Carbon capture and storage (CCS) by geological sequestration comprises a permeable formation (reservoir) for CO2 topped an impermeable (caprock). Time-lapse (4D) seismic is used to map movement in the subsurface: migration into caprock might change its properties thus impact integrity. Simultaneous forced-oscillation pulse-transmission measurements are combined quantify Young’s modulus Poisson’...

A stochastic approach to seismic inversion using the ensemble Kalman filter (EnKF) is proposed. Seismic depth and time image data are used as the input for EnKF stochastic seismic inversion. The sonic log is used to estimate source wavelet and create initial models for the inversion, which provides an efficient integration of sonic log data and seismic data. We use both travel time and waveform...

Abstract Time-lapse (4D) seismic processing is routinely used to monitor hydrocarbon reservoir production. Seismic reflections are sensitive formation pressure and fluid content. This means that repeated surveys can theoretically detect changes associated with field These measurements help optimize production strategy identify areas where hydrocarbons have been bypassed. However, the signal suc...

At an EOR field in South Oman an extensive synthetic modeling study was done in order understand steam flow behaviour within the reservoir. To understand the permeability distribution within the steam flooded zone, a simulated “Close-the-Loop” workflow was executed based on scenario modeling that relates changes in acoustic properties (velocity and density) with those in reservoir properties su...

We study the sensitivity of seismic waves to changes in the fracture normal and tangential compliances by analyzing the fracture sensitivity wave equation, which is derived by differentiating the elastic wave equation with respect to the fracture compliance. The sources for the sensitivity wavefield are the sensitivity moments, which are functions of fracture compliance, background elastic prop...

Remote sensing, medical imaging, and time-lapse seismic monitoring have common challenges in change detection. In this paper we introduce a statistical procedure developed in medical imaging to determine if anomalies in time-lapse seismic data are statistically significant. Using seismic data redundancy, we construct maps of statistical variation and apply an adaptive thresholding to them. The ...

It is a conceptually simple process to compute differences between two 3D seismic monitoring surveys. However, interpretation of seismic differences in terms of reservoir changes during production assumes repeatability of the surveys. As a result, the naive application of this methodology can lead to erroneous results. Ross et al. (1996, 1997) discussed many of the problems associated with diff...