WO2018101968A1

WO2018101968A1 - Anomaly detection systems and methods employing a downhole tool with axially-spaced sensor packages

Info

Publication number: WO2018101968A1
Application number: PCT/US2016/064841
Authority: WO
Inventors: Jason D. Dykstra; Venkata Madhukanth Vadali
Original assignee: Halliburton Energy Services, Inc.
Priority date: 2016-12-02
Filing date: 2016-12-02
Publication date: 2018-06-07

Abstract

A system includes a downhole tool deployed in a borehole, the downhole tool having a plurality of axially-spaced sensor packages. The system also includes a processor configured to analyze measurements collected at different times and by different ones of the plurality of axially-spaced sensor packages at a position of interest along the borehole. The processor detects an anomaly based on the collected measurements.

Description

ANOMALY DETECTION SYSTEMS AND METHODS EMPLOYING A DOWNHOLE TOOL WITH AXIALLY-SPACED SENSOR PACKAGES

BACKGROUND

Hydrocarbon exploration and production involves drilling boreholes, where different boreholes can be used for exploration operations, monitoring operations, injection operations, and production operations. The process of drilling boreholes is expensive and a poorly drilled borehole can increase the cost of subsequent operations (e.g., well completion and/or production operations). In some cases, a poorly drilled borehole can result in the borehole being unsuitable for production. In such case, the poorly drilled borehole may need to be plugged and a replacement borehole may be needed.

Efforts to improve hydrocarbon exploration and production operations are ongoing. For example, efficient detection of and accounting for downhole mistakes or anomalies would help reduce overall costs. However, efficient detection of and accounting for downhole mistakes or anomalies is often difficult due to the harsh downhole environment (e.g., high temperature, high pressure), limited accessibility (e.g., the space available for detection or correction tools is limited), and limited telemetry options (e.g., there is often a delay between when measurements are collected and when the measurements can be analyzed to detect a mistake or anomaly and respond).

As an example, a current limitation of directional drilling systems is the ability to detect twists and bends of the wellbore between surveys during the drilling process. Measurements are typically made during surveys that may be separated by 30, 60 or 90 feet (i.e., 9, 18, or 27 meters), depending on the length of a drill stand. The distance between measurements prevents accurate identification of wellbore micro undulations.

BRIEF DESCRIPTION OF THE DRAWINGS

Accordingly, there are disclosed herein anomaly detection systems and methods employing a downhole tool with axially-spaced sensor packages. In the drawings:

FIG. 1 is a block diagram showing an illustrative downhole tool;

FIG. 2A is a schematic diagram showing an illustrative drilling environment;

FIG. 2B is a schematic diagram showing an illustrative wireline logging environment;

FIG. 3 is a schematic diagram showing an illustrative time-lapse scenario involving a downhole tool with axially-spaced sensor packages; FIGS. 4 A and 4B are charts showing illustrative measurements collected by the axially- spaced sensor packages of FIG. 3;

FIG. 5 is a chart showing illustrative measurements collected by a downhole tool with axially-spaced sensor packages; and

FIG. 6 is a flowchart showing an illustrative method involving a downhole tool with axially-spaced sensor packages.

It should be understood, however, that the specific embodiments given in the drawings and detailed description below do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and other modifications that are encompassed in the scope of the appended claims.

DETAILED DESCRIPTION

Disclosed herein are anomaly detection systems and methods employing a downhole tool with axially-spaced sensor packages. In different embodiments, the downhole tool may be deployed in a borehole using drill string, wireline, slick line, coiled tubing, wired pipe, or another conveyance mechanism. While the downhole tool is deployed in the borehole, the axially-spaced sensor packages collect measurements as a function of position along the borehole and of time. The sensor packages may include, for example, accelerometers, gyroscopes, strain gauges, formation property sensors, and/or other sensors. Example formation properties that can be measured include electromagnetic poperties (e.g., resistivity, conductivity, dielectric constant, etc.), density, acoustic properties (velocity or slowness), gamma ray absorption or reflection, and/or other properties. To measure formation properties, one or more transmitters and one or more receivers may be used. In some embodiments, the same antenna is used for both transmitting an interrogation signal and receiving a response signal. Regardless of the particular arrangement, formation properties can be measured by transmitting at least one signal into the formation and receiving a corresponding response signal, where the properties of the response signal relative to the properties of the interrogation signal is indicative of the formation property being measured.

