Full text loading...
-
Quantitative thickness estimate of tectonically deformed coal using seismic amplitude and sequential Gaussian simulation
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE-HAGI 1st Asia Pacific Meeting on Near Surface Geoscience and Engineering, Apr 2018, Volume 2018, p.1 - 5
Abstract
Thickness of tectonically-deformed-coal (TDC) is a very important factor affecting safe mining and coalbed methane production. Instead of producing a deterministic estimate, we use variogram-based sequential Gaussian simulation (SGS) and seismic amplitude to produce a probabilistic quantitative assessment of TDC thickness. First of all, we use well-measured thickness of coalbed in a mine to model the variograms. Then, we use variogram-based SGS to simulate 100 realizations of coalbed thickness for every seismic grid in the mining zone. After that, we use those realizations to isolate the TDC-related amplitudes from the observed seismic amplitudes with estimated thin-bed tuning coefficients. Finally, we transform the TDC-related amplitudes of every grid into TDC thicknesses with a fitted linear equation. Through analysing thickness distribution of TDC for every seismic grid, we produce a TDC thickness estimate of the mining zone as well as its corresponding probability and uncertainty. The results show that the proposed method can take advantage of the large-scale regional well-measured coalbed thickness and the small-scale local seismic amplitude to produce a high accuracy and reliable TDC-thickness estimate.