Flow Guide Actuation

Abstract

In one aspect of the present invention, a downhole drill string assembly comprises a bore there through to receive drilling fluid. A turbine may be disposed within the bore and exposed to the drilling fluid. At least one flow guide may be disposed within the bore and exposed to the drilling fluid wherein the flow guide acts to redirect the flow of the drilling fluid across the turbine. The flow guide may be adjusted by an actuator. Adjustments to the flow guide may be controlled by a downhole telemetry system, a processing unit, a control loop, or any combination thereof. In various embodiments the turbine may comprise rotatable turbine blades.

Description

BACKGROUND OF THE INVENTION

This invention relates to the field of downhole turbines used in drilling. More specifically, the invention relates to controlling the rotational velocity of downhole turbines.

Previous attempts at controlling downhole turbine speed were performed by diverting a portion of the drilling fluid away from the turbine. It was believed that the diversion of drilling fluid away from the turbine may result in less torque on the turbine itself. However, this technique may also require the additional expense of having to over design the turbine to ensure that sufficient torque is delivered even when fluid flow is restricted.

U.S. Pat. No. 5,626,200 to Gilbert et al., which is herein incorporated by reference for all that it contains, discloses a logging-while-drilling tool for use in a wellbore in which a well fluid is circulated into the wellbore through the hollow drill string. In addition to measurement electronics, the tool includes an alternator for providing power to the electronics, and a turbine for driving the alternator. The turbine blades are driven by the well fluid introduced into the hollow drill string. The tool also includes a deflector to deflect a portion of the well fluid away from the turbine blades.

U.S. Pat. No. 5,839,508 to Tubel et al., which is herein incorporated by reference for all that it contains, discloses an electrical generating apparatus which connects to the production tubing. In a preferred embodiment, this apparatus includes a housing having a primary flow passageway in communication with the production tubing. The housing also includes a laterally displaced side passageway communicating with the primary flow passageway such that production fluid passes upwardly towards the surface through the primary and side passageways. A flow diverter may be positioned in the housing to divert a variable amount of the production fluid from the production tubing and into the side passageway. In accordance with an important feature of this invention, an electrical generator is located at least partially in or along the side passageway. The electrical generator generates electricity through the interaction of the flowing production fluid.

U.S. Pat. No. 4,211,291 to Kellner, which is herein incorporated by reference for all it contains, discloses a drill fluid powered hydraulic system used for driving a shaft connected to a drill bit. The apparatus includes a hydraulic fluid powered motor actuated and controlled by hydraulic fluid. The hydraulic fluid is supplied to the hydraulic fluid powered motor through an intermediate drive system actuated by drill fluid. The intermediate drive system is provided with two rotary valves and two double sided accumulators. One of the rotary valves routes the hydraulic fluid to and from the accumulators from the drill fluid supply and from the accumulators to the drill bit. The rotary valves are indexed by a gear system and Geneva drive connected to the motor or drill shaft. A heat exchanger is provided to cool the hydraulic fluid. The heat exchanger has one side of the exchange piped between the drill fluid inlet and the drill fluid rotary valve and the other side of the exchange piped between the hydraulic fluid side of the accumulators and the hydraulic fluid rotary valve.

U.S. Pat. No. 4,462,469 to Brown, which is herein incorporated by reference for all that it contains, discloses a motor for driving a rotary drilling bit within a well through which mud is circulated during a drilling operation, with the motor being driven by a secondary fluid which is isolated from the circulating mud but derives energy therefrom to power the motor. A pressure drop in the circulating mud across a choke in the drill string is utilized to cause motion of the secondary fluid through the motor. An instrument which is within the well and develops data to be transmitted to the surface of the earth controls the actuation of the motor between different operation conditions in correspondence with data signals produced by the instrument, and the resulting variations in torque in the drill string and/or the variations in torque in the drill string and/or the variations in circulating fluid pressure are sensed at the surface of the earth to control and produce a readout representative of the down hole data.