In at least some embodiments, measurements collected at different times and by different axially-spaced sensor packages when at a position of interest along the borehole are analyzed by a processor to detect an anomaly. In at least some embodiments, the processor analyzes collected measurements and detects anomalies based on a set of rules that are predetermined or adjustable over time. The processor may be part of a downhole system or a system located at earth's surface. Also, it should be appreciated that the processor may represent distributed processing units. For example, some processing operations to detect an anomaly may be performed downhole and other processing operations to detect an anomaly may be performed at earth's surface.

In at least some embodiments, the analysis of collected measurements to detect an anomaly involves comparing the measurements collected at different times and by different axially-spaced sensor packages at a position of interest along the borehole to each other. For example, if position of interest measurements for different axially-spaced sensor have an anomaly signature and match to within a threshold degree, the processor may output an anomaly detected signal or message or otherwise indicates that an anomaly has been detected. The anomaly detected signal or message could convey information such as a detected anomaly type and a degree of certainty. Another option is to compare position of interest measurements for different axially-spaced sensors to one or more predetermined anomaly signatures. In such case, if position of interest measurements for different axially-spaced sensor match a predetermined anomaly signature to within a threshold degree, the processor outputs an anomaly detected signal or message or otherwise indicates that an anomaly has been detected. As an example, comparing movement and/or strain measurements corresponding to different axially-spaced sensors at a position of interest enables detection of borehole path anomalies such as unwanted tortuosity, deviations, undulations, or twisting of the borehole path. Other anomalies that can be detected based on measurements corresponding to different axially- spaced sensors at a position of interest include sensor failures or changing borehole conditions. For sensor failure anomalies or changing borehole condition anomalies, a mismatch between position of interest measurements for different axially-spaced sensors can indicate an anomaly.

In response to an anomaly detected signal, one or more devices perform an operation. Different devices may be available to respond to different types of anomalies. Examples of devices that may operate in response a detected anomaly include output devices that display a representation/position of the anomaly. Additionally or alternatively, there are devices that can adjust drilling parameters in response to a detected anomaly. For example, bottomhole assembly (BHA) stabilizers, BHA directional drilling components, mud flow components, and/or surface drilling or top drive components can adjust drilling parameter in response to a detected anomaly. Additionally or alternatively, devices such as reamer components, backup sensors, and well completion components may perform operations in response to a detected anomaly. The operations performed in response to a detected anomaly may occur soon after an anomaly is detected (within seconds of detecting an anomaly) or these operations may be delayed (minutes, hours, days, or weeks later). In some embodiments, an output device may provide a log of anomalies determined at different positions along a borehole. In such case, anomaly response devices may operate based on a log of anomalies as a function of position along the borehole.

In at least some embodiments, an example system includes a downhole tool having a plurality of axially-spaced sensor packages. The system also includes a processor configured to analyze measurements collected at different times and by different ones of the plurality of axially-spaced sensor packages at a position of interest along the borehole. The processor detects an anomaly based on the analyzed measurements. The system may also include a device configured to perform an operation to display or respond to the detected anomaly.

Meanwhile, an example method includes deploying a downhole tool in a borehole, the downhole tool having a plurality of axially-spaced sensor packages. The method also includes collecting measurements at different times and by different ones of the plurality of axially- spaced sensor packages when at a position of interest along the borehole. The method also includes analyzing the collected measurements to detect an anomaly. The method may also include performing, by a device, an operation to display or respond to the detected anomaly. Various options related to anomaly detection using a downhole tool with axially-spaced sensor packages are described herein.

