Method for identifying lithological characters of sedimentary rocks by utilizing element logging

Abstract

The invention discloses a method for identifying lithological characters of sedimentary rocks by utilizing element logging. The method consists of the following steps: a, processing element logging data and converting the element logging data into percentage content; b, by utilizing percentage of content of a clastic sensitive element and a carbonate sensitive element, distinguishing two types of rocks of a carbonate rock and a clastic rock; c, in the carbonate rock type, calculating calcium sulfate content, magnesium calcium carbonate content and calcium carbonate content; d, in the clastic rock type, calculating sand content and shale content; e, carrying out normalization processing on the calculated content of calcium sulfate, magnesium calcium carbonate, calcium carbonate, sand and shale to respectively calculate content of gypsum, dolomite, lime, sand and shale so as to determine the lithological characters according to the content of gypsum, dolomite, lime, sand and shale. According to the method disclosed by the invention, the element logging measured data is used as parameters, and a set of lithological character identification model is established by analyzing chemical ingredients and rock forming principles of various lithological characters, so that the effect of distinguishing the lithological characters while drilling of element logging is realized.

Description

technical field [0001] The invention relates to a method for establishing lithology identification of sedimentary rock while drilling by using element logging, and belongs to the field of petroleum and natural gas exploration and development. Background technique [0002] In the process of oil and gas drilling, timely and accurate identification of formation lithology is an important guarantee for improving the efficiency of oil and gas exploration. The identification technology of formation lithology while drilling has always been an important topic in the field of geological logging. [0003] The traditional lithology identification method mainly uses on-site manual analysis and description or observes the composition of cuttings with the help of optical instruments for qualitative description. In "Sichuan Geological Journal", 2015(4):605-608, in the use of ETM+ data to identify the lithology of sedimentary rock areas, it disclosed the following main content: Changshou Dis...

AI Technical Summary

Problems solved by technology

According to the element mud logging measurement data as parameters, the present invention establishes a set of lithology identification models by analyzing the chemical composition and diagenetic principles of various lithologies, and solves the problem of element mud logging lithology while drilling discrimination