U.S. Pat. No. 5,098,258 to Barnetche-Gonzalez, which is herein incorporated by reference for all that it contains, discloses a multistage drag turbine assembly provided for use in a downhole motor, the drag turbine assembly comprising an outer sleeve and a central shaft positioned within the outer sleeve, the central shaft having a hollow center and a divider means extending longitudinally in the hollow center for forming first and second longitudinal channels therein. A stator is mounted on the shaft. The stator has a hub surrounding the shaft and a seal member fixed to the hub wherein the hub and the shaft each have first and second slot openings therein. A rotor comprising a rotor rim and a plurality of turbine blades mounted on the rotor rim is positioned within the outer sleeve for rotation therewith with respect to the stator such that a flow channel is formed in the outer sleeve between the turbine blades and the stator. A flow path is formed in the turbine assembly such that fluid flows though the turbine assembly, flows through the first longitudinal channel in the central shaft, through the first slot openings in the shaft and the stator hub, through the flow channel wherein the fluid contacts the edges of the turbine blades for causing a drag force thereon, and then through the second slot openings in the stator hub and the shaft into the second channel.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the present invention, a downhole drill string assembly comprises a bore there through formed to accept drilling fluid. The assembly may also comprise a turbine disposed within the bore. The turbine may comprise at least one turbine blade and be in communication with a generator, a gear box, a steering assembly, a hammer element, a pulse telemetry device or any combination thereof.

The assembly may also comprise at least one flow guide disposed within the bore. The flow guide may be controlled by a feedback loop. The at least one flow guide may comprise a fin, an adjustable vein, a flexible surface, a pivot point or any combination thereof. The flow guide may be in communication with an actuator. The actuator may comprise a rack and pinion, a solenoid valve, an aspirator, a hydraulic piston, a flange, a spring, a pump, a motor, a plate, at least one gear or any combination thereof.

In another aspect of the present invention, a method for adjusting the rotation of a turbine is disclosed. This method comprises the steps of providing a downhole drill string assembly comprising a bore there through to receive drilling fluid, a turbine disposed within the bore and exposed to the drilling fluid, and at least one flow guide disposed within the bore and exposed to the drilling fluid. Then adjusting the flow guide to alter the flow of the drilling fluid, wherein the altered flow of the drilling fluid adjusts the rotation of the turbine.

The adjustment of the rotation of the turbine may comprise slowing down or speeding up of the rotational velocity of the turbine, or increasing or decreasing the rotational torque of the turbine. The adjustments may be controlled by a downhole telemetry system, a processing unit, a control loop, or any combination of the previous. The control loop may control the voltage output from a generator, a rotational velocity of the turbine, or a rotational torque from the turbine. The gain values of the control loop may be adjustable by an uphole computer and fed down to the turbine by a telemetry system or may be autonomously generated by prior programming against a preset target.

The assembly may further comprise a hammer disposed within the drill string and mechanically coupled to the turbine, wherein an actuation of the hammer is changed by adjusting the rotation of the turbine. The change in the actuation of the hammer may take the form of a change in frequency. It is believed that this change in actuation may allow the hammer to be used to communicate uphole. The actuating hammer may be able to communicate through acoustic waves, vibrations of the drill string assembly, or changes in pressure created by the hammer impacting the formation or by the hammer impacting a surface within the drill string assembly. The turbine itself may also create a pressure pulse for use in communication or the turbine may actuate a valve to create a pressure pulse for use in communication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram of an embodiment of a drill string assembly suspended in a bore hole.

FIG. 2 is a cross-sectional diagram of an embodiment of a drill string assembly.

FIG. 3 is a perspective diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 4 a is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 4 b is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 5 is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 6 is a perspective diagram of an embodiment of a flow guide and actuator.

FIG. 7 is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 8 is another perspective diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 9 is a cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 10 a is another cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 10 b is another cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.

FIG. 11 is another cross-sectional diagram of an embodiment of a turbine, flow guide, and actuator.

