L&T Infotech Seismic Q-estimation Tool

Estimated Q for lithologic & hydrocarbon identification.

In addition to velocity and density, reliable estimates of Q could be a great help in improved understanding of lithology and physical state of subsurface rocks. Also the Q estimates help in hydrocarbon indicator, for example strong attenuation of seismic waves can result from gas trapped under overburden structures. The tool also aids in identifying broad lithological & structural heterogeneity.

Plug-in Overview

Estimation of Q factor for post stack data is tricky, as stacking reduces the original signal character. The tool estimates the absorption Q factor from the post stack seismic section using the time variant spectral ratio method and thereby, if corrected, will produce more realistic final image. The estimated Q factors provide an additional aid in the identification of hydrocarbons.

Specifications

• Seismic Q-estimation tool utilizes time variant spectral ratio method to estimate the Q factors.
• Standard input should be post-stack seismic cube.
• The algorithm applies on each sample for every trace which makes the Q-estimation more precise and robust.
• Measurements of consistent Q values, particularly when considered with confirming measurements such as AVO(Amplitude Variation with Offset), should provide an additional aid in the identification of significant accumulations of hydrocarbons.

Features

Prediction or estimation of the attenuation related quality factor is extremely difficult because of the complexities involved . This tool specifically deals with post stack sesimic data in estimating the Q factors which when corrected helps in enhancing the image resolution. Apart from providing an input to the resolution enhancement it also helps in providing aid for hydrocarbon identification.