BACKGROUND
In industries where access to subsurface reservoirs is provided through boreholes, it is sometimes desirable to have the ability to steer strings running in boreholes being drilled or even in preexisting boreholes to assist strings moving past deviations in the trajectory of the borehole. Bent subs are common means used to cause steering of a string creating or running in a borehole. While bent subs and other means for steering have been used with reasonable success, the art is always receptive to improvements in efficiency.
SUMMARY
An embodiment of a steering augmenter for a steering device of a drilling tool, the steering augmenter including a body having an inside surface and an outside surface and configured to attach to a drill bit, a first flow passage defined by the inside surface of the body and configured to convey a fluid supply, a channel at the outside surface of the body, the channel being configured to produce a Bernoulli effect therein during fluid flow therein, a second flow passage fluidly connecting the first flow passage to the channel, and a valve associated with the second flow passage and configured to allow, prevent or choke flow through the second flow passage.
An embodiment of a downhole drill bit assembly including a steering augmenter, the drill bit attached to the steering augmenter.
An embodiment of a method for drilling a borehole into the earth, the method including conveying the steering device into the borehole, operating the valve to allow, prevent or choke flow through the second flow passage, creating a steering force at the steering augmenter by the produced Bernoulli effect.
BRIEF DESCRIPTION OF THE DRAWINGS
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
FIG. 1 is a cross sectional view of a steering device as disclosed herein;
FIG. 1A is an alternative embodiment of the steering device as disclosed herein;
FIG. 1B is an alternative embodiment of the steering device as disclosed herein;
FIG. 2 illustrates is an embodiment of a flow barrier;
FIG. 3 is a view similar to FIG. 1 but having a single actuator;
FIG. 4 is a sectional view of a steering augmenter;
FIG. 5 is the view of FIG. 3 with a different stabilizer position; and
FIG. 6 is a view of a borehole system including the steering device as disclosed herein.
DETAILED DESCRIPTION
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to FIG. 1, a steering device 10 is illustrated in cross section. The device includes a drill bit 12 configured to cut and/or disintegrate a subsurface formation, such as subsurface formation 52, and having a flow passage 14 therein. Flow passage 14 may include one or more segments, such as connected segments to allow fluid flow through the segments and from one segment to the other segments. Three segments (14a, 14b, 14c) of flow passage 14 are illustrated in FIG. 1. These provide for a fluid path through flow passage 14 from a fluid supply 18 (which may be a conveyance or a source) of steering device 10 to an outside surface 16 of the drill bit 12. It is noted that the fluid supply 18 may be defined by an inside diameter (ID) of the steering device 10 that is fluidly connected to an ID of a string 20 (for example, drill string 20 or drill pipe 20) capable of supplying fluid 56 (e.g., drilling fluid, also known as drilling mud or mud) to the steering device 10 but also may use control lines to supply fluid 56 to other devices, such as one or more valves 22. Optionally, one or more additional permanent flow channels 37 provide continuous fluid flow through the drill bit in addition to the fluid flow through flow passage 14 via valve(s) 22. Permanent flow channels 37 in this context means that flow channels 37 are not connected to a valve that selectively or temporarily changes, reduces, or prevents fluid flow through permanent flow channels 37 even when a pressure difference between pressure in fluid supply 18 and pressure at the outside surface 16 of drill bit 12 occurs. Additional fluid flow through additional permanent flow channels 37 allows to cool and lubricate drill bit 12 even when all valves 22 are closed and/or when the fluid flow through valve(s) 22 is not sufficient. Drill bit 12 and steering device 10 are threadedly connected and rotate at the same speed when in operation. Flow passage 14 and valve 22 rotate with steering device 10. One or more stabilizer(s) 123 may be installed on steering device 10 or string 20 for stabilizing and guiding steering device 10/string 20 within borehole 40.
Valve 22, selectively operable by an actuator 24, is disposed in a fluid path from the fluid supply 18 to the flow passage 14. Valve 22 may be a rotary valve or a reciprocating valve in embodiments. Valve 22 has an inlet port 67 connected to the fluid supply 18. An outlet port 73 of the valve 22 is connected to the flow passage 14, which in turn leads to flow exit 130, such as an outlet nozzle which may be at an end of segment 14b or 14c. At the surface 54 (FIG. 2) fluid 56 may be pumped into the string 20 and consequently into the fluid supply 18 of steering device 10 (sometimes referred to herein as bore fluid channel) to become the fluid supply 18 that is then used for the steering device 10. Depending on the selected size of the flow passage 14, the pressure in the fluid supply 18 may be significantly higher than between the outside surface 16 of the drill bit 12 and an inside surface 38 of borehole 40.
