Intervention operations with high rate telemetry

A technique facilitates an improved operation of a tool, such as a downhole tool. The tool is operated in a manner which provides a dynamic or cyclical loading. The dynamic or cyclical loading of the tool is sampled by a suitable sensing system at a frequency greater than the frequency of the dynamic or cyclical loading to collect detailed data on the dynamic or cyclical loading. The data is used to adjust the tool in a manner which improves operation of the tool. One technique for adjusting the tool is changing the dynamic or cyclical loading of the tool by adjusting the frequency of the dynamic or cyclical loading.

BACKGROUND

In many well applications, downhole tools operate with a cyclic characteristic. For example, some downhole tools are designed to create a cyclical axial impact force to facilitate axial movement of a tool string or to achieve another desired result. Other types of tools create vibrations which can be beneficial or detrimental to optimal operation of the tool depending on the vibration magnitude and frequency. For example, some tools have a resonant frequency which can be used to optimize performance of the tool, e.g. to extend the reach of a coiled tubing tool into a well. However, the resonant frequency can limit the operation and/or lifespan of the tool by creating detrimental forces acting on the tool.

SUMMARY

In general, a system and methodology are provided for improving the operation of a tool, such as a downhole tool. The tool is operated in a manner which provides a cyclical activity, e.g. cyclical loading. The cyclical activity is sampled at a frequency greater than the frequency of the cyclical activity to collect data on the cyclical activity. The data is used to adjust the tool in a manner which improves operation of the tool. For example, the cyclical activity of the tool can be adjusted by changing the frequency of the cyclical activity or by making other suitable changes to the cycling of the tool.

DETAILED DESCRIPTION

The present disclosure generally relates to a system and methodology for improving the operation of a tool, such as a downhole tool. Many types of tools have cyclical or dynamic operating characteristics, such as vibration and/or reciprocation, which create cyclical loading and acceleration of the tool. Sometimes the cyclical loading is part of the intentional design of the tool, and sometimes the cyclical loading is a byproduct of the tool operation. In embodiments described herein, the cyclical loading comprises one or more cycles; and the cyclical loading can be sampled at a frequency greater than the frequency of the cyclical loading to enable detailed collection of data on the cyclical loading. It should be noted that the data may be collected on other cyclical characteristics, such as acceleration.

In a variety of applications, the cyclical or dynamic loading is sampled at a substantially higher frequency than the frequency of the cyclical loading to facilitate collection of a variety of desirable data on the tool loading, e.g. peak loading, resonant frequency, and other types of data. The data may then be used to adjust the tool to improve operation of the tool. In some applications, the operation of the tool is adjusted to change the cyclical loading of the tool, e.g. to change the magnitude or the frequency of the cyclical loading, in a manner which improves operation of the tool.

In some embodiments, the system and methodology are designed for downhole, well related applications. For example, the system and methodology may be used in obtaining data on high rate downhole load measurements (e.g. force and/or torque measurements) and providing that data to the surface in real-time for processing to improve the downhole operation. By way of further example, the high rate downhole load measurements may be obtained for tools used in intervention operations, such as coiled tubing intervention operations. The high rate measurements provide a variety of useful data on coiled tubing operations and other operations compared with low rate, e.g. 1 Hz, measurements. In some applications, high rate measurement data may be obtained for load and/or acceleration measurements, however load measurements may be used independently to improve performance in many types of applications.

The term “high rate measurements” refers to sampling the cyclical or dynamic loading at a frequency greater than the frequency of the cyclical loading to collect detailed data, e.g. multiple data points, on each cycle of the cyclical loading. In some applications, the high rate measurements may be taken at a frequency substantially higher than the load (or acceleration) cycles of the tool. For example, sampling of the cyclical activity, e.g. cyclical loading, may be at a frequency at least about 2 to about 5 times the frequency of the cyclical activity. In other applications, sampling of the cyclical activity may be at least about 10 times the frequency of the cyclical activity. In this latter example: to measure the peak force of a signal based on cyclical loading of a tool at 10 Hz, a sampling frequency of at least 100 Hz would be selected to achieve the 10× ratio. It should be noted that in many applications determination of peak loading, via the high rate sampling, is more useful than determination of peak acceleration.

