临兴气田致密砂岩气藏压裂后产水机理  

Water Production Mechanism in Tight Sandstone Gas Reservoirs After Fracturing in Linxing Gas Field

作　　者：石雪峰 游利军[2] 葛岩 胡云亭 马立涛 王艺钧 郭飒飒 SHI Xuefeng;YOU Lijun;GE Yan;HU Yunting;MA Litao;WANG Yijun;GUO Sasa(EnerTech-Drilling&Production Co.,CNOOC Energy Technology&Services Limited,Tianjin 300452,China;National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司,天津300452 [2]西南石油大学油气藏地质及开发工程全国重点实验室,成都610500

出　　处：《新疆石油地质》2024年第1期81-87,共7页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(51674209);非常规油气层保护四川省青年科技创新研究团队项目(2021JDTD0017);海油发展科研项目(HFKJ-GJ2020-02)。

摘　　要：鄂尔多斯盆地临兴气田致密砂岩气藏是陆上天然气开发的重点对象,由于构造条件复杂、物性致密以及气水关系复杂,压裂后多数气井持续产水,且井间产水量差异大,研究压裂后束缚水饱和度变化原因,对制定合理的控水采气措施、提高气井采收率具有重要意义。选取鄂尔多斯盆地临兴气田典型致密砂岩样品,通过气驱法研究了储集层物性、生产压差及压裂液对束缚水饱和度的影响。结果表明:Ⅰ类储集层基质与裂缝间的束缚水饱和度之差为13.32%~18.36%,Ⅱ类储集层为28.28%~34.19%,Ⅲ类储集层为39.10%~48.15%,水力压裂缝网显著提高了储集层水相渗流能力;水力压裂缝网使得水相渗流通道增多,生产压差增大、渗流压耗降低及水湿程度减弱是导致储集层束缚水能力减弱、压裂后气井产水的主要机理。可从控制压裂改造规模、优化生产制度、调整助排剂加量及注入时机等方面来提高高含水致密砂岩气藏压裂后控水采气效果,延缓气井见水时间,减小产水规模。The tight sandstone gas reservoirs in the Linxing gas field,Ordos basin,are key targets for onshore gas development.Due to the structural complexity,reservoir physical properties,and complicated gas⁃water relationship,most gas wells produce water continuously after fracturing,and their water production rates are very different.Understanding the reasons for irreducible water saturation variation after fracturing is of great significance for formulating effective water control and gas recovery measures to increase well productivity.In this study,representative tight sandstone samples from the Linxing gas field were tested by using the gas displacement method to clarify how reservoir properties,production pressure difference,and fracturing fluid affect irreducible water saturation.The results show that the difference in the irreducible water saturation between matrix and fractures is 13.32%~18.36%for ClassⅠreservoirs,28.28%~34.19%for ClassⅡreservoirs,and 39.10%~48.15%for ClassⅢreservoirs.Hydraulic fractures can significantly improve the water flow capacity of reservoirs,and provide additional water flow pathways.The increased production pressure difference,reduced flow pressure loss and weakened hydrophilic degree are the main mechanisms leading to the weakening capacity of the reservoir in bounding water and water production of gas wells after fracturing.To control water and produce gas efficiently in tight sandstone gas reservoirs with high water cut after fracturing,measures such as controlling fracturing scale,optimizing production systems,and adjusting fracturing additive amount can be implemented,which will help delay the onset of water breakthrough in gas wells and reduce the overall water production.

关 键 词：鄂尔多斯盆地 临兴气田 致密砂岩气藏 水力压裂 束缚水饱和度 可动水 

分 类 号：TE357[石油与天然气工程—油气田开发工程]