柴西狮子沟地区古近系下干柴沟组混积岩储层特征及影响因素分析

发布时间：2018-06-06 15:08

本文选题：柴西狮子沟 + 盐类矿物　；参考：《现代地质》2017年05期

【摘要】：柴西地区属于柴达木盆地咸化湖盆沉积中心,柴西咸化阶段持续时间长、湖盆分布范围广,渐新统湖相混积岩具有重要勘探潜力。通过对狮子沟地区样品进行岩心观察、岩石薄片鉴定及扫描电镜、电子探针分析,研究储层岩性、物性及储集空间特征,分析储层影响因素及形成机理。狮子沟地区储层具有混合沉积的特征,岩石矿物成分主要为碳酸盐岩和碎屑颗粒,但两者的相对含量均未超过50%;混积岩成因类型为相混合,以组构混合岩为主,见层系混合岩及少量生物混合岩,样品普遍含有盐类矿物。储层为特低渗-特低孔储层,连通性差,X衍射成分分析碳酸盐岩含量为10.9%~47.0%,平均为32.1%,同时孔隙度与碳酸盐岩含量具有很好的正相关关系;样品的储集空间主要为盐类矿物溶蚀孔、白云石晶间孔及裂缝;影响储层发育的主要成岩作用为胶结作用和白云石化作用,尤其盐类矿物胶结抑制了后期成岩作用,形成局部高压;灰质含量高及咸化环境为白云石化作用发生的重要条件,压实弱,先后两期的胶结作用,特别是晚期胶结的盐类矿物为溶蚀作用发生的主要部位。
[Abstract]:The western Qaidam basin belongs to the sedimentary center of the salted lake basin. The salinization stage of the western Qaidam basin lasts for a long time and the lake basin has a wide range of distribution. The Oligocene lacustrine migmatite has important exploration potential. The lithology, physical properties and reservoir spatial characteristics of the reservoir were studied by means of core observation, thin section identification, scanning electron microscope and electron probe analysis of the samples in Shizigou area, and the influencing factors and formation mechanism of the reservoir were analyzed. The reservoir in Shizigou area has the characteristics of mixed sedimentation, the rock mineral composition is mainly carbonate rock and clastic grain, but the relative content of both rocks is not more than 50%, the genetic type of migmatite is mixed facies, mainly composed of fabric migmatite. The salt minerals are commonly found in stratigraphic migmatite and a small amount of biological migmatite. The reservoir is very low permeability and very low porosity, the content of carbonate rock is 10.9% and the average is 32.1, and the porosity and carbonate rock content have good positive correlation, and the reservoir space of the sample is mainly salt mineral dissolution pore, the average is 32.1and the porosity has a good positive correlation with the carbonate rock content, and the reservoir space of the sample is mainly the salt mineral dissolution pore. The main diagenesis affecting reservoir development is cementation and dolomitization, especially the salt mineral cementation inhibits late diagenesis and forms local high pressure. The high content of gray matter and salinization environment are the important conditions for dolomitization, and the compaction is weak. The two stages of cementation, especially the salt minerals of late cementation, are the main sites of dissolution.
【作者单位】：中国石油勘探开发研究院西北分院;中国石油天然气集团公司油藏描述重点实验室;中国石油集团测井有限公司青海事业部;
【基金】：国家科技重大专项(2016ZX05003-006) 中国石油重大科技专项“柴达木盆地油气地质理论深化研究”(2016E-0101)
【分类号】：P618.13

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