东营凹陷泥页岩中碳酸盐成因及地质意义

断块油气田

FAULT-BLOCK OIL&GAS FIELD

第26卷第4期2019年7月doi:10.6056/dkyqt201904010

东营凹陷泥页岩中碳酸盐成因及地质意义

华彬曾建强W

(1.成都理工大学沉积地质研究院，四川成都610059；2,成都理工大学油气藏地质及开发工程国家重点实验室，四川成都610059/

摘要利用岩心、薄片、扫描电镜、全岩矿物分析、元素分析、低温氮气吸附和工程力学性质等测试手段和分析资料，对东营凹陷沙河街组沙三下一沙四上湖相泥页岩中的碳酸盐成因及地质意义进行研究，将碳酸盐分为透镜状粗晶、透镜状微晶、纹层状微细晶、纹层状隐晶和块状隐晶等5种类型。透镜状粗晶碳酸盐为重结晶作用的产物，透镜状微晶碳酸盐为浊流搬运再沉积的产物，纹层状微细晶碳酸盐为藻类诱发碳酸盐沉淀的产物，纹层状隐晶碳酸盐为藻类诱发碳酸盐和钙质藻类残体共同形成的，滨浅湖的碳酸盐经重力流搬运至深湖形成块状隐晶碳酸盐。碳酸盐类型可以反映沉积环境变化和成岩演化阶段的不同，并能够改善泥页岩的储集性能。

关键词碳酸盐；重结晶；浊流；东营凹陷

中图分类号：TE122.2Q1；P618.130.2+1文献标志码:A

Carbonate genesis and geological significance of shale in Dongying Sag

HUA Bin1-2,ZENG Jianqiang1-2

(l.Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu610059,China;2.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu610059,China) Abstract：Based on the data involving cores,thin sections,SEM,whole rock mineral components,elements,low temperature nitrogen adsorption and engineering mechanical properties,the genetic mechanism and geological significance of carbonate in the deep lacustrine shale of the lower submember of Member3and upper submember of Member4of Shahejie Formation were analyzed.It is considered that there are five kinds of carbonate developed in shale,including lenticular coarse crystalline,lenticular microcrystalline,lamellar micro-fine crystalline,lamellar cryptocrystalline and massive cryptocrystalline.The lenticular coarse crystalline carbonate was the product of diagenetic recrystallization.The lenticular cryptocrystalline carbonate was the product of turbidity transport and redeposition.The lamellar micro-fine crystalline carbonate was generated by algae induced carbonate precipitation.The lamellar cryptocrystalline carbonate was formed by algae inducing and calcareous algae residues.The carbonate from the shore-shallow lake was transported to the deep lake by gravity flow and formed the massive cryptocrystalline carbonate.

Carbonate can reflect sedimentary environment and diagenetic evolution stage,and improve the reservoir performance.

Key words：carbonate;recrystallization;turbidity;Dongying Sag

东营凹陷古近系沙三段下亚段一沙四段上亚段发育了一套湖相富有机质泥页岩。近年来，东营凹陷泥页岩引起了人们的广泛关注，诸多学者对其沉积、层序地层、岩相和储集空间等特征*1!11+进行了研究。碳酸盐是泥

页岩的重要组成矿物，然而，对于其成因及地质意义的系统研究仍较薄弱。通过对东营凹陷Fy1,Ny1,F112等取心井泥页岩样品进行岩心、薄片、扫描电镜观察，以及元素、X射线衍射、低温氮气吸附和工程力学性质分析,将泥页岩中发育的碳酸盐矿物进行分类，明确了不同类型碳酸盐的成因及其发育的地质意义，为泥页岩油气勘探开发提供了一定的理论依据。1地质背景

东营凹陷为济阳坳陷的一个次级构造单元，东接垦东-青坨子凸起，北以陈家庄-滨县凸起为界，西以林樊家低凸起和青城低凸起为界与惠民凹陷毗邻，南与鲁西

收稿日期：2019-01-19"改回日期：2019-05-05#

第一作者：华彬，女$1995年生，在读硕士研究生，主要研究方向为沉积地质。E-mail:1422778975@ o

通讯作者：曾建强，男$1995年生，在读硕士研究生，主要从事沉积地质方面的研究。E-mail：1164270297@%

引用格式：华彬，曾建强•东营凹陷泥页岩中碳酸盐成因及地质意义[J]•断块油气田，2019,26(4)：453-45/.

HUA Bin，ZENG Jianqiang.Carbonate genesis and geological significance of shale in Dongying Sag[J+.Fault-Block Oil&Gas Field，2019 26(4):453-458.