US20240376812A1

US20240376812A1 - Enhancing Borehole Resonance Signal For Through Tubing Cement Evaluation

Info

Publication number: US20240376812A1
Application number: US18/195,815
Authority: US
Inventors: Yao Ge; Ruijia Wang; Brenno Caetano Troca Cabella
Original assignee: Halliburton Energy Services Inc
Current assignee: Halliburton Energy Services Inc
Priority date: 2023-05-10
Filing date: 2023-05-10
Publication date: 2024-11-14
Also published as: NO20251081A1; WO2024232889A1

Abstract

A method comprising: transmitting an acoustic signal into at least part of a conduit string, measuring a return signal from at least part of the conduit string, computing one or more amplitudes of a resonance signal from the return signal, and forming a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal. Additionally, a system may be included and/or paired with the method. The system comprising: a transmitter configured to transmit an acoustic signal into at least part of a conduit string, a receiver configured to measuring a return signal from at least part of the conduit string, an information handling system configured for: computing one or more amplitudes of a resonance signal from the return signal, and forming a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.

Description

BACKGROUND

For oil and gas exploration and production, a network of wells, installations and other conduits may be established by connecting sections of metal pipe together. For example, a well installation may be completed, in part, by lowering multiple sections of metal pipe (i.e., a conduit string) into a wellbore, and cementing the conduit string in place. In some well installations, multiple conduit strings are employed (e.g., a concentric multi-string arrangement) to allow for different operations related to well completion, production, or enhanced oil recovery (EOR) options.
At the end of a well installations' life, the well installation may be plugged and abandoned. Understanding cement bond integrity to a conduit string may be beneficial in determining how to plug the well installation. Generally, acoustics may be implemented by acoustic tools to form CBLs (cement bond log). Traditional acoustic tools require the production tubing to be pulled out so that the signal may directly reach casing through borehole fluid. A need in the industry exists in which a CBL may be formed without removing production tubing. Through tubing cement evaluation is challenging because acoustic devices do not have enough energy to insonify the production tubing with acoustic waves. Thus, the casing response may be too low to the overall signal received signal, making it difficult to evaluate the cement property behind the casing.
Additionally, acoustic waves may form a resonance within a well, defined as resonance mode acoustic waves. Resonance mode acoustic waves may provide valuable information in CBL evaluation. Resonance mode acoustic waves may be sensitive to cement bonding with the casing in the presence of tubing. However, it may be difficult to evaluate a CBL in the presence of non-resonance acoustic waves.

BRIEF DESCRIPTION OF THE DRAWINGS

These drawings illustrate certain aspects of some examples of the present disclosure and should not be used to limit or define the disclosure.

FIG. 1 illustrates a system including an acoustic logging tool;

FIG. 2 illustrates an example of a transmitter and a receiver;

FIG. 3 illustrates an example information handling system;

FIG. 4 illustrates another example information handling system;

FIG. 5 illustrates the acoustic logging tool broadcasting a shaped signal;

FIG. 6 illustrates graph of a time domain signal from a single receiver for two cement bonding conditions;

FIG. 7 illustrates a dispersion curve;

FIG. 8 illustrates a time domain dipole signal;

FIG. 9 illustrates a time domain baseline-removed signal method;

FIG. 10 illustrates an example of time domain method with baseline-removal;

FIG. 11 illustrates a time domain without baseline-removal method;

FIG. 12 illustrates an example of time domain method without baseline-removal;

FIG. 13A illustrates FIG. 13A illustrates frequency-time domain wavelet analysis; and

FIG. 13B illustrates results from frequency-time domain wavelet analysis.

