US20150060141A1

US20150060141A1 - Downhole motor sensing assembly and method of using same

Info

Publication number: US20150060141A1
Application number: US14/015,253
Authority: US
Inventors: Gregory E. LEUENBERGER; Alamzeb Hafeez Khan; Jeffery CLAUSEN; Aaron Schen; Jacob Riddel
Original assignee: National Oilwell Varco LP
Current assignee: National Oilwell Varco LP
Priority date: 2013-08-30
Filing date: 2013-08-30
Publication date: 2015-03-05
Also published as: CA2861709A1

Abstract

A downhole sensing assembly for sensing motor parameters of a downhole motor positionable in a wellbore penetrating a subterranean formation is provided. The downhole motor has a stator and a rotor rotatable within the stator. The sensing assembly includes at least one rotor extension operatively connectable to the rotor and movable therewith, at least one marker positionable about the rotor extension, and at least one motor sensor positionable about a downhole tool and operatively coupled to the marker to detect movement of the marker whereby motor parameters, such as rotational speed of the motor, are detectable.

Description

BACKGROUND

This present disclosure relates generally to techniques for performing wellsite operations. More specifically, the present disclosure relates to techniques, such as drilling motors, for drilling wellbores.
Oilfield operations may be performed to locate and gather valuable downhole fluids. Oil rigs are positioned at wellsites, and downhole equipment, such as drilling tools, are deployed into the ground by a drill string to reach subsurface reservoirs. At the surface, an oil rig is provided to deploy stands of pipe into the wellbore to form the drill string. Various surface equipment, such as a top drive, or a Kelly and a rotating table, may be used to apply torque to the stands of pipe, to threadedly connect the stands of pipe together, and to rotate the drill bit. A drill bit is mounted on the lower end of the drill string, and advanced into the earth by the surface equipment to form a wellbore.
The drill string may be provided with various downhole components, such as a bottom hole assembly (BHA), drilling motor, measurement while drilling, logging while drilling, telemetry and other downhole tools, to perform various downhole operations. The drilling motor may be provided to drive the drill bit and advance the drill bit into the earth. Examples of drilling motors are provided in U.S. Pat. Nos. 7,419,018, 7,461,706, 6,439,318, 6,431,294, 2007/0181340, and 2011/0031020, the entire contents of which are hereby incorporated by reference herein.