FIGS. 12 a and 12b are side view diagrams of an embodiment of a turbine comprising dynamic turbine blades.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a perspective diagram of an embodiment of a drill string 100 suspended by a derrick 108 in a bore hole 102. A downhole drill string component comprising a drilling assembly 103 is located at the bottom of the bore hole 102 and comprises a drill bit 104. As the drill bit 104 rotates downhole the drill string 100 advances farther into subterranean formations 105. The drilling assembly 103 and/or downhole components may comprise data acquisition devices adapted to gather data that may be used to aid the drill string 100 in identifying and accessing desirable formations 107. The data may be sent to the surface via a transmission system to a data swivel 106. The data swivel 106 may send data and/or power to the drill string 100. U.S. Pat. No. 6,670,880 to Hall et al. which is herein incorporated by reference for all that it contains, discloses a telemetry system that may be compatible with the present invention; however, other forms of telemetry may also be compatible such as systems that include mud pulse systems, electromagnetic waves, radio waves, wired pipe, and/or short hop. The data swivel 106 may be connected to a processing unit 110 and/or additional surface equipment.

Referring now to FIG. 2, the drilling assembly 103 may comprise a jack element 202. The jack element 202 may aid in formation penetration and in drill string steering. A first turbine 207 and a second turbine 240 may be located within a bore 208 formed in the drilling assembly 103. The first turbine 207 or the second turbine 240 may be adapted for a variety of purposes including but not limited to power generation, jack element actuation, steering, or hammer actuation.

In the embodiment of FIG. 2 the first turbine 207 may be adapted to rotate the jack element 202 and the second turbine 240 may be adapted to actuate a hammer element 234. A gearbox 211 may be disposed in the bore 208 and may be adapted to transfer torque from the first turbine 207 to the jack element 202. The rotational speed of the first turbine 207 may be adjustable such that the rotational speed of the jack element 202 changes. The rotational speed of the second turbine 240 may be adjustable such that the actuation of the hammer element 234 changes. A downhole processing unit 203 may be disposed within the bore 208 and may be in communication with a first actuator 204 and/or a second actuator 241 such as planetary gear systems 206. The first actuator 204 may be in further communication with a first at least one flow guide 205, and the second actuator 241 may in turn be in communication with a second at least one flow guide 245. The downhole processing unit 203 may control the actuators 204, 245 independently such that the at least one flow guides 205, 245 are manipulated causing the turbines 207, 240 to change speeds.

Adjusting the second at least one flow guide 245 may cause the second turbine 240 to change rotational speed causing the frequency of the actuation of the hammer element 234 to change. It is believed that through the changing of the frequency of the actuation of the hammer element 234 that uphole communication may be possible. The communication signals may take the form of the hammer element 234 creating acoustic waves from the impact of the hammer element 234 on the formation or the impact of the hammer element 234 on a surface 246 within the drill string assembly 103. The communication signals may also take the form of vibration of the tool string assembly 103 or pressure changes of the drilling fluid within the assembly 103 caused by the hammer element's 234 actuation. An uphole sensor such as a geophone, a pressure sensor, or an acoustic sensor may be used to receive the communications uphole. Communication along the drill string may also take the form of pressure pulses created by changing the speed of the turbine itself or by rotating a valve with the turbine.

The processing unit 203 may also be in communication with a downhole telemetry system, such that an uphole operator can send commands to the actuator 204. The processing unit 203 may also comprise a feedback loop that controls the actuator 204. The feedback loop may be controlled by an output of the first turbine 207 and/or the second turbine 240. The controlling output of the first turbine 207 and/or the second turbine 240 may include a voltage output from a generator (not shown) that is powered by the first turbine 207 or the second turbine 240 respectively, a desired rotational velocity of first turbine 207 or the second turbine 240 respectively, or a desired rotational torque of the first turbine 207 or the second turbine 240 respectively. The controlling gains of the feedback loop and other aspects of the feedback loop may be adjustable by an uphole computer.

