渤海海域新生界地层水化学特征及主控因素

发布时间：2018-03-22 11:17

本文选题：渤海海域　切入点：地层水　出处：《天然气地球科学》2017年09期 　论文类型：期刊论文

【摘要】：以渤海海域取自探井的1 254个地层水数据点为基础,总结了渤海海域地层水矿化度特征及水型分布规律,并探讨了其差异分布的控制因素。结果表明:渤海海域地层水矿化度整体表现出随埋深增加而增大的正向水化学剖面特征,在东营组顶部(1 750~2 000m)出现矿化度的淡化带,将新生界分成新近系和古近系2个次级正向水化学剖面;古气候条件与沉积环境控制了研究区地层水矿化度的宏观展布格局,研究区南部莱州湾凹陷古近系盐岩、膏岩的发育是研究区矿化度呈现南高北低的主要原因;深大断裂通过调节深部流体活动进一步控制了浅层地层水的平面差异展布;垂向上,2 480m作为化学分异面,形成了上、下2个水化学系统,上部系统受平原组沉积期以来的海水覆盖,加之新近纪沉积的巨厚地层,导致地层水矿化度升高,氯化钙型水相对富集,而表现出与陆上油区迥异的水化学特征;下部系统(沙三段—东二下亚段)受控于烃源岩大量生排烃作用,形成高矿化度碳酸氢钠型地层水。
[Abstract]:Based on 1 254 formation water data points taken from exploration wells in Bohai Sea area, the characteristics of formation water mineralization and the distribution of formation water type in Bohai Sea area are summarized. The controlling factors of its differential distribution are discussed. The results show that the salinity of formation water in Bohai Sea shows the characteristics of forward hydrochemical profile with the increase of buried depth, and the desalination zone of salinity appears at the top of Dongying formation. The Cenozoic is divided into Neogene and Paleogene secondary forward hydrochemical profiles, paleoclimate conditions and sedimentary environment control the macro-distribution pattern of formation water salinity in the study area, and Paleogene salt rocks in the Laizhou Bay depression in the southern part of the study area. The development of gypsum rock is the main reason that the mineralization degree in the study area is high in the south and low in the north, the deep fault further controls the plane differential distribution of the shallow formation water by regulating the deep fluid activity, and the vertical upward movement of 2480m is used as the chemical differentiation surface, which forms the upper surface. In the lower two hydrochemical systems, the upper system is covered by sea water since the deposition period of the plain formation, combined with the extremely thick formation deposited in the Neogene, which leads to the increase of the salinity of formation water and the relative enrichment of calcium chloride type water. The lower system is controlled by a large amount of hydrocarbon generation and expulsion from source rocks and forms high salinity sodium bicarbonate formation water.
【作者单位】：中海石油(中国)有限公司天津分公司;
【基金】：国家自然科学基金(编号:41602111) 国家科技重大专项课题“渤海海域勘探新领域及关键技术研究”(编号:2016ZX05024-003)联合资助
【分类号】：P618.13;P736.22

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