Technical Content

Amplitude attenuation and phase distortion of seismic data are byproducts of the Earth’s anelasticity (Q). These effects are exacerbated under regions of anomalously high absorption, such as shallow gas, causing uneven illumination and migration artifacts. We present a case study from the Norwegian North ...

To improve image resolution in the vicinity of the well, 3D VSP data was acquired at the Atlantis field in the Gulf of Mexico to complement the existing towed-streamer and OBN data. Two unique data challenges require special consideration and innovative techniques in order ...

We investigate the benefits of considering the effects of the Hessian matrix in the reflection FWI (RFWI) reflectivity, i.e., using least-squares RTM (LSRTM) to estimate the short-wavelength component of the model. In addition, a more efficient approach using single-iteration LSRTM, more specifically, using curvelet-domain ...

Using full-waveform inversion (FWI) to update velocity models that contain salt bodies with high velocity contrasts is challenging. It is even harder if erroneous salt geometry is part of the velocity model. Shen et al. (2017) showed a successful FWI application that corrected some ...

Imaged based Q-compensation coupled with FWI can solve for significant frequency and amplitude losses below shallow overburden absorptive geologic bodies. Applying Q-compensation to both the baseline and monitor 4D surveys improves the consistency of the 4D response, leading to more reliable placement of development ...

In previous publications, a hybrid deblending flow was proposed in which the last step of residual guided noise attenuation using the Noise to Signal Ratio (NSR) map was employed. This flow was proven to be effective and efficient for many OBS surveys. However, due ...

A new non-linear tomographic inversion based method is put forward to resolve large velocity errors associated with complex geology which can cause poor imaging or migration artifacts. We propose to first create a series of trial-velocities from initial velocity by varying the values inside ...

Reservoir imaging under the triangular Conger salt remains very challenging even after significant velocity model building efforts in recent years. Continuity and focusing of reservoir reflectors are sub-optimal due to the subtle velocity errors from the Conger salt and its neighboring carapace, which are ...

Reflection FWI is effective at providing low-wavenumber velocity updates for deep areas beyond the penetration depth of diving waves and significantly improves seismic imaging. However, the tomographic term of the FWI gradient that is good for low-wavenumber velocity updates can be contaminated by the ...