DETAILED DESCRIPTION

Methods and systems herein may generally relate to methods and systems for enhancing the resonance mode acoustic wave(s) and removing the non-resonance wave(s). Specifically, acoustic sensing may incorporate resonance wave(s) and non-resonance wave(s) and provide continuous in situ measurements of parameters related to cement bonding to a casing. As a result, acoustic sensing may be used in cased borehole monitoring applications. As disclosed herein, acoustic logging tools may be used to emit an acoustic signal which may traverse through at least part of a conduit string to at least part of a casing. Reflected signals that are measured by the acoustic logging tool may be defined as result signals. Result signals may be analyzed to determine if the section of casing is fully bonded, is free pipe, or if a partially bonded section. The return signal may comprise the resonance mode signal as well as other signals such as reflection, guided waves, tool mode, and/or Stoneley wave. As described below, methods and systems may be utilized to extract one or more resonance mode signals and remove one or more non-resonance signals to increase signal-to-noise ratio. Specifically, methods and systems may apply a band pass filter to a resonance mode signal and to identify amplitude. In examples, the band pass filter may be implemented with or without baseline removal. Additionally, methods and systems herein may implement the frequency of the resonance mode as a bond indicator.
FIG. 1 illustrates an operating environment for an acoustic logging tool 100 as disclosed herein. Acoustic logging tool 100 may comprise a transmitter 102 and/or a receiver 104. Additionally, transmitter 102 and receiver 104 may be configured to rotate in acoustic logging tool 100. In examples, there may be any number of transmitters 102 and/or any number of receivers 104, which may be disponed on acoustic logging tool 100. Additionally, transmitter 102 and receiver 104 may be configured to rotate in acoustic logging tool 100. Acoustic logging tool 100 may be operatively coupled to a conveyance 106 (e.g., wireline, slickline, coiled tubing, pipe, downhole tractor, and/or the like) which may provide mechanical suspension, as well as electrical connectivity, for acoustic logging tool 100. Conveyance 106 and acoustic logging tool 100 may extend within conduit string 108 to a desired depth within the wellbore 110. In examples, tubing may be concentric in the casing, however in other examples the tubing may not be concentric Conveyance 106, which may include one or more electrical conductors, may exit wellhead 112, may pass around pulley 114, may engage odometer 116, and may be reeled onto winch 118, which may be employed to raise and lower the tool assembly in the wellbore 110. Signals recorded by acoustic logging tool 100 may be stored on memory and then processed by display and storage unit 120 after recovery of acoustic logging tool 100 from wellbore 110. Alternatively, signals recorded by acoustic logging tool 100 may be conducted to display and storage unit 120 by way of conveyance 106. Display and storage unit 120 may process the signals, and the information contained therein may be displayed for an operator to observe and stored for future processing and reference. Alternatively, signals may be processed downhole prior to receipt by display and storage unit 120 or both downhole and at surface 122, for example, by display and storage unit 120. Display and storage unit 120 may also contain an apparatus for supplying control signals and power to acoustic logging tool 100. Typical conduit string 108 may extend from wellhead 112 at or above ground level to a selected depth within a wellbore 110. Conduit string 108 may comprise a plurality of joints 130 or segments of conduit string 108, each joint 130 being connected to the adjacent segments by a collar 132. Additionally, conduit string 108 may include a plurality of tubing.
FIG. 1 also illustrates inner conduit string 108, which may be positioned inside of conduit string 108 extending part of the distance down wellbore 110. Inner conduit string 108 may be production tubing, tubing string, conduit string, or other pipe disposed within conduit string 108. Inner conduit string 108 may comprise concentric pipes. It should be noted that concentric pipes may be connected by collars 132. Acoustic logging tool 100 may be dimensioned so that it may be lowered into the wellbore 110 through inner conduit string 108, thus avoiding the difficulty and expense associated with pulling inner conduit string 108 out of wellbore 110. Herein conduit string 108 may be comprised of inner conduit string 138.
In logging systems, such as, for example, logging systems utilizing the acoustic logging tool 100, a digital telemetry system may be employed, wherein an electrical circuit may be used to both supply power to acoustic logging tool 100 and to transfer data between display and storage unit 120 and acoustic logging tool 100. A DC voltage may be provided to acoustic logging tool 100 by a power supply located above ground level, and data may be coupled to the DC power conductor by a baseband current pulse system. Alternatively, acoustic logging tool 100 may be powered by batteries located within the downhole tool assembly, and/or the data provided by acoustic logging tool 100 may be stored within the downhole tool assembly, rather than transmitted to surface 122 during logging (corrosion detection).
Acoustic logging tool 100 may be used for excitation of transmitter 102. As illustrated, one or more receivers 104 may be positioned on the acoustic logging tool 100 at selected distances (e.g., axial spacing) away from transmitter 102. The axial spacing of receiver 104 from transmitter 102 may vary, for example, from about 0 inches (0 cm) to about 40 inches (101.6 cm) or more. In some embodiments, at least one receiver 104 may be placed near the transmitter 102 (e.g., within at least 1 inch (2.5 cm) while one or more additional receivers may be spaced from 1 foot (30.5 cm) to about 5 feet (152 cm) or more from the transmitter 102. It should be understood that the configuration of acoustic logging tool 100 shown on FIG. 1 is merely illustrative and other configurations of acoustic logging tool 100 may be used with the present techniques. In addition, acoustic logging tool 100 may include more than one transmitter 102 and more than one receiver 104. For example, an array of receivers 104 may be used. Transmitters 102 may include any suitable acoustic source for generating acoustic waves downhole, including, but not limited to, monopole and multipole sources (e.g., dipole, cross-dipole, quadrupole, hexapole, or higher order multi-pole transmitters). Additionally, one or more transmitters 102 (which may include segmented transmitters) may be combined to excite a mode corresponding to an irregular/arbitrary mode shape. Specific examples of suitable transmitters 102 may include, but are not limited to, piezoelectric elements, bender bars, or other transducers suitable for generating acoustic waves downhole. Receiver 104 may include any suitable acoustic receiver suitable for use downhole, including piezoelectric elements that may convert acoustic waves into an electric signal.
FIG. 2 illustrates examples of transmitter 102 and receiver 104. As discussed above, transmitters 102 (as well as receivers 104) may be a monopole or include multipole sources (e.g., dipole, cross-dipole, quadrupole, hexapole, or higher order multi-pole transmitters). Additionally, one or more transmitters 102 (which may include segmented transmitters) may be combined to excite a mode corresponding to an irregular/arbitrary mode shape. For example, transmitter 102 may be cylindrical and/or segmented piezoelectric tube. Additionally, transmitter 103 may be a monopole, a dipole, a cross-dipole transmitter, a quadrupole, or a rotating transmitter of any mode, and/or a higher order transmitter. Receivers 104 may include a segmented piezoelectric tube, individual receiver, or azimuthal receiver array, which may produce azimuthal variation of bonding behind casing 134. It should be noted that transmitter 102 and receiver 104 may be combined into a single element with the ability to both transmit acoustic waves and receiver acoustic waves, which may be identified as a transceiver.
Referring back to FIG. 1 , transmission of acoustic waves by the transmitter 102 and the recordation of signals by receivers 104 may be controlled by display and storage unit 120, which may include an information handling system 144. As illustrated, the information handling system 144 may be a component of the display and storage unit 120. Alternatively, the information handling system 144 may be a component of acoustic logging tool 100. An information handling system 144 may include any instrumentality or aggregate of instrumentalities operable to compute, estimate, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system 144 may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. Information handling system 144 may include a processing unit 146 (e.g., microprocessor, central processing unit, etc.) that may process EM log data by executing software or instructions obtained from a local non-transitory computer readable media 148 (e.g., optical disks, magnetic disks). Non-transitory computer readable media 148 may store software or instructions of the methods described herein. Non-transitory computer readable media 148 may include any instrumentality or aggregation of instrumentalities that may retain data and/or instructions for a period of time. Non-transitory computer readable media 148 may include, for example, storage media such as a direct access storage device (e.g., a hard disk drive or floppy disk drive), a sequential access storage device (e.g., a tape disk drive), compact disk, CD-ROM, DVD, RAM, ROM, electrically erasable programmable read-only memory (EEPROM), and/or flash memory; as well as communications media such wires, optical fibers, microwaves, radio waves, and other electromagnetic and/or optical carriers; and/or any combination of the foregoing. Information handling system 144 may also include input device(s) 150 (e.g., keyboard, mouse, touchpad, etc.) and output device(s) 152 (e.g., monitor, printer, etc.). The input device(s) 150 and output device(s) 152 provide a user interface that enables an operator to interact with acoustic logging tool 100 and/or software executed by processing unit 146. For example, information handling system 144 may enable an operator to select analysis options, view collected log data, view analysis results, and/or perform other tasks.
