Results 151 to 160 of about 464 (176)
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Analysis of the Acoustic Wavefields Excited by the Logging-While-Drilling (LWD) Tool
Geosystem Engineering, 2003ABSTRACTS Synthetic seismograms recorded with a logging-while-drilling (LWD) tool in the presence of slow formation are computed by the discrete wavenumber method. Monopole, dipole, and quadrupole logging tools are simulated with a source center frequency of 4 kHz.
Joongmoo Byun
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A lossless acoustic logging while drill compression scheme based on differential prediction
Proceedings of 2011 International Conference on Electronic & Mechanical Engineering and Information Technology, 2011In this paper, by analyzing the characteristics of the data, we adopt lossless compression based on predictive coding method. First, we adopt two-way differential prediction for data, and then use the three classical adaptive compression algorithms, and have made a good compression ratio. Then, we tested our algorithms and compared with Winrar software,
Yujie Liu, Yunkai Zhou, Hongbing Xiao
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Acoustic waveform design for data transmission by using drill strings in logging-while-drilling
2006 8th international Conference on Signal Processing, 2006The logging-while-drilling (LWD) systems mainly use the mud-pulse telemetry to transmit the measured data from the bottom to the surface. Its transmission rate, however, is very low, which is a severe limitation for the real-time transmission. Recently, using the drill string as the transmission carrier draws people's attentions and becomes one of the ...
Chun-yan Wang +4 more
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Geometrical optimization of an acoustic logging-while-drilling isolator
International Meeting for Applied Geoscience & EnergyIn this study axial symmetric 2.5D finite difference (FD) modeling is used to optimize the geometry of an acoustic isolator in a 6-3/4” acoustic logging while drilling (LWD) tool. Two distinct designs were evaluated: one featuring outer grooves and another one with grooves located on the inner surface of the tool conduit.
Wolfgang Weinzierl +3 more
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Effects of tool eccentricity on acoustic logging while drilling (LWD) measurements
SEG Technical Program Expanded Abstracts 2004, 2004Summary Effects of eccentric tools on acoustic LWD measurements are investigated in both time domain and frequency domain using stretched grid finite difference algorithm and finite element eigenvalue approach, respectively. Monopole, dipole and quadrupole LWD tools are discussed. The study shows that an eccentric LWD tool affects the acoustic field in
Xiaojun Huang +2 more
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Acoustic logging-while-drilling isolator design: A simplified model
International Meeting for Applied Geoscience & EnergyIn this paper we develop a simplified acoustic isolator model that incorporates basic physical principles and we investigate to what extent this acoustic model can be used as a proxy for more detailed modeling (e.g., Finite Difference (FD) or Finite Element (FE)).
Tim Geerits +3 more
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Some properties of fundamental acoustic modes when logging while drilling
Geophysics of the 21st Century - The Leap into the Future, 2003The properties of the fundamental modes generated by acoustic monopole, dipole and quadrupole sources in the LWD environment are reviewed in the presence of homogeneous slow isotropic formations. The techniques that can be used to determine the formation shear wave velocity are also discussed.
J. Market, D.P. Schmitt
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The Journal of the Acoustical Society of America, 2019
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 ...
Xiao He +3 more
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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 ...
Xiao He +3 more
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SPE Kuwait Oil & Gas Show and Conference, 2017
Abstract Logging-While-Drilling (LWD) acoustic tools encounter interference from collar arrivals when attempting quantitative cement evaluation. In low-bonding condition, the interference is not significant, an amplitude-based bond index determination is reliable with the limitation in higher bonding conditions under most scenarios ...
Zhang Bin Qi +4 more
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Abstract Logging-While-Drilling (LWD) acoustic tools encounter interference from collar arrivals when attempting quantitative cement evaluation. In low-bonding condition, the interference is not significant, an amplitude-based bond index determination is reliable with the limitation in higher bonding conditions under most scenarios ...
Zhang Bin Qi +4 more
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Design of acoustic wireless remote transmission system for logging-while-drilling data
2013 IEEE 11th International Conference on Electronic Measurement & Instruments, 2013LWD data transmission is one of the key technologies for achieving intelligent drilling. Acoustic wave wireless transmission technology is a kind of LWD data transmission technologies. It takes the elastic waves propagating along the drill string as carrier to transmit measurement data to the ground.
Zhang Wei, Shi Yibing, Li Yanjun
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