BACKGROUND

Exploring, drilling, and completing hydrocarbon wells are complicated, time consuming, and expensive endeavors. As such, the hydrocarbon recovery industry often emphasizes well access. Specifically, access to a well is important for monitoring its condition and maintaining its proper health. Such access to the well is often provided by way of well access lines such as coiled tubing.

Well access lines may be configured to deliver interventional or monitoring tools downhole. In the case of coiled tubing and other tubular lines, fluid may also be introduced downhole. Coiled tubing is particularly well suited for being driven downhole through a horizontal or tortuous well, to depths of perhaps several thousand feet, by an injector at the Earth's surface.

When performing coiled tubing applications, it is common to use various forms of impact tools to free stuck tools, clean out debris, etc. A bit may even be attached to the coiled tubing for an alternative drilling application. However, it is not normally known what force these devices are delivering and what their impact might be on other devices in the coiled tubing string. Because these important variables in the applications are unknown, operators are unsure of the reasons for success or failure in a particular application thus resulting in an inability to credibly predict whether an application will be successful before committing resources to it. Even if experience has shown that a particular course of action will be successful in eliminating abnormal behavior during a coiled tubing application, because of the unknown nature of the forces acting on the coiled tubing, operators cannot say that such action is not wasteful of resources, i.e., inefficient.

BRIEF DESCRIPTION OF THE DRAWINGS

Accordingly, systems and methods of adjusting a variable element of a coiled tubing application based on vibration-based feedback are disclosed herein. In the following detailed description of the various disclosed embodiments, reference will be made to the accompanying drawings in which:

Figure 1 is a contextual view of an illustrative coiled tubing environment for a milling application;

Figure 2 is a contextual view of an illustrative coiled tubing environment for a stuck tool application and a clearing debris application; Figure 3 is a contextual view of an illustrative coiled tubing environment tor a perforation application, extended reaching application, and formation fluid detection application; and

Figure 4 is a flow diagram of an illustrative method of adjusting a variable element of a coiled tubing application based on feedback.

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

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claims to refer to particular system components and configurations. As one of ordinary skill will appreciate, companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function.

In the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to. . . ". Also, the term "couple" or "couples" is intended to mean either an indirect or a direct electrical or physical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, through an indirect electrical connection via other devices and connections, through a direct physical connection, or through an indirect physical connection via other devices and connections in various embodiments.

In the following discussion and in the claims, "vibration profile" means a collection of ranges for the measurements of vibrations sensors in a coiled tubing application. One or more vibration sensors reporting measurements outside of their corresponding range indicates abnormal behavior for the coiled tubing application. All vibration sensors reporting measurements inside their corresponding range indicate normal behavior for the coiled tubing application.

DETAILED DESCRIPTION

The issues identified in the background are at least partly addressed by systems and methods of adjusting a variable element of a coiled tubing application based on feedback. During coiled tubing applications, vibrations within the coiled tubing string may indicate any number of problems if the vibration characteristics are not within normal operating ranges that make up a vibration profile associated with the coiled tubing applications. Such vibrations may include longitudinal or axial vibration, torsional vibration, and lateral vibration, and the identification of the problems based on the vibration characteristics lead to solutions that may not only increase the efficiency of coiled tubing applications but save the applications from failure. The problems may be identified based on feedback of the status of the coiled tubing applications, and the solutions may include adjusting one or more variable elements of the coiled tubing applications. For example, in a stuck-tool application, a variable element such as the flow rate of fluid pumped through the coil tubing may be adjusted by a mechanical controller such as a valve that increases or decreases the flow rate by opening and closing respectively. As another example, in a milling application, a variable element such as bit rotational speed may be adjusted by a mechanical controller such as a bit motor. In this way, many variable elements of many applications may adjusted. The variable elements may be adjusted in response to an operator command or automatically, i.e. without human input, based on the feedback.

The disclosed systems and methods for adjusting a variable element of a coiled tubing application based on feedback are best understood in terms of the context in which they are employed. As such, Figure 1 shows a contextual view of a coiled tubing environment including a feedback system 100. The system 100 includes a coiled tubing string 54, which may include coiled tubing coupled with a bottomhole assembly made up of various subs 64 and tools 65. The coiled tubing is pulled from a spool 52 by a tubing injector 56 and injected into a borehole 62 through a packer 58 and a blowout preventer 60. In this way, the coiled tubing string 54 is conveyed along the borehole 62. As shown, the borehole 62 initially is vertical. However, as detailed further below, the borehole 64 may be of fairly extensive reach eventually turning horizontal. Additionally, directional drilling may result in a tortuous borehole with many bends and turns.

