潜山不同尺度裂缝凝析油气流动特征及界限研究  

Flow characteristics and threshold of condensate oil and gas in buried hill with fractures of different scales

作　　者：苏彦春 张利军 赵林 王志凯 谭先红 李聪聪 王硕亮[3] SU Yanchun;ZHANG Lijun;ZHAO Lin;WANG Zhikai;TAN Xianhong;LI Congcong;WANG Shuoliang(CNOOC Research Institute Ltd.,Beijing 100028,China,2.National Key Laboratory of Offshore Oil and Gas Exploitation,Beijing 102209,China,3.China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028 [2]海洋油气高效开发全国重点实验室,北京102209 [3]中国地质大学(北京),北京100083

出　　处：《中国海上油气》2025年第1期92-102,共11页China Offshore Oil and Gas

基　　金：中国海洋石油有限公司“十四五”重大科技项目“海上低渗及潜山油气田有效开发技术”课题“潜山临界流体油气藏有效开发技术(编号:KJGG2022-0702)”部分研究成果。

摘　　要：潜山凝析油气藏是中国油气增储上产的重要接替领域,受风化剥蚀及构造作用影响,此类储层裂缝高度发育,存在不同尺度的渗流空间,凝析油气在不同尺度渗流空间中流动及赋存状态复杂,准确表征其流动特征及动用界限是此类储层产量准确预测的基础。基于可视化微流控实验开展了高温高压条件下不同尺度裂缝凝析油气流动特征研究,分析了裂缝开度、储层压力以及注采压差对裂缝内油气流动的影响。结果表明,凝析气藏衰竭开发过程中会经历雾状微滴-微滴聚集-缝壁捕集-贴壁蠕动的演化过程。当裂缝开度大于200μm时,凝析油以波形膜状流及离散波状流为主,当裂缝开度为100μm时开始出现活塞流,当裂缝开度为5μm时,出现停滞段塞流,严重影响气体流动。实验与模拟结果表明,目标区块流体有效流动的界限为5μm。同时,明确了储层中裂缝开度和压差对凝析油气流动模式和演化的影响规律,随着压差和开度的增大,凝析油的相态由段塞流转为波浪流,再由波浪流转为混沌流,裂缝内流动状态会逐渐向分散流动转变。建立了临界凝析油饱和度和裂缝开度图版,为海上潜山裂缝型凝析气藏的高效开发提供支持。The condensate oil and gas reservoirs in buried hills have become an important replacement area for oil and gas storage and production increase in China. Due to weathering and erosion as well as structural effects, fractures are highly developed in such reservoirs, with different scales of flow spaces. The flow and occurrence of condensate oil and gas in flow spaces of different scales are complex, and accurately characterizing their flow characteristics and production boundaries is the basis for accurate prediction of production in such reservoirs. In this paper, through microfluidic visualization experiments, the flow characteristics of condensate oil and gas in fractures of different scales under high temperature and high pressure conditions were studied, and the effects of fracture aperture, reservoir pressure, and injection-production pressure difference on the flow of oil and gas in fractures were analyzed. The results show that the depletion development process of condensate gas reservoirs undergoes the evolution process of mist droplets-droplet aggregation-fracture wall capture-wall adhesion creep. When the fracture aperture is larger than 200 μm, condensate oil mainly flows in the form of wave-shaped film flow and discrete wave flow. When the fracture aperture is 100 μm, piston flow begins to appear. When the fracture aperture is 5 μm, stagnant slug flow occurs, which severely affects gas flow. Experimental and simulation results show that the threshold for effective fluid flow in the target block is 5 μm. At the same time, this study clarified the influence rule of fracture aperture and pressure difference on the flow pattern and evolution of condensate oil and gas in the reservoirs. With the increase of pressure difference and aperture, the phase of condensate oil changes from slug flow to wave flow and then to chaotic flow. The flow state in the fractures gradually transitions to dispersed flow. This study established the chart of critical condensate oil saturation and fracture aperture, which pro

关 键 词：潜山 裂缝储层 凝析油 流动特征 

分 类 号：TE341[石油与天然气工程—油气田开发工程]