SUMMARY

In at least one aspect, the disclosure relates to a downhole sensing assembly for sensing motor parameters of a downhole motor positionable in a wellbore penetrating a subterranean formation. The downhole motor has a stator and a rotor rotatable within the stator. The rotor extension is operatively connectable to the rotor and movable therewith. The marker is positionable about the at least one rotor extension. The motor sensor is positionable about the downhole tool and operatively coupled to the at least one marker to detect movement of the at least one marker whereby motor parameters comprising rotational speed of the motor are detectable.
At least one of the rotor extension, the marker and the motor sensor are positioned outside of the downhole motor. The marker is integral with the rotor extension. The marker is operatively connectable to the rotor extension. The rotor extension includes a rotor catch. The rotor extension includes a rod threadedly connectable to an end of the rotor. The rotor extension extends from an uphole end of the rotor. The rotor extension extends from the rotor and into a sub adjacent to the motor. The rotor extension includes a handle with a plurality of members extending therefrom. The members are integral with the marker. The marker is integral with the rotor extension. The marker is operatively connectable to the rotor extension.
The rotor extension includes an integral or a modular body. The rotor includes an upper portion and a lower portion threadly connectable to the rotor. The marker is positionable about the lower portion. The marker includes a magnet generating a magnetic field detectable by the sensor. The motor sensor includes at least one of a magnetic, electromagnetic, proximity, optical, electro-magnetic, acoustic, fluxgate, magneto-resistive, magnetometer, and Hall Effect sensor. The downhole sensing assembly may also include at least one downhole sensor comprising at least one of a temperature, pressure, vibration, force, and gyroscope sensor.
In another aspect, the disclosure relates to a drilling system for drilling a wellbore in a subterranean formation. The drilling system includes a downhole motor positionable in a downhole drilling tool disposable in the wellbore (the downhole motor includes a stator and a rotor), and a downhole sensing assembly. The downhole sensing assembly includes at least one rotor extension operatively connectable to the rotor and movable therewith, at least one marker positionable about the rotor extension, and at least one motor sensor positionable about the downhole tool and operatively coupled to the one marker to detect movement of the marker whereby motor parameters comprising rotational speed of the motor are detectable.
The drilling system may also include a surface unit and/or a downhole unit operatively connected to the downhole sensing assembly, telemetry operatively coupling the surface unit and the downhole sensing assembly, and/or a top sub operatively connected to the downhole motor. The rotor extension, the marker and/or the at least one motor sensor may be positioned in the top sub.
Finally, in another aspect, the disclosure relates to a method of sensing parameters of a motor of a downhole tool positionable in a wellbore penetrating a subterranean formation. The motor includes a stator and a rotor. The method involves providing the motor with a downhole sensing assembly. The downhole sensing assembly includes at least one rotor extension operatively connectable to the rotor and movable therewith, at least one marker positionable about the rotor extension, and at least one motor sensor positionable about the downhole tool and operatively coupled to the marker to detect movement of the marker. The method further involves detecting the at least one marker with the at least one marker sensor, determining downhole parameters comprising revolutions per minute of the motor based on the detecting, and determining downhole parameters with at least one downhole sensor. The method may also involve selectively adjusting drilling based on at least one of drilling parameters determined from the detecting, downhole parameters determined with the at least one downhole sensor, and known parameters.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above recited features and advantages of the present disclosure can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof that are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments and are, therefore, not to be considered limiting of its scope. The Figures are not necessarily to scale and certain features, and certain views of the Figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.

FIG. 1 depicts a schematic view, partially in cross-section of a downhole drilling tool deployed into a wellbore, the downhole drilling tool having a drilling motor with a motor sensing assembly.

FIG. 2 depicts a cross-sectional view of a portion of the downhole drilling assembly depicting the drilling motor and motor sensing assembly.

FIGS. 3A-3C depict cross-sectional, end and perspective views of a motor sensing assembly.

FIGS. 4A-4C depict cross-sectional, end and perspective views of another motor sensing assembly.

FIG. 5 depicts a flow chart of a method of sensing parameters of a motor.