The disclosed systems and methods are best understood when described in an illustrative usage context. FIG. 1 shows an illustrative downhole tool 10. The downhole tool

10 includes a plurality of axially-spaced sensor packages 11A-11N. Each of the sensor packages 11A-11N may include, for example, accelerometers, gyroscopes, strain gauges, formation measurement sensors, and/or other sensors. The axially-spaced sensor packages

11 A-l IN are spaced at known axial distances relative to each other. The known axial distance between adjacent sensor packages may be the same or may vary. In operation, the axially- spaced sensor packages 11 A-l IN collect measurements as a function of position and time along a borehole. While or after measurements are collected by the axially-spaced sensor packages 11 A-l IN, analysis of the collected measurements is performed.

In at least some embodiments, analysis of the collected measurements involves one or more digitizers 12 to digitize the collected measurements. The digitized measurements are then stored, for example, by data storage 13 and accessed, as needed, by a processor 16. In at least some embodiments, the data storage 13 comprises a computer-readable medium such as random-access memory (RAM) or read-only memory (ROM). Meanwhile, the processor 16 may correspond to one or more central processing units (CPUs), programmable logic units, application-specific integrated circuits (ASICs), and/or other processing units. In addition to the digitized measurements, the data storage 13 may also store borehole anomaly detection instructions 14 and tool/drilling anomaly detection instructions 15.

When executed, the borehole anomaly detection instructions 14 cause the processor 16 to analyze the digitized measurements collected by at least some of the axially-spaced sensor packages 11 A-l IN. In at least some embodiments, the digitized measurements to be analyzed may correspond to a position of interest along a borehole. For example, the analysis to detect a borehole anomaly may involve measurements collected by different axially-spaced sensor packages at a position of interest being compared to each other. Due to the axial spacing between the sensor packages 11 A-l IN, the collected measurements for a position of interest are collected at different times (as the downhole tool 10 moves through a borehole such that each of the sensor packages 11 A-l IN passes the position of interest in turn and collects measurements). Additionally or alternatively, analyzing collected measurements to determine borehole anomalies may involve the measurements collected by different axially-spaced sensor packages at a position of interest being compared to one or more predetermined signatures. As desired, the collected measurements related to each of a plurality of positions of interest along a borehole can be analyzed using one or both of the above comparison options such that a log of borehole anomalies as a function of position along the borehole is generated.

When executed, the tool/drilling anomaly detection instructions 15 cause the processor 16 to analyze the digitized measurements collected by at least some of the axially-spaced sensor packages 11 A-l IN. In at least some embodiments, the analysis to detect tool or drilling anomalies involves collected measurements for different axially-spaced sensor packages at a position of interest being compared to each other or to one or predetermined signatures. In at least some embodiments, detection of tool anomalies may involve identifying a mismatch between measurements collected by different ones of the axially-spaced sensor packages 11 A- 1 IN at a position of interest. The mismatch may indicate, for example, that one of the sensor packages or related components is defective. Additional or alternatively, the mismatch may indicate, for example, that the condition of the tool changed between the time a first sensor package collected measurements at a position of interest and the time a second sensor package collected measurement at the position of interest. Likewise, detection of drilling anomalies may involve identifying a mismatch between measurements collected by different ones of the axially-spaced sensor packages 11 A-l IN at a position of interest. The mismatch may indicate, for example, bit wear, stick slip, a formation change, cutting loading, and/or other drilling anomalies. In some embodiments, detection of drilling anomalies may involve comparing collected measurements for different axially-spaced sensor packages at a position of interest to one or more signatures or thresholds related to a drilling anomaly.