However, acceleration data may be useful to determine if a particular tool undergoing cyclical loading is in resonance. Additionally, acceleration data may provide information on whether something has happened, but such acceleration data often is more useful as qualitative data rather than quantitative data. Depending on the application, the acceleration data may be used as a qualitative indicator which signals the occurrence of a specific event, e.g. a perforating gun fires, a tool is jar actuated, a ball lands on a seat downhole, a mechanism shifts, or another event occurrence.

Referring generally toFIG. 1, an embodiment of a system20is illustrated as including a tool22which undergoes a cyclical activity, e.g. cyclical loading/cyclical acceleration, which is measured. In this embodiment, tool22is part of a bottom hole assembly23coupled into a tool string24and deployed in a wellbore26. Tool string24may be part of an intervention assembly25extending from surface equipment27. In some applications, wellbore26may be a deviated, e.g. horizontal, wellbore into which the tool22is delivered. Although tool22may be constructed for a variety of well and non-well related applications, many tools22are designed for well intervention applications. Examples of well intervention applications, include drilling related applications, deployment applications, perforating applications, treatment applications, and/or a variety of other well intervention applications.

The tool22and tool string24may be conveyed along wellbore26by a suitable conveyance28, such as a coiled tubing or slickline conveyance28. According to a specific example, conveyance28comprises coiled tubing30and the overall system20comprises tool string24which is part of coiled tubing intervention assembly25. Depending on the application, bottom hole assembly23may comprise a cutting device32attached to tool22or formed as part of tool22. Examples of cutting devices32include drilling bits for drilling wellbore26or milling bits for cutting through surrounding material, e.g. a surrounding casing34. Tool22undergoes a cyclical activity, e.g. cyclical loading, which may be incidental to operation of the tool22or specifically designed into operation of the tool22. By measuring and monitoring the cyclical activity, adjustments may be made to the operation of the tool22to enhance performance of the tool22. Examples of adjustments include adjustments to the cyclical frequency, adjustments to the loading, repair or replacement of tool22, or other appropriate adjustments.

Referring again toFIG. 1, a sensor system36having one or more sensors38may be used to monitor and collect data at a rate sufficient to evaluate a cyclical activity, e.g. a cyclical or dynamic loading, associated with the operation of tool22in the intervention operation or other operation. The sensor system36may be used to deliver data uphole to a control system40, such as a surface-based computer control system, which may be part of surface equipment27. In some applications, the sensor system36may be coupled with the control system40via a communication line42, such as a fiber optic communication line or an electrical conductor communication line designed to convey data from the sensor system36to the control system40and/or vice versa. In a coiled tubing intervention application, the communication line42may be routed along an interior (e.g. an interior flow path) of the coiled tubing30. InFIG. 1, the cyclical activity of tool22is represented by arrows44and the cyclical activity may comprise a vibration or reciprocal motion in an axial direction (or other direction), depending on the application and on the construction of tool22.

Referring generally toFIG. 2, an example of control system40is illustrated. In this embodiment, the various data collected by sensors38may be output to control system40via communication line42and processed on control system40. In some embodiments, the data is processed to construct control models and/or is subjected to modeling on the processor-based control system40. By way of example, the sensors may be of the type designed to measure load, acceleration, and/or other parameters indicative of the cyclical motion of tool22. The sensor data resulting from these measured parameters may be used to monitor/track in real-time the cyclical, e.g. reciprocating, motion at a substantially higher sampling rate than the frequency of the actual cyclic motion. The control system40may be designed to output data and/or to automatically control adjustment of the operation of tool22in a manner which improves operation of the tool22.