DETAILED DESCRIPTION OF THE INVENTION

The description that follows includes exemplary apparatus, methods, techniques, and/or instruction sequences that embody techniques of the present subject matter. However, it is understood that the described embodiments may be practiced without these specific details.
The present disclosure relates to a motor sensing assembly usable for sensing parameters, such as rotation, of a motor in a downhole tool. The motor sensing assembly may include a rotor extension (e.g., a rotor catch) coupled to a rotor of the motor, a marker positionable about the rotor extension, and a motor sensor coupled to a fixed portion of the downhole tool. The motor sensor may be used to detect changes in magnetic fields caused by rotation of the rotor. The marker may be detectable by the motor sensor to provide, for example, rotational speed of the drilling motor (e.g., revolutions per minute (RPMs) of a stator relative to a rotor of the drilling motor) and/or movement of the rotor (e.g., wobble or whirl).
The motor sensing assembly may be positioned outside of the motor and isolated from motion and/or vibration therein. The rotor extension may extend from the rotor and/or motor to facilitate access to the rotor and/or to provide measurements therefrom. The motor sensor may be positioned outside the drilling motor and in a non-rotating portion of the downhole tool to facilitate access to components of the assembly, transfer of measurement, and/or collection of data. The motor sensing assembly may be used for measurement of bit RPM through the motor. The measurements may be used for detection of bit stick/slip, motor performance, and mechanical specific energy (MSE), as well as other info.
FIG. 1 depicts an example environment in which a downhole motor with a motor sensing assembly may be used. While a land-based drilling rig with a specific configuration is depicted, the motor sensing assembly may be usable with a variety of land based or offshore applications. In each version, a drilling system 100 includes a rig 101 positionable at a wellsite 102 for performing various wellbore operations, such as drilling.
FIG. 1 depicts a schematic view, partially in cross-section, of the wellsite 102. The drilling system 100 also includes a drill string 103 with a downhole tool (or bottom hole assembly (BHA)) 108 and a drill bit 104 at an end thereof. The drill string 103 may include drill pipe, drill collars, coiled tubing or other tubing used in drilling operations. The drill bit 104 is advanced into a subterranean formation 105 to form a wellbore 106.
Various surface (or rig) equipment 107, such as a Kelly, rotary table, top drive, elevator, etc., may be provided at the rig 101 to rotate the drill bit 104. A surface unit 112 a is also provided at the surface to operate the drilling system. Downhole equipment, such as the downhole tool 108, is deployed from the surface equipment 107 and into the wellbore 106 by the drill string 103 to perform downhole operations.
The downhole tool 108 is at a lower end of the drill string 103 and contains various downhole equipment for performing downhole operations. Such equipment may include, for example, measurement while drilling, logging while drilling, telemetry, processors and/or other downhole tools. As shown, the downhole tool 108 includes a downhole unit 112 b for communication between the downhole tool 108 and the surface unit 112 a. One or more units 112 a,b may be provided.
The downhole tool 108 may also be provided with various devices, such as motor 111 for operating downhole equipment, such as the drill bit 104. The downhole tool 108 may be provided with one or more motors 111 for rotating the drill bit 104. As shown, a single motor 111 is positioned between the drill string 103 and the drill bit 104. The motor 111 may be used to convert hydraulic energy from the mud passing therethrough into rotational energy. The rotational energy may be used to power and/or drive components of the downhole tool 108.
The motor 111 may be any motor with moving parts, such as a moineau motor including a helical rotor 124 rotationally positionable in a helical stator 122 and driven by the flow of mud therethrough. The helical stator 122 may have a number of lobes along an inner surface. The helical rotor 124 may have a number of lobes along a cross-section of an outer surface thereof, with the number of rotor lobes being less than the number of stator lobes. An example of a moineau motor that may be usable is provided in U.S. Pat. No. 7,419,018 previously incorporated by reference herein. The motor 111 may be capable of providing rotation to the bit 104.
