Acoustic signatures of crossflow behind casing in commingled reservoirs: A case study from Teapot Dome

Geophysics ◽  
2008 ◽  
Vol 73 (4) ◽  
pp. E145-E152 ◽  
Author(s):  
Andrey Bakulin ◽  
Valeri Korneev

Cracks and channels in cement often create unwanted conduits behind casing that lead to crossflow between different producing zones. Crossflow results in lost production or aquifer contamination because fluid flows from a higher-pressure to a lower-pressure zone instead of traveling up the well. We present measurements of acoustic signatures of crossflow behind the pipe in time and frequency domains. Despite being called “noise,” they are shown to be propagating tube waves with impulsive signatures. When multiple crossflow locations are present along the well, these signatures are unique for each location and are highly repeatable. We observe time-lapse change in such signatures during air injection and release and suggest that these changes can be used for real-time acoustic characterization of depletion in stacked commingled reservoirs. We anticipate that such signals are typical for commingled production of multilayered reservoirs. Acoustic signatures can be used to characterize crossflow and depletion. In addition, crossflow signals represent a strong noise affecting downhole seismic surveillance with active sources.

Author(s):  
D. L. Callahan

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.


2011 ◽  
Author(s):  
Giorgio Rocco Cavanna ◽  
Ernesto Caselgrandi ◽  
Elisa Corti ◽  
Alessandro Amato del Monte ◽  
Massimo Fervari ◽  
...  

Author(s):  
Amy Poe ◽  
Steve Brockett ◽  
Tony Rubalcava

Abstract The intent of this work is to demonstrate the importance of charged device model (CDM) ESD testing and characterization by presenting a case study of a situation in which CDM testing proved invaluable in establishing the reliability of a GaAs radio frequency integrated circuit (RFIC). The problem originated when a sample of passing devices was retested to the final production test. Nine of the 200 sampled devices failed the retest, thus placing the reliability of all of the devices in question. The subsequent failure analysis indicated that the devices failed due to a short on one of two capacitors, bringing into question the reliability of the dielectric. Previous ESD characterization of the part had shown that a certain resistor was likely to fail at thresholds well below the level at which any capacitors were damaged. This paper will discuss the failure analysis techniques which were used and the testing performed to verify the failures were actually due to ESD, and not caused by weak capacitors.


Author(s):  
Sweta Pendyala ◽  
Dave Albert ◽  
Katherine Hawkins ◽  
Michael Tenney

Abstract Resistive gate defects are unusual and difficult to detect with conventional techniques [1] especially on advanced devices manufactured with deep submicron SOI technologies. An advanced localization technique such as Scanning Capacitance Imaging is essential for localizing these defects, which can be followed by DC probing, dC/dV, CV (Capacitance-Voltage) measurements to completely characterize the defect. This paper presents a case study demonstrating this work flow of characterization techniques.


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