CANCELLED North Tech Lunch: Joint Time-Variant Spectral Analysis: Time-Frequency and Time-Phase - Jan 23rd

Meeting Location:
2455 Technology Forest Blvd.
The Woodlands, TX  77381
** Please allow some extra time to sign in with security, and required escort to auditorium on 2nd floor.

Meeting Time: 
11:00 to 1:00 pm  
*Registration Begins at 11:00
**Presentation starts at 12:00

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Speaker: Ramses Meza, BHP

Using time-frequency and time-phase analysis we found that for an isolated thin bed in a binary-impedance setting, there is no observable sensitivity in preferential illumination as layered net-to-gross (NTG) changes within the isolated thin bed, regardless of the way the internal layering is distributed — either uniformly or semirandomly. The NTG signature is observed on the amplitude (magnitude) responses, rather than any specific frequency or phase component. On the other hand, external mutual thin-bed interference can significantly change the preferred phase component for each participating target. This phenomenon is largely driven by the embedded seismic wavelet that determines the nominal seismic response of an isolated thin layer and what phase component would preferentially illuminate it. For vertical separations between mutually interfering and elastically comparable thin beds in which mutual constructive interference is achieved, the target bed will be preferentially illuminated at a phase component that is very close to that of a total seismic isolation, whereas the occurrence of mutual destructive interference will cause a significant departure on the phase preferential illumination from that of an isolated seismic thin bed. All these observations can provide an avenue to yield
more robust stratigraphic interpretations of seismic data and enhance the confidence on subsurface description. 

The joint time-frequency and time-phase analysis applied to a field seismic data highlights lateral changes on preferential frequency and phase illumination at the target across secondary faults. Mutual thin-bed interference modeling suited for the case study area was performed using a well-tying well-based extracted wavelet assumed to be representative of the wavelet embedded on the input seismic data. The long coda of this wavelet is also present on the corresponding thin-bed waveform, indicating the possibility of more complex mutual interference patterns between thin beds and mutual interference at farther vertical separations between thin beds compared with what would occur for an embedded wavelet with a shorter coda. The observed lateral changes on preferential frequency and phase illumination on the seismic data are attributable to collocated lateral changes in the stacking patterns and variable occurrence of vertically adjacent thin beds, which are interpreted as lateral sediment deposition changes induced by the syndepositional activity of the secondary faults. This is a geologic scenario that had not been previously considered on the area until the evidence of this case study provide indirect support for it.

Speaker Biography: Ramses Meza, BHP
Ramses Meza is a Principal Geophysicist with BHP Petroleum. He obtained his PhD in Geophysics from the University of Houston, MsC in geophysics from the Colorado School of Mines (USA) and geophysical engineering degree from the Universidad Simon Bolivar (Venezuela). Early in his career he worked as a reservoir geophysicist at PDVSA in Puerto La Cruz, Venezuela; Harvest-Vinccler in Maturin, Venezuela and ConocoPhillips in Houston, USA. His responsibilities included support in terms of quantitative seismic interpretation for hydrocarbons exploration and production activities. Since 2012, he has been with BHP as a Subject-Matter Expert providing advanced geophysical support to all E&P assets with emphasis on integration of Quantitative Interpretation (QI) products, visualization, seismic attributes, QI quality assurance, seismic reservoir characterization, DHI analysis and risking. Ramses is member of the SEG, AAPG, EAGE and SOVG.

Price List:
Pre-Registered Late/Walk-Up
 $35  $45
 Non-Member  $45  $55
 Student Member
 $0  $10

1/23/2020 11:00 AM - 1:00 PM

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