The valve 22 is actuatable by the actuator 24 through electric, mechanical, hydraulic or other means in a selective way that is controlled by a controller 26 operatively connected to the actuator 24. Thus, in an actuated state, the valve connects the high pressure fluid supply 18 fluid with the flow passage 14. As a consequence of the differential pressure between the fluid supply 18 and the annular space between outside surface 16 of the drill bit 12 and inside surface 38 of borehole 40 (sometimes referred to herein as borehole annulus), drilling fluid is discharged at a velocity that induces a lower fluid pressure and accordingly pulls the drill bit 12 toward the inside surface 38 of borehole 40 where fluid is being expelled from passage 14c.
The controller 26 may be in or on the steering device 10 and, optionally, actuator 24 and/or controller 26 may rotate as well with the steering device 10. Alternatively, controller 26 may be located remotely either downhole or at the earth's surface 54 (cf. FIG. 6). Controller 26 may be hardwired to actuator 24 or wirelessly connected thereto. It is to be understood that more than one valve 22 may be controlled by one actuator 24 in embodiments or one controller 26 may operate more than one actuator 24. Controller 26 may be configured to control one or more actuators 24 and/or valves 22, individually. For example, controller 26 may be configured to control a first and a second actuator 24 and/or a first and a second valve 22 to allow a greater fluid flow through the first valve compared to the second valve. In some modes of operation, the controller 26 is configured to actuate the valve 22 in a way that causes fluid 56 to flow through flow passage 14 only when that passage is at or near a particular azimuthal direction of the steering device 10 about a rotational axis 28 thereof. For example, controller 26 may be connected to one or more directional sensors 43 internal or external of steering device 10 (e.g., in string 20), that provide information about the rotational positions (e.g., the rotational azimuth value about the rotational axis 28 of steering device 10 or a signal indicating that the rotational azimuth value of the steering device 10 is at a preselected rotational azimuth or with a preselected rotational azimuth interval) of steering device 10. Based on that information, the controller 26 operates the one or more valves 22. Controller 26 may, for example, operate valve 22 to increase fluid flow only when steering device 10 is at a preselected rotational position interval (i.e., when the rotational azimuth of steering device 10 about the rotational axis 28 is within a preselected range of values). Alternatively, directional sensor 43 provides a rotational velocity of steering device 10 and controller 26 operates valve 22 in a periodic way where the periodicity is related to the rotational velocity provided by directional sensor 43. For example, in some modes of operation such as when rotational velocity of steering device 10 is constant, the controller 26 is configured to actuate the valve 22 in a periodic way with constant periodicity that causes fluid 56 to flow through flow passage 14 only when that passage is at or near a particular azimuthal direction of the steering device 10 about the rotational axis 28 thereof. By so actuating the valve 22, the fluid 56 flowing in segment 14c, which may be a junk slot or a channel in the drill bit 12 created for the purpose of conveying fluid 56, will cause a steering force on the steering device 10. As a consequence of the differential pressure between the bore fluid channel and the annular channel in the borehole annulus between the steering device 10 and the inside surface 38 of the borehole 40, this is creating a high velocity fluid flow through segment 14c that causes a Bernoulli effect of a lower pressure resulting in a Bernoulli suction force that draws the steering device 10 in the direction of that fluid flow thereby acting as a steering force on the steering device 10 configured to change the direction of drilling the borehole 40 to steer steering device 10 including drill bit 12 while drilling progresses. Valve(s) 22, actuator(s) 24, and/or controller 26 may be operated in a way that the created Bernoulli suction force stays geostationary. Geostationary in this context means that the direction of the Bernoulli suction force is directed into the same azimuthal direction relative to a fixed reference, such as the formation, the earth's magnetic field and/or the direction of gravity. That is, the Bernoulli suction force does not change its azimuthal direction about the rotational axis 28 for a period of time. In embodiments, the Bernoulli suction force stays geostationary while the steering device 10 rotates. The geostationary nature of the Bernoulli suction force in some embodiments remains for a predefined time interval or a predefined number of rotations. For example, the Bernoulli suction force will remain geostationary while the steering device 10 rotates for at least ten rotations, such as for at least 20 rotations or even for at least 50 rotations of the steering device 10.
