A GENERALIZED IMAGE AND BOUNDARIES OF THE BAZHENOV FORMATION: CONSTRAINTS FROM WELL LOG DATA FOR SALYM-TYPE SECTIONS (West Siberia)
V.V. Lapkovsky1,2, V.A. Kontorovich1,2, N.E. Shmelev1,2
1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
Keywords: Bazhenov Formation, Salym area, Zhekovsky plot, automated well correlation, Galton’s composite portraiture, generalized image, average well
Abstract
A technique akin to Galton’s composite portraiture is suggested for creating a generalized image of a stratigraphic unit based on well log data from a group of well sections. The procedure begins with superimposing stratigraphically equivalent section points according to pairwise correlation models followed by weighted summation of similar logs. The superimposition highlights persistent common features of the sections while their minor individual details become suppressed. A generalized model of the Bazhenov Formation in the Salym area has been constructed from gamma-ray, apparent resistivity, and self-potential logs. Radioactivity and resistivity anomalies, which are often used as constraints on the Bazhenov Formation boundaries, show a significant spatial discrepancy. According to the correlation, the formation volume in each well depends on the depth interval corresponding to the hypostratotype. The results were used to map the Bazhenov Formation thickness and its standard deviation, as well as average values of different logs.
|