FIG. 3 illustrates an example information handling system 144 which may be employed to perform various steps, methods, and techniques disclosed herein. As illustrated, information handling system 144 includes a processing unit (CPU or processor) 302 and a system bus 304 that couples various system components including system memory 306 such as read only memory (ROM) 308 and random-access memory (RAM) 310 to processor 302. Processors disclosed herein may all be forms of this processor 302. Information handling system 144 may include a cache 312 of high-speed memory connected directly with, in close proximity to, or integrated as part of processor 302. Information handling system 144 copies data from memory 306 and/or storage device 314 to cache 312 for quick access by processor 302. In this way, cache 312 provides a performance boost that avoids processor 302 delays while waiting for data. These and other modules may control or be configured to control processor 302 to perform various operations or actions. Other system memory 306 may be available for use as well. Memory 306 may include multiple different types of memory with different performance characteristics. It may be appreciated that the disclosure may operate on information handling system 144 with more than one processor 302 or on a group or cluster of computing devices networked together to provide greater processing capability. Processor 302 may include any general purpose processor and a hardware module or software module, such as first module 316, second module 318, and third module 320 stored in storage device 314, configured to control processor 302 as well as a special-purpose processor where software instructions are incorporated into processor 302. Processor 302 may be a self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric. Processor 302 may include multiple processors, such as a system having multiple, physically separate processors in different sockets, or a system having multiple processor cores on a single physical chip. Similarly, processor 302 may include multiple distributed processors located in multiple separate computing devices but working together such as via a communications network. Multiple processors or processor cores may share resources such as memory 306 or cache 312 or may operate using independent resources. Processor 302 may include one or more state machines, an application specific integrated circuit (ASIC), or a programmable gate array (PGA) including a field PGA (FPGA).
The information handling system 144 may comprise a processor 302 that executes one or more instructions for processing the one or more measurements. The information handling system 144 may comprise processor 302 that executes one or more instructions for processing the one or more measurements. Information handling system 144 may process one or more measurements according to any one or more algorithms, functions, or calculations discussed below. In one or more embodiments, the information handling system 144 may output a return signal.
Processor 302 may include, for example a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), or any other digital or analog circuitry configured to interpret, execute program instructions, process data, or any combination thereof. Processor 302 may be configured to interpret and execute program instructions or other data retrieved and stored in any memory such as memory 306 or cache 312. Program instructions or other data may constitute portions of a software or application for carrying out one or more methods described herein. memory 306 or cache 312 may comprise read-only memory (ROM), random access memory (RAM), solid state memory, or disk-based memory. Each memory module may include any system, device or apparatus configured to retain program instructions, program data, or both for a period of time (e.g., computer-readable non-transitory media). For example, instructions from a software or application may be retrieved and stored in memory 306 for execution by processor 601.
Each individual component discussed above may be coupled to system bus 304, which may connect each and every individual component to each other. System bus 304 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. A basic input/output (BIOS) stored in ROM 308 or the like, may provide the basic routine that helps to transfer information between elements within information handling system 144, such as during start-up. Information handling system 144 further includes storage devices 314 or computer-readable storage media such as a hard disk drive, a magnetic disk drive, an optical disk drive, tape drive, solid-state drive, RAM drive, removable storage devices, a redundant array of inexpensive disks (RAID), hybrid storage device, or the like. Storage device 314 may include software modules 316, 318, and 320 for controlling processor 302. Information handling system 144 may include other hardware or software modules. Storage device 314 is connected to the system bus 304 by a drive interface. The drives and the associated computer-readable storage devices provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for information handling system 144. In one aspect, a hardware module that performs a particular function includes the software component stored in a tangible computer-readable storage device in connection with the necessary hardware components, such as processor 302, system bus 304, and so forth, to carry out a particular function. In another aspect, the system may use a processor and computer-readable storage device to store instructions which, when executed by the processor, cause the processor to perform operations, a method or other specific actions. The basic components and appropriate variations may be modified depending on the type of device, such as whether information handling system 144 is a small, handheld computing device, a desktop computer, or a computer server. When processor 302 executes instructions to perform “operations”, processor 302 may perform the operations directly and/or facilitate, direct, or cooperate with another device or component to perform the operations.
As illustrated, information handling system 144 employs storage device 314, which may be a hard disk or other types of computer-readable storage devices which may store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, digital versatile disks (DVDs), cartridges, random access memories (RAMs) 310, read only memory (ROM) 308, a cable containing a bit stream and the like, may also be used in the exemplary operating environment. Tangible computer-readable storage media, computer-readable storage devices, or computer-readable memory devices, expressly exclude media such as transitory waves, energy, carrier signals, electromagnetic waves, and signals per se.
To enable user interaction with information handling system 144, an input device 322 represents any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. Additionally, input device 322 may take in data from one or more sensors 136, discussed above. An output device 324 may also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems enable a user to provide multiple types of input to communicate with information handling system 144. Communications interface 326 generally governs and manages the user input and system output. There is no restriction on operating on any particular hardware arrangement and therefore the basic hardware depicted may easily be substituted for improved hardware or firmware arrangements as they are developed.
As illustrated, each individual component described above is depicted and disclosed as individual functional blocks. The functions these blocks represent may be provided through the use of either shared or dedicated hardware, including, but not limited to, hardware capable of executing software and hardware, such as a processor 302, that is purpose-built to operate as an equivalent to software executing on a general-purpose processor. For example, the functions of one or more processors presented in FIG. 3 may be provided by a single shared processor or multiple processors. (Use of the term “processor” should not be construed to refer exclusively to hardware capable of executing software.) Illustrative embodiments may include microprocessor and/or digital signal processor (DSP) hardware, read-only memory (ROM) 308 for storing software performing the operations described below, and random-access memory (RAM) 310 for storing results. Very large-scale integration (VLSI) hardware embodiments, as well as custom VLSI circuitry in combination with a general-purpose DSP circuit, may also be provided.
