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—下二叠统碎屑岩储集层为例  

Diagenesis in Alkaline Environment and Its Influences on Reservoir Quality:A Case Study of Middle-Lower Permian Clastic Reservoirs in Northwestern Margin of Junggar Basin

作　　者：单祥 郭华军 邹志文 李亚哲 王力宝 

机构地区：[1]中国石油杭州地质研究院,杭州310023

出　　处：《新疆石油地质》2018年第1期55-62,共8页Xinjiang Petroleum Geology

基　　金：国家973项目(2014CB239002);中国石油科技重大专项(ZX2012E-34-01)

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,详细研究了准噶尔盆地西北缘中—下二叠统碎屑岩岩石学特征、成岩作用,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—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、绿泥石形成等。碱性环境下发育多种伴生孔隙:火山碎屑碱性溶孔、钠长石化伴生孔、黏土矿物晶间微孔。碱性环境成岩作用对中—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孔隙可以成为重要的储集空间。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 Middle-Lower Permian clastics 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 resultsshow that the diagenesis in alkaline environment is commonly noted in the Middle-Lower Permian strata, such as tephra hydrolysis, tephraalbitization, 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 alkalineenvironment on the Middle-Lower Permian clastic reservoirs mainly include strong impaction of reservoir fluids resulted from alkaline flu-ids, i.e., 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 reduction amounts; high pore increaseefficiency due to the corrosion of alkaline fluid. Alkaline dissolved pore in tephra can be the important accumulation space.

关 键 词：准噶尔盆地 西北缘 中-下二叠统 碱性流体 成岩作用 碎屑岩储集层 

分 类 号：TE112.23[石油与天然气工程—油气勘探]