乌南次凹南屯组高精度层序划分及地质意义

第32卷第4期2019年8月

Vol.32No.4

Aug.2019

投稿网址： 石油化工高等学校学报

JOURNAL OF PETROCHEMICAL UNIVERSITIES

乌南次凹南屯组高精度层序划分及地质意义

邹希光

（大庆油田有限公司呼伦贝尔分公司，内蒙古呼伦贝尔021000）

摘要：依据岩芯、录井和测井等方面资料，对海拉尔盆地乌尔逊凹陷乌南次凹南屯组内的高精度层序地层格架及其控制下的沉积体系展布特征进行了研究。结果表明，研究区南屯组主要发育有5类层序界面，共划分出3个三级层序和9个四级层序。纵观各层序的残留地层厚度变化，可发现在南屯组沉积时期沉降中心逐渐西移，地层展布特征自下至上由“中厚-东、西薄”逐渐过渡为“西厚-东薄”的变化规律。乌南次凹南屯组沉积时期主要发育有辫状河三角洲、扇三角洲、湖底扇及湖泊4种沉积体系，沉积体系平面展布具有“东西分带”的特点，其中扇三角洲沉积体系主要发育在西部乌西陡坡带，辫状河三角洲沉积体系主要发育在东部乌东缓坡带，不同时期各沉积体系的平面展布特征具有明显的继承性。

关键词：海拉尔盆地；乌南次凹；南屯组；高精度地层划分对比；地层厚度；沉积体系

中图分类号：TE122.2文献标志码：A doi：10.3969/j.issn.1006⁃396X.2019.04.011

High Precision Sequence Division and Geological Significance of Nantun

Formation in Wunan Subsag

Zou Xiguang

（Development Technology Center of Hulunbier，Daqing Oilfield Company Ltd.，Hulunbier Inner Mongolia021000，China）Abstract:Based on core,logging and logging data,the high⁃precision sequence stratigraphic framework in Nantun formation of Wunan subsag,Wuerxun depression,Hailar basin and the distribution characteristics of sedimentary systems under its control are studied.The results show that there are five types of sequence boundaries in Nantun formation,which can be divided into three third⁃order sequences and nine fourth⁃order sequences.Throughout the variation of residual stratum thickness of each sequence,it can be found that the sedimentation center of Nantun formation moved westward gradually,and the stratum distribution characteristics changed from"moderate thickness to east and west thin"to"west thick to east thin"gradually from bottom to top. During the sedimentary period of Nantun formation in Wunan subsag,four sedimentary systems were developed,including braided river delta,fan delta,sublacustrine fan and lake.Each sedimentary system has the characteristics of"east⁃west zoning".The fan delta sedimentary system mainly develops in the western Wuxi steep slope zone,and the braided river delta sedimentary system mainly develops in the eastern Wudong gentle slope zone.The distribution characteristics of sedimentary system in different periods have obvious inheritance.

Keywords:Hailar basin；Wunan subsag；Nantun formation；High precision stratigraphic division and correlation；Stratum thickness；Sedimentary System

近年来高精度层序地层学及其相关技术方法[1⁃2]被广泛应用于我国复杂多变的陆相含油气盆地分析中[3⁃5]，该理论认为沉积的旋回性主要受全球海平面升降变化控制，对于分析气候变迁迅速、构造运动频繁、可容空间及沉积物供给速率（A/S）变化快的陆相断陷盆地具有很好的适用性[6⁃8]。目前海拉尔盆地乌尔逊凹陷乌南次凹的勘探主要领域已全面由构造油气藏向岩性油气藏转移，寻找和分析岩性圈闭的有利形成条件就显得更为重要[9⁃10]。前人对乌南次凹南屯组沉积时期的构造演化特征、构造对沉积体系的控制作用、主要成藏模式等[11⁃15]都进行了较为深入地研究，但对南屯组层序的划分

文章编号：1006⁃396X（2019）04⁃0064⁃07

收稿日期：2019⁃01⁃28修回日期：2019⁃02⁃26

基金项目：国家科技重大专项（20111202）。

作者简介：邹希光（1983⁃）,男,工程师,从事油藏工程及油藏描述方面研究；E⁃mail：zouxiguang@。