The coiled tubing may be a continuous length of steel, alloy steel, stainless steel, composite tubing, or other suitable metal or non-metal material that is flexible enough to be wound on the spool 52 for transportation, and the spool 52 itself may be located on a coiled tubing truck for mobility. Due to the relative lack of joints, it is advantageous to use coiled tubing when pumping chemicals downhole.

In the borehole 62, the coiled tubing string 54 includes a supervisory sub 64 and one or more tools 65 coupled to the coiled tubing 54 that make up the bottomhole assembly. The supervisory sub 64 may control communication between uphole and downhole elements, and may also control communication between downhole elements such as the one or more tools 65 by providing a common clock, power source, communication bus, and the like. The tools 65 may be subs, or other sections of the coiled tubing string 54, that perform functions particular to a coiled tubing application. For example, in a perforation application the tools 65 may include a perforation tool including perforating guns and the like. As another example, in a milling application the tools 65 may include a milling tool including a bit. Coiled tubing applications may be performed offshore as well.

The system 100 also includes a data processing system 66, which may be coupled to an uphole interface 67 at the surface by a wired connection or wireless connection, and may periodically obtain measurement data from the uphole interface 67 as a function of position and/or time. The uphole interface 67 may communicate with the supervisory sub 64, tools 65, and/or the computer system 66 and may enable communication between uphole and downhole elements. For example, mud pulse telemetry, acoustic telemetry, and the like may be used to provide communications from the supervisory sub 64 to the uphole interface 67. Among other things, the data processing system 66 processes data received from the uphole interface 67, or the supervisory sub 64 and/or the one or more tools 65 directly, and generates a representative display for the operator to perceive. Software (represented by information storage media 72) may run on the data processing system 66 to collect the data and organize it in a file or database stored on non-transient information storage media. Specifically, one or more processors coupled to memory may execute the software and perform any appropriate action described below. The software may respond to user input via a keyboard 70 or other input mechanism to display data as an image or movie on a monitor 68 or other output mechanism. The software may process the data to optimize coiled tubing applications using feedback as described below, and the data processing system 66 may send command signals to adjust a variable element based on the feedback. In at least one embodiment, the data processing system 66 is located downhole within a housing able to protect the system 66 from the harsh downhole environment. In another embodiment, processors both at the surface and downhole may work together or independently to obtain, store, and process measurement data. The supervisory sub 64 and/or the tools 65 may include such downhole processors.

The system 100 further includes one or more vibration sensors 90 coupled to the coiled tubing string. As shown, the vibration sensors are located on the supervisory sub 64, tool 65, and the coiled tubing, but one or more vibration sensors may be located anywhere on the coiled tubing string 54. For example, the vibration sensors 90 may be located on either side of a downhole element, such as a particular tool, in order to pinpoint the direction in which vibration waves travel at that location of the coiled tubing string. The vibration sensors 90 measure vibrations within the coiled tubing string 54 during the coiled tubing application by measuring the characteristics of vibration waves traveling through the string 54. For example, amplitude, frequency, and the like may be measured. A vibration sensor 90 may include a tri- axial accelerometer that senses three directional components of the vibration waves (one for each coordinate axis), a piezoelectric accelerometer, magnetometers, Hall Effect devices, and the like. The vibration sensors 90 may measure or monitor lateral vibration, longitudinal vibration, and torsional vibration.

By measuring the vibration characteristics, downhole conditions such as stress, load, frictional resistance, and the like may be monitored on an ongoing basis. The vibration sensors 90 may be used to collect and relay vibration measurement data to the uphole interface 67 and/or data processing system 66 for analysis of ongoing conditions during a coiled tubing application. Depending on the coiled tubing application, vibration sensors 90 at different locations will be relevant to monitoring downhole conditions, and irrelevant sensors 90 may be excluded from the comparison with the vibration profile. For example, in a milling application, the vibration sensor 90 closest to the distal end of the coiled tubing string 54 will be most relevant, whereas in a perforation application, the vibration sensor 90 closest to the perforation gun will be the most relevant. In this way, the data reported by the vibration sensors 90 may be weighted according to relevance. The weight may impact the significance attributed to the vibration measurement data when the vibration measurement data is compared with a vibration profile.

