Drill‐bit SWD and seismic interferometry for imaging around geothermal wells

2011 ◽  
Author(s):  
Flavio Poletto ◽  
Piero Corubolo ◽  
Biancamaria Farina ◽  
Andrea Schleifer ◽  
Joseph Pollard ◽  
...  
Keyword(s):  
Seismic Interferometry ◽  
Drill Bit ◽  
Geothermal Wells

scholarly journals Drill bit noise imaging without pilot trace, a near surface interferometry example

2019 ◽  
Author(s):  
Mehdi Asgharzadeh ◽  
Ashley Grant ◽  
Andrej Bona ◽  
Milovan Urosevic
Keyword(s):  
Source Function ◽  
Acoustic Energy ◽  
Seismic Interferometry ◽  
Drill Bit ◽  
Interferometric Imaging ◽  
Near Surface ◽  
Pilot Signal ◽  
Shallow Subsurface ◽  
Noise Data ◽  
Interferometry Method

Abstract. Acoustic energy emitted by drill bit can be recorded by geophones on the surface and processed for an image of the subsurface using seismic interferometry methods. Pilot sensors record bit signal on the drill rig and play an important role in processing geophone traces for the image. When pilot traces are not available, traces of the nearest geophone to the rig may be used in deconvolution and crosscorrelation of data but extra signal processing efforts are required to reduce the effect of source signature on crosscorrelation results. In this study, we use seismic interferometry method to image the shallow subsurface beneath a 2D geophone array by converting geophones to virtual sources. As there is no pilot signal available for this survey, we use nearest geophone trace for pilot crosscorrelation and pilot deconvolution. We modify the spectrum of pilot crosscorrelation and deconvolution results so that the effect of source function on virtual data is minimized. We then migrate the virtual shots and compare the results of interferometric imaging with the available image from 3D (active source) survey and assess the efficiency of our approach. We show that drill bit noise data can be used to generate a reasonably accurate image of the subsurface even in the absence of pilot recordings but the results should be checked for appearance of virtual multiples and depth inconsistencies that are caused by errors in the migration velocity.

Drill-bit seismic interferometry with and without pilot signals

2010 ◽  
Vol 58 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Flavio Poletto ◽  
Piero Corubolo ◽  
Paolo Comelli
Keyword(s):  
Seismic Interferometry ◽  
Drill Bit

scholarly journals Retrieving virtual reflection responses at drill-bit positions using seismic interferometry with drill-bit noise

2015 ◽  
Vol 64 (2) ◽  
pp. 348-360 ◽  
Author(s):  
Yi Liu ◽  
Deyan Draganov ◽  
Kees Wapenaar ◽  
Børge Arntsen
Keyword(s):  
Seismic Interferometry ◽  
Drill Bit

scholarly journals Drill bit noise imaging without pilot trace, a near-surface interferometry example

Solid Earth ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 1015-1023 ◽  
Author(s):  
Mehdi Asgharzadeh ◽  
Ashley Grant ◽  
Andrej Bona ◽  
Milovan Urosevic
Keyword(s):  
Cross Correlation ◽  
Acoustic Energy ◽  
Seismic Interferometry ◽  
Drill Bit ◽  
Interferometric Imaging ◽  
Near Surface ◽  
Pilot Signal ◽  
Shallow Subsurface ◽  
Drill Bits ◽  
Noise Data

Abstract. Acoustic energy emitted by drill bits can be recorded by geophones on the surface and processed for an image of the subsurface using seismic interferometry methods. Pilot sensors record bit signals on the drill rig and play an important role in processing geophone traces for the image. When pilot traces are not available, traces of the nearest geophone to the rig may be used in deconvolution and cross-correlation of data, but extra signal processing efforts are required to reduce the effect of source signature on cross-correlation results. In this study, we use the seismic interferometry method to image the shallow subsurface beneath a 2-D geophone array by converting geophones to virtual sources. As there is no pilot signal available for this survey, we use the nearest geophone trace for pilot cross-correlation and pilot deconvolution. We modify the spectrum of pilot cross-correlation and deconvolution results so that the effect of source function on virtual data is minimized. We then migrate the virtual shots and compare the results of interferometric imaging with the available image from 3-D (active source) survey and assess the efficiency of our approach. We show that drill bit noise data can be used to generate a reasonably accurate image of the subsurface even in the absence of pilot recordings, but the results should be checked for the appearance of virtual multiples and depth inconsistencies that are caused by errors in the migration velocity.

Preparation of cross-sectional samples for near-surface TEM studies

1987 ◽  
Vol 45 ◽  
pp. 380-381
Author(s):  
R.C. Dickenson ◽  
K.R. Lawless
Keyword(s):  
Standard Sample ◽  
Surface Region ◽  
Specimen Preparation ◽  
Thick Sheet ◽  
Drill Bit ◽  
Sample Holder ◽  
Metal Interface ◽  
Cross Sectional ◽  
Near Surface ◽  
Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

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