In FIG. 1, valve 22 is shown as a reciprocating valve (e.g., poppet valve or mushroom valve) where actuator 24 causes a reciprocating movement of an obstruction member (e.g., plug) 29 to press it onto or release it from an opening (e.g., seat) 27 to regulate flow of fluid 56 through flow passage 14. Alternatively, actuator 24 may also cause a rotating member (not shown) in operative connection with obstruction member 29 to rotate and to cause the reciprocating movement of obstruction member 29 (for example, when the rotating member is a cam shaft that is rotated by actuator 24 and is in operative connection with obstruction member 29 wherein the rotation of the cam shaft causes the reciprocating movement of obstruction member 29). In another example, valve 22 may be a rotary valve in which the rotation of a passage (e.g., a passage included in a transverse plug) connects or disconnects fluid supply 18 with flow passage 14 to regulate the flow of fluid 56 through the attached flow passage 14. For a rotary valve, the obstruction member 29 can be rotated relative to the opening 27. The rotation of the obstruction member 29 may be at the same rotational speed as the rotation of steering device 10 or at a different rotational speed to achieve the geostationary Bernoulli suction force.
Junk slots or channels that are adjacent to other junk slots or channels are at least partially hydraulically isolated from adjacent junk slots or channels to enhance the fluid flow that produces the Bernoulli effect. This is manageable by structure, such as a flow barrier 33 between adjacent junk slots or channels (which may be a cutting arm of the drill bit 12 or a dedicated structure, for example) that is within a certain distance to inside surface 38 of borehole 40. That distance is smaller than the distance of the outer surface of the channel to the surface 38 of borehole 40. For example, the distance of the flow barrier 33 to the inside surface 38 of borehole 40 may be about 10 mm or smaller or even 5 mm or smaller when the steering device 10 is in use. That is, the diameter of flow barrier 33 is 20 mm or less or even 10 mm or less smaller than the diameter of the outermost cutting structure of the drill bit 12. Further, it is contemplated to configure the flow barrier 33 with an extendible element 42 that can be moved toward the inside surface 38 of borehole 40 during use to enhance hydraulic isolation between adjacent junk slots or channels and then easily collapse so that drag is not created on the drill bit 12. It is noted that the extendible element 42 may be beneficial but is not required to take advantage of this disclosure. In contrast, some concepts disclosed here are suited to provide a steering device for downhole that has no extendible part, for example no extendible part in contact with the borehole wall 120.
Fluid flow in flow passage 14 may exit a portion of the flow passage 14 (which may be at an end of segment 14b or at an end of segment 14c), to the outside surface 16 of the drill bit 12, at a face 36 of the drill bit 12 or at a radial side of the drill bit 12. In some embodiments (cf. FIG. 6), the flow direction at the flow exit 130 out of flow passage 14 (e.g. at the ends of segment 14b and/or segment 14c) is in an uphole direction of the drill bit 12, which is also the downstream direction for the flowing fluid 56 (drilling mud, for example) returning to surface. For example, a flow exit 130 that is on the radial outside surface 16 of the drill bit 12 rather than on the drill bit face 36, creates a flow with a flow direction in an uphole direction of the drill bit 12. When steering is desired, flow through flow passage 14 is permitted (by actuator 24 and valve 22) mainly or even only near or at a selected azimuthal position. Fluid flow along the outside surface 16 of the drill bit 12 that comes from flow passage 14, causes a radial Bernoulli suction force (indicated by arrows 39) and a steering force in the same azimuthal direction.
Where more than one Bernoulli subsystem (flow passage 14, valve 22 and actuator 24) is included, the steering force may be created more than once per revolution of the steering device 10 by cycling sequential valves 22 at the appropriate time and appropriate azimuthal position of flow passage segments 14b/14c such that each valve provides fluid flow only if and when its associated flow passage segments 14b/14c are at the desired azimuthal position. When none of the flow passage segments 14b/14c is at the selected azimuthal position, valves 22 may be actuated to reduce or prevent fluid flow through their associated flow passage segments 14b/14c. FIG. 1 illustrates two Bernoulli subsystems though more are contemplated. At least three Bernoulli subsystems is contemplated in one desirable embodiment. In each Bernoulli subsystem, the actuators 24 may be individually addressable to cause repositioning of the associated valve 22 allowing for control of: 1) when a Bernoulli effect is created pursuant to fluid flow in the associated flow passage 14; and 2) the magnitude of the fluid flow to create a larger (greater Bernoulli effect) or smaller (lesser Bernoulli effect) steering force and radius of curvature of the drilled borehole 40. In embodiments, actuators 24 are operable at at least 3 Hertz, though faster and slower rates are also contemplated for various needs. It will also be appreciated that if valve(s) 22 are all open or all closed at the same time and hence at all azimuthal positions the steering device 10 will drill in a natural direction without a steering force imparted by the Bernoulli subsystem(s). Closing all valves 22 may also be helpful to remove any obstruction in permanent flow channels 37 that may occur during operation of steering device 10 by solids in fluid 56, for example.
