摘要
在气藏开采过程中,由于气体的产出引起了孔隙流体压力降低,在巨大的上覆岩层压力下,岩石变形,孔隙度降低和孔隙喉道体积缩小,部分束缚水释放形成自由水并随着气体产出。这说明在岩石变形过程中,孔隙中的束缚水体积是缩小的,同时也合理地解释了某些气井在产量增加的过程中出现产水的现象。而储层岩石变形后其束缚水饱和度是增加的,这主要是由于储层岩石孔隙及喉道体积缩小的同时,也增加了孔隙及喉道中毛管力的缘故。因此,气藏储层束缚水的应力敏感性是存在的,且束缚水体积及束缚水饱和度与岩石有效应力之间的变化关系为指数关系。
In the exploitation of gas reservoir, the pore pressure decreased with fluid issuing, and pressure between inside and outside of reservoir increased. The pressure has produced deformation of the reservoir rock. So pore volume and porosity of reservoir are reduced. And some free water is released from irreducible water going with fluid issuing. It shows that the irreducible water of pore reduced by the rock deformation, and phenomena of water produced in some gas wells by productivity increased are reasonable explained. At the same time, the irreducible water saturation is increased for capillary pressure increased by decrease of pore and throat's volume. So the stress sensitivity of the irreducible water is existed, and relationships between effective stress and the irreducible water or the irreducible water saturation are index relations.
出处
《天然气地球科学》
EI
CAS
CSCD
2004年第4期391-394,共4页
Natural Gas Geoscience
基金
国家重大基础研究发展规划项目子课题"气藏变形介质渗流规律研究"(编号:2001CB209108)资助.
关键词
气藏
束缚水
应力敏感性
孔隙度
数学模型
Gas reservior
Irreducible water
Stress sensitivity
Porosity
Mathematical model.
