火山岩气藏气水两相渗流特征分析

Characteristics analysis of gas-water two-phase flow in volcanic gas reservoir

章星 杨胜来 李芳芳 陈浩 聂向荣 丁景臣

中国石油大学石油工程教育部重点实验室，北京 102249

MOE Key Laboratory for Petroleum Engineering, China University of Petroleum, Beijing 102249, China

火山岩气藏的有效开发较为困难。针对该类气藏的储层特点，文中通过岩心实验研究火山岩的气水两相渗流特征，为气藏有效开发提供依据。室内实验结果表明：受岩心自身孔隙结构特征影响，水-气相渗曲线呈吸吮态，且岩心渗透率对相渗曲线的特征点影响较大，渗透率越大，残余气饱和度越高；对同一岩心而言，气-水相渗曲线的形状及特征点数值与实验温度和压力有关，温度、压力越高，气水两相渗流区越宽，岩心的束缚水饱和度越低，越有利于气水两相渗流。由此得出，在气藏开发过程中，应合理控制生产压差，避免气井过早出现水侵；一旦因水侵造成水锁，可通过提高气藏温度或压力，实现封闭气解封。

Abstract: It is difficult to develop volcanic gas reservoirs effectively. In response to the features of the reservoir, this paper studied the characteristics of gas-water two-phase flow through core experiments  in order to provide evidence for effective development of the gas reservoir. The laboratory experiment results show that the water-gas relative permeability curve shows the morphological characteristics of sucking relative permeability curves because of the pore structure characteristics of core. And the core permeability has great effect on the feature points of relative permeability curve. The greater the permeability is, the higher the  residual oil saturation is. The shapes of gas-water relative permeability curves and the values of feature points are related to the experimental temperature and pressure for the same core. The higher the temperature or the pressure is, the wider the area of gas-water two-phase flow is, the lower the irreducible water saturation is and the better the seepage effect of gas-water two-phase flow is. So the production pressure should be controlled reasonably in the process of gas reservoir development to avoid premature water invasion in gas well. Once water blocks form because of water invasion, sealed gas can be released through inceasing the temperature or the pressure of gas reservoir.

10.6056/dkyqt201305021