For purposes of illustration of the concepts herein, relative terms of "low," "medium" and "high" acceleration vibration measurements are used herein. Such terms are not intended to reflect any specific values, as the quantitative measurements will be recognized to those skilled in the art to be variable depending on the coiled tubing string utilized and the components therein. For example, in terms of actual forces experienced, in many operational situations the axial acceleration on the coiled tubing string 54 is generally on the order of 0.1 g; but it can exceed 100 g for short time intervals (for example, a few milliseconds); and the lateral shock can exceed 1,000 g. Hence, in absolute forces, low vibration might be characterized, for example, by a mean vibration axial vibration level less than about 0.1 g with peaks on the order of 1 g for a few ms, and cross-axial vibration less than about 1 g with peaks no larger than 10 g. These thresholds may change depending upon the application.

Similarly, high vibration might be characterized, for example, as a vibration in which either the axial vibration exceeds 1 g on average, it has peak accelerations exceeding 100 g, (for example, for 1 or more times per second), the lateral vibration exceeds 10 g on average, or the lateral vibration has peaks exceeding a few hundred g one or more times per second. Medium level vibration could then, in this example, be characterized by anything between those two states. These thresholds also may change depending upon the application, tor clarity, however, the above examples are only examples, and are representative only of absolute forces; and thus actual measured vibration forces may be substantially different from the example values, depending on the measurement system and the coiled tubing string 54 characteristics. The thresholds and baseline values used herein may be determined from modeling, previous experience, or measurement during the coiled tubing application itself.

Considering a general coiled tubing application (specific coiled tubing applications are discussed below), the one or more processors of the data processing system 66 obtain vibration measurement data from the vibration sensors 90 (e.g. located on the bottomhole assembly) and provide feedback during the coiled tubing application based on the vibration measurement data. The one or more processors may continuously provide, over a period of time, feedback based on changing vibration measurement data resulting from adjusting the variable element. Specifically, the system 100 includes a mechanical controller, and the controller adjusts a variable element of the coiled tubing application based on the feedback. The mechanical controller may be actuated mechanically, electrically, hydraulically, and the like. The controller may continuously adjust the variable element based on the feedback until the vibration measurement data conforms to a profile associated with the coiled tubing application. For example, in a stuck-tool application, a mechanical controller such as a valve 61 increases or decreases fluid flow rate by opening and closing respectively. Although such a valve 61 is shown downhole here, the valve may also be located at any point along the path in which such fluid circulates including at the surface. A vibration sensor 90 near the valve reports a low vibration that is out of the range of the vibration profile of a stuck-tool application. Next, the valve 61 opens wider to increase the fluid flow rate to help free the stuck tool, and the vibration measurement data is again compared with the vibration profile. If the vibration sensor 90 reports data within the vibration profile, then no further action need be taken. If the vibration sensor 90 reports data still outside the vibration profile, the valve 61 may be further widened until the vibration profile threshold is reached for that particular sensor. Such adjustment may occur automatically, i.e., without human input. In at least one embodiment, the feedback occurs in real-time.

Some examples of coiled tubing applications are milling, extended reaching, freeing a stuck tool, clearing debris, perforation, formation fluid detection, and the like. During milling operations, a milling bit or similar downhole cutting tool on the coiled tubing string 54 is used to cut and remove material from equipment or tools located in the borehole. As the coiled tubing is advanced downhole, it encounters frictional resistance to continued advancement. Ultimately, such resistance may halt the continued advancement of the coiled tubing. This resistance may be identified by a vibration sensor 90 sensing sinusoidal buckling in the vertical section of the borehole which eventually rises to the level of helical buckling at the elbow or heel of the borehole if it transitions to a lateral section. That is, vibrations that are prevalent throughout the advancing tubing begin to cease as the tubing becomes stuck and immobile due to the buckling. This marked decrease in amplitude, greater than about a 10% threshold, may be detected by a vibration sensor 90 located at the bottomhole assembly. Accordingly, a mechanical controller such as injector may adjust the force on the coiled tubing string 54 until the vibration sensor 90 indicates that the vibration measurement data is within the threshold again. In this way the feedback may also include milling efficiency, the variable element may include force on the coiled tubing string, bit rotational speed, force on bit, bit type, or flow rate of fluid pumped through the coiled tubing, and the mechanical controller may include a motor coupled to the bit, a bit selector that switches out bits automatically, or a valve respectively. Specifically, these mechanical controllers may adjust the variables such that vibration measurement data is within a milling vibration profile.

