Characteristics of Reservoir Sedimentology of Chang 9 Oil-Bearing Layer of Yanchang Formation in Longdong Area, Ordos Basin, China

详细信息   

• 责任者：Wang Xinxin (State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Zheng Rongcai
• 刊名：Journal of Chengdu University of Technology
• 出版年：2012
• 卷期：38(3)
• 页码：p.277-284
• issnNo：ISSN1671-9727
• isbnNo：CN51-1634/N

摘要

Based on the core observation of 36 wells and casting thin section, scanning electron microscope, physical property, pore structure and other comprehensive analyses of 108 samples, this paper studies Chang 9 sandstone reservoirs of Triassic Yanchang Formation in the Longdong area. The results show that there are develop the distributary channel and underwater distributary channel sandbodies of shallow-water deltas. The lithology is mainly gray medium-fine-grained lithic arkose sandstone. The space mainly includes primary remanent intergranular pores and intragranular dissolved pores. The major throats are medium-fine and fine. The reservoir properties are mainly worse. The reservoirs have medium-low permeability, and are mainly controlled by the deposition, sandbody thickness and diagenesis. The sedimentary facies control the distribution of reservoir sandbodies, and the compaction, cementation and dissolution control the pore structure and physical property. The reservoir sandstones of Chang 9 oil-bearing layer can be classified into four types. The most advantageous microfacies are distributary channels, underwater distributary channels and mouth bars of the shallow-water delta.