第39卷第1期 2018年2月
文章编号：1001-3873(2018)01-0055-08
新疆石油地质
XINJIANG PETROLEUM GEOLOCY D0I:10.7657/XJPG20180107
Vol. 39.No.1 Feb.2018
碱性环境成岩作用及其对储集层质量的影响
以准噶尔盆地西北缘中一下二叠统碎屑岩储集层为例
单祥，郭华军，邹志文，李亚哲，王力宝（中国石油杭州地质研究院，杭州310023）
摘要：根据铸体薄片、扫描电镜、电子探针、X射线衍射、岩石物性等资料，详细研究了准嘻尔盆地西北缘中一-下二叠统碎屑岩岩石学特征、成署作用，在此基础上探讨碱性环境成岩作用对储集层储集性能的影响。结果表明：中一下二叠统广泛发育碱性环境成岩作用，包括火山碎屑水解、火山碎屑钠长石化、沸石类矿物形成、螺泥石形成等。碱性环境下发育多种伴生孔隙：火山碎解减性溶孔、销长石化伴生孔、粘土矿物晶间微孔。碱性环境成卷作用对中一下二叠统碎屑岩储集层影响主要有：碱性流体造成储集层流体压实效应强，即碱性流体下储集层压实率高，对原生孔隙保存不利；碱性环境成岩作用下储集层自生矿物含量高，局部胶结减孔量大；碱性流体溶蚀增孔效率高，火山岩屑的碱性溶蚀无隙可以成为重要的储集空间。
关键调：准噶尔盆地；西北缘；中一下二叠统；碱性流体；成岩作用；醇屑岩储集层
文献标识码：A
中图分类号：TE112.23
Diagenesis in Alkaline Environment and Its Influences on Reservoir Quality :A Case Study of
Middle-LowerPermian ClasticReservoirs in Northwestern Margin of Junggar Basin
SHAN Xiang, GUO Huajun, ZOU Zhiwen, LI Yazhe, WANC Libao
(Hangzhou Research Institute of Ceology, PetroChina, Hangzhou, Zhejiang 310023, China)
Abstract: Based on the data of cast thin section, SEM, Electronic probe, X-ray diffraction and petrophysical properties etc., the paper de-tailedly studies the petrologic features and diagenesis of the MiddleLower Permian clastices in the northwestern margin of Junggar basin, based on which, the influence of the diagenesis in alkaline environment on accumulative properties of reservoirs is discussed. The results show that the diagenesis in alkaline environment is commoaly noted in the MiddleLower Permian strata, such as tephra hydrolysis, tephra albitization, formation of zeolites and chlorite and so on. Various associated pores including alkaline dissolved pore of tephra, albitized asso-ciated pore and intercrystalline micropore in clay minerals are developed in alkaline environment. The influences of diagenesis in alkaline environment on the MiddleLover Permian clastic reservoirs mainly include strong impaction of reservoir fluids resulted from alkaline flu-ids, ie, high reservoir compaction ratio in alkaline fluids, which is unfavorable for primary pore preservation; high authigenic mineral con-tent of reservoir under the diagenesis in alkaline environment and local cementation with large pore reduetion amounts; high pore increase
efficiency due to the corrosion of alkaline fluid. Alkaline dissolved pore in tephra can be the important accumulation space. Keywords: Junggar basin; northwestern margin; MiddleLower Permian; alkaline fluid; diagenesis; clastic reservoir
沉积物进入埋藏成岩环境后，随着温度、压力的增加，在孔隙流体作用下发生一系列的物理及化学变化，这种理埋藏成岩作用对储集层储集性能产生重要影响"-5]。文献[6]一文献[9]提出及建立了碎屑岩及碳酸盐岩有机酸溶蚀理论，酸性水溶蚀碎屑岩形成次生孔隙发育带的有机酸溶蚀模式被中国广大学者所采用-15]。在此背景之下，研究人员更多地关注酸性环境成岩作用下次生孔隙的形成以及分布，而对于碱性环境成岩作用对储集层储集性能的影响不够重视，直到20世纪90年代之后，才有少数学者开始讨论碱性环境成岩作用下硅酸盐的溶蚀及胶结作用。文献[16注意到储集层矿物在碱性驱替剂中可以发生溶
收橘日期：2017-11-27
修订日期：20171204
蚀-沉淀证实了碱性环境成岩作用的存在。文献[17]认为，鄂尔多斯盆地长7段早成岩阶段为碱性成岩环境，发生硅质溶蚀及交代、碳酸盐矿物胶结、钠长石化等多种碱性成岩作用，并影响储集层孔隙演化路径；文献[18]认为，泌阳凹陷在早期碱性地层水成岩作用下出现石英显著溶蚀、长石大规模次生加大的成岩特征；文献[19]发现四川盆地河包场须家河组的碱性成岩环境下石英溶蚀现象；文献[20]研究认为，东营凹陷陡坡带沙四段成岩环境继承了早期碱性盐湖的沉积环境，先后发生方解石胶结、旱期绿泥石胶结、石英熔结、长石加大等碱性环境成岩作用；文献[21] 研究认为，早期火山物质碱性水解是鄂尔多斯盆地延
基金项日：国家973项日（2014CB239002)；中国石油科技重大专项（ZX2012E-34-01)
作若简介：单祥（1988-），男，江苏扬州人，硕士.储层地质学，（Tei)18668010681（Email)）shamx_hz@petroxchinacom.an 万方数据