Method for predicting yield of gas well

Abstract

The invention provides a method for predicting the yield of a gas well. The method comprises the steps: establishing a one-point-method deliverability equation of a gas field; calculating average daily yield of sample points in the gas field in predetermined historical years, wherein the pressure drop speed of the sample points in the predetermined production historical years falls in a first predetermined range; calculating an absolute open-flow capacity of the sample points according to the daily yield and the bottom flow pressure of the sample points when in gas test; carrying out the regression analysis on the average daily yield of the sample points and the absolute open flow capacity of the sample points, and obtaining a first relation between the average daily yield and the absolute open flow capacity of the gas well in the gas field when in normal production; calculating the absolute open flow capacity of a to-be-put-into-production well according to the daily yield and the bottom flow pressure of the to-be-put-into-production well; calculating a first average daily yield of the to-be-put-into-production well according to the absolute open flow capacity of the to-be-put-into-production well. By adopting the method, the daily yield of the gas well can be predicted according to the real production situation after a compact sandstone gas reservoir is fractured.

Description

technical field [0001] The invention relates to the field of oil and gas exploitation, in particular to a method for estimating the output of a gas well. Background technique [0002] Tight sandstone gas reservoirs refer to unconventional gas reservoirs with low porosity, small pores, and poor permeability, which generally require fracturing to be put into production. This type of gas reservoir has the characteristics of poor reservoir physical properties and strong heterogeneity. Therefore, each well in the tight sandstone gas reservoir must be fractured before it can be put into normal production. After the well is put into production, the initial production is high, the stability is poor, and the production declines rapidly. , does not have the geological conditions for stable production. [0003] When exploiting a gas reservoir, it is first necessary to predict the gas well production of the gas reservoir. This is because the production of gas wells in gas reservoirs i...

AI Technical Summary

Problems solved by technology

For tight gas wells that cannot achieve stable production, the absolute open flow calculated by the "one-point method" can only represent the open flow at a certain moment after the fracturing of the gas well, which is obtained from an unstable point and has uncertainty; and in the past The conventional practice is to select 1 / 4 or 1 / 3 of the absolute open flow rate as the daily production, but the selected ratio of 1 / 4 or 1 / 3 is only an empirical estimate, whether it is in line with the actual production of tight sandstone gas reservoirs after fracturing There is no scientific basis, so there is no method for estimating the daily production of gas wells in tight sandstone gas reservoirs that can reflect the actual production of tight sandstone gas reservoirs after fracturing

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