Reply to comment by F. H. Cornet on 'Large-scale in situ permeability tensor of rocks from induced microseismicity'

Abstract

We appreciate Dr Cornet's interest (Cornet 2000) in our paper. Before starting with a direct reply to his comments let us first make a few preliminary remarks. Seismic methods have some fundamental difficulties in estimating hydraulic properties of rocks such as the fluid mobility or the perneability tensor (see e.g. Shapiro and Müller 1999 for references related to this problem). The main results of our paper (Shapiro et al. 1999; SAR99 hereafter) are the principles of the passive seismic-based method for in-situ estimation of large-scale permeability tensors in rocks, which are developed in Sections 1-3 of SAR99. In the following we will call the method SRBC: seismicity-based reservoir characterization. This method can be applied to microseismicity clouds induced by fluid injections of various kinds, not just by hydrofracturing in boreholes. As we understand it, Dr Cornet concentrates his criticism on the application of the SRBC to the case of hydrofracturing. We disagree with this arguments and think that cases of hydrofracturing injections do provide excellent possibilities for application of the method. Here are our replies to Dr Cornet's comments.