Blar i Publikasjoner fra CRIStin - NTNU på tidsskrift "Geophysics"
Viser treff 1-20 av 34
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A low frequency deghosting method: Analysis and numerical tests
(Journal article; Peer reviewed, 2017)The low-frequency component of seismic data can be beneficial for several reasons: improved signal penetration into the earth, enhanced resolution, and better constrained inversion results. We have developed a detailed ... -
A3Mark: Seismic attribute benchmarking
(Journal article; Peer reviewed, 2018)Seismic attribute computation is one of the most active research and engineering topics in the computational geophysics world. Although numerous algorithms for seismic attribute computation have been developed, relatively ... -
An adapted eigenvalue-based filter for ocean ambient noise processing
(Peer reviewed; Journal article, 2020)Accurate approximations of Green’s functions retrieved from the correlations of ambient noise require a homogeneous distribution of random and uncorrelated noise sources. In the real world, the existence of highly coherent, ... -
An anelliptic approximation for geometrical spreading in transversely isotropic and orthorhombic media
(Journal article; Peer reviewed, 2018)The relative geometric spreading along the raypath contributes to the amplitude decay of the seismic wave propagation that needs to be considered for amplitude variation with offset or other seismic data processing methods ... -
Approximate reflection coefficients for a thin VTI layer
(Journal article; Peer reviewed, 2018)We have developed an approximate method to derive simple expressions for the reflection coefficients of P- and SV-waves for a thin transversely isotropic layer with a vertical symmetry axis (VTI) embedded in a homogeneous ... -
Average Qp and Qs estimation in marine sediments using a dense receiver array
(Peer reviewed; Journal article, 2023) -
Bayesian rock physics inversion using a localized ensemble-based approach - with an application to the Alvheim field
(Peer reviewed; Journal article, 2023)We describe, implement and show results of a localized ensemble-based approach for seismic AVO inversion with uncertainty quantification. Ensembles are simulated from continuous prior probability distributions for fluid ... -
Bayesian seismic amplitude variation with offset inversion for reservoir variables with bimodal spatial histograms
(Peer reviewed; Journal article, 2021)A Bayesian seismic amplitude versus offset (AVO) inversion scheme with a laterally coupled prior model for porosity, water saturation, and volume of clay is proposed. A 2-D section and a 3-D volume of an oil reservoir are ... -
Bounds of elastic parameters characterizing transversely isotropic media: Application to shales
(Journal article; Peer reviewed, 2016)Several rocks, and in particular shales, are often described as transversely isotropic (TI) materials. Geophysical data coverage does not always permit reliable determination of all five elastic parameters, neither in ... -
Comparing the broadband acoustic frequency response of single, clustered and arrays of marine air guns
(Peer reviewed; Journal article, 2020)Field data acquired from a seismic vessel by a seabed hydrophone is used to analyze the broadband response (10 Hz to 62.5 kHz) for various source configurations: single air guns, clustered air guns, and a full array ... -
Detecting gas leakage using high-frequency signals generated by air-gun arrays
(Journal article; Peer reviewed, 2017)Recent field experiments have demonstrated that marine air-gun arrays create acoustic energy greater than 1 kHz. We have suggested to use the high-frequency signal as a source to look for gas leakage at, for instance, a ... -
Distributed acoustic sensing for near-surface imaging using submarine telecommunication cable: A case study in the Trondheimsfjord, Norway
(Journal article; Peer reviewed, 2021) -
Distributed acoustic sensing of ocean-bottom seismo-acoustics and distant storms: A case study from Svalbard, Norway
(Peer reviewed; Journal article, 2023)Distributed acoustic sensing (DAS) leverages an ocean-bottom telecommunication fiber-optic cable into a densely sampled array of strain sensors. We demonstrate DAS applications to passive acoustic monitoring (PAM) through ... -
Ensemble-based seismic inversion for a stratified medium
(Peer reviewed; Journal article, 2020)Seismic waveform inversion is a nontrivial optimization task, which is often complicated by the nonlinear relationship between the elastic attributes of interest and the large amount of data obtained in seismic experiments. ... -
Estimating source signatures from source-over-spread marine seismic data
(Journal article; Peer reviewed, 2018)Recent developments in marine seismic acquisition include deploying a source vessel above a towed-streamer spread. We have developed an inversion algorithm to estimate source signatures for such acquisition configurations, ... -
Estimation of rock physics properties from seismic attributes - Part 1: Strategy and sensitivity analysis
(Journal article; Peer reviewed, 2016)The quantitative estimation of rock physics properties is of great importance in any reservoir characterization. We have studied the sensitivity of such poroelastic rock physics properties to various seismic viscoelastic ... -
Estimation of rock physics properties from seismic attributes - Part 2: Applications
(Journal article; Peer reviewed, 2016)The estimation of quantitative rock physics properties is of great importance for reservoir characterization and monitoring in CO2CO2 storage or enhanced oil recovery as an example. We have combined the high-resolution ... -
How to adapt numerical simulation of wave propagation and ultrasonic laboratory experiments to be comparable — A case study for a complex topographic model
(Journal article; Peer reviewed, 2018)Numerical methods are widely used in seismic exploration to simulate wave propagation; however, the algorithms are based on various assumptions. The accuracy of numerical simulations is of particular interest in the case ... -
Low-frequency acoustic signal created by rising air-gun bubble
(Journal article; Peer reviewed, 2017)In the seismic industry, there is increasing interest in generating and recording low frequencies, which leads to better data quality and can be important for full-waveform inversion. The air gun is a seismic source with ... -
Numerical study of the effect of cement defects on flexural-wave logging
(Journal article; Peer reviewed, 2019)Cement-bond evaluation is needed for new wells and plug and abandonment activities. The ultrasonic leaky Lamb-wave (also called the flexural-wave) technique, in combination with the pulse-echo technique, has been widely ...