摘要
松辽盆地扶新隆起带北部扶杨油层地层水化学分布特征复杂,与油气成藏之间的关系也与其他盆地以及松辽盆地其他层系存在着较大差异。通过不同含油层系、不同埋藏深度段地层水化学参数的统计与相关性分析,在垂向上划分出5个地层水化学成因带。同时结合研究区石油地质背景分析,明确了地层水性质及其分布的主控因素。研究表明,扶新隆起带北部地层水性质主要受沉积物源区岩石类型、烃源岩热演化生烃、成岩过程中的水—岩相互作用、圈闭封闭性能等因素的综合影响。以中酸性岩浆岩和火山岩为母岩的沉积物源是NaHCO_(3)型为主的地层水形成的前提条件,烃源岩生烃高峰前排出的大量有机酸以及与生烃过程中伴生的CO_(2)是强化NaHCO_(3)型地层水分布的关键因素。相对高异常矿化度的NaHCO_(3)型地层水的形成与背斜圈闭对CO_(2)的良好捕集与封存条件以及由此导致的钠长石溶蚀作用密切相关。钠氯系数对于因富含CO_(2)的地层水对酸性长石的溶蚀作用产生的次生孔隙发育带具有较好的指示作用,因此是油气富集的标志。
The hydrochemical parameter distribution of Fuyang payzone in the north of Fuxin uplift of Songliao Basin is very complicated,and the relationship with oil and gas accumulation is also quite different from other basins or other payzones in Songliao Basin.Through the statistics and correlation analyses of the hydrochemical parameters in different formations,different depth intervals,five genetic hydrochemical zones of the formation water are determined.Furthermore,the main controls of the formation water properties and distribution are determined based on the petroleum geology background analysis.The study shows that the properties of the formation water in north Fuxin uplift are mainly affected by the rock types of the sediment provenance,the thermal evolution of source rocks,the water-rock interaction in diagenesis and so on.Composition of the parent rocks dominated by acid magmatic and volcanic rocks is the prerequisite for the origination of NaHCO_(3) type formation water.Large quantity of organic acids expelled before the peak of hydrocarbon generation and the companying CO_(2) are the key factors affecting the origin of NaHCO_(3) type formation water.Production of the high salinity formation water of NaHCO_(3) type is closely related to the perfect condition for CO_(2) capturing and sealing in local anticline traps and the dissolution of the albite.The Na/Cl coefficient is a good indicator of the secondary pores caused by the dissolution of acid feldspar under the condition of enriched CO_(2) in formation water,and so it is an index of oil richness.
作者
吴欣松
唐振兴
张琴
赵家宏
王武学
WU Xinsong;TANG Zhenxin;ZHANG Qin;ZHAO Jiahong;WANG Wuxue(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Jilin Oil Company Ltd.,PetroChina,Songyuan 138000,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2022年第6期979-991,共13页
Natural Gas Geoscience
基金
国家科技重大专项“我国含油气盆地深层油气富集规律与资源评价”(编号:2017ZX05008-006)资助。
关键词
地层水化学
水—岩相互作用
次生孔隙
松辽盆地
Hydrochemistry of formation water
Water-rock interaction
Secondary pore
Songliao Basin