The rotor 124 may be attached to a bottom of the motor 111 and allowed to spin relative to a top portion of the motor 111. The top portion of the motor 111 may be attached to a top sub 126. The top sub 126 may perform a secondary function of retaining the rotor 124 in case of some type of failure. The motor 111 may be provided with a downhole sensing assembly 119 for detecting downhole parameters, such as rotation of the rotor, as will be described more fully herein.
A mud pit 110 may be provided at the surface for passing mud through the drill string 103, the downhole tool 108 and out the bit 104 as indicated by the arrows. The motor 111 may be activated by fluid flow from the mud pit 110 and through the drill string 103. Flow of mud from pit 110 may be used to activate the motor 111 during drilling, for example by rotationally driving the motor 111 and/or other downhole components. Pressurized mud flowing through the motor 111 may be used to increase relative RPM from the stator 122 to the rotor 124.
FIG. 2 depicts a portion of the downhole tool 108 of FIG. 1 with a downhole sensing assembly 219 operatively connected to the motor 111. As shown in this view, the motor 111 includes a drill collar 220 with a helical stator 222 and helical rotor 224 therein. The top sub 126 includes a drill collar 228 operatively connected to the drill collar 220 of the motor 111 uphole therefrom.
The downhole sensing assembly 219 includes a rotor extension 230, a marker 232, a motor sensor 234, and units 112 a,b. The rotor extension 230 is operatively connected to the rotor 224. As shown, the rotor extension 230 is connected to an uphole end of the rotor 224, but may be at other locations. As also shown, the rotor extension 230 is positioned in the motor 111, and extends into the sub 126.
As depicted in FIG. 2, the marker 232 and motor sensor 234 are positioned in the sub 126 outside of the motor 111. The position of the sensing assembly 219 and its components may be selected based on need. For example, the components of the sensing assembly 219 may be positioned outside the motor 111 to isolate such components from movement of the motor 111 and/or fluid turbulence passing therethrough. In at least some cases, components of the sensing assembly 219, such as the rotor extension 230, may be positioned outside the motor 111 to prevent interference with the motor 111. Components of the sensing assembly 219 may also be positioned outside the motor 111 and/or in sub 126 where additional space may be provided for accessing the downhole sensing assembly 219.
The rotor extension 230 may be any device positionable about the rotor 224 and movable therewith for supporting the marker 232. The rotor extension 230 may be, for example, a rotor catch or handle operatively connected (e.g., threadedly connected) to the rotor 224. Rotor catches may be used, for example, to access and grip the rotor 224 for retrieval from the motor 111. The rotor extension 230 may perform other functions associated with the motor 111 and/or downhole tool 108, such as facilitating removal of the rotor 224, affecting movement of the rotor 224, extending the rotor 224 outside of the motor 111, among others.
The marker 232 may be positioned on, in or about the rotor extension 230. The marker 232 may optionally be a portion of the rotor extension 230 itself and/or be formed integrally therewith. The marker 232 is positioned offset from a central axis A of the rotor 224. The marker 232 may be identifiable by the motor sensor 234 for measuring various downhole parameters, such as motor parameters of the motor 111.
In an example, the marker 232 may be a magnetic device (such as a magnet, electromagnetic, Hall Effect sensor, etc.) generating a magnetic field M detectable by the motor sensor 234. As the rotor 224 rotates during operation, the marker 232 moves with the rotor 224 such that the marker 232 is detectable by the motor sensor 234. The motor sensor 234 may be used, for example, to count the number of times the marker 232 passes by the motor sensor 234. The frequency with which the magnetic field M changes may be used to calculate, for example, angular rotation rate of the motor 111. This information may be used, for example, to provide revolutions per minute (RPM) of the rotor 224 and/or torsional vibration of the motor 111.
The motor sensor 234 is positioned along a fixed location along the downhole tool 108, such as in the drill collar 228 or the stator 222. The motor sensor 234 may be, for example, removably embedded in the drill collar 228 with a portion extending therefrom. The motor sensor 234 may be positioned for operative coupling with the marker 232. The motor sensor 234 may also be positioned on a shoulder 236 of the drill collar 228 of the sub 126. The location of the motor sensor 234 may be in a top, side, and/or bottom portion of the drill collar 228. The motor sensor 234 may be positioned so that the motor sensor 234 monitors any location of the marker 232. The motor sensor 234 may also provide other information, such as the location of the motor 111 and/or motor and/or downhole parameters.
