Full-waveform inversion (FWI), proposed by Lailly and Tarantola in the 1980s, is considered the most promising data-driven tool to automatically build velocity models. Many successful examples have been reported using FWI to update shallow sediments, gas pockets, and mud volcanoes. However, successful applications of ...
Machine learning is rapidly becoming a standard technology within the oil and gas industry. This is especially true in petrophysics, where Big Data tend to need more efficient and faster data analysis. The term “machine learning” was coined in 1959 by Arthur Samuel and ...
In this paper we demonstrate the ability of acoustic land FWI to recover a high-resolution velocity model using reflected waves in addition to diving waves and inverting up to 13 Hz.
Well-tie analysis is a starting point for mapping facies and geology observed at well locations onto seismic cubes. This step is very important for any application that uses seismic and well data together, and can secure more accurate results by increasing consistency between seismic ...
Below is a case study of the ongoing work on the Monarb and Seagull reprocessing projects in the Central North Sea, with a focus on the use of legacy near field hydrophone recordings, 3D recursive MWD, wave equation deconvolution and AVO QC (In particular ...
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 ...
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 ...