FIG. 3 is a diagram of an embodiment of a portion of a drilling assembly 103. In this figure a turbine 207, an actuator 204 and at least one flow guide 205 are depicted. The actuator 204 in this embodiment may comprise a plate 301. The plate 301 may be disposed axially around the drilling assembly 103. The plate 301 may comprise pass through slots 302 adapted to allow fluid to flow through the plate 301. The plate 301 may also comprise attachment points 303 adapted to attach to at least one flow guide 205. The at least one flow guide 205 may comprise a clamp 305. The clamp 305 may be adapted to attach to the drill assembly 103 through a connection point 304. The flow guide 205 may comprise a flexible vein 306.

As drilling fluid travels down the drill string and enters into the drilling assembly 103 the turbine 207 may begin to rotate. The rotational force generated by the turbine 207 may be used for a variety of applications including but not limited to generating power or actuating devices downhole. It may be beneficial to control the rotational speed of the turbine 207 to better meet requirements at a given time.

The plate 301 may be part of an actuator 204 such as a gear system or motor that actuates rotational movement. Alternatively, the plate 301 may hold the flow guide 205 stationary. A downhole processing unit 203 disposed within the drill string (see FIG. 2) or surface processing unit 110 (see FIG. 1) may be in communication with the plate 301 through the actuator 204. Rotating the plate 301 may cause the veins 306 to flex and bend such that the downwash angle of the drilling fluid may change below the at least one flow guide 205. The flexible veins 306 of the flow guide 205 may also restrict the rotational movement of the plate 301.

FIGS. 4 a and 4b depict embodiments of flow guides 205 in various positions. In this embodiment drilling fluid 410 is depicted flowing down the drill string and engaging the turbine 207. It is believed that adjusting the at least one flow guide 205 by rotating 454 the plate 301 may flex the flexible veins 306 and change the downwash angle that the drilling fluid will engage the turbine 207. Changing the downwash angle may cause the turbine 207 to travel at different speeds based upon the rotation of the plate 301. This method could be used to slow down or speed up the turbine or to increase or decrease the rotational torque from the turbine. FIG. 4a depicts the plate 301 having no rotational torque applied to it. In this embodiment the veins 306 are not flexed or bent. The drilling fluid 410 may flow past the veins 306 nearly uninterrupted. The drilling fluid 410 may go on to exert a given force on the turbine 207 by generating lift as it passes the turbine 207. In FIG. 4b the plate 301 is rotated such that the veins 306 are flexed. It is believed that the flexed veins 306 may change the downwash angle of the drilling fluid 410. The drilling fluid 410 may engage the turbine 207 at an angle. It is believed that the turbine 207 would turn faster in this case due to increased lift than it would in the case depicted in FIG. 4a.

FIG. 5 depicts a diagram of a portion of a drilling assembly 103 comprising at least one flow guide 205, a turbine 207, and a generator 572. In some embodiments the rotation of the turbine 207 may actuate the generator 572 creating electrical power. The at least one flow guide 205 may be controlled by a feedback loop that is driven by the output voltage of the generator 572. In one embodiment, it is believed that the feedback loop may position the at least one flow guide 205 in such a way as to prevent the generator 572 from creating either too little power or too much power. Excess power created by the generator 572 may turn into heat which can adversely affect downhole instruments and too little power may prevent downhole instruments from operating.

In another embodiment, the positioning of the at least one flow guide 205 may be set by an uphole user. An uphole user may desire to set the position of the at least one flow guide 205 based upon the flow rate of drilling fluid entering the drilling assembly 103, based upon a desired power output, or based upon some other desired parameter.