In at least some embodiments, the downhole tool 10 includes an anomaly response device 17. The anomaly response device 17 may be in communication with the processor 16 such that when the processor 16 detects an anomaly, the anomaly response device 17 is directed to perform an operation. In different embodiments, the anomaly response device 17 may correspond to BHA stabilizers, BHA directional drilling components, reamer components, backup sensor packages, communication interfaces, and/or other devices. The anomaly response device 17 may respond to commands from the processor 16 and/or may convey detected anomaly information to another downhole tool or to earth's surface. For transmitting messages to another downhole tool and/or to earth's surface, anomaly response component 17 and/or the communication interface 18 employs available wired or wireless telemetry technology (e.g., electrical transmission line telemetry, optical transmission line telemetry, acoustic telemetry, mud pulse telemetry, electromagnetic telemetry, etc.).

In at least some embodiments, a processor at earth's surface (e.g., processor 52 in FIG. 2 A) may receive and analyze measurements collected by the plurality of sensor packages 11 A- 1 IN described herein. The analysis may occur as the measurements are collected (e.g., using uplink and/or downlink telemetry) and/or may occur in a delayed manner (e.g., after the downhole tool is retrieved or after some processing/analysis operations have been performed). Once the processor at earth's surface detects an anomaly, one or more operations are performed at earth's surface and/or downhole. Any downhole operations performed in response to a detected anomaly may be performed by the downhole tool 10 and/or another downhole component.

FIG. 2A shows an illustrative drilling environment 20A. In FIG. 2A, a drilling assembly 24 enables a drill string 31 to be lowered and raised in a borehole 25 that penetrates formations 29 of the earth 28. The drill string 31 is formed, for example, from a modular set of drill string segments 32 and adaptors 33. At the lower end of the drill string 31, a bottomhole assembly 34 with a drill bit 35 removes material from the formations 29 using known drilling techniques. The bottomhole assembly 34 also includes one or more drill collars 37 and a downhole tool 10 with a plurality of axially-spaced sensor packages 11 A- UN and other components for detecting an anomaly as described for FIG. 1.

In addition to the axially-spaced sensor packages 11A-11N, the downhole tool 10 may also include electronics for data storage, data processing, communication, and/or other operations as described for FIG. 1. In different embodiments, measurements collected by the downhole tool 10 and/or analysis results are used to perform surface or downhole operations in response to a detected anomaly. Additionally or alternatively, measurements collected by the downhole tool 10 and/or analysis results are conveyed to earth's surface using known telemetry techniques (e.g., wired pipe telemetry, mud pulse telemetry, acoustic telemetry, electromagnetic, etc.) and/or are stored by the downhole tool 10. In at least some embodiments, a cable 27 may extend from the BHA 34 to earth's surface. For example, the cable 27 may take different forms such as embedded electrical conductors and/or optical waveguides (e.g., fibers) to enable transfer of power and/or communications between the bottomhole assembly 34 and earth' s surface. In other words, the cable 27 may be integrated with, attached to, or inside the modular components of the drill string 3 1.

In FIG. 2 A, an interface 26 at earth's surface may receive measurements collected by the downhole tool 10 and/or analysis results via cable 27 or another telemetry channel and conveys the measurements and/or analysis results to a computer system 50. In some embodiments, the surface interface 26 and/or the computer system 50 may perform various operations such as converting signals from one format to another, storing collected measurements, analyzing the collected measurements to detect anomalies, responding to a detected anomaly, and/or directing another component to respond to a detected anomaly as described herein.

In at least some embodiments, the computer system 50 includes a processor 52 that displays downhole tool options, measurements collection options, measurement analysis options, anomaly detection options and/or anomaly detection results by executing software or instructions obtained from a local or remote non-transitory computer-readable medium 58. The computer system 50 also may include input device(s) 56 (e.g., a keyboard, mouse, touchpad, etc.) and output device(s) 54 (e.g., a monitor, printer, etc.). Such input device(s) 56 and/or output device(s) 54 provide a user interface that enables an operator to interact with the downhole tool 10 and/or software executed by the processor 52. For example, the computer system 50 may enable an operator to review/select downhole tool options, to review/select analysis options, to review measurements collected by the downhole tool 10, to review measurement analysis results, to review information regarding detected anomalies, to review/select anomaly response options, and/or to perform other tasks.

