Method and system for identifying fragmental rock lithological characters

Abstract

The invention discloses a method and a system for identifying fragmental rock lithological characters, which aim to overcome the defect of incapability of accurately and continuously identifying the lithological characters of strata. The method includes the steps: determining lithological character types of rock samples of rock cores or wall cores in terms of size fractions according to experimental analysis data and logging data of the rock cores or the wall cores; performing interaction analysis for the lithological character types of the rock samples of the rock cores or wall cores and regular logging curves, and establishing mathematical statistic relation among electrical property values of the regular logging curves and the lithological character types of different size fractions; establishing lithological profiles of core unsampled sections and whole well intervals according to the regular logging curves based on the mathematical statistic relation among the electrical property values of the regular logging curves and the lithological character types of different size fractions; and correcting thicknesses of different lithological characters and rocks containing gravels in the lithological profiles by means of image logging data, and establishing the continuous stratum lithological character size fraction sequence. The method can accurately reflect change characteristics of stratum deposition, so as to provide reliable basis for meticulously evaluating reservoir physical properties and sedimentology research.

Description

technical field [0001] The invention relates to lithology identification technology, in particular to a clastic rock lithology identification method and system. Background technique [0002] There are currently two techniques for determining formation lithology. The first is a purely geological analysis method, which uses physical samples for quantitative analysis. The identification results are very accurate, but it is difficult to establish a continuous stratum lithology profile due to the small and scattered downhole cores, and the purpose of systematic research on the stratum cannot be realized. The second is the pure logging processing method, which can establish a continuous stratum lithology profile and continuously reflect the change of stratum lithology, but it can only identify simple sandstone and mudstone profiles, even if imaging data is used for lithology identification. Because it is easily affected by factors such as fluid properties, the resolution is low, ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to overcome the defect that the lithology of the formation cannot be accurately and continuously identified at present.

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