多孔岩石中天然气择优渗流规律  

Preferential flow law of natural gas in porous rocks

作　　者：王国锋 胡勇[2,3] 奎明清 焦春艳[2,3] 王继平[5] 郭长敏 张园园[5] 李娅[5] 陈璐瑶 WANG Guofeng;HU Yong;KUI Mingqing;JIAO Chunyan;WANG Jiping;GUO Changmin;ZHANG Yuanyuan;LI Ya;CHEN Luyao(China Southern Petroleum Exploration&Development Corporation,Haikou 570216,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;CNPC Key Laboratory of Gas Reservoir Formation and Development,Langfang 065007,China;PetroChina Qinghai Oilfield Company,Dunhuang 736200,China;PetroChina Changqing Oilfield Company,Xi’an 710018,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国石油南方石油勘探开发有限公司,海南海口570216 [2]中国石油勘探开发研究院,北京100083 [3]中国石油天然气成藏与开发重点实验室,河北廊坊065007 [4]中国石油青海油田公司,甘肃敦煌736200 [5]中国石油长庆油田公司,陕西西安710018 [6]中国科学院大学工程科学学院,北京100049

出　　处：《大庆石油地质与开发》2025年第1期71-76,共6页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油天然气集团有限公司青海油田公司科技项目“涩北气田40亿方压舱石工程配套技术”(2023KJ10)。

摘　　要：在渗流力学分析基础上建立了多层同源气驱水实验方法,揭示多孔岩石中天然气渗流规律和含水砂岩气藏水封气形成的临界力学条件。选用鄂尔多斯盆地苏里格气田天然岩心,根据气井钻遇纵向储层物性分布特征进行并联组合,开展了完全饱和水条件下岩心同源逐级增压气驱水实验。结果表明:天然气流动路径与储层渗透率和气驱水压力大小密切相关,在特定气驱水压力条件下,天然气优先选择高渗岩心流动,随着气驱水压力逐级增加,逐级覆盖低渗致密岩心;在基质渗透率小于4.77×10^(-3)μm^(2)的储层,尤其是基质渗透率小于等于1.0×10^(-3)μm^(2)的储层,气驱水临界流动压差与渗透率存在良好的幂函数关系;随着储层渗透率的降低,气驱水临界流动压差反而增大,在气藏衰竭开采过程中,当地层压力下降至无法突破水封阻力时,容易形成水封气。研究成果可为气藏剩余气评价和补能降阻解水封提高采收率提供依据。A multi-layers homologous gas driving water experimental method is established based on fluid flow me‐chanics analysis,revealing natural gas flow law in porous rocks and critical mechanical conditions for the formation of water-trapped gas in water-bearing sandstone gas reservoirs.Natural cores from Sulige gas field in Ordos Basin are selected,and parallelly combined based on vertical distribution characteristics of gas well drilled reservoir prop‐erties.Homologous stepwised pressurized gas driving water experiments are carried out for completely water-saturat‐ed cores.The results show that gas flow path is closely related to reservoir permeability and the pressure of gas driv‐ing water.In specific gas driving water pressure conditions,gas flows preferentially through cores with high permeability,and gradually covers low-permeability tight cores with stepwised increase of gas driving water pressure.Critical flow pressure difference of gas driving water has good power function relationship with permeability in reservoirs with matrix permeability of<4.77×10^(-3)μm^(2),especially those with matrix permeability of≤1.0×10^(-3)μm^(2),while increases with reservoir permeability decrease.Formation pressure decrease during depletion production of gas reservoirs cannot break through water trapping resistance,causing water-trapped gas easily formed.The research provides basis for evaluation of remaining gas in reservoirs and recovery improvement through energy replenishing,resistance reducing and water-trap removal.

关 键 词：多孔岩石 天然气 择优渗流 水封气 提高采收率 实验研究 

分 类 号：TE312[石油与天然气工程—油气田开发工程]