塔里木盆地麦盖提斜坡奥陶系储层成因与分布

Formation and distribution of the Ordovician reservoir in Maigaiti slope,Tarim Basin

岩心、薄片、钻井及成像测井资料综合研究表明,塔里木盆地麦盖提斜坡奥陶系储集空间以裂缝、孔洞为主,不同区带储层发育程度差异大,玉北地区东部储层最好,发育2套优质储层。按成因将储层类型划分为3种:潜山缝洞型、不整合面岩溶型、顺层深潜流岩溶型。鹰山组缝洞型储层受古地貌与裂缝控制,蓬莱坝组具备发育顺层深潜流带岩溶条件,建立了不同类型储层发育的地质模式。以此为指导,结合地震储层预测成果,预测了麦盖提斜坡不同类型储层分布,指出玉北地区东部断褶翼部及断洼区、中西部岩溶残丘带为有利储层勘探区。

A comprehensive study of cores, thin sections, drilling, and imaging logging data indicates that fractures and caves are dominating in the Ordovieian reservoir in the Maigaiti slope of Tarim Basin. The Ordovician reservoir is developed to varying degrees in different zones of the slope area, with the best quality （including two sets of high quality reservoir） found in the east area of Yu- bei. The Ordovician reservoir can be classified into three types according to its genesis, i. e. , burial and epidiagenetie fracture-cave reservoir, unconformity karst reservoir, and bedding deep-underflow karst reservoir. The fracture-cave reservoir of Yingshan For- mation is controlled by ancient landform and fractures, whereas the geological conditions of Penglaiha Formation support the develop- ment of bedding deep-underflow karst reservoir. A geological development model for different types of Ordovician reservoirs is established and then used in combination with seismic reservoir prediction data for predicting the distribution patterns of different types of reservoirs in the Maigaiti slope. The eastern fault-fold wing and fault depression areas as well as the mid-western karst hill-beh are identified as favorable zones for reservoir exploration in Yubei area.