The motor sensor 234 may be any sensor, such as a proximity sensor with magnetic, electromagnetic, proximity, optical or other capabilities, capable of detecting the marker 224. The motor sensors 234 may include, for example, a sensor that senses a changing magnetic field, such as an electro-magnetic, acoustic, fluxgate, magneto-resistive, or magnetometer (e.g., Hall Effect) type sensor. For example, the sensor may be a magnetometer (scalar or vector) that may be used to measure a change in magnetic field strength. The motor sensor 234 may also be a distance sensor, such as electro-magnetic or acoustic sensor, that is designed to measure the distance or stand-off of the marker 232 from the motor sensor 234.
Additional sensors, such as downhole sensors S1 and S2 may be provided to measure other downhole parameters, such as temperature, pressure, vibration, forces (e.g., torque, bending force, weight on bit), motor dynamics, and other measurements. As shown, downhole sensor S1 is positioned in the rotor and downhole sensor S2 is positioned in the rotor extension 230, and be positioned in any location about motor 111 and/or downhole tool 108.
Measurements made by the motor sensor 234 and the downhole sensors S1 and S2 may be analyzed to understand performance and operation of the motor 111 and associated equipment. In an example, the downhole sensors S1 and/or S2 may be a gyroscope to provide an ‘earth reference’ and/or position in 3D space. The earth reference may be associated with the RPMs of the motor sensor 234. The earth reference and RPMs may be analyzed to determine, for example, motor stalling, string driven stick slip dynamics, mechanical specific energy (MSE), among others. The earth reference may also be used to differentiate motor stalling and string driven stick slip dynamics.
The motor sensor 234 and downhole sensors S1 and S2 may be operatively connected to the surface unit 112 a and/or a downhole unit 112 b as schematically depicted. The motor sensing assembly 219 may be wired or wireless coupled to the surface and downhole units 112 a,b for interaction therewith. Data and/or other signals may be passed between the motor sensor 234 and the surface and/or downhole units 112 a,b. The motor sensor 234 may be used, for example, to count revolutions of the rotor 224 as the marker 232 moves relative to the motor sensor 234. The revolutions counted may be passed to the surface and/or downhole units 112 a,b. The data may be collected and/or analyzed to provide motor parameters, such as RPM, speed of rotation, vibration, pressure, etc.
Based on the data received, various equipment at the wellsite may be selectively activated. For example, based on the RPMs detected by the motor sensors 234, the mud flow through the downhole tool, torque applied at the rig, and/or other operating parameters may be selectively adjusted. Optimum operational (e.g., drilling) and/or operational parameters may be determined and/or selected based on the measurements taken using the sensing assembly 219.
The surface and/or downhole units 112 a,b may be provided with, for example, a processor (e.g., central processing unit (CPU)), filters, memory, and/or other devices for communicating, collecting, processing, analyzing and/or otherwise using the data collected by one or more sensors. Other communication and/or processing devices, such as a telemetry device (e.g., wired-drill pipe, mud pulse, electro-magnetic, acoustic, and/or inductive coupling), transceivers, and antennas may also be coupled to the motor sensor 234. For example, the drill collars may be wired for wired telemetry through the drill string such that data may be passes through the wired telemetry system.
The data taken from the various sensors may be filtered with the filter (e.g., a low-pass, high-pass, or bandpass filter). The filtered data may then be acquired by an analog-to-digital converter, frequency-counter, or digital input. The acquired data may then be passed to the CPU (e.g., a microcontroller or other processor). The CPU may use the acquired data to determine an increase in RPM from the top sub 126 of the motor 111 to the rotor 224 of the motor 111. An increase in rotation rate may be saved to internal or external memory. The increase in rotation rate may be passed to the surface using telemetry.
