Method for judging gas source of high-to-over mature natural gas

Abstract

The invention provides a method for judging a gas source of high-to-over mature natural gas. The method comprises the following steps: testing and analyzing geochemistry characteristics of natural gas, reservoir stratum asphalt and a hydrocarbon source rock, and establishing a natural gas-reservoir stratum asphalt-hydrocarbon source rock factor relation; and judging the gas source of the high-to-over mature natural gas. According to the method for judging the gas source of the high-to-over mature natural gas, the reservoir stratum asphalt is taken as a core entry point and the stored asphalt is used as a bond and a bridge for connecting gas and a source, so that the natural gas-reservoir stratum asphalt-hydrocarbon source rock three-end-member factor relation is established, and the comprehensive judgment of the gas source of the high-to-over mature natural gas is realized; and the situation that a corresponding available application does not exist is solved, and the actual production requirements on comparison of the gas source of the high-to-over mature natural gas, recovery of a complicated reservoir forming process, potential evaluation of high-to-over mature region resources, old marine facies seismic exploration and district selection and the like in superimposed basin deep-layer oil-gas exploration are met.

Description

technical field [0001] The invention relates to a method for identifying high-over-mature natural gas sources, and belongs to the technical field of geology-geochemistry in oil and gas exploration. Background technique [0002] Highly over-mature natural gas is an important resource type in deep marine strata in superimposed basins in my country. With the development of the oil and gas industry, the proportion of natural gas in the energy structure is increasing. However, over-mature natural gas in the deep layers of superimposed basins in my country is the main body of natural gas resources, so issues such as gas source identification, resource potential evaluation, and accumulation process recovery have received more and more attention. [0003] As we all know, most of my country's onshore oil and gas-bearing basins are superimposed basins, and two sets of combinations of deep marine strata and mid-shallow marine-continental transitional-terrestrial strata are generally d...

AI Technical Summary

Problems solved by technology

However, the comparative indicators of biomarkers in highly over-mature organic matter have been basically balanced or invalid, and it is difficult to effectively distinguish the supply and contribution of different source rocks to oil and gas; highly over-mature natural gas often appears as dry gas, and its components are mainly methane , the content of propane and even ethane and other components is very small, and the information of its origin and accumulation is very limited

Therefore, conventional oil and gas source comparison methods and indicators are not applicable to highly mature natural gas

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