第38卷第3期 2017年6月
文章编号：1001-3873(2017)03-0264-05
新疆石油地质
XINJIANG PETROLEUM GEOLOGY DOI:10.7657/XJPG20170302
Vol.38,No.3 Jun.2017
鄂尔多斯盆地志丹地区山西组砂岩致密化发育时限探讨
李艳霞，刘洁琪
（西安石油大学a.地球科学与工程学院；b.全国石油和化工行业重点实验室，西安710065）
摘要：借助于显微镜的单偏光和荧光，对鄂尔多斯盆地志丹地区山西组政密砂岩的岩石学特征进行观察，同时，采用显微冷热台对石英次生加大边中的包裹体进行测温，并使用激光拉受光谱对包衰体的组分进行分析。金地模拟研完发现，志丹地区山西组致密砂岩石英次生加大边中发育无机盐水包裹体、含烃盐水包裹体、气液态烃包裹体和气态烃包衰体4种类型包裹体；赋存在I期石美次生加大边内的盐水包衰体均一温度在80~100℃，冰点温度在-4~-2℃，推测形成时间为200x10—190x10°a；Ⅱ期石英次生加大边的盐水包裹体均一温度在105~125℃，冰点温度在-6~=4℃，包衰体气相组分以C0,为主，少量C,Hs，推测第一期天然气充注时间及砂岩初次致密化时间为190x10—160x10°a；Ⅲ 期石英次生加大边中的盐水包裹体均一温度在135~155℃，冰点温度在-10~-8℃，包衰体气相组分以CH和C,H为主，伴随有大量后期高成熟天然气充注，推测天然气成裁及砂岩进一步致密化的时间为160x10—140x10°a，天然气的充注伴随着砂岩的后期致密化发育。
关键调：鄂尔多斯盆；志丹地区；山西组；致密砂岩；石英次生加大边；流体包豪体；激光拉曼光谱
中图分类号：TE112.113
文献标识码：A
Discussions onSandstoneDensificationTime:A Case Studyfrom ShanxiFormation inZhidan
Area, Ordos Basin LI Yanxia,LIU Jieqi
(Xi'an Shiyou University, a.School of Earth Science and Engineering; b.Key Laboratory of National Petroleum and Petrochemical Industry,
Xi'an, Shaanxi 710065, China)
Abstract: By means of polarized-light and fluorescence microscopes, petrological characteristices of the tight sandstones of Shanxi forma-tion in Zhidan area, Ordos basin are observed. Meanwhile, temperatures of the inclusion in the quartz overgrowth edges are measured by us-ing microscopic heating-freezing stages and components of the inclusion are analyzed with laser Raman spectroscopy. The study shows that four types of inclusions are developed in the quartz overgrowth edges of the tight sandstones in Shanxi formation of Zhidan area, namely, in-organic brine inclusion, hydrocarbon-bearing brine inclusion, gaseous and liquid hydrocarbon inclusion, and gaseous hydrocarbon inclu-sion. The homogenization temperature of the brine inclusion occurred in the quartz overgrowth edges of Stage I ranges from 80°C to 100°C and its freezing temperature is 4~2°C. Based on which, it is assumed that the quartz overgrowth edge was formed 200x10°190x10° years ago; brine inclusion in the quartz overgrowth edges of Stage II has a homogenization temperature of 105125C and freezing temperature of 6~4C, whose gaseous components are dominated by CO; with minor C,Hs, indicating the time for Stage I natural gas charging and initial sandstone densification was 190x10°~160x10° years ago. The homogenization temperature and freezing temperature of the brine in-clusion in the quartz overgrowth edges of Stage II are 135~155°C and 10~8°C, respectively. The gasceous components are dominated by CH4 and C,He, accompanied by large amount of high-matured natural gas charging at the late stage. Then it is assumed that the time for nat-ural gas aceumulation and further sandstone densification occurred 160x10°~140x10° years ago. Natural gas charging was accompanied by late-stage sandstone densification.
Keywords: Ordos basin; Zhidan area; Shanxi formation; tight sandstone; quartz overgrowth edge; fluid inclusion; laser Raman spectrum
流体包裹体是地质历史时期保存下来的古流体，广泛应用于油气成藏史的研究，盐水及含烃类的包裹体可以用来确定油气成藏期次和运移时间、示踪油气运移路径和恢复充注过程中的流体的古地温，确定古流体化学组分1-，随着对油气成藏及成岩作用关系的深人探讨，包裹体应用开始逐渐向其他方面拓展，
收稿日期：2016-12-20
修订日期：2017-03-27
基金项目：国家自然科学基金（41372148）
尤其在探讨古流体成分的变化与成岩作用的关系方面，其重要性逐渐凸显。
本文应用鄂尔多斯盆地志丹地区下二叠统山西组致密砂岩石英次生加大边中发育的流体包裹体来探讨不同时期古流体与成岩作用关系，以此判定致密砂岩储集层中石英次生加大边形成时序与气藏充注时限。
作者简介：李艳霞（1967-），女，陕西西安人，教授，博士，油气地化及油气成藏，（Tel>029-88382783(E-mail)lyx4164@xsyu.edu.cn 万方数据