Borehole transient electromagnetic stereo imaging method based on horizontal component anomaly feature clustering

This paper presents a fast approximate 1-D inversion algorithm for transient electromagnetic (EM) data that can be applied for all measuring configurationsand transmitter waveforms and for all field components. The inversion is based on an approximate forward mapping in the adaptive Born approximation. The generality is obtained through a separation of the forward problem into a configuration-independent part, mapping layer conductivities into apparent conductivity, and a configuration-dependent part, the half-space step response. The EM response from any waveform can then be found by a convolution with the time derivative of the waveform. The approach does not involve inherently unstable deconvolution computations or nonunique transformations, and it is about 100 times faster than ordinary nonlinear inversion. Nonlinear model responses of the models obtained through the approximate inversion fit the data typically within 5%.

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Improvement of Accuracy and Robustness on Stereo Imaging Method by Using Shadow

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.79.2093 ◽

2013 ◽

Vol 79 (802) ◽

pp. 2093-2102

Author(s):

Yasuharu KUNII ◽

Tomoya SATO ◽

Takahiro USHIODA

Keyword(s):

Imaging Method ◽

Stereo Imaging

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The study of imaging method for the moving controlled-source electromagnetic method

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-019-00774-7 ◽

2019 ◽

Vol 10 (2) ◽

pp. 363-370

Author(s):

Fengjiao Xu ◽

Liangjun Yan ◽

Osborne Kachaje

Keyword(s):

Quantitative Relationship ◽

Electromagnetic Method ◽

Imaging Method ◽

Oil Reservoir ◽

Controlled Source ◽

Transient Electromagnetic ◽

Detection Depth ◽

Resistivity Inversion ◽

Oil Water ◽

Set Up

Abstract Improving the accuracy and enhancing the reliability of controlled-source electromagnetic (CSEM) inversion in oil exploration in order to identify the interface between oil and water is a great challenge. In this paper, we proposed a variable-angle geometry imaging method by moving the source of CSEM (MCSEM). Firstly, based on the concept of multi-channel transient electromagnetic method, we obtained the quantitative relationship between the offset and detection depth, and then the geometry imaging principle of MCSEM was set up. Secondly, the feasibility study of the geometry imaging method was tested through the 1-D and 3-D forward modeling. Finally, by analyzing the collected field data of MCSEM method in Daqing oil reservoir, high-accuracy pseudo-apparent resistivity profile was obtained based on the geometry imaging method with the help of well-logging calibration. The results showed good compatibility with the 2-D TEM resistivity inversion which demonstrates that the MCSEM has great prospect potential in the identification of oil–water interface explorations.

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An Array Source TEM Apparent Resistivity Conversion and Differential Conductivity Imaging Method and its Potential Applications

Journal of Environmental and Engineering Geophysics ◽

10.2113/jeeg24.04.579 ◽

2019 ◽

Vol 24 (4) ◽

pp. 579-592

Author(s):

Zhipeng Qi ◽

Xiu Li ◽

Yingying Zhang ◽

He Li ◽

Naiquan Sun

Keyword(s):

Apparent Resistivity ◽

Fdtd Method ◽

Inverse Function ◽

Imaging Method ◽

Inversion Algorithm ◽

Electromagnetic Device ◽

Transient Electromagnetic ◽

Potential Applications ◽

Anomalous Bodies ◽

Differential Imaging

In this study, for the purpose of accurately detecting fissured disaster sources and diversion channels during tunnel construction, an array source transient electromagnetic device is proposed. Then, an apparent resistance conversion method and an approximate inversion algorithm for the proposed transient electromagnetic device are presented. First, a finite-difference time-domain (FDTD) method is used for the forward modeling of the proposed array source transient electromagnetic device, and the electromagnetic responses of the cracks and water-conducting channels are obtained. When compared with the transient electromagnetic square responses of the traditional loop sources, it is found that the data confirmed that the responses to the anomalies of the proposed array source transient electromagnetic device are more apparent. Then, the transformation from the array source transient electromagnetic field to the apparent resistivity is realized according to the principle of inverse function. In order to clearly identify the boundaries of the targeted anomalous bodies, a multi-source S-inversion algorithm is used to realize the array source transient electromagnetic differential imaging. The method is validated using a theoretical model. It was determined that the results of the differential imaging had effectively identified the boundaries of the anomalous bodies, and the apparent resistivity imaging had successfully determined the resistivity distributions of the anomalous bodies. Furthermore, a combination of the aforementioned methods is used to effectively identify the faults and water-flowing fractures in the model. This study's proposed algorithm was applied to the actually measured data, and the interpretation results were found to be consistent with the excavation results, which fully demonstrated the feasibility of the proposed method.

