FIELD OF THE INVENTION 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 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.
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 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 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:
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;
FIG. 2 is a section view of a circulating sub in default drilling mode;
FIG. 3 is a section view of a circulating sub with actuating ball siting within the restrictor;
FIG. 4 is a section view of a circulating sub in bypass mode;
FIG. 5 is a section view of a circulating sub in a position of ready to release ball;
FIG. 6 is a section view of a circulating sub with ball released from restrictor;
FIG. 7 is a section view of an alternative example of a circulating sub in default drilling mode;
FIG. 8 is a section view of an alternative example of a circulating sub with mechanical parts protected from mud;
FIG. 9 is a section view of an alternative example of a circulating sub with actuating ball siting within the restrictor;
FIG. 10 is a section view of an alternative example of a circulating sub in bypass mode;
FIG. 11 is a section view of an alternative example of a circulating sub in a position of ready to release ball;
FIG. 12 is a section view of an alternative example of a circulating sub with ball released from restrictor;
FIG. 13 is a perspective view of a barrel cam having first post, a second post, and a ball release post on cam track;
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;
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;
FIG. 16 is a section view of an alternative example of circulating sub with energy harvesting for forcing closure of side port;
FIG. 17 is a section view of a ball catcher sub;
FIG. 18 is a cross section view of a ball catcher sub; and
FIG. 19 is a sketch view of a method of changing fluid flow pattern whing a wellbore.
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 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:
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
FIG. 9 is a section view of the SWiFT circulating sub 50 explained in FIG. 3 having an orifice 130 explained in FIG. 7.
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
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
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.