The increase in rotation rate may also be combined with additional RPM measurements taken at or above the top sub 126 of the motor 111. Adding these measurements together may result in the total RPM of the rotor 224 of the motor 111. Measured RPM of the motor 111 may be combined with other measurements for comparison and/or evaluation. Other measurements may be used for further analysis. For example, RPM may also be determined at the drill bit (e.g., 104 of FIG. 1) by measuring RPM and recording the data to memory for comparison and/or analysis with the RPM measurements of the rotor extension 230. In another example, bit RPM through the motor, MSE, bit stick/slip, and motor performance may be determined.
Based on the data received from the sensors and/or other sources, the units 112 a, b may also be capable of sending signals to operate, activate, adjust, or otherwise control operation of the wellsite. The motor 111 and/or downhole tool 108 (as well as other wellsite components) may be selectively activated based on control signals received from the units 112 a,b.
As demonstrated by FIGS. 3A-4C, the rotor extension 230 may take various forms, such as a unitary or modular configuration shaped as desired to achieve the desired function. The rotor extension 230 may be removable and/or replaceable so that various rotor extensions 230 may be tailored for use with specific applications.
FIGS. 3A-3C depict various views of an example downhole sensing assembly 319 usable with the downhole tool 108 of FIG. 2. FIG. 3A shows the downhole sensing assembly 319 positioned in the downhole tool 108 about the downhole motor 111. FIG. 3B shows a top view of the downhole sensing assembly 319. FIG. 3C shows a perspective view of a rotor extension 330 of the downhole sensing assembly 419. The rotor extension in this version may be a rotor extension 330 with a unitary body.
The rotor extension 330 has a rotor end 340 threadedly connected to an uphole end of a rotor 224. The rotor extension 330 has an elongate body 342 extending from the rotor end 340 to a flow end 344. A shoulder portion 343 extends radially about the elongate body 342 adjacent the rotor end 340.
The rotor extension 330 also has a handle 346 at the flow end 344. The handle 346 may be secured to the body 342 by a bolt 345. The handle 346 has a generally elliptical shape with radial members 350 extending therefrom and with the flow holes 348 for the passage of fluid therethrough. Flow holes 348 through the handle 346 may allow flow through the motor 111 without much flow restriction. The handle 346 may be in the form of a spinning disk (or hub) with interrupted outer diameter or a series of the members (or splines) 350 extending from the handle 346 either above or below a motor end of the top sub 126.
The members 350 of the rotor extension 330 may be modified to increase resolution and/or accuracy of the measurement. The members 350 may be expanded to reach further out toward the wall of the drill collar 228 of the sub 126. Additional members 350 may be added to rotor extension 330. The members 350 may be individual spokes extending from the hub of the handle 346. In another example, the members 350 may be contoured lobes extending from a central portion of the handle 346.
Portions of the rotor extension 330, such as members 350, may be used as a marker 332 with or without additional markers 232. In this version, the members 350 may act as the marker 332 detectable by the motor sensor 234. The members 350 may be made of a metal (e.g., steel) that changes a magnetic field of the sensor. The members 350 may also have additional magnetism added thereon, for example, in a form of a magnet. The additional magnetism may be specifically polarized to allow for a north and/or south pole at various specific members 350 in various orders to allow for rotation direction determination. A separate marker (e.g., 232 of FIG. 2) may optionally be provided with or without the member 350 as the marker 332.
The members 350 and/or markers 332, 232 may be positioned above, below, or through a motor end of the top sub 126. The motor sensor 234 may be positioned facing uphole, downhole, or perpendicular to the centerline A of the rotor 224 with these members 350 extending off the handle 346. The spinning handle 346 with members 350/markers 332 may take the place of the extensions or interrupted geometry of the handle 346. Various embodiments of members 350, markers 332, or other interrupted geometry are possible.
The motor sensor 234 may be capable of detecting the members 350 and/or marker 232 as they pass adjacent the motor sensor 234 as shown in FIG. 3B. The members 350 may be counted to determine rotation of the handle 346, and thereby the RPMs of the rotor 224 relative to the stator 222. Motor sensor 234 and units 112 a,b may be provided in the sub 126 as previously described.
The motor sensor 234 may be positioned and adjusted to provide a desired standoff between the marker 332 and the motor sensor 234. The motor sensor 234 may be positioned in the sub 126 and view the members 350 of the handle 346 as they pass by the motor sensor 234.