As discussed above, control system40may be in the form of a computer-based system having a processor46, such as a central processing unit (CPU). The processor46is operatively employed to intake and process data obtained from the sensor or sensors38of sensor system36. The processor46also may be operatively coupled with a memory48, an input device50, and an output device52. Input device50may comprise a variety of devices, such as a keyboard, mouse, voice recognition unit, touchscreen, other input devices, or combinations of such devices. Output device52may comprise a visual and/or audio output device, such as a computer display, monitor, or other display medium having a graphical user interface. Additionally, the processing may be done on a single device or multiple devices on location, e.g. a well site, away from the location, or with some devices located on location and other devices located remotely or with some devices locating downhole, such as devices utilized as part of the bottom hole assembly23. Once the desired processing of data from sensors38is performed on control system40, appropriate information may be output to output device52for review by an operator. The operator may then input instructions via input device50to adjust the operation of tool22, e.g. the cyclical rate or the force output, based on the sensor data monitored, collected and processed. In a variety of applications, the processor46may be programmed to automatically take action, based on data from sensors38, to improve the performance of tool22. Depending on the application, processor46may be programmed with a variety of models or algorithms designed to optimize or otherwise enhance operation of tool22. In an embodiment, the data processing may be performed downhole with a device as part of the bottom hole assembly23utilized for, in a non-limiting example, converting raw data to acceleration or force, for automatically deciding what portion of data to send uphole to the control system40.

The adjustments to tool22based on data from sensor system36may take a variety of forms depending on the tool type, environment, and application. For example, high-frequency load and/or acceleration measurements obtained from sensors38may be used to optimize the performance of various tools22used for coiled tubing interventions or other operations.

By way of example, the data obtained from sensors38may be used to maintain resonant frequency. According to one embodiment, tool22illustrated inFIG. 1is a mechanical vibration tool. The mechanical vibration tool22may be used to create a cyclic actuation, e.g. a cyclic loading, which helps advance movement of the tool22. In coiled tubing intervention operations, the mechanical vibration of tool22may be used to extend the reach of coiled tubing30and tool22into the well, particularly along a horizontal or otherwise deviated section of the well.

In this type of application, the cyclical loading/mechanical vibration may be induced by a variety of mechanisms. For example, mechanical vibration may be induced by fluid pumped along an interior of coiled tubing30and through tool22in a manner which causes mechanical vibration in an axial direction and creates a nominally sinusoidal axial force, as represented by arrow44. The axial force may be created, for example, by generating an impact load with an internal mass or by creating pressure pulses that indirectly result in a cyclical axial force acting on the tool22and thus on coiled tubing30.

Because these types of tools generally have some combination of springs and masses to create the cyclical activity, there often is a natural resonant frequency at which the mechanical vibration is maximized. A measurement, e.g. a real-time measurement, of axial force and/or acceleration can be provided by sensor system36at a frequency substantially higher than the frequency of the cyclical activity. This data is then processed and used to ensure the system/tool22remains in resonance by, for example, varying the flow rate of fluid through the tool22or otherwise changing the frequency of the cyclical activity. As discussed above, the sampling rate of sensor system36is higher than the frequency of the mechanical vibration and often is substantially higher, e.g. at least about 2 to about 5 times and in some cases at least about 10 times the frequency of the cyclical activity of tool22. This allows sensor system36to provide detailed data to control system40on the loading and/or acceleration of tool22as it vibrates in an axial direction. In other applications, the sensor data may be used for avoiding resonant frequencies to, for example, protect the tool22from undue wear.

An example of the output from sensor system36is illustrated graphically inFIG. 3. In this example, a plot is provided showing high rate axial force data for a vibrating tool in which the axial vibration is induced by fluid flow moving through an interior flow path of the coiled tubing30and tool22. The peak axial force is affected substantially as the flow rate of fluid and thus the induced vibration in tool22is changed over time. The data received from sensor system36may be monitored and collected by control system40to facilitate adjustment of the cyclical loading/mechanical vibration of tool22to a level, e.g. a resonant level, which facilitates increased movement and reach of the coiled tubing system along wellbore26.

In another example, tool22comprises a jarring tool and the data obtained on the cyclical activity of the tool22is used to optimize jar preload. Jarring tools22create an axial impact force which may be rated as a multiple of the load applied to the jar before it actuates. In other words, if about 5000 pounds of tension are applied to a 4 to 1 jar, then the jar should deliver about 20,000 pounds of peak impact force to its attachment point. The amount of preload may be chosen or selected so that the peak force does not exceed the tensile limits of any component of tool22or associated equipment. For example, tool22may be used in bottom hole assembly23, and the cyclical activity of tool22, e.g. the cyclical jarring force, is limited so as to not exceed the tensile limits of any component in the bottom hole assembly23. If, for example, a housing in the bottom hole assembly23is rated to 40,000 pounds and a 4 to 1 jar is used, a preload of 10,000 pounds may be set as a maximum so as to protect the housing.