Figure 2 is a partial contextual view of the system 200 of feedback in coiled tubing environments illustrative of stuck tool and clearing debris applications. For clarity, the depiction and description of the data processing system is not repeated. When trying to run into a borehole 10, understanding the vibration and load forces may provide the operator on the surface information to avoid situations that would cause the cutting tool 22 to get stuck, and may also provide information on targeting debris with a cutting tool 22. For example, a whipstock 20 may be set to divert the coiled tubing string 16 such that a cutting tool 22, including a bit attached to the end of the coiled tubing string 16, targets debris to be cleared after cutting by borehole fluid. Of course, the coiled tubing string 16 may also be diverted to avoid debris as well. As the flow rate and/or pressure of fluid within the coiled tubing string 16 increases, a motor 30 is actuated and turns the cutting tool 22. A hydraulic anchor 38 and whipstock 20 have been oriented and set in position using the coiled tubing string 16, and sufficient torque created by the motor 30 shears any coupling between the whipstock 20 and the coiled tubing string 16. The cutting tool 22 begins to turn, and is guided at an angle to the borehole 10 by the whipstock 20. As the coiled tubing string 16 is further lowered downhole, the cutting tool 22 cuts at an angle through the casing 14 and creates an angled exit 36 therethrough. In some embodiments, the borehole 10 may not be cased, however cutting an angled exit applies to an uncased borehole as well.

By adjusting the flow rate, e.g. with a valve 82, the actuation of the motor 30 may be adjusted based on vibration measurement data collected by vibration sensors 90 in order to free stuck tools and clear debris. Vibration sensors 90 may be placed at any location along the coiled tubing string 16. For example, as shown the vibration sensors are placed on either side of the motor 30 as well as between the motor 30 and the cutting tool 22. The difference between the measurements obtained by each sensor 90 may be used to identify abnormal behavior during comparison with a vibration profile.

Also, the system 200 may prevent stuck tools in addition to freeing stuck tools.

Specifically, the speed of coiled tubing injection is known, but the actual speed of the bottomhole assembly may not be known. However, with the addition of tri-axial accelerometers for vibration sensing, the actual trajectory of the bottomhole assembly may be determined and used as feedback. Here, the mechanical controller includes the injector, which controls the speed at which the tubing is inserted and the force used for insertion. By using the feedback, the injector provides smoother travel through the wellbore and reduction in the possibility of sticking. In at least one embodiment, a load cell sensor is incorporated into the feedback to detect when the bottomhole assembly has come into contact with a wellbore obstruction.

Figure 3 is a cross-sectional view of an illustrative, fractured borehole 302. The illustrative borehole 302 has been fully drilled, all drilling equipment has been removed, and the borehole 302 has been cased with casing 304 and cemented to sustain the structural integrity and stability of the borehole 302. The borehole 302 is formed within the target formation 300, which extends beyond the limited scope with which it is represented in Figure 3. The target formation 300 may include multiple layers, each layer with a different type of rock formation, including the hydrocarbon-containing target formation within which the borehole may extend horizontally for some distance. The coiled tubing string 320 includes a perforation tool 322 that creates multiple perforations 306 through which a fracturing fluid, such as water, is injected with high pressure into the target formation. This high-pressure fluid injection creates and opens fractures 308 that extend laterally through the target formation. The high pressure fluid may contain additional chemicals and materials, such as a proppant material (e.g., sand) that maintains the structural stability of the fractures and prevents the fractures 308 from fully collapsing. Typically, the horizontal portions of the borehole are drilled generally parallel to the direction of maximum stress, causing the fractures 308 to propagate generally perpendicular to the borehole. (As fractures tend to propagate perpendicular to the direction of maximum stress, such propagation may be expected to occur at a predictable angle from the borehole axis when the borehole is not aligned with the maximum stress direction.) The overlying and underlying formation layers tend to resist fracture propagation, consequently fractures tend to propagate laterally within the target formation, to a length that depends on the rate and volume of the injected fracturing fluid. Thus each fracture 308 has a length 310 relative to the casing 304. Each fracture 308 also has an initiation location 314 determined by the perforation position, which is typically measured relative to the distal end of the borehole 302. Where regular spacing is employed, the perforations (and hence the fracture initiation points) have a fixed spacing 312 between them. Though represented in the figures as generally planar, the actual fractures 308 may be represented as a branching network having a form and size that depends not only on the properties of the fracturing injection stream, but also on the nature of the rocks and formation materials of the target formation. Accordingly, fracture shapes and sizes are not limited to those shown in Figure 3.

