大庆石油地质与开发2025，Vol.44Issue(2)：68-78,11.DOI:10.19597/J.ISSN.1000-3754.202308070
玛湖凹陷砾岩储层CO2前置压裂工艺支撑剂嵌入特征
Proppant embedment characteristics of CO2 pre-pad fracturing techique for conglomerate reservoir in Mahu Sag
摘要
Abstract
Some conglomerate reservoirs in Mahu Sag have serious decline of fracture conductivity after water-based fracturing.CO2 pre-pad fracturing has huge potential of application,but the behavior characterization of proppant embedment after CO2 pre-pad fracturing is unclear.In order to clarify proppant embedment characteristics and mech-anism of CO2 pre-pad fracturing,conglomerate rocks of Upper Wuerhe Formation are selected for proppant embed-ment experiment to characterize difference of proppant embedment characteristics between water-based fracturing and CO2 pre-pad fracturing in reservoir conditions.Numerical model is established to compare conductivity.Mecha-nism of reducing embedment by CO2 pre-pad fracturing is analyzed via electric double layer theory.The results show that CO2 pre-pad fracturing can reduce proppant embedment caused by clay hydration while maintaining proppant carrying capacity.Compared with water-based fracturing,the relative frequency of embedment pits at[0.15,0.25)mm depth with CO2 pre-pad fracturing is reduced by 13%～70%,while the relative frequency of embedment pits at[0.25,0.4)mm depth is reduced by 78%,and conductivity is increased by 24%～30%.CO2 pre-pad fracturing has the optimal effect on samples with low clay mineral content,and the effect decreases with the increase of clay mineral content.CO2 pre-pad fracturing shortens water-rock contact time,and"capillary trapping"and"water dry"reduce capacity of weakly bound water film absorbing free water,weakening hydration expansion of clay and weakening proppant embedment degree.CO2 pre-pad fracturing contributes to efficient exploitation of water-sensitive reservoirs.关键词
CO2前置压裂/水敏/黏土矿物/支撑剂嵌入/砾岩储层/玛湖凹陷Key words
CO2 pre-pad fracturing/water sensitive/clay mineral/proppant embedment/conglomerate reservoir/Mahu Sag分类
石油、天然气工程引用本文复制引用
刘凯新,杜布戈,李杰,董景锋,王斌,王笑涵,彭岩..玛湖凹陷砾岩储层CO2前置压裂工艺支撑剂嵌入特征[J].大庆石油地质与开发,2025,44(2):68-78,11.基金项目
国家自然科学基金项目"致密储层缝内变载荷驱动裂缝疲劳扩展机理研究"(51974356) （51974356）
中国石油大学(北京)科研基金项目"砾岩油藏变载荷压裂井筒完整性失效力学机理研究"(2462021YXZZ012). （北京）