FIG. 6 depicts an embodiment of a portion of a drilling assembly 103 comprising an actuator 204 and at least one flow guide 205. In this embodiment the at least one flow guide 205 may comprise a rigid fin 503. The fin 503 may attach to the drill string through a pivot point 504. The actuator 204 may comprise a plate 301 with slots 501 disposed around its circumference. The slots 501 may be adapted to receive tabs 502 disposed on the fins 503. The actuator 204 may be able to control the flow guides 205 by rotating the plate 301 such that the tabs 502 are engaged within the slots 501 causing the fins 503 to rotate on their pivot point 504. The rotated fins 503 may cause drilling fluid to change the angle at which it engages a turbine.

FIG. 7 is a diagram of an embodiment of a turbine 207, an actuator 204, and at least one flow guide 205. The flow guides 205 may comprise fins 503. In this embodiment the actuator 204 comprises a rack 601 and pinion 602. The rotation of the rack 601 may cause the fins 503 to rotate around a pivot point 504. The rotated fins 503 may change the angle at which drilling fluid engages the turbine 207 and change the rotational speed of the turbine 207.

FIG. 8 is a depiction of another embodiment of a turbine 207, an actuator 204 and at least one flow guide 205. In this embodiment the actuator 204 may comprise a slider 701. The slider 701 may be disposed radially around a central axis of the drill string 103. The actuator 204 may comprise a motor, a pump, a piston, at least one gear, or a combination thereof adapted to move the slider 701 parallel to the central axis of the drilling assembly 103. The slider 701 may comprise at least one flange 702. The flow guide 205 may comprise a fin 503 connected to the drill string at a pivot point 504. The flow guide 205 may also comprise a lip 703. The flange 702 of the slider 701 may be adapted to fit on the lip 703 of the flow guide 205. As the slider 701 moves towards the flow guide 205 the flange 702 may exert a force on the lip 703 and cause the flow guide 205 to rotate. The rotated fins 503 may change the angle at which drilling fluid engages the turbine 207, generating additional lift and changing the rotational speed of the turbine 207.

FIG. 9 is a cross-sectional diagram depicting an embodiment of a drilling assembly 103. In this embodiment the actuator 204 may comprise a solenoid valve 800. The solenoid valve 800 may comprise a coil of wire 801 wrapped circumferentially around a central axis of the drilling assembly 103. When the coil of wire 801 is electrically excited a slider 701 may be displaced such that a flow guide 205 is actuated. A preloaded torsion spring 802 may then return the flow guide 205 to an original position after the solenoid valve 800 disengages.

FIGS. 10 a and 10b depict embodiments of a turbine 207, an actuator 204, and a flow guide 205. The drill string assembly 103 may comprise a plurality of turbines 207. In this embodiment, the flow guide 205 comprises a funnel 905. As the funnel 905 is axially translated it may alter the flow space across the turbines 207. It is believed that as the funnel 905 restricts the flow space across the turbines 207 the drilling fluid velocity may increase thus increasing the rotational speed of the turbines 207.

The funnel 905 may be axially translated by means of a Venturi tube 910. The Venturi tube 910 may comprise at least one constricted section 915 of higher velocity and lower pressure drilling fluid and at least one wider section 920 of lower velocity and higher pressure drilling fluid. The Venturi tube 910 also comprises at least one low pressure aspirator 930 and at least one high pressure aspirator 940. The at least one low pressure aspirator 930 may be opened by at least one low pressure valve 935 and the at least one high pressure aspirator may be opened by at least one high pressure valve (not shown). It is believed that if the high pressure aspirator 940 is opened and the low pressure aspirator 930 is closed that drilling fluid may flow from the bore 208 to a chamber 950. A piston element 955 attached to the funnel 905 and slidably housed within the chamber 950 may form a pressure cavity. As drilling fluid flows into the chamber 950 the pressure cavity may expand thus axially translating the funnel 905. (See FIG. 10a) It is further believed that if the low pressure aspirator 930 is opened and the high pressure aspirator 940 is closed that drilling fluid may flow from the chamber 950 to the bore 208. As drilling fluid flows out of the chamber 950 the pressure cavity may contract thus reversing the axial translation of the funnel 905. (See FIG. 10b)

FIG. 11 discloses an embodiment of a flow guide 205 comprising a funnel 905. In this embodiment the funnel 905 may be axially translated by means of at least one motor 1001. The motor 1001 may be in communication with a rack 1005 and pinion 1010. The rack 1005 may be connected to the funnel 905 and the pinion 1010 may comprise a worm gear. It is believed that as the pinion 1010 is rotated by the motor 1001 the rack 1005 and funnel 905 will be axially translated.