At various times during the drilling process, the drill string 31 shown in FIG. 2A may be removed from the borehole 25. With the drill string 31 removed, another option for anomaly detection systems and methods employing a downhole tool with axially-spaced sensor packages involves the wireline environment 20B of FIG. 2B. In FIG. 2B, a wireline tool string 60 is suspended in a borehole 25 that penetrates formations 29 of the earth 28. For example, the wireline tool string 60 may be suspended by a cable 42 having conductors and/or optical fibers for conveying power to the wireline tool string 60. The cable 42 may also be used as a communication interface for uplink and/or downlink communications. In at least some embodiments, the cable 42 wraps and unwraps as needed around cable reel 44 when lowering or raising the wireline tool string 60. As shown, the cable reel 44 may be part of a movable logging facility or vehicle 40 having a cable guide 46.

In at least some embodiments, the wireline tool string 60 includes logging tool(s) 64 (e.g., for resistivity logging, acoustic logging, gamma ray logging, nuclear magnetic resonance logging, etc.) and a downhole tool 10 with a plurality of axially-spaced sensor packages 11A- 1 IN as described for FIG. 1. The downhole tool 10 may also include electronics for data storage, data processing, communication, etc. In different embodiments, measurements collected by the downhole tool 10 and/or analysis results are used to perform surface or downhole operations in response to a detected anomaly. Additionally or alternatively, measurements collected by the downhole tool 10 and/or analysis results are conveyed to earth's surface using known telemetry techniques and/or are stored by the downhole tool 10.

In FIG. 2B, an interface 26 at earth's surface may receive measurements collected by the downhole tool 10 and/or analysis results via cable 42 or another telemetry channel and may convey the measurements and/or analysis results to a computer system 50 (e.g., part of the movable logging facility or vehicle 40). In some embodiments, the surface interface 26 and/or the computer system 50 may perform various operations such as converting signals from one format to another, storing collected measurements, analyzing the collected measurements to detect anomalies, responding to a detected anomaly, and/or directing another component to respond to a detected anomaly as described herein.

As an alternative to the wireline environment 20B of FIG. 2B, other options for deploying a downhole tool 10 in a borehole 25 include, but are not limited to, slick line, coiled tubing, a casing string, or combinations. For deployment options that do not provide power to the downhole tool 10 (e.g., a powerless slick line, coiled tubing, drillstring, or casing string), the downhole tool 10 may include a remote power source (e.g., a battery or other remote power source) to power the axially-spaced sensor packages 11 A- 1 IN or other electronics.

FIG. 3 is a schematic diagram showing an illustrative time-lapse scenario involving a downhole tool with axially-spaced sensor packages. While three axially-spaced sensors packages (SP1, SP2, SP3) are represented for the downhole tool 10 in FIG. 3, more axially- spaced sensor packages are possible. Without limitation, SP1, SP2, and SP3 may be comprised of accelerometers, gyroscopes, strain gauges, formation property sensors, and/or other types of sensors.

At a first time, ti, SP1 of downhole tool 10 collects measurements at a first position of interest, A, along the borehole 25. At a second time, t₂, SP2 of downhole tool 10 collects measurements at position A along the borehole 25 while SP1 collects measurements at a second position of interest, B, along the borehole 25. At a third time, t₃, SP3 of downhole tool 10 collects measurements at position A along the borehole 25, while SP2 collects measurements at position B along the borehole 25, and while SP1 collection measurements at a third position of interest, C, along the borehole 25. In FIG. 3, the distance (Dl) between positions A and B is approximately the same as the distance (D2) between positions B and C. In other words, the spacing between the SP1 and SP2 is the same as the spacing between SP2 and SP3. In different embodiments, the spacing between adjacent sensor packages may vary. Likewise, the distances between adjacent positions of interest may vary (i.e., Dl does not necessarily equal D2).

