Results 91 to 100 of about 144 (128)

A multi-modes coupling receiver for acoustic logging while drilling

Proceedings of the 2014 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications, 2014
Acoustic logging while drilling (LWD) technology plays a more and more important role in highly deviated angle and horizontal well logging due to the advantages such as high efficiency, low cost and etc. However, there still exist bottleneck problems because of the acoustic LWD environment in the borehole including noise of mud and drilling bit and ...
Qian Wei, Jian-sheng Cong, Xiu-ming Wang
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Initial Results from an Acoustic Logging-While-Drilling Tool

SPE Annual Technical Conference and Exhibition, 1996
Abstract This paper presents the initial results from field tests of an acoustic logging-while-drilling tool. Over 60,000 ft of well have been logged with 6.75-in.- and 8-in.-diameter versions of the tool. Various types of formations were encountered with compressional slowness values ranging from 55 µsec/ft to 170 µsec/ft.
John W. Minear, Dale R. Heysse, Paul M. Boonen   +2 more
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Geometrical optimization of an acoustic logging-while-drilling isolator

International Meeting for Applied Geoscience & Energy
In 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, Stefan Schimschal, Anna Swiatek, Tim Geerits   +3 more
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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, 2011
In 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, 2006
The 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, Wen-xiao Qiao, Wei-qiang Zhang, Xiao-hua Che, Jun Li   +4 more
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A New Design of Unipole Source For Azimuth Acoustic Logging While Drilling

2019 13th Symposium on Piezoelectrcity, Acoustic Waves and Device Applications (SPAWDA), 2019
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.
Qian WEI, Bin LIU, Cheng-xuan CHE, Jian-sheng CONG, Xiu-ming WANG   +4 more
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Acoustic logging-while-drilling isolator design: A simplified model

International Meeting for Applied Geoscience & Energy
In 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, Wolfgang Weinzierl, Stefan Schimschal, Anna Swiatek   +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, 2003
The 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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Analysis of the Acoustic Wavefields Excited by the Logging-While-Drilling (LWD) Tool

Geosystem Engineering, 2003
ABSTRACTS 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, M. Nafi Toksöz
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Effects of tool eccentricity on acoustic logging while drilling (LWD) measurements

SEG Technical Program Expanded Abstracts 2004, 2004
Summary 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, Yibing Zheng, M. Nafi Toksöz   +2 more
openaire   +1 more source