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Acoustic Logging

The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

Junqiang Lu – 1st expert on this subject based on the ideXlab platform

  • Intelligent Fault-Diagnosis System for Acoustic Logging Tool Based on Multi-Technology Fusion
    Sensors, 2019
    Co-Authors: Xiaodong Ju, Junqiang Lu, Jing Zhou

    Abstract:

    To improve the performance of Acoustic Logging tool in detecting three-dimensional formation, larger and more complicated transducer arrays have been used, which will greatly increase the difficulty of fault diagnosis during tool assembly and maintenance. As a result, traditional passive diagnostic methods become inefficient, and very skilled assemblers and maintainers are required. In this study, fault-diagnosis requirement for the Acoustic Logging tool at different levels has been analyzed from the perspective of the tool designer. An intelligent fault-diagnosis system consisting of a master-slave hardware architecture and a systemic diagnosis strategy was developed. The hardware system is based on the embedded technology, while the diagnosis strategy is built upon fault-tree analysis and data-driven methods. Diagnostic practice shows that this intelligent system can achieve four levels of fault diagnosis for the Acoustic Logging tool: System, subsystem, circuit board, and component. This study provided a more rigorous and professional fault diagnosis during tool assembly and maintenance. It is expected that this proposed method would be of great help in achieving cost reduction and improving work efficiency.

  • azimuthally Acoustic Logging tool to evaluate cementing quality
    Journal of Geophysics and Engineering, 2014
    Co-Authors: Junqiang Lu, Xiaodong Ju, Wen-xiao Qiao, Rui-jia Wang, Jinping Wu

    Abstract:

    An azimuthally sensitive Acoustic bond tool (AABT) uses a phased arc array transmitter that can provide directionally focused radiation. The Acoustic sonde consists of a phased arc array transmitter and two monopole receivers, the spaces from the transmitter being 0.91 m and 1.52 m, respectively. The transmitter includes eight transducer sub-units. By controlling the high-voltage firing signal phase for each transmitter, the radiation energy of the phased arc array transducer can be focused in a single direction. Compared with conventional monopole and dipole transmitters, the new transmitter provides cement quality evaluation with azimuthal sensitivity, which is not possible with conventional cement bond log/variable density log tools. Laboratory measurements indicate that the directivity curves for the phased arc array and those computed theoretically are consistent and show good agreement. We acquire measurements from a laboratory cistern and from the field to validate the reliability and applicability of the AABT. Results indicate that the AABT accurately evaluates the azimuthal cement quality of case-cement interfaces by imaging the amplitude of the first-arrival wave. This tool visualizes the size, position and orientation of channeling and holes. In the case of good case-cement bonding, the AABT also evaluates the azimuthal cementing quality of the cement formation interface by imaging the amplitude of formation waves.

  • design of Acoustic Logging signal source of imitation based on field programmable gate array
    Journal of Geophysics and Engineering, 2014
    Co-Authors: Kunheng Zhang, X D Ju, Junqiang Lu

    Abstract:

    An Acoustic Logging signal source of imitation is designed and realized, based on the Field Programmable Gate Array (FPGA), to improve the efficiency of examining and repairing Acoustic Logging tools during research and field application, and to inspect and verify Acoustic receiving circuits and corresponding algorithms. The design of this signal source contains hardware design and software design,and the hardware design uses an FPGA as the control core. Four signals are made first by reading the Random Access Memory (RAM) data which are inside the FPGA, then dealing with the data by digital to analog conversion, amplification, smoothing and so on. Software design uses VHDL, a kind of hardware description language, to program the FPGA. Experiments illustrate that the ratio of signal to noise for the signal source is high, the waveforms are stable, and also its functions of amplitude adjustment, frequency adjustment and delay adjustment are in accord with the characteristics of real Acoustic Logging waveforms. These adjustments can be used to imitate influences on sonic Logging received waveforms caused by many kinds of factors such as spacing and span of Acoustic tools, sonic speeds of different layers and fluids, and Acoustic attenuations of different cementation planes.

