The embodiment of the invention discloses a lithofacies division method for the shale based on Fisher
discriminant analysis. According to mineral compositions, a sedimentary structure and
organic matter contents, mud rock lithofacies division is carried out to obtain a mud rock lithofacies division class result; a
logging identification mode pattern of the mud rock lithofacies is established and awell
logging curve class reflecting the
lithology of the rock is selected based on the
logging identification mode pattern; Fisher
discriminant analysis is performed by SPSS
software; on the basis ofcore logging data, a mud rock lithofacies class is determined and, the
well logging curve reflecting the lithofacies characteristics is selected, and a lithofacies determination classification equation is established; according to a
well logging curve of an unknown lithofacies, a function value of the lithofacies
discriminant classification equation is obtained; and on the basis of the function value, a mud rock lithofacies division class to which the unknown lithofacies is determined. According to the invention, for the well section being lack of data like the core, logging, and diffractionanalysis, the mud rock lithofacies can be divided in details by using the lithofacies determination equation based on the
well logging data, thereby improving the division precision and promoting theoil exploration.