball  200  catcher sub  400  while the ball trap  410  has a width that allows the ball  200  to be trapped to one side of the cavity within the catcher body  405 . 
         [0049]      FIG. 19  is a flow chart explaining steps of a method for fluid circulation in a well. A SWIFT circulating sub  50  is disposed within a wellbore  10  with a tubular string. When it is desire to change the SWiFT circulating sub  50  mode from default drilling mode to bypass mode, step  1   510 , is to drop a ball  200  arranged to engage with the restrictor  140 . Step  2   520  is to pump fluid from surface into the inner passage of the tubular string forcing the ball  200  to travel within the inner passage of the tubular string until it reach the restrictor  140 . Step  3   530  is when the ball  200  reach and sets in the restrictor  140 . Step  4   540  is to pump fluid from surface forcing the ball  200  sitting in the restrictor  140  to move the sleeve  120  such that the orifice  130  is aligned with the port  110  and the inner flow passage  60  at one side of the ball  200  is in fluid communication with the annulus  70  and the SWiFT circulating sub  50  is said to be in bypass mode. Operator may continue to pump fluid from surface as long as desired. Step  5   550  is when the pump stops, resulting in sleeve  120  travel under effect of the resilient element and the orifice  130  is not aligned with the port  110 . At a sequence defined by the cam track  250 , in step  6   560 , fluid is introduced from surface. Step  7   570 , fluid introduced from surface will cause the cam follower  180  to travel the cam track  250  and reach a ball release post  280 . Step  8   580 , when it is desired to release the ball  200  from the restrictor  140  into the ball  200  catcher, a sufficient force is applied from surface. Step  9   590 , the force will cause the ball  200  to squeeze within the restrictor  140  and pass through into the ball  200  catcher. Step  10   592 , if it is not desired to release the ball  200  at this stage and to continue circulation in bypass mode, apply pressure from surface sufficient to overcome the resilient element force but lower than the force needed to release the ball  200 . Step  11   594 , stop the pump and the sleeve  120  will travel under the effect of energy stored in the resilient element. The cam follower  180  will travel the cam track  250  to reach first post  260  that is precede a second post  270 . 
         [0050]    Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
         [0051]    Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.