Quick Links

CWP Seminars - 2014 Fall

CWP seminars discuss topics pertaining to our broad areas of research interests. These seminars are led by CWP faculty, students and, on occasion, by guest presenters. CWP seminars are held every Monday at 4 p.m. in the Green Center on the Colorado School of Mines campus. Click here to see previous CWP Seminars.

Note: To view weekly seminar schedules of individual CWP teams, click a link below:

A-Team seminars

C-Team seminars

iTeam seminars

Steam seminars

 

Fall 2014 CWP seminars

Date Speaker(s) Title Abstract
9/15

Tariq

Tariq Alkhalifah

FWI+MVA the natural way

Integrating migration velocity analysis (MVA) and full waveform inversion (FWI) can help reduce the high nonlinearity of the classic FWI objective function. The combination of inverting for the long and short wavelength components of the velocity model using a dual objective function that is sensitive to both components is still very expensive and have produced mixed results. We develop an approach that includes both components integrated to complement each other. We specifically utilize the image to generate reflections in our synthetic data only when the velocity model is not capable of producing such reflections. As a result, we get the MVA working when we need it, and mitigate it's influence when the velocity model produces accurate reflections (possibly first for the low frequencies). This is achieved using a novel objective function that includes both objectives. Applications to a layered model, as well as, the Marmousi model demonstrate the approach main features.

9/8

Hui

Hui Wang

Prestack exploding reflector modeling and migration in TI media

Prestack depth migration in anisotropic media, especially those that exhibit tilt, can be costy using reverse time migration (RTM). I will present a two-way spectral wavefield extrapolation using prestack exploding reflector model (PERM) in acoustic transversely isotropic (TI) media. This technique can naturally export the common image gathers compared to cross-correlation imaging condition and poynting vectors approaches. I construct systematic ways to evaluate phase angles and phase velocities in dip oriented TI (DTI), vertical TI (VTI) and tilted TI (TTI) media, which are required by the spectral time-steppings of wavefields. I will show migration results from the Marmousi VTI model and the BP2007 TTI model.

9/1

Kanu

Chinaemerem Kanu

Sensitivity to time-lapse velocity change using multiply elastic scattered waves

Multiply scattered waves provide the potential for increased illumination or increased detectability of the weak perturbations presence within a medium. One of the proven use of the multiply scattered waves is in the detection of the weak time-lapse changes, such as velocity changes due geomechanical processes within the sub-surface or localized defects/cracks within mechanical structures. However, using multiply scattered waves to resolve localized weak changes within a medium requires the characterization of the distribution of the scattered waves within the medium. In a couple of meetings back we explored the characteristics of acoustic sensitivity kernel that can be used to resolve weak changes within a scattering medium. In this presentation, we will look at the computation of the elastic sensitivity kernels and explore their characteristics.

8/25

1st CWP seminar of the Fall 2014 semester (CWP administrative topics)

 

Previous CWP Seminars

2014

Spring

 

2013

Spring

Fall

2012

Spring

Fall

 

 

Back to Top