FIGS. 12 a and 12b disclose an embodiment of a turbine 207 comprising at least one turbine blade 1107. The turbine blade 1107 may be aligned along an initial vector 1110. The turbine blade 1107 may rotate a given angle 1115 to a subsequent vector 1120. The given angle 1115 may remain the same for several rotations of the turbine blade 1107 or the given angle 1115 may vary for different rotations. It is believed that rotation of the turbine blade 1107 from the initial vector 1110 to the subsequent vector 1120 may alter the rotational speed of the turbine 207.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.

Claims

1. A method for adjusting the rotation of a turbine comprising the steps of: providing a downhole drill string assembly comprising a bore there through to receive drilling fluid, a turbine disposed within the bore and exposed to the drilling fluid, and at least one flow guide disposed within the bore and exposed to the drilling fluid; andadjusting the flow guide to alter the flow of the drilling fluid, wherein the altered flow of the drilling fluid adjusts the rotation of the turbine.

2. The method of claim 1, wherein the adjustment of the rotation of the turbine comprises slowing down or speeding up of the rotational velocity of the turbine.

3. The method of claim 1, wherein the adjustment of the rotation of the turbine comprises increasing or decreasing the rotational torque or the turbine.

4. The method of claim 1, wherein the adjusting the flow guide is controlled by a downhole telemetry system.

5. The method of claim 1, further comprising the step of sending a command signal from a processing unit to the flow guide causing the flow guide to adjust.

6. The method of claim 1, wherein the adjusting the flow guide is controlled by a feedback loop.

7. The method of claim 6, further comprising providing a generator powered by the turbine, wherein the feedback loop is controlled by a desired voltage output from the generator.

8. The method of claim 6, wherein the feedback loop is controlled by a desired rotational velocity of the turbine.

9. The method of claim 6, wherein the feedback loop is controlled by a desired rotational torque of the turbine.

10. The method of claim 6, wherein the feedback loop is adjustable by an uphole computer.

11. The method of claim 1, further comprising a hammer disposed within the drill string and mechanically coupled to the turbine, wherein an actuation of the hammer is changed by adjusting the rotation of the turbine.

12. The method of claim 12, wherein the changing of the actuation of the hammer comprises changing the frequency of the actuation of the hammer.

13. The method of claim 12, further comprising communicating uphole through the actuation of the hammer.

14. The method of claim 14, wherein an acoustic wave created by an impact of the hammer is used to transmit data uphole.

15. The method of claim 15, wherein the acoustic wave is created by the hammer impacting an earthen formation.

16. The method of claim 15, wherein the acoustic wave is created by the hammer impacting a surface of the downhole drill string assembly.

17. The method of claim 14, further comprising the step of changing the pressure of drilling fluid within the bore of the downhole drill string assembly through actuation of the hammer to transmit data uphole.

18. The method of claim 14, further comprising vibrating the downhole drill string assembly through actuation of the hammer to transmit data uphole.

19. A downhole drill string assembly comprising: a bore there through to receive drilling fluid;a turbine disposed within the bore and exposed to the drilling fluid;at least one flow guide disposed within the bore and exposed to the drilling fluid; anda hammer element in communication with the turbine.

20. A downhole drill string assembly comprising: a bore there through to receive drilling fluid;a turbine disposed within the bore and exposed to the drilling fluid;at least one flow guide disposed within the bore and exposed to the drilling fluid; anda feedback loop component in communication with the flow guide.