Study on cyclic injection gas override in condensate gas reservoir

International Conference on Energy Engineering and Environmental Protection 2017

能源学;生态环境科学

Sun, Yan^1 ; Zhu, Weiyao^1 ; Xia, Jing^2 ; Li, Baozhu^2

School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing

100083, China^1

PetroChina Research Institute of Petroleum Exploration and Development, Beijing

100083, China^2

关键词: Condensate gas reservoirs;    Density difference;    Gas condensate reservoirs;    Injection wells;    Production wells;    Radial direction;    Radial pressure;    Vertical migration;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/121/5/052050/pdf
DOI  :  10.1088/1755-1315/121/5/052050

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Cyclic injection gas override in condensate gas reservoirs for the large density difference between injection gas and condensate gas has been studied, but no relevant mathematical models have been built. In this paper, a mathematical model of cyclic injection gas override in condensate gas reservoir is established, considering density difference between the injected gas and the remaining condensate gas in the formation. The vertical flow ratio and override degree are used to reflect the override law of injected dry gas. Combined with the actual data of Tarim gas condensate reservoir, the parameters of injected dry gas override are calculated and analysed. The results show that the radial pressure rises or falls rapidly and the pressure gradient varies greatly in the near wells. The radial pressure varies slowly and the pressure gradient changes little in the reservoir which is within a certain distance from the wells. In the near injection well, the injected dry gas mainly migrates along the radial direction, and the vertical migration is relatively not obvious. With the distance from the injection well, the vertical flow ratio and override degree of injected dry gas increases, and the vertical flow ratio reaches the maximum in the middle of the injection well and the production well.