ABSTRACT
The early identification of water invasion risk and the prediction of water breakthrough time of gas wells are helpful to better formulate the gas reservoir development plan and reasonably arrange the daily management of gas wells. It is of great significance to adjust the technical countermeasures of gas reservoir development. This paper illustrates the water production characteristics and water invasion mode of M gas reservoir, identifies the water invasion risk wells by using the early water invasion identification method, verifies the applicability of the water breakthrough time prediction model of edge water gas reservoir in M gas reservoir by using its water breakthrough time, and predicts the water breakthrough time of water invasion risk wells. The research shows that the water production characteristics of M gas reservoir mainly include three types: the rapid rise of water production and water-gas ratio, the slow rise and gradual stability of water-gas ratio, and the low value of water production and water-gas ratio. There are four principal water invasion modes: edge water tongue (as the main mode), edge water finger, bottom water cone and sealed water tongue. The unstable well test method, water invasion volume coefficient method, and apparent geological reserve method can be used for the early identification of water invasion. The prediction model of water breakthrough time of gas wells in edge water gas reservoir is applicable to the prediction of water breakthrough time of M gas reservoir, and its prediction results provide a reference value for further investigation.