The logical operations of the various methods, described below, are implemented as: (1) a sequence of computer implemented steps, operations, or procedures running on a programmable circuit within a general use computer, (2) a sequence of computer implemented steps, operations, or procedures running on a specific-use programmable circuit; and/or (3) interconnected machine modules or program engines within the programmable circuits. Information handling system 144 may practice all or part of the recited methods, may be a part of the recited systems, and/or may operate according to instructions in the recited tangible computer-readable storage devices. Such logical operations may be implemented as modules configured to control processor 302 to perform particular functions according to the programming of software modules 316, 318, and 320.
In examples, one or more parts of the example information handling system 144, up to and including the entire information handling system 144, may be virtualized. For example, a virtual processor may be a software object that executes according to a particular instruction set, even when a physical processor of the same type as the virtual processor is unavailable. A virtualization layer or a virtual “host” may enable virtualized components of one or more different computing devices or device types by translating virtualized operations to actual operations. Ultimately however, virtualized hardware of every type is implemented or executed by some underlying physical hardware. Thus, a virtualization computer layer may operate on top of a physical computer layer. The virtualization computer layer may include one or more virtual machines, an overlay network, a hypervisor, virtual switching, and any other virtualization application.
FIG. 4 illustrates another example information handling system 144 having a chipset architecture that may be used in executing the described method and generating and displaying a graphical user interface (GUI). Information handling system 144 is an example of computer hardware, software, and firmware that may be used to implement the disclosed technology. Information handling system 144 may include a processor 302, representative of any number of physically and/or logically distinct resources capable of executing software, firmware, and hardware configured to perform identified computations. Processor 302 may communicate with a chipset 400 that may control input to and output from processor 302. In this example, chipset 400 outputs information to output device 324, such as a display, and may read and write information to storage device 314, which may include, for example, magnetic media, and solid-state media. Chipset 400 may also read data from and write data to RAM 310. A bridge 402 for interfacing with a variety of user interface components 404 may be provided for interfacing with chipset 400. Such user interface components 404 may include a keyboard, a microphone, touch detection and processing circuitry, a pointing device, such as a mouse, and so on. In general, inputs to information handling system 144 may come from any of a variety of sources, machine generated and/or human generated.
Chipset 400 may also interface with one or more communication interfaces 326 that may have different physical interfaces. Such communication interfaces may include interfaces for wired and wireless local area networks, for broadband wireless networks, as well as personal area networks. Some applications of the methods for generating, displaying, and using the GUI disclosed herein may include receiving ordered datasets over the physical interface or be generated by the machine itself by processor 302 analyzing data stored in storage device 314 or RAM 310. Further, information handling system 144 receives inputs from a user via user interface components 404 and executes appropriate functions, such as browsing functions by interpreting these inputs using processor 302.
In examples, information handling system 144 may also include tangible and/or non-transitory computer-readable storage devices for carrying or having computer-executable instructions or data structures stored thereon. Such tangible computer-readable storage devices may be any available device that may be accessed by a general purpose or special purpose computer, including the functional design of any special purpose processor as described above. By way of example, and not limitation, such tangible computer-readable devices may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other device which may be used to carry or store desired program code in the form of computer-executable instructions, data structures, or processor chip design. When information or instructions are provided via a network, or another communications connection (either hardwired, wireless, or combination thereof), to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of the computer-readable storage devices.
Computer-executable instructions include, for example, instructions and data which cause a general-purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Computer-executable instructions also include program modules that are executed by computers in stand-alone or network environments. Generally, program modules include routines, programs, components, data structures, objects, and the functions inherent in the design of special-purpose processors, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of the program code means for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps.
In additional examples, methods may be practiced in network computing environments with many types of computer system configurations, including personal computers, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. Examples may also be practiced in distributed computing environments where tasks are performed by local and remote processing devices that are linked (either by hardwired links, wireless links, or by a combination thereof) through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
FIG. 5 illustrates acoustic logging tool 100 disposed in wellbore 110, wherein transmitter 102 may broadcast a shaped acoustic signal 500 through inner conduit string 108, which may excite a fluid 502 that may be disposed between inner conduit string 108 and casing 134. Shaped acoustic signal 500 may be transmitted at 1 Hz to 100 MHz. It should be noted that fluid 502 may comprise mud, formation fluid, and/or reservoir fluid disposed downhole for drilling operations. Additionally, fluid 502 may be disposed within conduit string 108. Thus, fluid 502 may be within pipes string 138 and be disposed between pipiest ring 138 and casing 134. Shaped acoustic signal 500 may lose energy as it passes through conduit string 108, however, shaped acoustic signal 500 may continue to resonate through fluid 502 to casing 134. At casing 134, shaped acoustic signal 500 may interact with boundary 504 that is casing 134 and material 506. Material 506 may be cement, water, air, and/or any combination thereof. The interaction at boundary 504 may cause result signal 508 and dissipated signal 510. Result signal 508 may be reflected off boundary 504 back to acoustic logging tool 100. In examples, result signal 508 comprises reflections, refractions, and/or a resonance which is formed in late time.
As illustrated in FIG. 5 , result signal 508 may interact with conduit string 108, pass through conduit string 108, and be sense, recorded, and/or measured by receiver 104. Result signal 508 may be between 1 to 100 kHz. Dissipated signal 510 may continue to move through material 506, which may continuously capture energy from dissipated signal 510 until dissipated signal 510 is extinguished. Result signal 508 may be processed to further determine if material 506 (i.e., cement, water, air, and/or the like) may be bonded to casing 134.
For example, FIG. 6 illustrates a graph of one or more result signals 508, which was captured by receiver 104 (e.g., referring to FIG. 5 ). As illustrated, early time arrivals 602 comprises acoustic energy, which may include reflections from conduit string 108, reflections from casing 134 through conduit string 108, guided wave refractions from conduit string 108, guided-wave refractions from casing 134 through conduit string 108 (e.g., referring to FIG. 5 ), Stoneley waves, tool waves, and/or the like. These waves may be categorized as non-resonance waves. After a certain time, certain waves propagate away from receiver 104 in the form of guided casing wave, guided tubing wave, tool wave, Stoneley wave and/or multiple reflections (e.g., not illustrated and represented by dissipated signal 510). Hence in late time arrivals 604, result signal 508 is observed to have fixed frequency components and with decreasing amplitude over time. As such, late arrivals 604 may comprise at least part of a resonance mode signal. Herein, resonance mode may be defined as the resonance of the conduit string 108 (e.g., referring to FIG. 1 ), conduit string 108, tool 100, and fluid 502 (e.g., referring to FIG. 5 ).
The resonance mode signal may be categorized into one or any number of poles. For example, a monopole transmitter (e.g., referring to FIG. 2 ) may generate monopole resonance modes. With borehole asymmetry, a monopole transmitter may also generate other multiple resonance modes, such as dipole and quadrupole modes. A signal received by receiver 104 may be decomposed to monopole, dipole, unipole, quadrupole and higher order responses, or a response with any specific mode shape. Each resonance mode may comprise a unique frequency, mode shape, modal decay rate, and/or attenuation rate. Each multipole resonance mode may be identified by mode analysis. Mode analysis may be used to identify the resonance frequency.