In one or more embodiments, actuator 24 is also activatable to position the valve 22 at other than fully open or fully closed. The valve 22 may in fact be positioned anywhere between (and including) fully open and fully closed, which allows for control of the degree Bernoulli suction force and/or of steering force created in the steering device 10. The Bernoulli suction force can thus be adjustable to create a particular magnitude of steering force that is changeable on demand at all times. Specifically, if a smaller flow of fluid 56 is released through flow passage 14, by opening the valve 22 only part way, a smaller Bernoulli suction force is created and therefore a smaller steering force. The greater the fluid flow through flow passage 14 is, the greater is the Bernoulli effect and hence the greater the steering force induced. In some embodiments, a desired steering parameter, such as a desired steering force, Bernoulli suction force, flow of fluid 56, radius of curvature of the drilled borehole 40, or similar may be determined and communicated to controller 26. Communication of the desired steering parameter to controller 26 may be done before steering device 10 operates downhole or while drilling progresses and steering device 10 is in operation (e.g., in real time). Controller 26 uses the desired steering parameter to adjust the one or more valve(s) 22, accordingly.
The actuator 24, in embodiments, may include a position feedback configuration that may comprise a sensor 17 operably connected to the actuator 24 or valve 22 or to flow passage 14. Sensor 17 may provide data of the relative position of valve 22, or data of fluid flow through flow passage 14 to controller 26 to adjust valve 22 by actuator 24 until the measured data by sensor 17 is close enough to a predetermined value (e.g., until the difference between the measured data by sensor 17 and the predetermined value is smaller than a predetermined threshold). For example, when the sensor is a flow meter, it can be used to measure the fluid flow in flow passage 14, thereby creating fluid flow data and the fluid flow data can be used by controller 26 to adjust valve 22 by actuator 24 until the desired fluid flow is measured by sensor 17. In another example, the position feedback configuration reports position of the Bernoulli subsystem (e.g., position of obstruction member 29 relative to opening 27) to the controller 26, for example in real time. In other embodiments, the actuator 24 may include a resolver motor so that motor position may be known by the controller.
FIG. 1A shows an alternate embodiment that includes one or more channels 145 machined into the steering device 10 (for example, by milling or by welding, brazing, or screwing additional material onto the OD of the tool body), and a timed thread connection 165 between the drill bit 12 and the steering device 10. The timed thread connection 165 ensures that segments 14c, which may be a junk slot or a channel in the drill bit 12, are aligned to the one or more channels 145 so that fluid flowing through segment 14c will also flow through channel 145. Advantageously, the one or more channels 145 may be machined into a portion 155 of the steering device 10 that is larger than an adjacent portion 175. For example, portion 155 may have an outer diameter that is larger than the outer diameter of adjacent portion 175. The one or more channels 145 provide additional flow channels behind the drill bit 12. The one or more channels 145 increase the active area of lower pressure, resulting in a higher Bernoulli suction force and steering force of steering device 10 and drill bit 12.
FIG. 1B shows another alternate embodiment, where one or more flow channels 115 are machined into a sleeve 105 that is mounted on the outer diameter of the steering device 10. The sleeve 105 may be fixed by a retaining feature 125, such as a retaining sleeve, for example a threaded retaining sleeve. Sleeve 105 can be aligned to drill bit 12 so that segments 14c, which may be a junk slot or a channel in the drill bit 12, are aligned to the one or more channels 115 in sleeve 105, so that fluid flowing through segment 14c will also flow through channel 115. The alignment between segment 14c and channel 115 may be secured (for example, locked) by a rotational locking feature 135 (e.g., fastener, —such as a locking key, a bolt, a screw, or a pin—or the shape of the mating surfaces of drill bit 12 and sleeve 105, (such as a spline, a profile, or a castellation) which allows the use of a standard, not-timed thread connection 117 between drill bit 12 and steering device 10. The one or more channels 115 provide additional flow channels behind the drill bit 12. The one or more channels 115 increase the active area of lower pressure, resulting in a higher Bernoulli suction force and an accordingly higher steering force of steering device 10 and drill bit 12.
