Tight gas reservoir supply boundary identification method and system

Abstract

The invention provides a tight gas reservoir supply boundary identification method and system, and the method comprises the steps: obtaining the geology and production data, and obtaining the input and output parameters of a well testing dynamic inversion identification method according to the geology and production data; Quantitatively characterizing the supply boundary model based on the radialcomposite stratum model; Fitting a double logarithmic curve of well testing data according to input and output parameters of the well testing dynamic inversion identification method, and performing inversion according to the double logarithmic curve and the supply boundary model to obtain supply boundary parameters; According to the supply boundary parameters and the geological and production data, obtaining a first gas supply amount through calculation; According to a material balance equation and the geological and production data, obtaining a dynamic curve through a linear regression method, and obtaining a second gas supply amount through calculation according to the dynamic curve; And when the first gas supply amount and the second gas supply amount are smaller than a preset thresholdvalue, taking the supply boundary parameter as a supply boundary parameter identification result.

Description

technical field [0001] The invention relates to the technical field of oil and gas development, in particular to a method and system for identifying the recharge boundary of tight gas reservoirs. Background technique [0002] In recent years, my country's total natural gas imports have been increasing, and domestic economic construction and social development have been greatly affected. Due to my country's unique geological structure, most of the proven gas reservoirs are medium and low permeability reservoirs, of which tight sandstone reservoirs account for a large proportion. It is very important to develop unconventional gas reservoirs such as tight gas reservoirs economically and effectively. of. [0003] During the development of tight gas reservoirs, it is often necessary to monitor wellbore production performance, formation physical properties, formation gas supply, etc. Therefore, it is often necessary to start research from the aspect of reservoir seepage. The well...

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Problems solved by technology

[0004] However, due to the characteristics of low porosity and low permeability of tight gas reservoirs, there is a phenomenon of weak recharge of external gas flowing to the inner region at the boundary, and the conventional closed boundary to deal with the boundary problem of tight gas reservoirs can no longer meet the actual geological conditions. Well testing and inversion results in large errors in relevant geological parameters, which misleads the formulation of tight gas reservoir development plans and causes large economic losses

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