FIGS. 4A-4C depict various views of an example downhole sensing assembly 419 usable with the downhole tool 108 of FIG. 2. FIG. 4A shows the downhole sensing assembly 419 positioned in the downhole tool 108 about the downhole motor 111 (FIG. 1). FIG. 4B shows a top view of the downhole sensing assembly 419. FIG. 4C shows a perspective view of a rotor extension 430 of the downhole sensing assembly 419. The rotor extension 430 may be a rotor catch with a modular body.
As shown in FIG. 4A, the rotor extension 430 has a rotor end 440 threadedly connected to an uphole end of a rotor 224. As shown in FIGS. 4A and 4B, the rotor extension 430 has a lower body portion 443 and an upper elongate body portion 445 extending from the rotor end 440 to a flow end 444. The lower body portion 443 has a flanged end 447 extending radially therefrom.
The upper body portion 445 has a threaded connection end 449 threadedly connected to the flanged end 447. The upper body portion 445 also has an elongate body 451 extending from the connection end 449 to the flow end 444, and a handle 456 at the flow end 444. The handle 456 may be secured to the body 451 by a bolt 445.
As shown in the top view of FIG. 4B, the flanged end 447 has a generally elliptical shape with radial members 450 extending therefrom. In this version, the flanged end 447 acts as a marker 432. The members 450 and/or marker 432 may be similar to the members 350 and/or marker 332 of FIGS. 3A-3C. Additional markers 232 may also be provided.
The motor sensor 234 is positioned in the drill collar 228 adjacent the flanged end 447. The motor sensor 234 is capable of detecting the members 450 as they pass adjacent the motor sensor 234 as shown in FIG. 4B. The members 450 may be counted to determine rotation of the handle 456, and thereby the RPMs of the rotor 224 in the stator 222. Motor sensor 234 and units 112 a,b may be provided in the sub 126 as described herein.
FIG. 5 is a flow chart depicting a method of sensing parameters of a motor. The motor may be the motor 111 of a downhole tool 108 and having a rotor and stator as provided herein. The method involves 560—providing the motor with a downhole sensing assembly. The downhole sensing assembly includes at least one rotor extension operatively connectable to the rotor and movable therewith, at least one marker positionable about the rotor extension, and at least one marker sensor positionable about the downhole tool and operatively coupled to the marker. The method also involves 562—detecting the marker(s) with the marker sensor (s).
The method may also involve 564—determining downhole parameters (e.g., revolutions per minute) of the motor based on the detecting, 566—determining downhole parameters with at least one downhole sensor, and/or 568—selectively adjusting drilling based on drilling parameters determined from the detecting, downhole parameters determined with downhole sensor, and/or other known parameters. The method may be performed in any order, and repeated as desired.
It will be appreciated by those skilled in the art that the techniques disclosed herein can be implemented for automated/autonomous applications via software configured with algorithms to perform the desired functions. These aspects can be implemented by programming one or more suitable general-purpose computers having appropriate hardware. The programming may be accomplished through the use of one or more program storage devices readable by the processor(s) and encoding one or more programs of instructions executable by the computer for performing the operations described herein. The program storage device may take the form of, e.g., one or more floppy disks; a CD ROM or other optical disk; a read-only memory chip (ROM); and other forms of the kind well known in the art or subsequently developed. The program of instructions may be “object code,” i.e., in binary form that is executable more-or-less directly by the computer; in “source code” that requires compilation or interpretation before execution; or in some intermediate form such as partially compiled code. The precise forms of the program storage device and of the encoding of instructions are immaterial here. Aspects of the invention may also be configured to perform the described functions (via appropriate hardware/software) solely on site and/or remotely controlled via an extended communication (e.g., wireless, internet, satellite, etc.) network.
While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. For example, one or more motor sensing assemblies, motor sensors, markers, members, and/or other features provided herein may be utilized about the motor and/or downhole tool.
Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.

