Discrimination method for charging period of underground biodegradation heavy oil reservoir

Abstract

The invention relates to a discrimination method for the charging period of an underground biodegradation heavy oil reservoir, and belongs to the field of petroleum geological exploration. According to the specific technical scheme, biomarkers with high anti-biodegradation ability and good sensitivity of crude oil charging and related parameters thereof are selected, a molecular biomarker parameter TA (I)/TA (I+II) of the underground biodegradation heavy oil maturity and a quantitative relation of TA (I)/TA (I+II) and the vitrinite reflectivity Ro are calibrated, and the charging period of biodegradation heavy oil is discriminated by employing the parameter. According to the method, based on chromatography mass spectrometry characteristics and molecular biomarker response of biodegradation crude oil, effective discrimination of the charging period of the biodegradation heavy oil can be realized, the reservoir forming process of the biodegradation heavy oil is tracked, and the problem of the calculation of the proportion of crude oil being charged in different periods for multi-period mixed crude oil is solved.

Description

technical field [0001] The invention belongs to the field of petroleum geological exploration, and in particular relates to a method for discriminating charging periods of underground biodegradable heavy oil reservoirs. Background technique [0002] Biodegradation of crude oil refers to the alteration phenomenon of crude oil under the action of living organisms such as bacteria. Biodegradation of crude oil is a very common phenomenon in natural sedimentary basins. Most of the crude oil in the world has been destroyed and modified by bacteria. Biodegradable crude oil will be an important type of unconventional energy in the future society. [0003] Biodegradable heavy oil reservoirs are widely distributed in China. Taking the Junggar Basin in the west as an example, its biodegradable heavy oil resources account for a considerable proportion. Large-scale surface oil sands, natural bitumen and shallow heavy oil reservoirs are important features of the northwestern margin of ...

AI Technical Summary

Problems solved by technology

However, due to the fluid heterogeneity in the reservoir and the mixing characteristics of multi-stage fluids, it is actually difficult for these existing technologies to accurately identify the crude oil charged in different stages in the reservoir. For the mirror of biodegradable heavy oil The lower characteristics are more blurred, and it is more difficult to distinguish based on the existing technology. The existing technology cannot solve the problem of the charging period of biodegradable heavy oil after multi-stage mixing and the proportion of crude oil charged in different periods.

That is, the traditional technology solves the problem of macroscopic oil and gas accumulation stages in the study area, but the problem of heterogeneity and mixing characteristics of fluids such as crude oil in the reservoir cannot be solved well by traditional technology; especially for biodegradable heavy oil, due to Complex biodegradation changes occurred in the later period, and it is more difficult for traditional technology to judge which period of specific crude oil accumulation, or which phases of mixed accumulation

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