Method for determining charging time of natural gas

Abstract

The invention provides a method for determining charging time of natural gas. The method includes the following steps that a rock core sample and a rock debris sample of a well are collected and analyzed, and a double-face polished fluid inclusion thin piece is made; the occurrence and capturing relative sequence of a pure gas phase natural gas inclusion are determined; the pure gas phase naturalgas inclusion is divided to have different capturing time periods; the homogenization temperature of the pure gas phase natural gas inclusion and the homogenization temperature of a saline water inclusion in the same period are determined; natural gas components of the pure gas phase natural gas inclusion are determined, and relative contents of all the natural gas components are quantified; a pressure-temperature phase diagram is calculated; the capturing pressure of the pure gas phase natural gas inclusion is determined; the capturing depth of the pure gas phase natural gas inclusion is calculated; geological data at the position of the well is obtained and analyzed, and a single-well bury history diagram is reconstructed; the single-well bury history diagram is used for obtaining the bury history curve of the depth of the fluid inclusion thin piece; the capturing depths of the pure gas phase natural gas inclusion at different time periods are projected onto the bury history curve, so that the charging time of natural gas at different time periods is obtained.

Description

technical field [0001] The invention relates to the technical field of oil and gas accumulation, in particular to a method for determining the charging period of natural gas. Background technique [0002] Determining the period of natural gas charging is an important content in the study of natural gas accumulation. The traditional method is to use the homogeneous temperature-thermal evolution history of brine inclusions coexisting with natural gas inclusions to determine the gas charging period. However, this method is mainly applicable to the determination of the natural gas charging period under the condition of conduction temperature field, and cannot solve the determination of the natural gas charging period under the condition of thermal fluid activity. Natural gas charging is often accompanied by high-temperature thermal fluid activities. Generally, the temperature of the fluid carried by natural gas charging is much higher than the ancient geothermal temperature of ...

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Problems solved by technology

However, this method is mainly applicable to the determination of the natural gas filling period under the condition of conduction temperature field, and cannot solve the problem of determining the natural gas filling period under the condition of thermal fluid activity.

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