Portion 155 in FIG. 1A and sleeve 105 in FIG. 1B may provide additional mounting space for electronics or sensors or one or more flow barriers 33, such as a seal. The one or more flow barriers 33 may be provided by extendible element 42 (FIG. 1) and/or by an additional fluid flow, introduced in addition to fluid flow through segments 14c, channels 145, and/or channels 115 and which may be directed and configured to reduce or prevent fluid exchange between channels segments 14c, channels 145, and/or channels 115. Flow barriers 33 may support the development of sufficient Bernoulli suction forces in case of larger distance between outside surface 16 of drill bit 12 and/or steering device 10 and inside surface 38 of borehole 40 (FIG. 1). Flow barriers 33 can thereby ensure that sufficient steering force is available for pushing drill bit 12 into the desired direction. In some embodiments, channels 145 on or in portion 155 of steering device 10 and/or channels 115 on or in sleeve 105 may independently be longer than the segment 14c, such as junk slot or channels on drill bit 12.
In some embodiments, the one or more valves 22 may be interacting to control the fluid flow in the specific mud channels 14e (e.g., interacting by controller 26). For example, if three or more valves 22 are used, such as a first, a second, and a third valve, the fluid flow through one of the first, the second, and the third valve may be adjusted based on the fluid flow through the other two of the first, the second, and the third valve. For example, in a particular rotational position of steering device 10, the first valve may allow a first fluid flow, the second valve may allow a second fluid flow, and the third valve may allow a third fluid flow. In this example, one or more of the first, the second, and the third fluid flows may be zero. The first fluid flow may be adjusted by the first valve based on the second and the third fluid flow, the second fluid flow may be adjusted by the second valve based on the first and the third fluid flow, and/or the third fluid flow may be adjusted by the third valve based on the first and the second fluid flow. Accordingly, the first, the second, and the third fluid flow may be different and may vary independently over time. Alternatively, or in addition, the fluid flow through one of the one or more valves 22 may be adjusted individually based on the downhole pressure and/or the total available fluid flow through fluid supply 18 of steering device 10. In addition, one or more of the valves 22 may be operated to compensate disturbances in the steering force, for example, by systematic amplification or attenuation of the steering forces or Bernoulli suction forces.
Turning now to FIG. 2, the flow barrier 33 may include an apex seal 210 (cf. FIG. 2), for example, in a groove 240 (such as an elongated groove) along the junk slot or between junk slots. The flow barrier 33 including the apex seal 210 may be substantially parallel to the rotational axis 28 of steering device axis. 10 or may be arranged at an angle with respect to the rotational axis 28 of steering device 10. Such apex seal 210 may be energized by biasing members 230, which may include active elements such as actuators and/or which may include passive elements such as (weak) springs in embodiments (for example, springs with a relatively low stiffness that are configured to expand and engage with the borehole wall 220 at relatively low force to keep the rubbing and friction force at a relatively low level while still inhibiting fluid flow therepast. In some cases, the shape of the radial outside surface 16 of the drill bit 12 may not exactly match the shape of the inner surface of the borehole wall 220. In these cases, there may be fluid filled spaces or one or more cavities between drill bit 12/steering device 10 and borehole wall 220, such as a first cavity 250 and/or a second cavity 260. The flow barrier 33 or apex seal 210 has the effect to limit or reduce the fluid connection between adjacent first and second cavity or junk slots, thus fluid flow between first and second cavity and thereby increasing the sealing effect between the cavities or junk slots. Reducing the fluid connection between adjacent first and second cavity or junk slots further limits the area of relatively high flow to a separated azimuth range that is defined by the first cavity or the second cavity. If the Bernoulli suction force is creating the desired lateral offset towards the borehole into direction of the low pressure area, the apex seal 210 can retract against the springs accordingly. Springs are sized to maintain extended position of the apex seal 210.
In some embodiments, valve(s) 22 rotate with the steering device 10 and in other embodiments, the actuator(s) 24 also rotate with the steering device 10. In yet other embodiments, referring to FIG. 3, a single actuator 30 is configured to operate more than one valve 22. Single actuator 30 may operate one or more valves 22 and/or all valves 22 in the steering device 10. FIG. 3 illustrates one iteration of steering device 10 wherein a single actuator 30 operates a plurality of valves 22 and does so by a swashplate 32 attached to a motor 34. The swashplate 32 may be rotated to ensure valves 22 will be operated periodically, for example to generate Bernoulli suction force stays geostationary. Geostationary in this context means that the direction of the Bernoulli suction force is directed into the same azimuthal direction relative to a fixed reference, such as the formation, the earth's magnetic field and/or the direction of gravity. That is, the Bernoulli suction force does not change its azimuthal direction about the rotational axis 28 of the steering device 10 for a period of time. In embodiments, then, the swashplate 32 will remain geostationary while the steering device 10 rotates. The geostationary nature of the Bernoulli suction force in some embodiments remains for a predefined time interval or a predefined number of rotations. For example, the swashplate 32 will remain geostationary while the steering device 10 rotates for at least ten rotations, for at least 20 rotations or even for at least 50 rotations of the steering device 10. Motor 34 may be an electric, motor, a hydraulic motor, etc.
