Technical Content

The desire to extend all the benefits of broadband 3D data to 4D time-lapse surveys has been hampered by the requirement for repeatability between successive surveys. The use of deep-towed multi-sensor streamers in time-lapse acquisition creates challenges, as the existing baseline surveys will often ...

In this paper, we look at the HeliFalcon AGG survey conducted in the Aso-Oguni area exploring for geothermal fields, examine the technical challenges presented by the rugged terrains, describe some aspects of the data acquisition and processing, and present the survey results.

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 ...

Deriving high-resolution velocity models in heavily faulted areas is challenging. This is further complicated by the presence of gas bodies at multiple depth levels. In case of a WAZ or FAZ dataset, azimuthal anisotropy effect can be significant, depending on the presence of a ...