FIG. 7 illustrates a dispersion curve (wavenumber vs. frequency) generated from mode analysis simulation from at least part of a conduit string 108 and conduit string 108 (e.g., referring to FIG. 1 ) dispersion configuration 700. Resonance mode signals 704 for dispersion configuration 700 may be identified by a curve approaching the x-axis (zero wavenumber) vertically due to the group velocity of a standing wave being zero. Each resonance mode signal 704 represents a specific mode shape. The corresponding mode shape from each resonance mode signal 704 may also be identified from mode analysis. Mode analysis may identify the nature of the mode and whether it is sensitive to cement bonding. The mode shape of a specific mode may be expressed as pressure level in the fluid 502 (e.g., referring to FIG. 5 ) or the displacement/stress in the conduit string 108 and/or conduit string 108. Mode analysis may be enhanced with numerical simulation. For example, monopole resonance signal 706, dipole resonance signal 708, and quadrupole resonance signal 710 resonance mode may be a first order radial direction acoustic resonance mode shapes. Second order dipole resonance signal 712, second order quadrupole resonance signal 714, and second order monopole resonance signal 716 may depict a second order dipole acoustic resonance mode shapes. A resonance mode may be excited by a transmitter 102 (e.g., referring to FIG. 1 ) of the same mode at the corresponding resonance frequency. A resonance mode may be generated from mode conversion due to eccentricity, bonding condition, or other asymmetry.
A resonance mode may also be categorized by a dominant domain of vibration, such as inner annulus, outer annulus or both inner and outer annulus. For example, monopole acoustic resonance mode shape 706, quadrupole acoustic resonance mode shape 710, second order dipole acoustic resonance mode shape 712, and second order monopole acoustic resonance mode shape 716 may comprise energy in conduit string 108 and conduit string 108. The pressure in conduit string 108 may induce a displacement in the casing, forming leaky waves within the cement behind and/or within one or more tubulars of conduit string 108. Hence monopole resonance signal 706, quadrupole acoustic resonance signal 710, second order dipole resonance signal 712, and second order monopole resonance signal 716 may be particularly sensitive to cement bonding. In effect, higher tubing displacement indicates higher cement-sensitivity. Alternatively, mode analysis of casing displacement may be another indicator of the sensitivity of a mode to cement bonding. In examples, casing displacement shows the casing and tubing displacement under a particular resonance frequency. A higher casing displacement may indicate sensitivity to cement.
The early arriving non-resonance signal in time domain may not be very sensitive to cement bonding. Additionally, this phenomenon may be further explored in FIG. 8 . FIG. 8 illustrates a time domain dipole signal for free pipe signal, fully bonded signal and free pipe signal with baseline signal removed where baseline signal is taken as the fully bonded signal. As shown in FIGS. 6 and 8 , there is little difference between the free pipe signal and the fully bonded signal in the early time. Hence one way to extract cement-sensitive resonance signal is to take the late time response, filter to the frequency of the mode of interest, and calculate the amplitude.
Another way to remove early time arrivals 602 (e.g., referring to FIG. 6 ) is by subtracting a baseline time-domain signal. Free pipe signal minus fully bounded 802 may be the signal after baseline-removal. The baseline signal is taken as the fully bonded signal 804. After removal, free pipe signal minus fully bounded 802 becomes free pipe 804. Free pipe 804 may be identified as the resonance signal with the non-resonance signal (reflections, guided waves, tool mode, etc.) removed. For the baseline-removed signal, the amplitude may be computed from early time or from time zero.
FIG. 9 illustrates a time domain baseline-removed signal method 900. In examples, baseline-removed signal method 900 may be performed and/or operated on information handling system 144 (e.g., referring to FIG. 1 ). In block 902, transmitter 102 (e.g., referring to FIG. 5 ) may emit shaped acoustic signal 500. Shaped acoustic signal 500 may be any mode type such as monopole, dipole, or any other higher pole acoustic signal. In block 904, receiver 104 may measure result signal 508. Any number of receivers 102 may comprise azimuthal receivers, monopole receivers, monopole receiver, dipole receiver or receiver for higher order multipoles. In block 906, a cement-sensitive resonance mode may be determined from modal analysis or a pre-computed library. In examples, modal analysis or a pre-computed library may determine a resonance mode selected from monopole acoustic resonance mode shape 706, dipole resonance signal 708, quadrupole acoustic resonance mode shape 710, second order dipole acoustic resonance mode shape 712, second order quadrupole resonance signal 714, and second order monopole acoustic resonance mode shape 716. In block 908, received signal 508 may be decomposed according to the mode of a specific cement-sensitive mode, forming a decomposed waveform. If receivers 102 comprise an azimuthal array receiver, the signals may be decomposed to monopole, dipole, quadrupole and higher order multipole responses. In block 910, a baseline signal may be subtracted from the decomposed waveform to remove the non-resonance signal. For example, this may be performed by subtracting a decomposed baseline signal from the decomposed waveform from a range of depths or result signal 508 to remove non-resonance and form a free pipe signal 806 (e.g., referring to FIG. 8 ). Thus, the baseline-signal may be decomposed to the mode of the resonance mode. The baseline signal may be the fully bonded signal 804 or free pipe signal 806.
In block 912, a band-pass filter may be used on the product of block 910 free pipe signal 806 from block 910 to form a filtered time domain waveform. A frequency band of the band-pass filter may be used according to the frequency of a specific cement-sensitive mode. In effect, a band-pass filter may be used to form the filtered time domain signal within a certain bandwidth. The band for a band pass filter may be equally distributed for each resonance frequency. In examples, the frequency band may be determined by a pre-determined cement-sensitive resonance mode, as discussed in block 906. If a resonance frequency is 10 kHz, the band may be from 8-12 kHz. The band may range from 1 Hz to 1 MHz. In block 914, propagating waves may be removed from the filtered time domain signal to form a resonance signal. In examples, the propagating waves (such as guided waves or Stoneley waves) may be removed with signal processing methods, such as frequency-wavenumber filtering, slant-stack transform, the Radon transform, etc.
In block 916, a time segment of the resonance signal is selected to compute the amplitude of the filtered time domain waveform. The time segment may be selected from early time and comprises resonance and non-resonance signals. In effect, the end time is selected to avoid late time reflection signals. Amplitude may be computed as the root-mean squared amplitude, peak-to-peak amplitude or from wavelet convolution or Hilbert transform. In block 918, amplitude may be plotted on an amplitude log at the depth of acoustic logging tool 100 (e.g., referring to FIG. 1 ). Additionally, acoustic logging tool 100 may be conveyed to a plurality of depths and repeat blocks 902-918 to populate an amplitude log. Further, a plurality of resonance modes may be employed to produce a plurality of amplitude logs. In block 920, the plurality of amplitude logs may be combined from multiple resonance modes and calibrate the amplitude of the log to produce an aggregate cement bond log. For example, logs from several cement-sensitive modes may be combined to produce the aggregate cement bond log. The overall cement bond log may be a weighted average of logs from several cement-sensitive modes, where the weights depend on the sensitivity of individual modes. Finally, the amplitude of the log needs to be normalized with the amplitude of free pipe or fully bonded section which is from field test, laboratory test or simulation. The final generalized log is normalized to have a unified free pipe value (e.g., one), and a unified fully bonded value (e.g., zero). Additionally, time domain baseline-removed signal method 900 may be repeated for different frequencies. The results may be illustrated in FIG. 10 .
FIG. 10 illustrates an example of time domain method with baseline-removal. Decompressed waveform 1002 from block 908 (e.g., referring to FIG. 9 ) provides a monopole response of azimuthal receiver signals. Similarly, resonance signal 1004 from block 916 shows the signal after subtracting the fully bonded signal, band pass filter and propagating wave removal. A time segment of 0-3 ms may be used to capture the arrivals of the amplitude log 1006, from block 918. The RMS (root mean squared) amplitude of the time segmented signal may be computed and plotted in amplitude log 1006. Amplitude log 1006 shows the difference between fully bonded and free pipe section and partially bonded section. As such, amplitude log 1006 produces a correlation to how proficient a cement bond is at a given depth. In examples, the cement bond quality may be measured in terms of bond percent between fully bonded and free pipe. As such, a fully bonded section may yield a 100% cement bond quality. If the cement bond is not proficient at a given depth, then a remediation plan may be implemented. Herein, a proficient cement bond may be 100%-75% full bonded, 75%-25% fully bonded, or 25%-1% fully bonded. A non-proficient cement bond may be any fully bonded percent less than a proficient cement bond. The difference between free pipe and fully bonded may be illustrated in amplitude variation 1008. FIGS. 9 and 10 illustrate a method for time domain baseline-removed signal and provide a graphical representation of its effectiveness. In other examples, a time domain method without baseline-removal may be implemented.