In at least some embodiments, detecting an anomaly at position A along the borehole 25 involves analysis of the measurements collected by SP1 for position A at ti and the measurements collected by SP2 for position A at t₂. As desired, the measurements collected by SP3 for position A at t₃, or measurements collected by other sensors packages at different times may also be used. As described herein, the collected measurements may be compared to each other and/or may be compared to one or more predetermined signatures associated with an anomaly. As an example, the measurements of a particular sensor package (e.g., SP1) can be used as a signature for detecting an anomaly (e.g., a pathway undulation or other phenomenon), subject to certain criteria (e.g., upon verification that the particular sensor package is working). Later measurements (e.g., from SP2 and SP3) can then be compared with the available signature to verify presence of the anomaly.

As an example, a bottomhole assembly can be modeled as a dynamic system as follows:

M = F Equation

(1)

where F = / (WOB, TOB, DOC, wear, TD RPM, hook load, mud pressure). In Equation 1, WOB is weight-on-bit, TOB is torque-on-bit, DOC is depth-of-cut, wear represents the deterioration of the drill bit or other downhole components, TD RPM is the rotations per minute of the top drive, hook load is the total force pulling down on the hook, and mud pressure is a measurement or estimate of the drilling mud flow.

In some embodiments, a data driven model may be used instead of those derived from first principles as in Equation 1. Also, in some embodiments, the measurements or signature of a position of interest, along with measurements made by SP1 at t₂ may be transformed to an expectation of measurements at a later time. For example, at t₂, when the sensor package SP2 is at location A, the expected measurements for SP2 may be given as:

£(SP2)_t=t2 = f( ₁(SPl \ _t=ti), T₂ (SPl\ _t=t2 ), OP \ _t=ti, OP \ _t=t2 ), Equation

(2)

where OP is an operating point that varies as a function of WOB, TOB, DOC, RPM, hook load, and mud pressure. With an appropriate model (for a drilling or non-drilling environment), the measurement differences of axially-spaced sensor packages that are due to position along a downhole tool can be accounted for to improve anomaly detection. For more information about dynamic model options, reference may be had to Vadali et al., Dynamic Modeling of Bottomhole Assembly, ASME DSCC2014-5927.

If the measurements of SP2 represent a statistically similar wellbore condition as that represented by the computed expectation using Equation 2, then that these measurements truly represent the wellbore condition, i.e., they provide confirmation of the well bore condition and provide information such as micro undulations, tortuosity etc. FIGS. 4 A and 4B are charts showing illustrative measurements collected by the axially-spaced sensor packages of FIG. 3. In FIG. 4A, the measurements collected by SP1 at or near ti (i.e., at or near position A) match the measurements collected by SP2 at or near t₂ (i.e., at or near position A) and also match the measurements collected by SP3 at or near t₃ (i.e., at or near position A). In at least some embodiments, the match between the measurements collected by SP1, SP2, and SP3 corresponding to position A indicates a borehole anomaly at position A. As a specific example, if the collected measurements (ai, i2, as) of FIG. 4A correspond to accelerometer measurements, matching measurements between axially-spaced sensor packages at or around position A indicates borehole micro undulations at position A.

In FIG. 4B, the measurements collected by SP1 at or near ti (i.e., at or near position A) match the measurements collected by SP2 at or near t₂ (i.e., at or near position A) and also match the measurements collected by SP3 at or near t₃ (i.e., at or near position A). In at least some embodiments, the match between the measurements collected by SP1, SP2, and SP3 corresponding to position A indicates a borehole anomaly at position A. As a specific example, if the collected measurements (σι, θ2, oi) of FIG. 4B correspond to stain measurements, matching measurements between axially-spaced sensor packages at or around position A indicates borehole micro undulations at position A. As desired, a historical database can be created to represent different conditions to pre-populate the sensor signatures. The historical database can be used with a learning algorithm to further improve the signatures.

