Method and system used for characterizing hydrocarbon generation and expulsion features of hydrocarbon source rock and capable of compensating light hydrocarbon evaporation capacity

Abstract

The invention provides a method and system used for characterizing hydrocarbon generation and expulsion features of hydrocarbon source rock and capable of compensating the light hydrocarbon evaporation capacity. The method comprises the steps: through hydrocarbon source rock pyrolysis data and organic matter abundance, a hydrogen index corresponding to a hydrocarbon source rock sample is obtained;an evolution model of the hydrogen index of the hydrocarbon source rock along with the pyrolysis peak temperature data is fitted out, and an initial hydrogen index of the hydrocarbon source rock anda hydrogen index corresponding to the pyrolysis peak temperature are obtained; the hydrocarbon conversion rate corresponding to the pyrolysis peak temperature data is calculated; the pyrolysis peak temperature data are converted into the vitrinite reflectance, and the hydrocarbon conversion rate corresponding to the vitrinite reflectance is obtained; a hydrocarbon source rock hydrocarbon generation and expulsion model is established, and the hydrocarbon expulsion threshold of the hydrocarbon source rock is determined; and according to the geological and geochemical features of the hydrocarbonsource rock, the hydrocarbon generation and expulsion intensity of the hydrocarbon source rock is obtained. The method and the system can accurately represent the hydrocarbon generation and expulsionfeatures of the hydrocarbon source rock, and have certain guiding significance for exploration of oil and gas reservoirs subjected to near-source reservoir forming, especially the compact oil and gasreservoirs.

Description

technical field [0001] The invention relates to the technical field of predicting favorable distribution ranges of oil and gas reservoirs, in particular to a method and system for characterization of hydrocarbon generation and expulsion characteristics of source rocks that compensate light hydrocarbon evaporation. Background technique [0002] Source rocks are one of the most important factors controlling oil and gas accumulation. The study of hydrocarbon generation and expulsion characteristics of source rocks provides a solid scientific basis for improving resource evaluation and predicting favorable exploration areas, which has important guiding significance for the exploration and development of oil and gas reservoirs. Starting from the simulation of hydrocarbon generation kinetics of source rocks, establishing a model of hydrocarbon generation and expulsion characteristics of source rocks, determining the threshold of hydrocarbon expulsion of source rocks, and calculati...

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Problems solved by technology

However, with the research of a large number of scholars, an important parameter (S1) in the pyrolysis data of source rocks will be greatly lost during the test process. Some scholars have found that the evaporation of light hydrocarbons (Qloss) can exceed 80% of the total content.

Therefore, the existing hydrocarbon generation potential model may produce large errors when quantitatively characterizing the hydrocarbon generation and expulsion characteristics of source rocks, so that it is impossible to accurately predict the hydrocarbon generation and expulsion intensity of source rocks and accurately indicate the favorable oil and gas enrichment zones.

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