Referring to FIGS. 4 and 5, a steering augmenter 60 is also disclosed. The augmenter 60 may be employed in addition to the steering device 10 disclosed above or as a separate entity to be coupled with other tools that require a steering input. Where the augmenter 60 is used in conjunction with the steering device 10, the augmenter will increase a total length of a channel or junk slot to improve overall Bernoulli effect. In some embodiments, augmenter channels may independently be longer than the segment 14c (FIG. 1), such as junk slot or channels on drill bit 12. The augmenter 60 includes a body 62 having a longitudinal extent and which defines an inside surface 64 and an outside surface 66. The body in some embodiments is configured to attach to a drill bit 12, though it is also contemplated that the body could be configured to attach to other downhole tools instead of a drill bit that still would benefit from a steering input that the augmenter can provide. The inside surface 64 delineates a longitudinally oriented flow passage 68 that is supplied with a fluid 56 such as drilling mud from a string 20 connected thereto. Body 62 further defines a radially oriented flow passage 70 (i.e., a flow passage with a radial direction component) fluidly connecting the longitudinally oriented flow passage 68 to the outside surface 66 of the body 62. Further, a first channel 72 is created at the outside surface 66 of the body 62 to produce a Bernoulli effect with a wall of the borehole 40 during fluid flow therein. Additional channels 72 may also be used and may be distributed about a circumferential direction of the augmenter 60, e.g., evenly if desired. One, two, three or more channels 72 are contemplated. The number of channels 72 is limited only by the available space about the periphery of the augmenter 60. A first valve 74 is associated with the radially oriented flow passage 68 such that the valve 74 may allow, prevent or choke fluid flow through the radially oriented flow passage 68 upon demand or in response to a program in a controller (e.g., controller 26 in FIG. 1) so that the Bernoulli effect may be generated at or near a target azimuthal direction relative to an axis 76 of the augmenter 60. Actuators and valves may be any of those discussed above and may further include a disk valve as shown in FIGS. 4 and 5 and identified with numeral 74. The disk valve may be operated by a single motor 34 having the capability of maintaining the valve 74 substantially geostationary.
Referring back to channels 72, it is to be understood that such channels may be cut into the body 62 or built up on the outside surface 66 thereof. Barriers 78 between adjacent channels 72 may be of any material and in embodiments may be sized to extend from body 62 about 10 mm or less or even 5 mm or less of the inside surface 38 of the borehole 40. Materials for the barriers 78 may be attached to surface 66 via welding, brazing, adhesives, by fasteners, etc. The barriers 78 may have only that dedicated purpose or may be configured to have additional purpose such as a mounting area for electronics or sensors, sealing function to reduce or prevent leakage of fluid between channels 72, etc. The sealing function may be provided by seals on the barriers 78, e.g. using extendible elements like the extendible element 42 as discussed above, or by fluid flow. Creating the sealing function by fluid flow would be possible in several different ways, one of which would be providing additional flow channels between inner surface 64 and each of the barriers 78. A portion of the total flow will exit these flow channels instead of the nozzles in the drill bit 12 or the flow passages 70. The additional sealing flow channels may preferably be oriented such that the drilling fluid exits the barriers 78 substantially perpendicular to the inside surface 38 of borehole 40. Because this additional sealing flow will be slowed down by hitting the bore hole wall, it will develop a volume of increased pressure between the outer surface of barriers 78 and the inside surface 38 of borehole 40. This volume of increased pressure is counteracting the pressure equalization between adjacent channels 72, providing benefits similar to extendible elements 42, but without moving parts that may be subject to wear and tear during operation.