FIG. 11 illustrates a time domain without baseline-removal method 1100. In examples, time domain without baseline-removal method 1100 may be performed and/or operated on information handling system 144 (e.g., referring to FIG. 1 ). In block 1102, transmitter 102 (e.g., referring to FIG. 5 ) may emit shaped acoustic signal 500. Shaped acoustic signal 500 may be any mode type such as monopole, dipole, or any other higher pole acoustic signal. In block 1104, receiver 104 may measure result signal 508. Any number of receivers 102 may comprise azimuthal receivers, monopole receivers, monopole receiver, dipole receiver or receiver for higher order multipoles. In block 1106, a cut-off time may be determined to remove the early time non-resonance arrivals. As such, the cut-off time indicates the distinction between the early arrival times 602 and late arrival times 604. Thus, when applied the cut-off time may remove at least a portion of the return signal. Herein, cut-off time may be defined as the starting time when selecting the segment of time domain signal and may be determined by the length of source waveform, tubing and casing diameters, degree of eccentricity and transmitter-receiver (TR) offset. A time segment may be taken from the cut-off time to a time when most of the signal is decayed. In examples, a cut-off time may be estimated with the time domain signal. In examples, cut-off time may range from 0.01 ms-1 ms, 1 ms-2 ms, 2 ms-10 s, or 10 s-2 minutes. In block 1108, a cement-sensitive resonance mode is determined from modal analysis or from a pre-computed library. Modal analysis may consider the tool, tubing and casing dimension, and material property as an input. By solving a system of equations, it may generate the frequency (eigenvalues of the system) and mode shape (eigenvectors of the system) of all resonance modes. Numerical simulation software may perform this task and a sample of all mode shapes is shown in FIG. 7 . Additionally, the cement-sensitive modes may be selected as described above. Alternatively, the cement-sensitive resonance mode can be related to the tubing/casing size using empirical equations. They may also be pre-computed and stored in a library or look-up table.
In block 1110, received signal 508 may be decomposed according to the mode of a specific cement-sensitive mode, forming a decomposed waveform. For azimuthal array receiver, the signals are decomposed to monopole, dipole, quadrupole and higher order multipole responses. For a monopole, dipole or higher order multipole receiver, the receiver may receive signal of a specific multimode and do not require decomposition. In block 1112, a band-pass filter may be used on decomposed waveform from block 1110 to form a filtered time domain waveform. A frequency band of the band pass filter may be used according to the frequency of a specific cement-sensitive mode. In effect, a band-pass filter may be used to form the filtered time domain signal within a certain bandwidth. In examples, the frequency band may be determined by a pre-determined cement-sensitive resonance mode. In block 1114, propagating waves may be removed from the filtered time domain signal to remove non-resonance signal so that the remaining signal is resonance signal. In examples, the propagating waves (such as guided waves or Stoneley waves) may be removed with signal processing methods, such as frequency-wavenumber filtering, slant-stack transform, the Radon transform, etc.
In block 1116, a time segment of the resonance signal is selected to compute the amplitude of the filtered time domain waveform. The start of a time segment may be selected at the end of early time and comprising only a resonance signal. The end of the time segment is cut off before the resonance signal is decayed. In effect, the end time is selected to avoid late time reflection signals. Amplitude may be computed as the root-mean squared amplitude, peak-to-peak amplitude or from wavelet convolution or Hilbert transform. In block 1118, amplitude may be plotted on an amplitude log at the depth of acoustic logging tool 100 (e.g., referring to FIG. 1 ). Additionally, acoustic logging tool 100 may be conveyed to a plurality of depths and repeat blocks 1102-1118 to populate an amplitude log. Further, a plurality of resonance modes may be employed to produce a plurality of amplitude logs. In block 1120, the plurality of amplitude logs may be combined from multiple resonance modes and calibrate the amplitude of the log to produce an aggregate cement bond log. For example, logs from several cement-sensitive modes may be combined to produce the aggregate cement bond log. The overall cement bond log may be a weighted average of logs from several cement-sensitive modes, where the weights depend on the sensitivity of individual modes. Finally, the amplitude of the log needs to be normalized with the amplitude of free pipe or fully bonded section which is from field test, laboratory test or simulation. The final generalized log is normalized to have a unified free pipe value (e.g., one), and a unified fully bonded value (e.g., zero). Additionally, time domain without baseline-removal method 1100 may be repeated for different frequencies. The results may be shown in FIG. 12 .
FIG. 12 illustrates an example of time domain method without baseline-removal. The data is taken from a test well with different bonding conditions, which are free pipe, fully bonded, and partially bonded section with fluid 502 (e.g., referring to FIG. 5 ) channel width. The cement sensitive mode is a dipole mode, and the signal is excited with a dipole source and received by segmented receivers. Decompressed waveform 1202 from block 1110 (e.g., referring to FIG. 11 ) provides a monopole response of azimuthal receiver signals. Similarly, resonance signal 1204 from block 1112 shows the product after the band pass filter and propagating wave removal, band pass filter and propagating wave removal. A time segment of 1-3 ms may be used to capture the arrivals of the amplitude log 1206, from block 1118. The RMS (root mean squared) amplitude of the time segmented signal may be computed and plotted in amplitude log 1206. Amplitude log 1206 shows the difference between fully bonded and free pipe section and partially bonded section. As such, amplitude log 1206 produces a correlation to how proficient a cement bond is at a given depth. If the cement bond is not proficient at a given depth, then a remediation plan may be implemented. Herein, a proficient cement bond may be 100%-75% full bonded, 75%-25% fully bonded, or 25%-1% fully bonded. The difference between free pipe and fully bonded may be illustrated in amplitude variation 1008. FIGS. 9-12 illustrate a method for time domain methods. In other examples, a frequency-time domain method implementing wavelet analysis may be performed.
FIG. 13A illustrates frequency-time domain wavelet analysis 1300. In examples, frequency-time domain wavelet analysis 1300 may be performed and/or operated on information handling system 144 (e.g., referring to FIG. 1 ). In block 1302, transmitter 102 (e.g., referring to FIG. 5 ) may emit shaped acoustic signal 500. Shaped acoustic signal 500 may be any mode type such as monopole, dipole, or any other higher pole acoustic signal. In block 1304, receiver 104 may measure result signal 508. Any number of receivers 102 may comprise azimuthal receivers, monopole receivers, monopole receiver, dipole receiver or receiver for higher order multipoles. In block 1306, a cement-sensitive resonance mode is determined from modal analysis or from a pre-computed library, as discussed in block 906. In block 1308, received signal 508 may be decomposed according to the mode of a specific cement-sensitive mode, forming a decomposed waveform. If receiver 102 comprises an azimuthal array receiver, the signals may be decomposed to monopole, dipole, quadrupole and higher order multipole responses. For a monopole, dipole or higher order multipole receiver, receiver 102 may receive signal of a specific multimode and may not utilize decomposition.
In block 1310, the decomposed waveform from block 1308 may be transformed into a frequency-time domain using wavelet analysis. Time-frequency window 1320 may be used to compute the amplitude from the 2D time-frequency domain. FIG. 13B illustrates results from frequency-time domain wavelet analysis 1300. The frequency window may be determined by the frequency of the cement-sensitive mode, as discussed in block 912 (e.g., referring to FIG. 9 ). For example, In FIG. 13B, the cement-sensitive mode is a 16 kHz monopole, so the frequency range of the time-frequency window is selected from 9 kHz to 22 kHz. Additionally, the time window may be the same as the time segment from block 916.
