A method and device for determining the gas content of tight reservoirs

Abstract

The embodiment of the invention provides a method and a device for determining gas content of tight reservoirs. The method comprises the following steps: preparing a plunger sample with first specification and a particle sample with second specification from a sample of tight reservoirs; carrying out an adsorption experiment on the particle sample to obtain a reservoir sample gas-adsorption quantity calculation model including temperature, pressure and rock thermal evolution degree parameters; carrying out porosity and rock density determination on the plunger sample to obtain a free gas quantity calculation model including porosity, density, gas saturation, adsorption gas density, stratum correction factor and methane molecule molar mass; and calculating gas content of the tight reservoirby the utilization of the reservoir sample gas-adsorption quantity calculation model and the free gas quantity calculation model. By the technical scheme provided by the embodiment of the invention,gas content of the tight reservoirs can be accurately determined so as to provide data support for accurate evaluation of unconventional natural gas resource quantity.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration, in particular to a method and a device for determining the gas content of tight reservoirs. Background technique [0002] In the process of oil and gas exploration, unconventional natural gas is one of the main sources of oil and gas extraction. Unconventional natural gas mainly includes shale gas, coalbed methane and tight sandstone gas, which are important natural gas resources. Accurate measurement and calculation of gas content in tight reservoirs is a key parameter for correct evaluation of unconventional natural gas resources. [0003] In the prior art, the gas content of tight reservoirs is often determined by logging data or adsorption-desorption methods. However, there are often many influencing factors in the logging data, resulting in errors in the gas content of tight reservoirs calculated based on logging data. However, the adsorption-desorption method mostly focuses...

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Problems solved by technology

[0003] In the prior art, the gas content of tight reservoirs is often determined by logging data or adsorption-desorption methods. However, there are often many influencing factors in the logging data, resulting in errors in the gas content of tight reservoirs calculated based on logging data. The adsorption-desorption method mostly focuses on the adsorbed gas content, and the existing technology cannot accurately obtain the gas content of tight reservoirs.

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