The augmenter 60 body may be configured with timed threads 80 that ensure the channels 72 will approximately align with junk slots or channels (which make up segment 14c in some embodiments) in the drill bit 12 when used therewith. Approximate alignment in this context means that the azimuth difference between junk slots/channels of drill bit 12 and channels 72 is in the range of +90° to −90, such as +45° to −45° or even +20° to −20° Aligning the channels 72 with segment 14c, for example, will enhance the steering input by extending the length of flow channel in which a Bernoulli effect may be achieved and therefore increase the steering moment created thereby. In some embodiments, aligning the channels 72 approximately 180° (i.e., the azimuth difference between junk slots/channels of drill bit 12 and channels 72 is in the range of 90° to 270°. such as in the range of 135° to 225° or even in the range of 160° to 200°) apart from segment 14c may also have a steering effect, in particular when a stabilizer 84 is installed between channels 72 and drill bit 12 (see below discussion with respect to FIG. 5). While timed threads work well for the purpose of aligning channels 72 with segment 14c in drill bit 12 of aligning channels 72 approximately 180° apart from segment 14c in drill bit 12, they are more tedious to create and hence it is also contemplated that the body 62 may include a sleeve 82 disposed thereon that is rotatable about the body 62 until secured (e.g., locked, for example) in place by a fastener, such as a locking key, a bolt, a screw, or a pin or through the shape of the mating surfaces of drill bit 12 and sleeve 105, such as spline, a profile, or a castellation, etc. Thus, the body 62 may be attached to the tool to be steered without timed threads and then the sleeve 82 rotated to align the channels 72 as needed and the sleeve secured in place. The additional length of channels associated with higher Bernoulli effect could also be achieved by lengthening the drill bit 12 but that would increase expense of the drill bit and the augmenter 60 provides the advantage without the added expense.
As a further feature of the augmenter 60, a stabilizer 84 may be disposed in the position of FIG. 4 or the position of FIG. 5. For example, as it is depicted in FIG. 4, in some embodiments, the stabilizer 84 may be located above the channel 72 which puts the channel 72 between the stabilizer 84 and the drill bit 12. In other embodiments, as it is depicted in FIG. 5, the stabilizer 84 may be located between the channel 72 and the drill bit 12 (where a continuation of the channel from the segment 14c (FIG. 1), which may be a channel or a junk slot of drill bit 12 is not required) or other tool, located uphole of the channel 72. In other embodiments, there is more than one stabilizer 84 installed and one of the stabilizer 84 is below and another stabilizer 84 is located above channel 72.
It will also be appreciated that if valve(s) 22, 74 are not operated during one or more rotations of steering device 10 and hence at all azimuthal positions of steering device 10 (for example, if valve(s) 22, 74 are open or closed or at a fixed position between fully open or fully closed during one or more rotations of steering device 10), then the steering force that is caused by the fluid 56 that exits flow exit 130 will also rotate with steering device 10 and thus will cancel out over one or more rotations of steering device 10 or becomes distributed about 360 degrees of the steering device 10 and cancels out thus providing no steering effect to steering device 10 and/or drill bit 12. Thus, when valve(s) 22 are not operated during one or more rotations of steering device 10, the steering device 10 will drill in a natural direction, such as in a straight or tangential direction thus creating a straight or tangential section of borehole 40 (such as straight or tangential section 99 of borehole 40 as opposed to a curved section 93 borehole that is achieved when a geostationary steering force is created, cf. FIG. 6). In use, the augmenter 60 may be configured such that a sum of flow through valve(s) 22, 74 (e.g., a first flow through the first valve and a second flow through a second valve) remains constant within about 20% or less during 5 or more revolutions of the steering augmenter 60 to drill in a natural direction, such as in a straight or tangential direction thus creating a straight or tangential section of borehole 40. A similar effect is achieved when controller 26 operates the one or more valve(s) 22, 74 in a periodic way, wherein the period of the valve operation is not a multiple of the revolution period of rotation of the steering device 10. That is, when controller 26 operates the one or more valve(s) 22, 74 in a periodic way, wherein the period of the valve operation is not a multiple of the revolution period of rotation of the steering device 10 during one or more rotations of steering device 10, then the steering force that is caused by the fluid 56 that exits flow exit 130 will cancel out over one or more rotations of steering device 10 or becomes distributed about 360 degrees of the steering device 10 and cancels out thus providing no steering effect to steering device 10 and/or drill bit 12. Thus, when controller 26 operates the one or more valve(s) 22, 74 in a periodic way, wherein the period of the valve operation is not a multiple of the revolution period of rotation of the steering device 10 during one or more rotations of steering device 10, the steering device 10 will drill in a natural direction, such as in a straight or tangential direction thus creating a straight or tangential section of borehole 40 (such as straight or tangential section 99 of borehole 40, cf. FIG. 6). In one embodiment, valve(s) 22, 74 will be randomly operated (e.g., randomly operated opened and closed) during one or more rotations of steering device 10 so that the steering force that is caused by the fluid 56 that exits flow exit 130 will cancel out over one or more rotations of steering device 10 or becomes distributed about 360 degrees of the steering device 10 and cancels out thus providing no steering effect to steering device 10 and/or drill bit 12 to drill in a natural direction, such as in a straight or tangential direction thus creating a straight or tangential section of borehole 40 (such as straight or tangential section 99 of borehole 40, cf. FIG. 6).