If the measurements of SP2 do not match to the expectations, then one of the following possibilities may be true: 1) either SPl or SP2 is faulty; or 2) the wellbore condition at location A changed from ti to t₂. The first possibility (either SPl or SP2 is faulty) may be further confirmed through an iterative measurement process using the trailing sensor packages. For example, at t₃ sensor package SP3 arrives at location A and makes the measurements. Depending on whether these conform to the expectations based on 8Ρ2|α or SPl |ti, one of the sensor packages may be deemed faulty. This procedure can be repeated over a necessary length to confirm the fault within the required threshold. In response to identifying a faulty sensor package, the faulty sensor package may be recommended for maintenance and/or may be disabled or ignored. The second possibility (the wellbore condition at location A changed from ti to t₂) may arise due to circumstances such as a change in cuttings loading at location A between ti to t₂, change in vibration spectrum from the bit during the time interval, induced equipment wear (e.g., the drill bit may be worn), a change in formation type encountered by the bit, and/or other circumstances. This again may be confirmed through trends observed when the trailing sensor packages make the measurements. For example, if the change in formation type may be detected from a sudden shift in the measurements while change in wear may be sensed through slow, steady and monotonic change in measurements. Another example would be increased cuttings loading, that may add additional damping into the system and damp out the some frequencies in the measurements. FIG. 5 is a chart illustrating the effect of cutting loading, formation change, stick slip, and wear (the collected measurements will vary from the expected measurements).

FIG. 6 is a flowchart showing an illustrative method 200 involving a downhole tool with axially-spaced sensor packages. At block 202, the method 200 comprises deploying a downhole tool (e.g., tool 10 of FIG. 1) in a borehole, the downhole tool having a plurality of axially-spaced sensor packages (e.g., sensor packages 11A-11N of FIG. 1). At block 204, measurements are collected at different times by different ones of the plurality of axially- spaced sensor packages. At block 206, the collected measurements area analyzed to a detect an anomaly. The analysis operations of block 206 may be performed by a downhole processor, a processor at earth's surface, or a combination of processing units that are downhole or at surface processors. At block 208, at least one device is directed to perform an operation to display or respond to the detected anomaly. For example, in at least some embodiments, anomalies detected using the disclosed techniques can be used to guide directional drilling devices or operations (surface and/or downhole operations can be adjusted). As another option, reaming or borehole adjustment devices can be deployed or initiated in response to a detected anomaly. Additionally or alternatively, an output device can display a position or representation of a detected anomaly. Additionally or alternatively, downhole tool repair operations can be performed in response to a detected anomaly.

Embodiments disclosed herein include:

A: A system that comprises a downhole tool having a plurality of axially-spaced sensor packages. The system also comprises a processor configured to analyze measurements collected at different times and by different ones of the axially-spaced sensor packages when at a position of interest along the borehole. The processor detects an anomaly based on the analyzed measurements. B: A method that comprises deploying a downhole tool in a borehole, the downhole tool having a plurality of axially-spaced sensor packages. The method also comprises collecting measurements at different times and by different ones of the plurality of axially-spaced sensor packages when at a position of interest along the borehole. The method also includes analyzing the collected measurements to detect an anomaly.