Xiu-ming Wang – 2nd expert on this subject based on the ideXlab platform

  • monopole collar wave characteristics for Acoustic Logging while drilling in fast formations in the frequency and spatial domains
    Wave Motion, 2019
    Co-Authors: Yunjia Ji, Xiu-ming Wang, Xiao He, Hao Chen, Hailan Zhang

    Abstract:

    Abstract Collar waves generated by the presence of the massive steel collar can interfere with or even cover formation signals, which has been a challenge for designing Acoustic Logging while drilling (ALWD) tools. In order to seek the means for the suppression of collar waves, it is necessary to study their propagation characteristics. In this study, considering azimuthally symmetric modes only, we compare the radial distribution of the excitation intensity for the first-order collar mode (hereinafter referred to as the collar wave) with varying frequencies obtained by solving elastic wave equations. And the characteristics of the particle vibration trajectories contributed by the collar wave are investigated. It is found that the radial position corresponding to the excitation peak of the collar wave depends on frequencies. As the frequency increases, the peak gradually moves from the inner wall to the outer wall in the collar. According to this feature, it is concluded that interior grooves cut on the drill collar are more suitable for weakening the collar wave than exterior grooves with lower frequencies. On the contrary, in the high-frequency range, exterior grooves attenuate the collar wave more effectively. To confirm these conclusions, we design numerical models and validate the collar wave attenuation by finite difference time-domain simulations. Furthermore, by analyzing vibration properties of particles contributed by the collar wave with varying frequencies, we reveal that the polarization of collar wave motions at the low frequency is similar to that of the longitudinal wave, while at the high frequency it becomes the transverse-wave-like vibration. Inspired by the observation, it is proposed that the collar wave can be weakened by using a steel collar containing an interlayer whose material differ from that of the steel collar. Two layered models are designed and the synthetic waveforms are numerically simulated to examine the proposal. The comparison of wave amplitudes indicates that the collar with an axial interlayer attenuates more collar waves than the collar containing a radial interlayer in the low-frequency range, while in the higher frequency range, the radial layered structures are better for collar wave suppression. Finally, the feasibility analysis of ALWD in the high-frequency range is carried out. The analysis illustrates that when the source frequency is within 20–25 kHz, the excitation amplitude of the second-order collar mode is relatively weak and the first-order collar mode is mainly concentrated near the outer surface of the collar. Appropriate exterior grooves cut on the collar may lead to a clear arrival of formation signals.

  • simulations of collar waves for Acoustic Logging while drilling in the frequency and the spatial domains
    Journal of the Acoustical Society of America, 2019
    Co-Authors: Xiao He, Yunjia Ji, Hao Chen, Xiu-ming Wang

    Abstract:

    Tool waves generated by the presence of the drill collar can cover the formation signals we need. The suppression for those collar waves has been a challenge for designing Acoustic Logging while drilling (ALWD) tools. To study the collar wave characteristics, we evaluate the excitation intensity of the modes with varying frequencies and positions by solving the elastic wave equations. Analysis results show that the collar wave energy concentrates in the cylindrical tool model. And the radial location of its peak gradually moves from the inner surface to the outer wall with the increasing frequency. The particle vibration trajectories contributed by the collar wave are also investigated. It is revealed that the collar mode in the lower frequency range has an approximately longitudinal polarization, while it tends to the transverse-wave-like motion at high frequencies. According to these features, we propose strategies on the tool structure designs to suppress the collar waves in the lower- and the higher- …

  • A New Design of Unipole Source For Azimuth Acoustic Logging While Drilling
    2019 13th Symposium on Piezoelectrcity Acoustic Waves and Device Applications (SPAWDA), 2019
    Co-Authors: Jian-sheng Cong, Xiu-ming Wang

    Abstract:

    A new model of unipole source with U shape was designed for azimuthal Acoustic Logging while drilling. The transmitter was simulated numerically by finite elements method. The model was established and multi-mode couplings were analyzed by eigenfrequency calculations. By harmonic response analysis, the admittance curves and transmitting voltage response curves were given with changing frequencies. In the frequency range of 2.5-25 kHz, the maximum value of transmitting voltage response is up to 156dB, and the -3 dB bandwidth is up to 9.5 kHz. This work provides a theoretical basis for unipole source design in azimuth Logging while drilling applications.