In practice, the actual peak force may be substantially lower than the predicted value. By measuring the peak impact force in, for example, real-time, the amount of preload may be increased until the peak force approaches the tool limit, e.g. the tensile limit of tool22and its associated equipment. Thus, the cyclical activity may be adjusted based on the data from sensor system36to increase the peak force and to effectively improve or optimize the jarring operation. An example of adjusting the peak force to a more optimal level is illustrated graphically inFIG. 4. As illustrated, data provided to control system40from sensors38may be used to adjust the preload over time to optimize the peak force of the jarring tool22, thus improving the jarring operation. In an embodiment, the tool22may comprise include an impact hammer and the operation may comprising an impact hammer operation.

In another tool optimization example, data supplied in real-time from system36may be used to prevent an undesirable result, such as motor stall. For example, in many coiled tubing intervention operations, the operation may be optimized by improving the rate of penetration of tool22and its cutting device32through a given material. In a specific example, the coiled tubing intervention operation involves a milling operation which benefits from an increased rate of penetration through the cement, hard fill, and other materials surrounding wellbore26. The rate of penetration may be increased to some extent by increasing the set down weight on bottom hole assembly23and tool22. The increased set down weight increases the contact force between the cutting device32and the material cut/milled by cutting device32. However, too much set down weight may cause stalling of the bottom hole assembly mud motor31used to rotate cutting device32. The mud motor31is provides rotational energy to the cutting device32by utilizing fluid flowing within the coiled tubing30, as will be appreciated by those skilled in the art. If the mud motor stalls, the bit32stops turning and fluid bypasses the rotor of the mud motor. Repeated stalls may shorten the life of the mud motor and damage a sealing element of the mud motor. When the motor31stalls, the efficiency of the operation also decreases because the operator stops pumping fluid through the motor and pulls up before re-engaging the milling/cutting device32.

By monitoring the cyclical activity of the downhole mud motor torque at a high rate in real-time via sensor system36, the potential stall may be predicted. The control system40may be used to output this information to output device52. The control system40also may be programmed to automatically intervene and take action by, for example, modifying the set down load or pump rate to effectively change the frequency of the cyclical torque output and to prevent stalling of the motor31. InFIG. 5, a graphical representation provides a plot which illustrates how the irregular frequency content of the torque signal changes (low-frequency component introduced) before the stall occurs (flat region on graph). By monitoring and collecting data on the cyclical torque signal via sensor system36, the potential for stalling may be substantially reduced. In this example, the sensors38may again be used to sample the signal at a much higher rate than the frequency at which the torque signal cycles, thus enhancing the information available for indicating potential motor stalling.

The sensor system36and control system40also may be used in a variety of applications for tool protection. The high frequency load measurements may be used to ensure that a tool does not exceed predetermined operating limits during a given operation.

In an example, tool22is a jarring tool and sensor system36is used to monitor peak jar force. The jarring tool22creates an impact force downhole in wellbore26that may be several times greater than the preload applied to the jar before it actuates. If the peak force exceeds the limit of a load bearing member in the bottom hole assembly23or other associated equipment, then a failure may occur. By monitoring the peak jar force at a high sampling rate in real time (e.g. a sampling rate at least about 10 times the jar cycle frequency), an operator and/or control system40may ensure that the tool limit is not exceeded regardless of the preload applied or the rating of the jar tool22. During cycling of the jarring loads, if a jarring impact load approaches the predetermined limit of tool22(or associated equipment in the bottom hole assembly23), an operator and/or control system40adjusts the cyclical loading by, for example, reducing the preload on subsequent jarring impacts. The adjustment is helpful in protecting the components of the bottom hole assembly23and also in maintaining operation of the jar tool22over many potential, successive jars that may be utilized in executing a jarring operation.