Each of the embodiments, A and B, may have one or more of the following additional elements in any combination. Element 1 : wherein the processor and the device are downhole components. Element 2: wherein the processor or the device are located at earth's surface. Element 3 : wherein the processor compares movement or strain measurements collected by different ones of the plurality of axially-spaced sensor packages at the position of interest to each other to detect the anomaly. Element 4: wherein the processor compares movement or strain measurements collected by different ones of the plurality of axially-spaced sensor packages at the position of interest to one or more predetermined signatures to detect the anomaly. Element 5: wherein the detected anomaly corresponds to a borehole condition. Element 6: wherein the detected anomaly corresponds to a drilling condition. Element 7: wherein the detected anomaly corresponds to a condition of at least one of the sensor packages. Element 8: wherein the downhole tool is deployed in the borehole as part of a drill string. Element 9: wherein the downhole tool is deployed in the borehole via wireline, slick line, or coiled tubing. Element 10: further comprising a device that displays a representation or position of the detected anomaly. Element 11 : further comprising a device that adjusts a drilling parameter in response to the detected anomaly. Element 12: displaying, by a device, a representation or position of the detected anomaly. Element 13 : adjusting, by a device, a drilling parameter in response to the detected anomaly. Element 14: wherein said analyzing the collected measurements comprises comparing movement or strain measurements collected by different ones of the plurality of axially-spaced sensor packages at the position of interest to each other to detect the anomaly. Element 15: wherein said analyzing collected measurements comprises comparing movement or strain measurements collected by different axially-spaced sensor packages at the position of interest to one or more predetermined signatures to detect the anomaly. Element 16: wherein the detected anomaly corresponds to at least one of a borehole condition, a drilling condition, and a sensor package condition. Element 17: wherein deploying the downhole tool in the borehole involves a drill string. Element 18: wherein deploying the downhole tool in the borehole involves a wireline, slick line, or coiled tubing.

Numerous other variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications where applicable.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A system that comprises:

a downhole tool having a plurality of axially-spaced sensor packages; and

a processor configured to analyze measurements collected at different times and by different ones of the plurality of axially-spaced sensor packages when at a position of interest along the borehole, wherein the processor detects an anomaly based on the analyzed measurements.

2. The system of claim 1, wherein the processor is a downhole component.

3. The system of claim 1, wherein the processor is located at earth's surface.

4. The system of claim 1, wherein the processor compares movement or strain measurements collected by different ones of the plurality of axially-spaced sensor packages at the position of interest to each other to detect the anomaly.

5. The system of claim 1, wherein the processor compares movement or strain measurements collected by different ones of the plurality of axially-spaced sensor packages at the position of interest to one or more predetermined signatures to detect the anomaly.

6. The system of claim 1, wherein the detected anomaly corresponds to a borehole condition.

7. The system of claim 1, wherein the detected anomaly corresponds to a drilling condition.

8. The system of claim 1, wherein the detected anomaly corresponds to a condition of at least one of the sensor packages.

9. The system according to anyone of claims 1 to 8, wherein the downhole tool is deployed in the borehole as part of a drill string.

10. The system according to anyone of claims 1 to 8, wherein the downhole tool is deployed in the borehole via wireline, slick line, or coiled tubing.

11. The system according to anyone of claims 1 to 8, further comprising a device that displays a representation or position of the detected anomaly.

12. The system according to anyone of claims 1 to 8, further comprising a device that adjusts a drilling parameter in response to the detected anomaly.

13. A method that comprises:

deploying a downhole tool in a borehole, the downhole tool having a plurality of axially-spaced sensor packages,

collecting measurements at different times and by different ones of the plurality of axially-spaced sensor packages when at a position of interest along the borehole; and

analyzing the collected measurements to detect an anomaly.

14. The method according to claim 13, further comprising displaying, by a device, a representation or position of the detected anomaly.

15. The method according to claim 13, adjusting, by a device, a drilling parameter in response to the detected anomaly.

16. The method of claim 13, wherein said analyzing the collected measurements comprises comparing movement or strain measurements collected by different ones of the plurality of axially-spaced sensor packages at the position of interest to each other to detect the anomaly.

17. The method of claim 13, wherein said analyzing collected measurements comprises comparing movement or strain measurements collected by different axially-spaced sensor packages at the position of interest to one or more predetermined signatures to detect the anomaly.

18. The method of claim 13, wherein the detected anomaly corresponds to at least one of a borehole condition, a drilling condition, and a sensor package condition.

19. The method according to anyone of claims 13 to 18, wherein deploying the downhole tool in the borehole involves a drill string.

20. The method according to anyone of claims 13 to 18, wherein deploying the downhole tool in the borehole involves a wireline, slick line, or coiled tubing.