In block 1312, amplitude may be plotted from a range of depth as amplitude log 1318. The amplitude of amplitude log may be indicative of cement bonding. As such, amplitude log 1318 produces a correlation to how proficient a cement bond is at a given depth. If the cement bond is not proficient at a given depth, then a remediation plan may be implemented. Herein, a proficient cement bond may be 100%-75% full bonded, 75%-25% fully bonded, or 25%-1% fully bonded. A non-proficient cement bond may be any fully bonded percent less than a proficient cement bond. In block 1314, amplitude log 1318 may be an aggregate from multiple resonance modes amplitudes. The logs from several cement-sensitive modes may be combined to produce an aggregate cement bond log. The over-all cement bond log may be a weighted average of individual log, where the weights depend on the sensitivity of individual modes. Finally, the amplitude of the log needs to be normalized with the amplitude of free pipe or fully bonded section which is from field test, laboratory test or simulation. The final generalized log is normalized to have a unified free pipe value (e.g., one), and a unified fully bonded value (e.g., zero).
Remediation procedures may be implemented to correct for non-proficient cement bonds. In examples, remediations procedures may include oil excavation, soil vapor extraction, soil vapor extraction with air sparge, in-situ chemical oxidation, groundwater extraction and treatment through mechanical, chemical or biological means, and dual phase extraction. Additionally, one or more remediation operations may be identified and performed on the wellbore. General remediation may be performed by a downhole squeeze job. In some examples, for wellbore remediation, coiled tubing may deliver the remediation chemicals to the location of non-ideal cement bond. Further, remediation operations such as squeeze jobs, chemical remediations, oil excavation, soil vapor extraction, soil vapor extraction with air sparge, in-situ chemical oxidation, groundwater extraction and treatment through mechanical, chemical or biological means, and dual phase extraction, and/or the like may be performed to improve or at least partially repair one or more non-ideal cement bonds.
The methods and systems described above are an improvement over current technology in the method and systems herein remove non-resonance signals and enhance resonance signals. Specifically, methods and systems described herein determine amplitude of resonance signals from band-pass filtered time domain signal, with or without baseline removal. In effect, amplitude of resonance signals may be used to determine the quality of cement bonds. In contrast, current methods and techniques do not identify resonance modes.
The preceding description provides various examples of the systems and methods of use disclosed herein which may contain different method steps and alternative combinations of components. It should be understood that, although individual examples may be discussed herein, the present disclosure covers all combinations of the disclosed examples, including, without limitation, the different component combinations, method step combinations, and properties of the system. It should be understood that the compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods may also “consist essentially of” or “consist of” the various components and steps. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces. The systems and methods for using a distributed acoustic system in a subsea environment may include any of the various features of the systems and methods disclosed herein, including one or more of the following statements. Additionally, the systems and methods for an acoustic tool in a downhole environment may include any of the various features of the systems and methods disclosed herein, including one or more of the following statements.
Statement 1. A method comprising: transmitting an acoustic signal into at least part of a conduit string, measuring a return signal from at least part of the conduit string, computing one or more amplitudes of a resonance signal from the return signal, and forming a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.
Statement 2. The method of statement 1, further comprising decomposing the return signal to form a decomposed waveform, forming the resonance signal by implementing a filter with at least the decomposed waveform, and determining a resonance mode of the return signal.
Statement 3. The method of statement 2, wherein the filter is a band pass filter and the band pass filter is formed from at least on the resonance mode of the return signal.
Statement 4. The method of statements 1 or 2, further comprising subtracting a baseline signal from the decomposed waveform.
Statement 5. The method of statement 4, wherein the baseline signal is a fully bounded return signal or a free pipe return signal.
Statement 6. The method of any previous statements 1, 2, or 4, wherein decomposing is based on at least the resonance mode.
Statement 7. The method of any previous statements 1, 2, 4, or 6, further comprising forming at least one time-frequency window and performing wavelet analysis on the decomposed waveform.
Statement 8. The method of statements 1 or 2, further comprising forming at least one time-frequency window and performing wavelet analysis on the decomposed waveform.
Statement 9. The method of any previous statements 1, 2, or 8, further comprising forming a time segment from late time arrivals, wherein the late time arrivals comprise only resonance signals.
Statement 10. The method of any previous statements 1, 2, 8, or 9, wherein one or more amplitudes are computed by root-mean squared amplitude, peak-to-peak amplitude or from wavelet convolution or Hilbert transform.
Statement 11. The method of any previous statements 1, 2, or 8-10, further comprising determining a cut-off time by at least a length of return waveform, tubing and casing diameters, degree of eccentricity, or transmitter-receiver (TR) offset.
Statement 12. The method of statement 11, further comprising taking a portion of the return signal after a cut-off time.
Statement 13. The method of any previous statements 1, 2, 8-10, or 11, further comprising forming a cement bond quality with at least the depth-resonance amplitude log.
Statement 14. A system comprising: a transmitter configured to transmit an acoustic signal into at least part of a conduit string, a receiver configured to measuring a return signal from at least part of the conduit string, an information handling system configured for: computing one or more amplitudes of a resonance signal from the return signal, and forming a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.
Statement 15. The system of statement 14, wherein the information handling system is further configured to decompose the return signal and form the resonance signal by implementing a filter with at least a decomposed waveform.
Statement 16. The system of statements 14 or 15, wherein the information handling system is further configured to take a portion of the return signal after a cut-off time.
Statement 17. The system of any previous statements 14-16, wherein the information handling system is further configured to subtract a baseline signal from the decomposed waveform.
Statement 18. A non-transitory storage computer-readable medium storing one or more instructions that, when executed by a processor, cause the processor to: obtain a return signal from a receiver configured to measure the return signal from at least part of a conduit string, compute one or more amplitudes of a resonance signal from the return signal, and form a depth-resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.
Statement 19. The non-transitory storage computer readable medium of statement 18, wherein the one or more instructions, that when executed by the processor, further cause the processor to take a portion of the return signal after a cut-off time.
Statement 20. The non-transitory storage computer readable medium of statements 18 or 19, wherein the one or more instructions, that when executed by the processor, further cause the processor to form a decomposed waveform from the return signal and subtract a baseline signal from the decomposed waveform.
The preceding description provides various examples of the systems and methods of use disclosed herein which may contain different method steps and alternative combinations of components. It should be noted that, although individual examples may be discussed herein, the present disclosure covers all combinations of the disclosed examples, including, without limitation, the different component combinations, method step combinations, and properties of the system. It should be understood that the compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods may also “consist essentially of” or “consist of” the various components and steps. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the elements that it introduces.
For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values even if not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.
Therefore, the present examples are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular examples disclosed above are illustrative only, and may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Although individual examples are discussed, the disclosure covers all combinations of all of the examples. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. It is therefore evident that the particular illustrative examples disclosed above may be altered or modified and all such variations are considered within the scope and spirit of those examples. If there is any conflict in the usages of a word or term in this specification and one or more patent(s) or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.

