塔里木盆地于奇地区碳酸盐岩储集层特征及其控制因素

Carbonate Reservoir Characteristics and Control Factors in Yuqi Area, Tarim Basin

利用岩心观测、岩石薄片、物性分析、测井等资料,综合分析了塔里木盆地于奇地区碳酸盐岩剥蚀残留区中下奥陶统鹰山组储集层岩石学特征及储集性能,并在此基础上进行了储集层综合评价。研究区内鹰山组主要岩石类型为泥晶灰岩、砂屑灰岩和白云岩,其中泥晶灰岩、砂屑灰岩发育最好,分布最广;储集类型为洞穴型、裂缝-孔洞复合型和裂缝型,储集层物性中等,其中洞穴型储集层普遍发育,但充填严重,裂缝-孔洞复合型储集性能相对较好;影响缝洞发育的主控因素为构造作用、岩溶作用及成岩作用;有利的储集层分布于于奇西部YQ2-YQ3-YQ4-LN13井区一带。这为该区及整个塔里木盆地奥陶系碳酸盐岩剥蚀残留区下一步油气勘探提供了重要的理论依据。

The lithologic feature, spatial type and reservoir quality in Yingshan carbonate reservoir of Middle-Lower Ordovician in Yuqi area of Tarim basin are analyzed comprehensively by using core observation, east thin section, cathodology, SEM. porosity and permeability analysis and mercury injection method, etc., and the reservoir is synthetically evaluated then. The results show that the main rock types in Yingshan formation are micrities, calcarenite and dolomite,of which, micritics and calcarenite have the best development and the widest distribution. The carbonate reservoirs belong to cave, fracture-pore and fracture types with intermediate physical properly. The cave reservioir develops widely in the west slope of Yuqi area, hut cave filling is very compact. Fracture-pore reservoir is relatively a better kind of reservoir. The key factors influencing the reservoir quality are structure, karst and diagenesis.The favorable reservoirs are distributed along Wellblock YQ2-YQ3-YQ4-LNI3 in western Yuqi area. This conclusion provides and important theoretical basis for the next exploration in Yuqi area and its vicinities where carbonate rocks are partially eroded.