柴达木盆地乌南油田N2^1、N2^2碎屑岩储层特征及其影响因素分析  

Detrital Reservoir Characteristics and Its Controlling Factors in Clastic Reservoir N2^1 and N2^2 of Wunan Oilfield , Qaidam Basin

作　　者：刘得文[1,2] 陈国俊[1] 吕成福[1,2] 杜贵超[1,2] 

机构地区：[1]中国科学院地质与地球物理研究所油气资源研究重点实验室,兰州730000 [2]中国科学院研究生院,北京100049

出　　处：《沉积学报》2009年第4期657-666,共10页Acta Sedimentologica Sinica

摘　　要：利用岩石和铸体薄片、扫描电镜、元素分析、压汞等分析测试手段,特针对N21和N22碎屑岩储层特征、成岩作用以及影响因素,对30余口井的样品和资料进行了分析研究。结果表明,乌南油田N21和N22砂岩储层岩石类型为长石岩屑砂岩和岩屑长石砂岩;经历的主要成岩作用类型有粘土膜(粘土环边)的形成、机械压实作用、胶结作用、交代作用和溶解作用。砂岩储层孔隙类型主要是次生孔隙和原生粒间孔隙,其中次生粒间溶孔占绝对优势,其次是基质内微孔隙和裂缝孔隙。孔隙度多为8%～18%,渗透率多为0.5×10-3～10×10-3μm2,属中低孔低渗储层。影响研究区储层物性的主要因素有沉积相带、成岩作用和孔隙结构,其中最有利的储集砂体微相为分流河道和河口坝(细砂岩和粉砂岩相),其次为远砂坝粉砂岩相,间湾薄层砂岩储集性能差。胶结作用和溶蚀作用是影响乌南油田N12和N22储层的最主要的成岩作用。Abstract Wunan Oilfield is one of the most important oil and gas fields in Qaidam basin. Its exploration since the beginning of 1957. The Nancan-2 Well found industrial oil flow after the oil test in 1979. In recent years, in the Lv- 6 Well, Lv-2 Well, Wu-3 Well and Wu-4 Well and many much wells were found industrial oil flow in the stratum of N2^1 and N2^2. This article aims at clastic reservoir characteristics, diagenesis and the factors influencing on the stratum of N2^1 and N2^2. Through analyse the data of at least 30 wells, use the sections, scanning electron microscope , element analysis, mercury porosimetry and many other means studies, the result shows that the sandstone reservoir rock-type are feldspar debris sandstone and debris feldspar sandstone in stratum of N2^1 and N2^2 Wunan Oilfield. The main diagenesis types include of clay film （Clay-Central）, the machine-made compaction, cementation.displaeement and dissolution. Thereinto cementation and dissolution is the most important diagenesis in the stratum of N2^1 and N2^2 in Wunan Oilfield. Porosity mainly distributed in 8% to 18% , the permeability are mainly distributed in the 0.5×10^-3～10×10^-3μm2, as the low-porosity and permeability reservoir. The main effect factors of reservoir porosity and permeability include sedimentary facies, diagenesis and structure of reservoir, thereinto, the favorable sedimentary facies are distributary channel and estuary （ sandstone and siltite facies）, secondly, sihstone facies of distal bar, at last, the reservoir quality of thin sand of the bay is poor.

关 键 词：储层特征 成岩作用 物性 乌南油田 柴达木盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]