The impact of firing a perforating gun from the perforation tool 322 may be measured by vibration sensors 90. Additionally, determining that the perforating gun has fired is non- trivial due to noisy and chaotic downhole conditions. A mechanical controller, such as a lockout switch, may prevent other activities from occurring if the vibration sensor 90 has not detected vibrations associated with the firing of the perforating gun. For example, activities such as injection of fracturing fluid, a sand cleanout, pulling out of hole, and moving to another perforation location may be prevented.

Extended reach boreholes refer to long horizontal boreholes. The aims of an extended reach borehole are to reach a larger area from one surface drilling location and to keep the borehole within a reservoir for a longer distance in order to maximize its productivity and drainage capability. It is a challenge to clean such a borehole, manage the mechanical loads on the coiled tubing string 320, and manage downhole pressure. As such, the vibration sensors 90 may measure characteristics indicative of excess loads and pressures, such as buckling, and mechanical controllers such as injectors or valves may adjust the force on the coiled tubing string 320 or flow rate of fluid pumped through the coiled tubing to alleviate loads, pressure, and the like. Additionally, in fluid detection applications, the feedback may include an indication of a formation fluid entering the borehole 302 based on vibration measurement data from fluid passing through holes in casing 304 or production tubing. Specifically, the vibration sensors 90 may detect evidence that such fluid is entering the borehole at a particular rate based on impact of the fluid with the coiled tubing string 320.

A method 400 of performing a coiled tubing application using feedback is shown in the flow diagram of Figure 4. At 402, a coiled tubing string is conveyed along a borehole. The coiled tubing string may be pulled from a spool by a tubing injector and injected into the borehole. The coiled tubing string may include tools to perform a particular coiled tubing application and vibration sensors to measure characteristics of vibrations traveling within the coiled tubing string during the coiled tubing application. The tools, along with a supervisory sub, may make up the coiled tubing bottomhole assembly.

At 404, vibration measurement data is obtained based on vibrations within the coiled tubing string. For example, the tools, supervisory sub, or data processing system may include one or more processors coupled to the vibration sensors, and the one or more processors may be coupled to memory to record the vibration measurement data. The vibration measurement data may include characteristics of the vibrations such as frequency and amplitude and may also be obtained as tri-axial vibration component measurements (axial vibration, torsional vibration, and a lateral vibration). The vibration measurement data may be obtained from vibrations anywhere along the coiled tubing string including the bottomhole assembly. For different coiled tubing applications, vibration measurement data from different locations will be relevant.

In one embodiment, obtaining vibrations in this manner may include recording a baseline of vibration data, e.g. over the course of a successful coiled tubing operation. Thus, future analysis indicative of abnormal conditions may be ascertained with a greater degree of precision by comparing the newly obtained vibration measurement data with the baseline.

At 406, feedback is provided, during the coiled tubing application, based on the vibration measurement data. In at least one embodiment, the vibration measurement data is processed to determine the status of the coiled tubing application. For example, the vibration measurement data is compared with the vibration profile for the particular coiled tubing application. The profile may include at least one threshold or range of frequency, amplitude, or average energy associated with each sensor that measures vibrations within the coiled tubing string. If the data is within the ranges of the profile, at 408, then a normal status feedback may be reported and the method may end.

If the data is not within the profile, at 408, then an abnormal status is reported along with relevant information about the vibration sensor that is outside of the profile, and in at least one embodiment, suggested solutions based on the characteristics of the abnormality. At 410, a mechanical controller is used to adjust a variable element of the coiled tubing application based on the feedback. The variable element may be continuously adjusted based on the feedback until the vibration measurement data conforms to a profile associated with the coiled tubing application. Adjusting the variable element may include adjusting the variable element of the coiled tubing application automatically based on the feedback, i.e. without human input.

