Method for identifying oil sources of mixed crude oil and degraded crude oil

Abstract

The invention provides a method for identifying oil sources of mixed crude oil and degraded crude oil, and belongs to the field of petroleum geology. According to infrared spectral features of crude oil with different sources and degradation degrees, functional group characteristic parameters capable of sensitively reflecting oil source features and indicating degradation intensity are screened. The functional group parameters are used for researching the oil sources of mixed crude oil and degraded crude oil and have great significance to hydrocarbon accumulation analysis. The method comprises the following steps: taking a sample of mixed crude oil and degraded crude oil in a research zone; preliminarily judging the oil source of the sample, according to relative ratio parameters of organic molecular biological markers of hydrocarbon source rock and reservoir crude oil in the research zone; pulverizing the sample to 180-220 mesh, and performing infrared spectral measurement to the sample, the oil source of which is preliminarily judged according to the organic molecular biological markers; and according to the infrared spectral measurement results, screening functional group parameters that indicate oil sources and degradation intensity, and using the functional group parameters to identify oil sources of mixed crude oil and degraded crude oil.

Description

technical field [0001] The invention relates to the field of petroleum geology, in particular to a method for identifying sources of mixed crude oil and degraded crude oil. Background technique [0002] The mixing of crude oil refers to the mixing phenomenon of crude oil from different sources in the same accumulation process; the degradation of crude oil refers to the alteration of crude oil in the process of migration and accumulation. The mixing and degradation of crude oil is a very common phenomenon in oil and gas systems in oil and gas basins. Most of the oil reservoirs in the world have been mixed and degraded. Mixed crude oil and degraded crude oil are very important oil resources. [0003] Mixed reservoirs and degraded reservoirs are widely distributed in China. Taking the Junggar Basin in the west as an example, its mixed and degraded oil reservoirs account for a considerable proportion. The Mesozoic mixed oil reservoirs in the southern margin of the basin, and t...

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Problems solved by technology

However, due to the modification of crude oil biomarkers by similar source crude oil and later degradation, it is actually difficult for these existing technologies to effectively identify the oil source of crude oil from different sources and with a high degree of degradation in the reservoir, which is the problem solved by traditional technology. It is an oil source identification problem with a single oil source and a low degree of degradation, but the traditional technology cannot solve the oil source identification problem of multi-source mixed and severely degraded crude oil

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