南海北部沉积盆地油田水水化学特征及其成因分析  

Hydrochemical characteristics and origin analysis of the oilfield water in the north part of the sedimentary basins in the South China Sea

作　　者：肖骢[1,2] 杜尧[1,2] 陈柳竹[1,2] 姜平 马腾[1,2] 

机构地区：[1]中国地质大学(武汉)环境学院,湖北武汉430074 [2]生物地质与环境地质国家重点实验室,湖北武汉430074 [3]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《水文地质工程地质》2015年第2期16-23,共8页Hydrogeology & Engineering Geology

基　　金：国家水体污染控制与治理科技重大专项(2012ZX07204-003-04);国家自然科学基金(41372252);国家重点基础研究发展规划(973项目)(2010CB428802);高等学校博士学科点专项科研基金(20110145110003);国家高技术研究发展计划(863计划)(2012AA062602)

摘　　要：油田水是沉积盆地中的重要流体,研究其水文地球化学特征对油气生成、富集等有重要指示意义。为进一步研究南海珠江口盆地珠三拗陷和北部湾盆地涠西南凹陷油田水的特征和成因,分别在珠三坳陷的珠江组和珠海组采集油田水样5个,在涠西南凹陷的涠洲组采集油田水样4个,对研究区油田水进行了常规阴阳离子含量、D和18O同位素组成分析。结果显示:珠江口和北部湾盆地油田水溶解性总固体总体较高,均为Cl—Na型水,油田水各特征离子间关系(钠氯系数、氯镁系数、钙镁系数)和氢氧同位素关系共同显示两处油田水均起源于海水并储存于封闭性较好的地层中,在埋藏过程中可能还经历了较小程度的蒸发和降水补给,并推测其形成受薄膜渗滤作用影响。Abstract： Oilfield water is an important fluid in sedimentary basins. Studies of the hydrogeochemical characteristics of oilfield brines are of important significance in the oil and gas generation and preservation. In order to further study the characteristics and genesis of oilfield brines in the Zhusan depression of the Zhujiangkou Basin and the Weixinan depression of the Beibuwan Basin, five oilfield brine samples were collected in the Zhujiang group and the Zhuhai group of the Zhusan depression and four oilfield brine samples in the Weizhou group of the Weixinan depression, respectively. Research on hydrochemistry and stable isotopes （D, （18O ） was also carried out. The results how that the hydrochemieal type of the oilfield brines in the Zhujiangkou and Beibuwan Basins is of C1--Na type with high salinity. Chemical factors （such as Na/C1, C1/Mg and Ca/Mg） of the brines and the relationship between hydrogen and oxygen isotopes show that the oilfield brines originated from seawater and were stored in the closed formations. The oilfield brines may also experience a weak degree of evaporation and precipitation during the burial, and it is speculated that their formation is influenced by membrane filtration.

关 键 词：南海 油田水 水化学 同位素 

分 类 号：P641.3[天文地球—地质矿产勘探]