致密砂岩气藏水锁效应机理探析——以苏里格气田东南区上古生界盒8段储层为例  

Water Lock Effect Mechanism of Tight Sandstone Gas Reservoir:An Example of the He 8 Reservoir of the Upper Paleozoic in the Southeast Region of Sulige Gasfield

作　　者：盛军[1,2] 孙卫[1,2] 段宝虹 刘艳妮[4] 张弢 曹雷[1,2] 

机构地区：[1]西北大学大陆动力学国家重点实验室,陕西西安710069 [2]西北大学地质学系,陕西西安710069 [3]中国石油青海油田分公司钻采工艺研究院,甘肃敦煌736202 [4]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [5]中国石油川庆钻探工程有限公司工程技术研究院,陕西西安710018

出　　处：《天然气地球科学》2015年第10期1972-1978,共7页Natural Gas Geoscience

基　　金：国家科技重大专项大型油气田及煤层气开发(编号:2011ZX05044);西北大学研究生创新人才培养项目"致密砂岩气藏微观孔隙结构与渗流机理研究"(编号:YZZ14023)联合资助

摘　　要：水锁效应是影响气井生产开采的重要因素,在低渗透、特低渗透的致密砂岩气藏中,由于孔喉细小,水锁效应影响更加显著。根据致密砂岩气藏储层岩石中液相流体的开采前后受力特征;探讨了致密砂岩气藏生产过程中水锁效应的发生机理。利用高压压汞、气水相渗等实验分析资料,分析了压力与含水饱和度以及气相相对渗透率的关系;结果表明:压力与含水饱和度呈良好的指数关系,而压力与气相相对渗透率呈明显对数关系。随着生产压差的增大,会导致含水饱和度的升高,而含水饱和度的升高使得气相渗流能力降低,最终造成了水锁伤害程度的加重。合理的控制生产压差对于减轻气井生产过程中水锁效应,延缓气井见水有着重要意义。Water lock effect is an important factor affecting the production of gas well mining. In the tight sandstone gas reservoirs with low and ultra-low permeability, due to small pore and throat, effect of water lock is more obvious than that in other gas reservoirs. This paper has discussed the mechanism of the water lock effect in tight sandstone gas reservoir during the process of production by analyzing the stress charac- teristics of liquid phase in reservoir sandstone before and after development. Ascertained the relationships between pressure and water saturation, pressure and gas phase relative permeability by the analytical data of high pressure mercury and gas water relative permeability experiments. The results showed that, the pressure has good exponential relationship with water saturation, while the pressure and the relative per- meability of the gas phase showed a significant logarithmic relationship. With the increase of production pressure difference, it will lead to the increase of water saturation. The increased water saturation will re- sult in decrease of the gas phase percolation capacity. The result aggravated the water locking damage de- gree ultimately. Reasonable production pressure has great significance for reducing the water lock effect of gas well and delaying the water breakthrough time.

关 键 词：致密砂岩气藏 苏里格气田 水锁效应机理 水锁伤害率 

分 类 号：TE258[石油与天然气工程—油气井工程]