Effects of instantaneous shut-in of high production gas well on fluid flow in tubing

作     者：ZHANG Zhi WANG Jiawei LI Yanjun LUO Ming ZHANG Chao ZHANG Zhi;WANG Jiawei;LI Yanjun;LUO Ming;ZHANG Chao

作者机构：State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)Chengdu 610500China Zhanjiang BranchCNOOC(China)Co.Ltd.Zhanjiang 524057China 

出 版 物：《Petroleum Exploration and Development》 (石油勘探与开发（英文版）)

年 卷 期：2020年第47卷第3期

页      面：642-650页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082003[工学-油气储运工程] 

基　　金：Supported by National Science and Technology Major Project of the Ministry of Science and Technology of China(2016ZX05026-002 2016ZX05028-001 2016ZX05024-005) 

主　　题：high production gas well instantaneous shut-in water hammer effect wellbore damage multiphase flow transient flow model of gas well optimization of shut-in parameters 

摘      要：As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect and the theory of multiphase flow. With this model, the transient flow of gas well can be simulated by segmenting the curved part of tubing and calculating numerical solution with the method of characteristic curve. The results show that the higher the opening coefficient of the valve when closed, the larger the peak value of the wellhead pressure, the more gentle the pressure fluctuation, and the less obvious the pressure mutation area will be. On the premise of not exceeding the maximum shut-in pressure of the tubing, adopting large opening coefficient can reduce the impact of the pressure wave. The higher the cross-section liquid holdup, the greater the pressure wave speed, and the shorter the propagation period will be. The larger the liquid holdup, the larger the variation range of pressure, and the greater the pressure will be. In actual production, the production parameters can be adjusted to get the appropriate liquid holdup, control the magnitude and range of fluctuation pressure, and reduce the impact of water hammer effect. When the valve closing time increases, the maximum fluctuating pressure value of the wellhead decreases, the time of pressure peak delays, and the pressure mutation area gradually disappears. The shorter the valve closing time, the faster the pressure wave propagates. Case simulation proves that the transient flow model of gas well can optimize the reasonable valve opening coefficient and valve closing time, reduce the harm of water hammer impact on the wellhead device and tubing, and ensure the integrity of the wellbore.