Resumen

SANCHEZ, Francisco; ALDANA, Milagrosa  y  FALCON, Rafael. Spectral decomposition of well logs using the Wavelet Transform for stratigraphic and ciclicity analysis, Lama Field, Venezuela . Rev. Téc. Ing. Univ. Zulia [online]. 2017, vol.40, n.1, pp.3-10. ISSN 0254-0770.

In this work we use the Wavelet Transform to analyze well logs, trying to determine the possible presence of stratigraphic cyclicities related to Milankovitch cycles and to define stratigraphic boundaries. The logs belong to 4 wells located at the Lama Field, Venezuela. Gamma Ray, Resistivity and Spontaneous Potential logs, among others, were analyzed to obtain the scalograms (frequency vs depth graphs that reveal the frequency content and the depth location of the most representative components). In addition, the signal was decomposed in high and low frequency submultiples, which allowed performing a cycle-analysis in order to evaluate the possible presence of Milankovitch <cycles within the studied interval. The scalograms showed important information not previously detected in the visual examination of the well logs. This information was a key factor in the stratigraphic interpretation. Besides, the decomposition of the signal in high and low submultiple frequencies revealed that some sedimentary processes in the area could be associated to Milankovitch cycles. The mean sedimentation rate obtained using scalograms, periodograms and multiresolution analysis, agree with previous values reported in the area.

Palabras clave : Wavelet Transform; multi-resolution analysis; scalograms; well logs; periodogram; sequence stratigraphy.