Evaluation method of maturity of lower paleozoic marine shale organic matter

Abstract

The invention discloses an evaluation method of the maturity of lower paleozoic marine shale organic matter. The evaluation method comprises the steps that (1) samples are collected and screened, wherein a marine shale sample is selected, and the sample is polished or made into a polished section through mechanical polishing equipment or an argon ion polishing machine and other equipment; (2) microscopic components are observed; (3) a conversion formula (EqVRo=1.055*R<gr>-0.053) of graptolite dermatosome random reflectance (R<gr>) and equivalent vitrinite reflectance (EqVRo) and a conversion formula (EqVRo=0.9096*R+0.1643) of raw asphalt random reflectance (R) and the equivalent vitrinite reflectance (EqVRo) are established, wherein R<2>=0.98 in the first conversion formula, and R<2>=0.96 in the second conversion formula; and (4) the maturity of the lower paleozoic marine shale organic matter is evaluated. According to the evaluation method, through microscopic component observation on lower paleozoic marine shale, correct classification and interference elimination, an equivalent relation between the graptolite dermatosome reflectance and the vitrinite reflectance and an equivalent relation between the raw asphalt reflectance and the vitrinite reflectance in the lower paleozoic marine shale are established, and correct evaluation of the maturity of the lower paleozoicmarine shale organic matter is realized.

Description

Technical field [0001] The invention relates to the field of rock physics research, in particular to a method for evaluating the organic matter maturity of the Lower Paleozoic marine shale. Background technique [0002] Vitrinite reflectance is considered to be the most reliable parameter to evaluate the maturity of organic matter. Due to the old age and high maturity of the marine shale in southern my country, the Early Paleozoic strata such as the Lower Cambrian Niutitang Formation and Wufeng Formation-Longmaxi Formation have high maturity and lack of vitrinite derived from higher plants. Group, it is impossible to evaluate the maturity of organic matter by vitrinite reflectance. Many scholars at home and abroad have proposed to use vitrinite, marine vitrinite, solid asphalt, graptolite epidermis, chitin and other animal organic debris reflectance as an indicator of organic matter maturity. The micro-components are complex, and there is no unified understanding of the photomet...

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Problems solved by technology

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to solve the problem that the prior art does not effectively classify the organic matter of the Lower Paleozoic marine shale, and that the existing vitrinite reflectance method cannot be used to evaluate the lower Paleozoic shale organic matter. The problem of organic matter maturity of marine shale in the Zozoic, providing an evaluation method for the maturity of organic matter in marine shale in the Lower Paleozoic

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