Method for recognizing petrographic rhythm change in siltstone and mudstone alternate stratum through imaging logging image

Abstract

The invention relates to a method for recognizing the petrographic rhythm change in the siltstone and mudstone alternate stratum through an imaging logging image. The method mainly includes the steps of firstly, reading RGB values of legend pixel points in the imaging logging image, and conducting interpolation to generate a normalized resistivity curve according to the number of the pixel points so that the different RGB values of each set can correspond to a specific resistivity value; secondly, reading the RGB values of the pixel points of the imaging logging image point by point, and calculating the quadratic sum of the RGB value of each the pixel point on the imaging logging image and the deviation of the RGB values of all the pixel points in a legend through the least square method, wherein the less the quadratic sum of the deviation is, the closer the RGB values of every two corresponding pixel points are; thirdly, searching the imaging logging image for the pixel point with the RGB value closest to the RGB value of each pixel point on the imaging logging image, and endowing the corresponding point on the imaging logging image with the resistivity value of the corresponding pixel point on the imaging logging image; fourthly, conducting solution line by line to obtain the arithmetic mean for the resistivity value of the imaging logging image so that the imaging logging image can be converted into a one-dimensional resistivity curve; fifthly, selecting wavelet package decomposition for the resistivity curve, and judging the petrographic rhythm change in the siltstone and mudstone alternate stratum through low-frequency components obtained through decomposition.

Description

Technical field: [0001] The invention relates to a method for identifying lithofacies rhythm changes in alternate formations of siltstone and mudstone by using imaging logging images. Background technique: [0002] The micro-conductivity imaging logging curve reflects the relative change of formation micro-conductivity. This change can be converted into a color image or a grayscale image, thereby converting the stratum sequence encountered in the well into the stratum imaging logging data. Light colors represent low Conductivity strata, the dark color represents high conductivity strata, which can accurately reflect the rock type, rock structure, sedimentary structure, sedimentary rhythm, and sedimentary energy changes inside the sand body. According to the characteristics reflected in the imaging logging images, the method of establishing interpretation models and typical templates and judging sedimentary microfacies has a good effect in glutenite areas. Therefore, it is p...

AI Technical Summary

Problems solved by technology

According to the characteristics reflected in the imaging logging images, the method of establishing interpretation models and typical templates and judging sedimentary microfacies has a good effect in the sandy conglomerate area, but due to the limitation of the accuracy of the imaging logging images itself, this method does not work well in silty sandstone. Therefore, it is possible to try to propose a new research method for the study of sedimentary facies in silty sandstone areas.

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