摘要
针对深部裂缝型碳酸盐岩储层酸化蚓孔扩展机理不清的问题,基于双尺度连续模型和裂缝离散处理方法,建立了渗流场-化学场-温度场耦合多矿物成分酸化的MFCAC数学模型,分析了考虑温度效应的裂缝型储层蚓孔扩展机理和酸蚀特征,研究了CaMg(CO_(3))2与CaCO_(3)初始含量比、酸液温度和反应放热对蚓孔扩展的影响。研究表明:主蚓孔扩展方向主要受周围距离较近的裂缝控制域主导;温度效应导致酸岩反应速率增加,H+有效传质距离缩短,导致主蚓孔沟通的天然裂缝数量减少;反应放热导致的H+扩散速率增加使酸液更容易向各方向孔隙扩散,蚓孔形态更复杂;酸液突破体积比随CaMg(CO_(3))_(2)初始含量的增加先减小后增大;CaMg(CO_(3))_(2)与CaCO_(3)初始含量比为1.5时,对应的酸液突破体积比最小;酸液突破体积比随酸液温度的增加而变大;与不考虑反应放热相比,考虑反应放热的酸液突破体积比更小。该研究为深部裂缝型碳酸盐岩储层酸化施工中动态蚓孔扩展的精准调控及施工参数优化提供了理论依据。
To address the unclear mechanism of wormhole propagation during acidizing in deep fractured carbonate rocks,an MFCAC mathematical model coupling seepage field,chemical field,and temperature field for multi-mineral component acidizing was established based on a dual-scale continuum model and discrete fracture treatment method.The mechanism of wormhole propagation and acid-etching characteristics in fractured reservoirs considering temperature effects were analyzed,and the influences of the initial content ratio of CaMg(CO_(3))_(2) to CaCO_(3),acid temperature,and reaction exotherm on wormhole propagation were studied.The study shows that the propagation direction of the main wormhole is mainly dominated by the control domain of nearby fractures;temperature effects increase the acid-rock reaction rate but decrease the H+mass transfer rate,resulting in fewer natural fractures connected by the main wormhole;the increased H+diffusion rate caused by temperature effects makes acid easier to diffuse into pores in all directions,leading to more complex wormhole morphology;the pore volume to breakthrough(PVBT)first decreases and then increases with increasing initial CaMg(CO_(3))_(2) content;when the initial content ratio of CaMg(CO_(3))2 to CaCO_(3) is 1.5,the corresponding PVBT is the smallest;PVBT increases with increasing acid temperature;compared to ignoring reaction exotherm,considering reaction exotherm results in a smaller PVBT.This research provides a theoretical basis for the precise control of dynamic wormhole propagation and optimization of operational parameters during acidizing operations in deep fractured carbonate reservoirs.
作者
杨俊超
程远方
韩忠英
韩松财
闫传梁
赵珠宇
孙波
YANG Junchao;CHENG Yuanfang;HAN Zhongying;HAN Songcai;YAN Chuanliang;ZHAO Zhuyu;SUN Bo(China University of Petroleum(East China),Qingdao,Shandong 266580,China;Key Laboratory of Unconventional Oil and Gas Development,Ministry of Education,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Chengdu University of Technology,Chengdu,Sichuan 610059,China)
出处
《特种油气藏》
北大核心
2025年第4期149-157,共9页
Special Oil & Gas Reservoirs
基金
国家自然科学基金“超深特深层油气钻采流动调控”(52288101)
四川省自然科学基金“液氮压裂页岩储层多重致裂机制耦合分析及复杂缝网动态演化模拟研究”(2022NSFSC1227)
山东省高等学校“青创团队计划”“天然气水合物多场耦合创新团队”(2022KJ072)。
关键词
蚓孔扩展
含量比
酸液突破体积比
酸液温度
反应放热
wormhole propagation
content ratio
pore volume to breakthrough(PVBT)
acid temperature
reaction exotherm