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Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092918 ◽

1976 ◽

Vol 34 ◽

pp. 590-591

Author(s):

T. Y. Tan ◽

W. K. Tice

Keyword(s):

Fast Neutron ◽

Rapid Determination ◽

Stacking Faults ◽

Imaging Method ◽

Large Reduction ◽

Dislocation Loops ◽

Fringe Spacing ◽

Weak Beam ◽

Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

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Mitochondrial Reconstructions Based on Serial Thick Sections and HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100115055 ◽

1975 ◽

Vol 33 ◽

pp. 286-287

Author(s):

Jerome J. Paulin

Keyword(s):

Imaging Techniques ◽

Three Dimensional ◽

Posterior Pole ◽

Dimensional Structure ◽

Stereo Imaging ◽

Thin Sections ◽

Anatomical Features ◽

The Past ◽

Cellular Components ◽

Mitochondrial Reticulum

Within the past decade it has become apparent that HVEM offers the biologist a means to explore the three-dimensional structure of cells and/or organelles. Stereo-imaging of thick sections (e.g. 0.25-10 μm) not only reveals anatomical features of cellular components, but also reduces errors of interpretation associated with overlap of structures seen in thick sections. Concomitant with stereo-imaging techniques conventional serial Sectioning methods developed with thin sections have been adopted to serial thick sections (≥ 0.25 μm). Three-dimensional reconstructions of the chondriome of several species of trypanosomatid flagellates have been made from tracings of mitochondrial profiles on cellulose acetate sheets. The sheets are flooded with acetone, gluing them together, and the model sawed from the composite and redrawn.The extensive mitochondrial reticulum can be seen in consecutive thick sections of (0.25 μm thick) Crithidia fasciculata (Figs. 1-2). Profiles of the mitochondrion are distinguishable from the anterior apex of the cell (small arrow, Fig. 1) to the posterior pole (small arrow, Fig. 2).

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Stereo imaging in the shadow electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107745 ◽

1978 ◽

Vol 36 (1) ◽

pp. 120-121

Author(s):

W. C. T. Dowell

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Convenient Method ◽

Patent Application ◽

Standard Technique ◽

Stereo Imaging ◽

Stereo Images ◽

Specimen Height

Stereo imaging is not new to electron microscopy. Von Ardenne, who first published transmission pairs nearly forty hears ago, himself refers to a patent application by Ruska in 1934. In the early days of the electron microscope von Ardenne employed a pair of magnetic lenses to view untilted specimens but soon opted for the now standard technique of tilting the specimen with respect to the beam.In the shadow electron microscope stereo images can, of course, be obtained by tilting the specimen between micrographs. This obvious method suffers from the disadvantage that the magnification is very sensitive to small changes in specimen height which accompany tilting in the less sophisticated stages and it is also time consuming. A more convenient method is provided by horizontally displacing the specimen between micrographs. The specimen is not tilted and the technique is both simple and rapid, stereo pairs being obtained in less than thirty seconds.

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Performance and applications of the holography electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151222 ◽

1993 ◽

Vol 51 ◽

pp. 1078-1079

Author(s):

Akira Tonomura

Keyword(s):

Electron Beam ◽

Electron Microscope ◽

Phase Measurement ◽

Electron Holography ◽

Imaging Method ◽

High Contrast ◽

Magnetic Lens ◽

High Brightness ◽

Holographic Imaging ◽

Dynamic Observation

Electron holography is a two-step imaging method. However, the ultimate performance of holographic imaging is mainly determined by the brightness of the electron beam used in the hologram-formation process. In our 350kV holography electron microscope (see Fig. 1), the decrease in the inherently high brightness of field-emitted electrons is minimized by superposing a magnetic lens in the gun, for a resulting value of 2 × 109 A/cm2 sr. This high brightness has lead to the following distinguished features. The minimum spacing (d) of carrier fringes is d = 0.09 Å, thus allowing a reconstructed image with a resolution, at least in principle, as high as 3d=0.3 Å. The precision in phase measurement can be as high as 2π/100, since the position of fringes can be known precisely from a high-contrast hologram formed under highly collimated illumination. Dynamic observation becomes possible because the current density is high.

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