缝洞型油藏裂缝中泡沫辅助气驱运移特征  

Migration features of foam-assisted gas drive in fractures of fracture-vuggy reservoirs

作　　者：屈鸣[1,2] 侯吉瑞[1,2] 闻宇晨 梁拓 马什希 杨景斌 QU Ming;HOU Jirui;WEN Yuchen;LIANG Tuo;MA Shixi;YANG Jingbin(Research Institute of Unconventional Petroleum Science and Technology,China University of Petroleum-Beijing,Beijing 102249,China;MOE Key Laboratory of Petroleum Engineering,China University of Petroleum-Beijing,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)非常规油气科学技术研究院,北京102249 [2]中国石油大学(北京)石油工程教育部重点实验室,北京102249

出　　处：《石油科学通报》2019年第3期300-309,共10页Petroleum Science Bulletin

基　　金：国家科技重大专项“缝洞型油藏泡沫辅助气驱提高采收率技术研究”(2016ZX05014-004-004);国家科技重大专项“缝洞型油藏注气提高采收率机理研究”(2016ZX05014-004-001)联合资助

摘　　要：泡沫辅助气驱是缝洞型油藏极具潜力的提高采收率技术。裂缝作为缝洞型油藏流体的主要流动通道,在岩溶成藏过程中以“等径”和“变径”形式发育。为了系统地研究泡沫辅助气驱在缝洞型碳酸盐岩油藏裂缝介质中的流动特征及驱油效果,本文设计了不同开度的等径、变径裂缝相似模型和微观可视化模型,开展泡沫辅助气驱物理模拟实验。结果表明:小开度裂缝中,泡沫辅助气驱容易形成气液段塞,气体被微小压缩后易突破泡沫段塞形成气体优势通道;大开度裂缝中,泡沫以多个微小段塞的形式堆积,产生堆积叠加效应,驱油效果优于比小开度裂缝;在变开度裂缝中,泡沫段塞随裂缝开度变化而发生形变,泡沫堆积程度越高,则稳定性越强,提高采收率效果越好。泡沫前缘有4种类型:微尺度泡沫伴随堆积型、小尺度泡沫堆积型、中尺度泡沫轻微变形型、大尺度泡沫严重变形型,它们的稳定性依次递减。在亲油性裂缝中,泡沫前缘气液界面的流动基本符合Poiseuille速度分布,随着弯曲液面附加压力不平衡逐渐加剧,气相逐渐突破气液界面的趋势明显。Foam assisted gas drive is a potential EOR technology for fracture-vuggy reservoirs.Fractures are the main flow channel of fluid in fracture-vuggy reservoirs.They developed in an expanding-aperture or shrinking-aperture way during the reservoir formation process.In order to systematically study the flow characteristics and displacement effect of foam-assisted gas drive in fracture-vuggy carbonate reservoirs,this article describes a fracture similarity model and microscopic visualization model with both equal-apertures and variable-apertures,and carried out physical simulation experiments on foam-assisted gas drive.The results show that the foam assisted gas drive easily formed gas-liquid slugs in small-aperture fractures.Gas could easily break through the foam slug and form a gas dominant channel after a little compression;The foam was accumulated in the form of multiple small slugs in large-aperture fractures,resulting in a superimposed accumulation effect.The displacement effect of large-aperture fractures was better than that of the small-aperture fractures.The foam slugs would be deformed with the change of aperture in variable-aperture fractures.The higher the degree of foam accumulation,the stronger the stability and the better the EOR.In the fractures,the foam displacement front changed in the following four forms:micro-scale foam accumulative types,small-scale foam accumulative type,mesoscale foam slightly deformed type and large-scale foam seriously deformed type.The stability decreased from the first form to the last form.In the lipophilic fractures,the flow of gas and liquid interface at the foam displacement front basically conformed to a Poiseuille velocity distribution.The trend of the gas phase breaking through the gas-liquid interface was more obvious with the increasing imbalance of additional pressure on the curved liquid surface.

关 键 词：可视化模型 缝洞型油藏 裂缝开度 泡沫驱 

分 类 号：TE3[石油与天然气工程—油气田开发工程]