For example, the coiled tubing application may include freeing a stuck tool, the feedback may include an indication of movement in the tool, and the variable element may include force on the coiled tubing string, flow rate of fluid pumped through the coiled tubing, or composition of the fluid pumped through the coiled tubing. The mechanical controller that adjusts the variable element may include a coiled tubing injector, a valve, or a fluid mixer respectively.

As another example, the coiled tubing application may include clearing debris using a tool, the feedback may include an indication of jetting performance of the tool, and the variable element may include flow rate of fluid pumped through the coiled tubing or composition of the fluid pumped through the coiled tubing. The mechanical controller that adjusts the variable element may include a valve or a fluid mixer respectively.

In at least one embodiment, a method of performing a coiled tubing application using feedback includes conveying a coiled tubing string along a borehole and obtaining vibration measurement data based on vibrations within the coiled tubing string. The method further includes providing, during the coiled tubing application, feedback based on the vibration measurement data. The method further includes using a mechanical controller to adjust a variable element of the coiled tubing application based on the feedback.

In another embodiment, a feedback system for a coiled tubing application includes coiled tubing string. The system further includes a vibration sensor coupled to the coiled tubing string. The vibration sensor measures vibrations within the coiled tubing string. The system further includes one or more processors. The one or more processors obtain vibration measurement data from the vibration sensor and provide feedback during the coiled tubing application based on the vibration measurement data. The system further includes a mechanical controller, wherein the controller enables adjustment of a variable element of the coiled tubing application based on the feedback.

The following features may be incorporated into the various embodiments. Feedback may be continuously provided, over a period of time, based on changing vibration measurement data resulting from adjusting the variable element. The variable element may be continuously adjusted based on the feedback until the vibration measurement data conforms to a profile associated with the coiled tubing application. The profile may include at least one threshold of frequency, amplitude, or average energy associated with each sensor that measures vibrations within the coiled tubing string. The coiled tubing application may include milling, the feedback may include the vibration measurement data exceeding an amplitude or frequency threshold, and the variable element may include force on the coiled tubing string. The coiled tubing application may include milling, the feedback may include milling efficiency, and the variable element may include force on the coiled tubing string, bit rotational speed, force on bit, bit type, or flow rate of fluid pumped through the coiled tubing. The coiled tubing application may include freeing a stuck tool, the feedback may include an indication of movement in the tool, and the variable element may include force on the coiled tubing string, flow rate of fluid pumped through the coiled tubing, or composition of the fluid pumped through the coiled tubing. The coiled tubing application may include clearing debris using a tool, the feedback may include an indication of jetting performance of the tool, and the variable element may include flow rate of fluid pumped through the coiled tubing or composition of the fluid pumped through the coiled tubing. The coiled tubing application may include perforation, the feedback may include an indication that a perforation gun has not fired, and the variable element may include flow rate of fluid being pumped through the coiled tubing or depth of a perforation tool in the borehole. The coiled tubing application may include formation fluid detection, and the feedback may include an indication of a formation fluid entering the borehole based on vibration measurement data from fluid passing through holes in borehole casing or production tubing. The coiled tubing application may include extended reaching, and the variable element may include force on the coiled tubing string or flow rate of fluid pumped through the coiled tubing. Obtaining vibration measurement data may include obtaining vibration measurement data based on vibrations within a bottom-hole assembly of the coiled tubing string. Adjusting the variable element may include adjusting the variable element of the coiled tubing application based on the feedback without human input. The coiled tubing string may include a bottom-hole assembly, and the processor may adjust the variable element based on a speed of the bottom-hole assembly as well as the feedback. The vibration sensor may include a tri-axial vibration sensor. The vibration sensor may include a piezoelectric accelerometer. The coiled tubing string may include a bottom- hole assembly, and the processor may obtain vibration measurement data based on vibrations within the bottom-hole assembly. The one or more processors may continuously provide, over a period of time, feedback based on changing vibration measurement data resulting from adjusting the variable element. The controller may continuously adjust the variable element based on the feedback until the vibration measurement data conforms to a profile associated with the coiled tubing application.

Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. The ensuing claims are intended to cover such variations where applicable.