塔里木盆地玉北地区奥陶系储层类型及主控因素

对塔里木盆地玉北地区奥陶系钻井岩心、岩石薄片、铸体薄片及测井资料的详细分析,认为该地区奥陶系碳酸盐岩储集空间以孔洞、裂缝为主,主要发育4种储层类型:孔洞-裂缝型、裂缝型、孔隙-孔洞-裂缝型和孔隙-孔洞型。鹰山组上部储层受多期暴露不整合面和中高角度裂缝控制,而鹰山组下部及蓬莱坝组储层与白云石化作用及层间低角度缝发育关系密切。综合分析认为断褶翼部是下奥陶统鹰山组上部缝洞型储层发育有利区;过胜和2井EW向断裂带及东部的NE向断裂带附近是鹰山组下部-蓬莱坝组孔隙-孔洞型白云岩储层分布有利区。

Types and main controlling factors of Ordovician reservoirs in Yubei area,Tarim Basin

Based on observations of cores, rock sections, casting sections, logging data of Ordovician carbonate reservoirs in the Yubei area, Tarim Basin,reservoir space is dominated by cavities and fractures, and can be classified into four types, i.e. cavity-fracture type, fracture type, pore-cavity-fracture type and pore-cavity type. Specifically, reservoirs in the upper part of the Lower Ordovician Yingshan Formation are controlled by multi-period unconformities and mid- to high-angle fractures, while reservoirs in the lower Yingshan Formation and the Penglaiba Formation are closely related to dolomitization and development of interlayer low-angle fractures. Integrated analyses indicate that flank province of fault folded structures are favourable to development of cavity-fracture reservoirs in the lower part of the Lower Ordovician Yingshan Formation, while the east-west oriented fault zone through Well shenghe 2 and the vicinity of the north-east oriented fault zone in the east part of Yubei area are favorable areas to prospect for pore-cavity dolostone reservoirs in the lower Yingshan Formation and the Penglaiba Formation.