Referring to FIG. 6, a borehole system 50 comprises a borehole 40 in a subsurface formation 52. A drilling system or string 20 is disposed within the borehole 40. The steering device 10 is disposed as a part of the string 20.
In use, the steering device 10 contributes to successful placement of the borehole 40 being drilled thereby by selectively unevenly distributing fluid toward a selected azimuthal direction relative to the formation, the earth's magnetic field and/or the direction of gravity and thereby causing a Bernoulli effect related steering force on the steering device 10.
Further, with regard to any of the above, it is contemplated to associate a directional sensor with the process whose function it is to ensure that geodirection is always known and hence can be used by a controller controlling the actuators and valves so that a steering input and direction or no steering input may be selected in real time. Also, it is noted that some embodiments will also include mud pathways 37 (see FIG. 1 for example) extending to the drill bit that are not valve controlled. To the extent it is desirable to pulse fluid in these pathways, this is achievable simply by closing all valves or if a disk type valve having a position where there is no alignment of the disk valve with an outflow opportunity.
Set forth below are some embodiments of the foregoing disclosure:
Embodiment 1: A steering augmenter for a steering device of a drilling tool, the steering augmenter including a body having an inside surface and an outside surface and configured to attach to a drill bit, a first flow passage defined by the inside surface of the body and configured to convey a fluid supply, a channel at the outside surface of the body, the channel being configured to produce a Bernoulli effect therein during fluid flow therein, a second flow passage fluidly connecting the first flow passage to the channel, and a valve associated with the second flow passage and configured to allow, prevent or choke flow through the second flow passage.
Embodiment 2: The steering augmenter as in any prior embodiment wherein the configuration to attach to the drill bit is a timed thread.
Embodiment 3: The steering augmenter as in any prior embodiment wherein an azimuth difference between a junk slot of the drill bit and the channel is in the range of +90° to −90.
Embodiment 4: The steering augmenter as in any prior embodiment wherein an azimuth difference between a junk slot of the drill bit and the channel is in the range of 90° to 270°.
Embodiment 5: The steering augmenter as in any prior embodiment wherein the channel is in the outside surface of the body.
Embodiment 6: The steering augmenter as in any prior embodiment wherein the channel is in a sleeve that nests with the body and is selectively rotatable on the body and fixable to the body.
Embodiment 7: The steering augmenter as in any prior embodiment, wherein the sleeve is selectively fixable by mating surfaces of the drill bit and the sleeve.
Embodiment 8: The steering augmenter as in any prior embodiment, further comprising a stabilizer between the channel and the drill bit.
Embodiment 9: The steering augmenter as in any prior embodiment, wherein the sleeve is fixable by a fastener.
Embodiment 10: The steering augmenter as in any prior embodiment wherein the steering device is rotatable within a borehole and the valve rotates with the steering device.
Embodiment 11: The steering augmenter as in any prior embodiment wherein the valve is between the inside surface and an outside surface of the body.
Embodiment 12: The steering augmenter as in any prior embodiment wherein the valve includes an actuator.
Embodiment 13: The steering augmenter as in any prior embodiment, wherein the valve is rotationally independent of the steering augmenter.
Embodiment 14: A downhole drill bit assembly including a steering augmenter as in any prior embodiment, the drill bit attached to the steering augmenter.
Embodiment 15: A method for drilling a borehole into the earth, the method including conveying the steering device as in any prior embodiment into the borehole, operating the valve to allow, prevent or choke flow through the second flow passage, creating a steering force at the steering augmenter by the produced Bernoulli effect.
Embodiment 16: The method as in any prior embodiment, further comprising aligning the channel with a junk slot of the drill bit, so that an azimuth difference between the junk slot and the channel is in the range of +90° to −90.
Embodiment 17: The method as in any prior embodiment, further comprising aligning the channel with a junk slot of the drill bit, so that an azimuth difference between the junk slot and the channel is in the range of 90° to 270°.
Embodiment 18: The method as in any prior embodiment, wherein the channel is in a sleeve that nests with the body and further comprising rotating the sleeve to align the channel and securing the sleeve to the body after the alignment.
Embodiment 19: The method as in any prior embodiment, further comprising installing a stabilizer between the channel and the drill bit.
Embodiment 20: The method as in any prior embodiment, further comprising rotating the steering device and rotating the valve with the steering device within the borehole.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially”, and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” and/or “generally” includes a range of ±8% of a given value.
The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a borehole, and/or equipment in the borehole, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.
Patent Application
20240159109
