摘要
库车山前克拉苏构造带白垩系亚格列木组地质构造和压力体系复杂,天然裂缝的发育对储层渗流能力具有重要影响。针对白垩系亚格列木组裂缝性储层有效性评价,优选出裂缝宽度、力缝夹角差、摩擦系数等渗透率敏感参数,通过多参数耦合,建立了基于地应力的裂缝有效性指数(FEI)分类标准。研究结果表明:①库车山前克拉苏构造带白垩系亚格列木组储层有效裂缝(未充填、半充填)与无效裂缝(全充填)的渗透率界限约0.2 mD,裂缝宽度的增大可提高储层渗透率。②高力缝夹角差与高法向应力可通过影响裂缝的闭合程度来降低裂缝的有效性,高摩擦系数通过提高裂缝面之间的剪切滑移性来提高裂缝的有效性。③根据影响裂缝有效性的各个地应力参数权重,构建了一个裂缝FEI评价标准,利用该标准对研究区储层进行分类评价,中部地区的Ⅰ类、Ⅱ类有效裂缝占比较高,储层有效性越好,越往东部或西部占比越低,储层有效性越差。
The geological structures and pressure systems of Cretaceous Yageliemu Formation in Kelasu structural belt of Kuqa piedmont are complex.The development of natural fractures has significant impacts on the reservoir flow capacity.Focused on evaluation effectiveness of fracture reservoirs from Cretaceous Yageliemu Formation,permeability sensitive parameters such as fracture width,stress-fracture angle difference,and friction coefficient were optimized to establish a fracture effectiveness index(FEI)classification standard based on in-situ stress through multi-parameter coupling.The results show that:(1)The permeability boundary between effective fractures(unfilled or semi-filled)and ineffective fractures(fully filled)of reservoirs from Cretaceous Yageliemu Formation is around 0.2 mD.Increasing fracture width can improve the reservoir permeability.(2)High stressfracture angle differences and high normal stress reduce fracture effectiveness by influencing fracture closure.While high friction coefficients improve fracture effectiveness by increasing shear slip between fracture surfaces.(3)Based on the weights of various in-situ stress parameters that affect the fracture effectiveness,the FEI evaluation standard was established.Applying this FEI evaluation standard to classify and evaluate the reservoirs in the study area,the proportion of ClassⅠand ClassⅡeffective fractures in the central part of the study area is higher,indicating better reservoir effectiveness.Towards the east and west,the proportion of such fractures decreases,resulting in poorer reservoir effectiveness.
作者
徐思慧
赵军
赵新建
汪峻宇
李兆平
林宗鹏
XU Sihui;ZHAO Jun;ZHAO Xinjian;WANG Junyu;LI Zhaoping;LIN Zongpeng(Research Institute of Exploration and Development,PetroChina Tarim Oilfield Company,Korla 841000,Xinjiang,China;R&D Center for Ultra-Deep Complex Reservoir Exploration and Development,CNPC,Korla 841000,Xinjiang,China;Engineering Research Center for Ultra-Deep Complex Reservoir Exploration and Development,Xinjiang Uygur Autonomous Region,Korla 841000,Xinjiang,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China)
出处
《岩性油气藏》
北大核心
2025年第5期155-165,共11页
Lithologic Reservoirs
基金
中石油股份公司重大专项“前陆区测录井技术攻关研究”(编号:T202424)资助。
关键词
地应力
力缝夹角差
摩擦系数
法向应力
剪切应力比
裂缝有效性指数
亚格列木组
白垩系
克拉苏构造带
库车坳陷
in-situ stress
stress-fracture angle difference
friction coefficient
normal stress
shear stress ratio
fracture effectiveness index
Yageliemu Formation
Cretaceous
Kelasu structural belt
Kuqa Depression
