Reconstruction of the diagenesis of the fluvial-lacustrine-deltaic sandstones and its influence on the reservoir quality evolution——Evidence from Jurassic and Triassic sandstones, Yanchang Oil Field, Ordos Basin

作     者：罗静兰 S.Morad 张晓莉 闫世可 武富礼 李玉宏 薛军民 

作者机构：Key Laboratory for Continental Dynamics Ministry of Education of China Department of Geology Northwest University Xi'an 710069 China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2002年第45卷第7期

页      面：616-634页

学科分类：0709[理学-地质学] 081803[工学-地质工程] 07[理学] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：This work was supported by the National Natural Science Faundation of China (Grant No. 40192055) 

主　　题：Yanchang Oil Field, Jurassic and Triassic fluvial lacustrine-deltaic sandstone, diagenesis, reservoir-quality evolution. 

摘      要：The reservoir quality of Jurassic and Triassic fluvial and lacustrine-deltaic sandstones of the Yanchang Oil Field in the Ordos Basin is strongly influenced by the burial history and facies-related diagenetic events. The fluvial sandstones have a higher average porosity (14.8%) and a higher permeability (12.7×10?3 ?m2) than those of the deltaic sandstones (9.8% and 5.8 ×10?3 ?m2, respectively). The burial compaction, which resulted in 15% and 20% porosity loss for Jurassic and Triassic sandstones, respectively, is the main factor causing the loss of porosity both for the Jurassic and Triassic sandstones. Among the cements, carbonate is the main one that reduced the reservoir quality of the sandstones. The organic acidic fluid derived from organic matter in the source rocks, the inorganic fluid from rock-water reaction during the late diagenesis, and meteoric waters during the epidiagenesis resulted in the formation of dissolution porosity, which is the main reason for the enhancement of reservoir-quality.