摘要
地层水化学特征及流体成因的分析对油气成藏的研究具有重要意义,对库车坳陷克拉苏构造带的地层水化学特征及流体成因的研究有助于油气藏的勘探开发。塔里木盆地库车坳陷克拉苏构造带构造特征复杂,地层水化学特征及流体系统缺乏系统研究。为了明确克拉苏构造带地层水化学特征及其流体系统,对地层水的溶解性总固体(TDS)、离子比例系数及压力分布特征进行了分析。研究结果表明:克拉苏构造带地层水以高TDS的卤水为主(平均值为154.92 g/L),按照苏林分类主要为CaCl_(2)型,按照舒卡列夫分类为Cl-Na型和Cl-Na·Ca型,为典型的沉积埋藏水。地层水的脱硫系数较低(平均值小于1.2)、变质系数较高(平均值大于6),表明地层的封闭性较好,地层水经历了较强的水岩反应。参照地层压力场、岩性特征及地层水特征,将库车凹陷克拉苏构造带划分为第四系—新近系、古近系、白垩系、侏罗系及下伏地层四套流体系统。结合研究区岩性组成、构造演化特征及地层水化学特征分析,明确了白垩系巴什基奇克组地层水的成因为白垩系原始沉积水与侏罗系烃源岩生烃时排出的有机物转化流体、沉积水及古近系膏盐层高盐度流体的混合。
The Kelasu structure belt in Kuqa depression,Tarim basin has complex structural characteristics and lacks systematic research on chemical characteristics of formation water and fluid system.In order to clarify the chemical characteristics and fluid system of formation water in Kelasu structure belt,the characteristics of salinity,ion proportion coefficient and pressure distribution of formation water are analyzed.The results show that the formation water of Kelasu structural belt is mainly brines with high salinity,which are classified as CaCl_(2)type according to Surin classification,Cl-Na type and Cl-Na·Ca type according to Schukarev classification,and are typical sedimentary buried water.The formation water has low desulfurization coefficient and high metamorphism coefficient,indicating that the formation water has experienced strong water-rock reaction.According to the characteristics of formation pressure field,lithology and formation water,it can be divided into four fluid systems in the study area:Quaternary-Neogene,Paleogene,Cretaceous,Jurassic and its underlying strata.Based on the analysis of lithologic composition,structural evolution characteristics and chemical characteristics of formation water in the study area,it is concluded that the chemical characteristics of formation water is influenced by the mixture of organic transformation fluid,sedimentary water and high salinity fluid of Paleogene and hydrocarbon fluids from Jurassic source rocks during hydrocarbon generation.
作者
朱传庆
徐同
邱楠生
张海祖
王祥
王冰
ZHU Chuanqing;XU Tong;QIU Nansheng;ZHANG Haizu;WANG Xiang;WANG Bing(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;College of Geosciences,China University of Petroleum,Beijing 102249,China;Research Institute of Exploration and Development,PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000,China)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2023年第1期250-261,共12页
Acta Geologica Sinica
基金
塔里木油田公司委托科研项目(编号041020050021)
国家科技重大专项(编号2017ZX05008-004)联合资助的成果。
