MULTISCALE ANALYSIS OF CYCLICITIES IN WELL LOGS FROM THE WAVELET TRANSFORM, APPLIED TO CAMPO COLORADO

Abstract

This paper shows the application of the mathematical tool wavelet transform to the analysis of Gamma Ray (GR) and Resistivity (ILD) logs from the C54, C56, C63, C65, C66 and C68 wells of campo Colorado, located in the Middle Magdalena Basin (Colombia). Records were processed through the tool wavelet transform in the Wavelet Toolbox from MATLAB 7.1. With this tool, 12 scalograms were obtained, which allowed corroborating stratigraphic tops of the Zones B1-B2 and the Zone C of the Mugrosa Formation. Tops were established by the presence of high intensity signals in scalograms. With the discrete wavelet transform the multiresolution analysis of logs GR was realized in the Zone B of the Mugrosa Formation from C63, C65, C66 and C68 wells. In the wells C63, C65 and C68 it was found that the relation 1:2 showed the periodicities of 20 ka precessions and 41 ka obliquity from Milankovitch cycles. However, the absence of detailed sedimentological description does not let showing the relationship of these cyclicities with the sedimentary model for each well. These periodicities are related with electroforms channel and flood plain defined sedimentological and stratigraphic model of campo Colorado.