Another example of utilizing sensor system36in monitoring and collecting cyclical activity data at a high rate involves measurement of peak force during a perforation operation. In this example, tool22comprises a perforating tool which may be part of a bottom hole assembly, such as the bottom hole assembly23, deployed on coiled tubing30. When a perforating gun fires, the resulting pressure wave may create a very large axial force on perforating tool22, on the bottom hole assembly23, and on the corresponding coiled tubing30. By measuring the axial force at a high rate and in real-time, data may be provided to control system40indicating whether the resulting load approaches or exceeds a load limit for the bottom hole assembly23/perforating tool22.

Based on the data obtained from sensors38of sensor system36, the cyclical activity of the perforating tool may be adjusted. In this application, that adjustment may comprise taking measures to reduce the impact force which occurs during future perforating runs in the same or in a similar well. For example, the shot density may be lowered or the perforated interval length may be decreased to reduce the peak loading which occurs during the load cycle following firing of the perforating tool22. An example of cyclical loading caused by shock from a perforating operation is illustrated graphically inFIG. 6. As illustrated, data from sensors38provided to control system40indicates a peak force from perforating. This peak force data may be used to adjust subsequent perforating operations so that the peak force during the load cycle does not exceed tool limits of the bottom hole assembly23and/or the perforating tool22. Such adjustment protects the tool22and associated equipment during future load cycles resulting from future perforating operations.

Another example of utilizing sensor system36in monitoring and collecting cyclical activity data at a high rate involves performance verification of tool22. For example, high-frequency load measurements may be used to ensure that tool22is operating within its specifications. By way of example, tool22may comprise a jarring tool, a mechanical vibration tool, a perforation tool, or another tool which undergoes cyclical loading of one or more cycles.

In a specific embodiment, tool22is in the form of a jarring tool which creates an axial impact force rated as a multiple of the load applied to the jar before it actuates (the preload). As discussed above, the axial impact force can be expressed as 2 to 1, 4 to 1, 8 to 1, or another suitable ratio. Sometimes the jarring tool22can malfunction due to bad seals, broken springs, or other faulty components. By monitoring the axial load at a high rate in real-time, the peak force may be compared with the preload. The comparison allows control system40and/or an operator to determine if the jar tool22is performing properly. If the tool22is functioning improperly, adjustments may be made to the tool. For example, the rate of cyclical loading may be adjusted or the tool22may be pulled to the surface for repair or replacement.

According to another embodiment, tool22is in the form of a vibrating tool with a force specification. For example, tool22may be a mechanical vibration tool designed to create a nominally sinusoidal axial force. The sinusoidal axial force may be used to extend the reach of coiled tubing into a well, to facilitate movement of the tool as it cuts through a material, and/or to enhance other types of tool movement. The peak force of the vibrating tool22is sometimes given as a specification. By measuring the axial force at a high rate in real-time via sensor system36, the control system40and/or an operator may determine if the vibrating tool22is operating within its specifications. If not, the cyclical loading may be adjusted or other actions may be taken, e.g. retrieving tool22to the surface for repair or replacement.

As described herein, the systems, cyclically loaded tools, sensors, and control systems may be used in a variety of operations, including tool optimization operations, tool protection operations, and tool performance verification operations. Depending on the specifics of a given tool system, operation, and environment, the design of the overall system20and of the cyclically loaded tool22may vary. Additionally, the control system40may be designed to process data from the sensor system36and to output helpful data to an operator. However, the control system40also may be a processor-based system programmed to automatically control adjustment to the tool22. For example, based on data obtained from the sensor system36(data obtained at a high sampling frequency relative to the frequency of the cyclical loading of the tool22), many types of automatic adjustments to the tool22may be undertaken via control system40. In some applications, the cyclical loading frequency of the tool may be adjusted to improve operation of the tool. However, other actions may comprise repairing the tool, replacing the tool, and/or other suitable responses to the data obtained from sensor system36. Sensors38also may comprise a variety of sensor types having sample rates higher than the cyclical frequency of the tool22. By way of example, sensors38may comprise load sensors, stress/strain sensors, accelerometers, other types of sensors, or combinations of sensors.