Xiaodong Ju – 3rd expert on this subject based on the ideXlab platform

  • Intelligent Fault-Diagnosis System for Acoustic Logging Tool Based on Multi-Technology Fusion
    Sensors, 2019
    Co-Authors: Xiaodong Ju, Junqiang Lu, Jing Zhou

    Abstract:

    To improve the performance of Acoustic Logging tool in detecting three-dimensional formation, larger and more complicated transducer arrays have been used, which will greatly increase the difficulty of fault diagnosis during tool assembly and maintenance. As a result, traditional passive diagnostic methods become inefficient, and very skilled assemblers and maintainers are required. In this study, fault-diagnosis requirement for the Acoustic Logging tool at different levels has been analyzed from the perspective of the tool designer. An intelligent fault-diagnosis system consisting of a master-slave hardware architecture and a systemic diagnosis strategy was developed. The hardware system is based on the embedded technology, while the diagnosis strategy is built upon fault-tree analysis and data-driven methods. Diagnostic practice shows that this intelligent system can achieve four levels of fault diagnosis for the Acoustic Logging tool: System, subsystem, circuit board, and component. This study provided a more rigorous and professional fault diagnosis during tool assembly and maintenance. It is expected that this proposed method would be of great help in achieving cost reduction and improving work efficiency.

  • azimuthally Acoustic Logging tool to evaluate cementing quality
    Journal of Geophysics and Engineering, 2014
    Co-Authors: Junqiang Lu, Xiaodong Ju, Wen-xiao Qiao, Rui-jia Wang, Jinping Wu

    Abstract:

    An azimuthally sensitive Acoustic bond tool (AABT) uses a phased arc array transmitter that can provide directionally focused radiation. The Acoustic sonde consists of a phased arc array transmitter and two monopole receivers, the spaces from the transmitter being 0.91 m and 1.52 m, respectively. The transmitter includes eight transducer sub-units. By controlling the high-voltage firing signal phase for each transmitter, the radiation energy of the phased arc array transducer can be focused in a single direction. Compared with conventional monopole and dipole transmitters, the new transmitter provides cement quality evaluation with azimuthal sensitivity, which is not possible with conventional cement bond log/variable density log tools. Laboratory measurements indicate that the directivity curves for the phased arc array and those computed theoretically are consistent and show good agreement. We acquire measurements from a laboratory cistern and from the field to validate the reliability and applicability of the AABT. Results indicate that the AABT accurately evaluates the azimuthal cement quality of case-cement interfaces by imaging the amplitude of the first-arrival wave. This tool visualizes the size, position and orientation of channeling and holes. In the case of good case-cement bonding, the AABT also evaluates the azimuthal cementing quality of the cement formation interface by imaging the amplitude of formation waves.

  • A board level test system for the multi-pole array Acoustic Logging tool
    2014 7th International Congress on Image and Signal Processing, 2014
    Co-Authors: Junqiang Lu, Xiaodong Ju, Kai Zhang

    Abstract:

    To improve examining and repairing efficiency of Acoustic Multi-Pole Logging Tool (MPAL) in the process of industrialization, a kind of board level test system is introduced to test the MPAL analog signal receiving and acquisition circuit and the transmitting control circuit. Also, the basic principles of analog signal’s consistency test and the design of the test system interface circuit are introduced. Experimental results show that the board level test system can measure the performance and consistency of the analog signal receiving and acquisition circuit and the transmitting control circuit accurately. It has a guiding significance for the process of adjusting circuit parameters. In other words, it is a kind of effective monitoring equipment during the industrialization and debugging of Acoustic Logging tools.