Abstract
The stratigraphic division and sand bed correlation are an important and difficult work for exploration and development of oil-gas field. The application of “three instantaneous” attribute spectrum of logging data on the research of stratigraphic division and sand bed correlation is carried out first time by the authors. In the method, mainly Hilbert-Huang transformation was used to extract the three attributes from logging data (natural gamma ray, Acoustic, and so on), i.e. “instantaneous frequency”, “instantaneous amplitude” and “instantaneous phase”, and then the technology of high-resolution profile reconstruction was adopted to reconstruct the “three instantaneous” attribute spectrum, to reveal the geological response characteristics on each depth of the internal formation, and to clearly reflect the variation characteristics of geological phenomena in the formation. The sequence boundary is scaled according to the alternating change of “three instantaneous” attribute energy spectrum, the migration cycle changes and distribution characteristics of attribute spectrum energy cluster of different frequency components are used to scale the stratigraphic units of different sizes and the response characteristics of sand and mud, and then the oscillation change trend and distribution information of “three instantaneous” attribute spectra energy cluster from low frequency to high frequency is utilized to do the division and correlation of formation and sand body, and to depict geological characteristics of formation internal. From the change and distribution of attribute spectrum energy cluster, the boundary of different sequence grade and distribution of sand bed in stratigraphic sequence can be clearly found. Then, sequence division and single sand body identification of all levels are realized. The single sand body isochronous correlation is compared under the control of all levels sequence division. The research results of this paper promote sedimentary reservoir bed and sequence stratigraphy development toward quantification and digitalization, and provide a new method for geological studies.