Well Test Theory And Application Of Gas Well In Bottom Water Gas Reservoir

As the percentage natural gas occupies in the energy structure improves rapidly, it’s position and development become more and more important. The attitude of natural gas is relative complex and most natural gas reservoirs have the feature of low porosity and low permeability, what’s worse, the formation is connected with aquifer, so water will appear during the middle and later period of development. This brings much difficulty to the development of gas fields. So, the filtration theory and pressure transient testing analysis of gas reservoir with water aquifer seems extremely urgent.This article deals with gas reservoir with water aquifer from edge-water gas reservoir and bottom-water gas reservoir. Main contents of this article performed:(1) Establishing and solving edge-water gas reservoir well-testing analysis mathematical model considering wellbore storage effect and skin effect in different outer boundary conditions. Drawing the log-log curves of the dimensionless bottom-hole pressure curve and pressure derivative curve and analyzing the characteristics and influencing factors.(2) Using the numerical simulation method to establish edge-water radial mechanism model and simulating the log-log curves in different affecting factors. Through comparing with the curves of analytical model and analyzing them, it can be seen that edge-water gas reservoir well-testing data can be analyzed with two-zone composite model and pressure derivative curve upturned.(3) Establishing and solving the well-testing analysis mathematical model of bottom-water gas reservoir with partly perforation in constant pressure top and closed bottom. Drawing the log-log curves of the dimensionless bottom-hole pressure curve and pressure derivative curve and analyzing the characteristics and influencing factors such as perforation position and the level of perforation.(4) Using the numerical simulation method to establish bottom-water radial mechanism model and simulating how the energy of bottom-water and the level of perforation affect the log-log curves. Through comparing with the curves of analytical model and analyzing them, it can be seen that bottom-water gas reservoir well-testing data can be analyzed with partly perforation model with constant pressure top and closed bottom.(5) Proving the analytic model method and numerical simulation method below through example analysis.