Claims

1. A downhole sensing assembly for sensing motor parameters of a downhole motor positionable in a wellbore penetrating a subterranean formation, the downhole motor having a stator and a rotor rotatable within the stator, comprising:

at least one rotor extension operatively connectable to the rotor and movable therewith;

at least one marker positionable about the at least one rotor extension; and

at least one motor sensor positionable about a downhole tool and operatively coupled to the at least one marker to detect movement of the at least one marker whereby motor parameters comprising rotational speed of the downhole motor are detectable.

2. The downhole sensing assembly of claim 1, wherein at least one of the rotor extension, the at least one marker and the at least one motor sensor is positioned outside of the downhole motor.

3. The downhole sensing assembly of claim 1, wherein the at least one marker is integral with the at least one rotor extension.

4. The downhole sensing assembly of claim 1, wherein the at least one marker is operatively connectable to the at least one rotor extension.

5. The downhole sensing assembly of claim 1, wherein the at least one rotor extension comprises a rotor catch.

6. The downhole sensing assembly of claim 1, wherein the at least one rotor extension comprises a rod threadedly connectable to an end of the rotor.

7. The downhole sensing assembly of claim 1, wherein the at least one rotor extension extends from an uphole end of the rotor.

8. The downhole sensing assembly of claim 1, wherein the at least one rotor extension extends from the rotor and into a sub adjacent to the downhole motor.

9. The downhole sensing assembly of claim 1, wherein the at least one rotor extension comprises a handle with a plurality of members extending therefrom, the plurality of members integral with the at least one marker.

10. The downhole sensing assembly of claim 1, wherein the at least one marker is integral with the at least one rotor extension.

11. The downhole sensing assembly of claim 1, wherein the at least one marker is operatively connectable to the at least one rotor extension.

12. The downhole sensing assembly of claim 1, wherein the at least one rotor extension comprises one of an integral and a modular body.

13. The downhole sensing assembly of claim 1, wherein the at least one rotor comprises an upper portion and a lower portion threadly connectable to the at least one rotor, the at least one marker positionable about the lower portion.

14. The downhole sensing assembly of claim 1, wherein the at least one marker comprises a magnet generating a magnetic field detectable by the at least one motor sensor.

15. The downhole sensing assembly of claim 1, wherein the at least one motor sensor comprises at least one of a magnetic, electromagnetic, proximity, optical, electro-magnetic, acoustic, fluxgate, magneto-resistive, magnetometer, and Hall Effect sensor.

16. The downhole sensing assembly of claim 1, further comprising at least one downhole sensor comprising at least one of a temperature, pressure, vibration, force, and gyroscope sensor.

17. A drilling system for drilling a wellbore in a subterranean formation, the drilling system comprising:

a downhole motor positionable in a downhole drilling tool disposable in the wellbore, the downhole motor comprising a stator and a rotor;

a downhole sensing assembly, comprising:

at least one marker positionable about the at least one rotor extension; and

at least one motor sensor positionable about the downhole drilling tool and operatively coupled to the at least one marker to detect movement of the at least one marker whereby motor parameters comprising rotational speed of the downhole motor are detectable.

18. The drilling system of claim 17, further comprising at least one of a surface unit and a downhole unit operatively connected to the downhole sensing assembly.

19. The drilling system of claim 17, further comprising telemetry operatively coupling the surface unit and the downhole sensing assembly.

20. The drilling system of claim 17, further comprising a top sub operatively connected to the downhole motor, and wherein at least one of the at least one rotor extension, the at least one marker and the at least one motor sensor are positioned in the top sub.

21. A method of sensing parameters of a motor of a downhole tool positionable in a wellbore penetrating a subterranean formation, the motor comprising a stator and a rotor, the method comprising:

providing the motor with a downhole sensing assembly, the downhole sensing assembly comprising:

at least one marker positionable about the at least one rotor extension; and

at least one motor sensor positionable about the downhole tool and operatively coupled to the at least one marker to detect movement of the at least one marker;

detecting the at least one marker with the at least one marker sensor.

22. The method of claim 21, further comprising determining downhole parameters comprising revolutions per minute of the motor based on the detecting.

23. The method of claim 21, further comprising determining downhole parameters with at least one downhole sensor.

24. The method of claim 21, further comprising selectively adjusting drilling based on at least one of drilling parameters determined from the detecting, downhole parameters determined with the at least one downhole sensor, and known parameters.

25. The downhole assembly of claim 1, wherein the at least one marker comprises a magnet, and wherein the at least one rotor extension comprises a rotor catch, the at least one magnet positionable in the rotor catch.