Claims

What is claimed is:

1. A method comprising:

transmitting an acoustic signal into at least part of a conduit string;

measuring a return signal from at least part of the conduit string;

computing one or more amplitudes of a resonance signal from the return signal; and

forming a depth resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.

2. The method of claim 1, further comprising decomposing the return signal to form a decomposed waveform, forming the resonance signal by implementing a filter with at least the decomposed waveform, and determining a resonance mode of the return signal.

3. The method of claim 2, wherein the filter is a band pass filter and the band pass filter is formed from at least on the resonance mode of the return signal.

4. The method of claim 2 further comprising subtracting a baseline signal from the decomposed waveform.

5. The method of claim 4, wherein the baseline signal is a fully bounded return signal or a free pipe return signal.

6. The method of claim 2, wherein decomposing is based on at least the resonance mode.

7. The method of claim 2, further comprising forming at least one time-frequency window and performing wavelet analysis on the decomposed waveform.

8. The method of claim 1, further comprising forming a time segment from early time arrivals, wherein the early time arrivals comprise resonance and non-resonance signals.

9. The method of claim 1, further comprising forming a time segment from late time arrivals, wherein the late time arrivals comprise only resonance signals.

10. The method of claim 1, wherein one or more amplitudes are computed by root-mean squared amplitude, peak-to-peak amplitude or from wavelet convolution or Hilbert transform.

11. The method of claim 1, further comprising determining a cut-off time by at least a length of return waveform, tubing and casing diameters, degree of eccentricity, or transmitter-receiver (TR) offset.

12. The method of claim 11, further comprising taking a portion of the return signal after a cut-off time.

13. The method of claim 1, further comprising forming a cement bond quality with at least the depth resonance amplitude log.

14. A system comprising:

a transmitter configured to transmit an acoustic signal into at least part of a conduit string;

a receiver configured to measuring a return signal from at least part of the conduit string;

an information handling system configured for:

15. The system of claim 14, wherein the information handling system is further configured to decompose the return signal and form the resonance signal by implementing a filter with at least a decomposed waveform.

16. The system of claim 14, wherein the information handling system is further configured to take a portion of the return signal after a cut-off time.

17. The system of claim 14, wherein the information handling system is further configured to subtract a baseline signal from the decomposed waveform.

18. A non-transitory storage computer-readable medium storing one or more instructions that, when executed by a processor, cause the processor to:

obtain a return signal from a receiver configured to measure the return signal from at least part of a conduit string;

compute one or more amplitudes of a resonance signal from the return signal; and

form a depth resonance amplitude log of the resonance signal with at least one of the one or more amplitudes of the resonance signal.

19. The non-transitory storage computer readable medium of claim 18, wherein the one or more instructions, that when executed by the processor, further cause the processor to take a portion of the return signal after a cut-off time.

20. The non-transitory storage computer readable medium of claim 18, wherein the one or more instructions, that when executed by the processor, further cause the processor to form a decomposed waveform from the return signal and subtract a baseline signal from the decomposed waveform.