摘要
东濮凹陷文留地区断裂及盐岩发育,油气运聚过程及油、气、水分布关系复杂。在分析文留地区古近系现今地层水化学纵向及平面分布特征的基础上,利用地层水氘、氧同位素测试资料确定地层水来源。结合文留地区构造以及水动力特征,深入研究文留地区古近系地下水化学特征与油气富集、分布之间的关系。同时,通过解剖文218—文245井典型剖面,进一步分析水化学特征与油气运移、聚集、成藏之间的耦合关系。地层水氢、氧同位素分析表明,文留地区地层水以原生沉积水为主,局部曾经受到古大气水下渗影响,反映其地层封闭性较好,有利于油气成藏、保存。纵向上,文留地区水化学可以分为(古)大气水下渗淡化带、越流泄水浓缩带、泥岩压实排水淡化带、断层越流淡化带和末端越流浓缩带等5个水化学垂向分带;平面上,文东滚动背斜带和文东地堑带为两侧凹陷离心流的共同指向区,地层水在越流过程中不断浓缩,矿化度、氯离子浓度增加,矿化度、氯离子浓度高值区与油气富集区有一致性。文留地区断裂连通性好,油气以垂向运移为主,侧向运移为辅。
Faults and salts are widely developed in Wenliu region in Dongpu sag,Bohai Bay Basin. And hydrocarbon migration processes and the contacts between water-,oil and gas are complex. Based on analysis of the current vertical and horizontal hydrochemical distribution of the Paleogene formation water,this paper determined the origin of formation water by using isotopes of hydrogen and oxygen. Combined with the features of regional tectonics and hydrodynamics,we also studied the relationship between the hydrochemical property and the accumulation and distribution of hydrocarbon in Wenliu region. Besides,by means of dissecting the typical profiles of Well Wen 218 to Well Wen 245,the coupling relation between hydrochemical characteristic and hydrocarbon migration and accumulation was further analyzed. The analysis of isotopes of hydrogen and oxygen show that the formation water of this region is primarily composed of the connate water,with paleo-meteoric water permeating only in some local areas. This indicates that the sealing conditions area good in the Wenliu region,favorable for hydrocarbon accumulation and preservation. Moreover,the hydrochemistry of this region can be divided into five zones in vertical,namely diluting zones due to permeating of( paleo-) meteoric water,released water of mudstone compaction and fault communication,concentration zones due to cross-formational flow and end over flow.In the plane,the Wendong rolling anticline belt and graben belt are the common areas for the gathering of released water from mudstone compaction and meteoric water. The concentrations of salinity and chloridion gradually increase as a result of the condensation process of cross-formational flow of formation water. The areas with high concentration of salinity and chloridion correlate well to hydrocarbon enrichment areas. In addition,the Wenliu region displays good connectivity of faults,resulting in the vertical hydrocarbon migration being dominant while the lateral migration being subsidiary.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2014年第4期449-455,共7页
Oil & Gas Geology
基金
油气藏地质及开发工程国家重点实验室开放研究基金项目(PLC201105)
国家自然科学基金项目(40839902)
国家科技重大专项(2008ZX05005-003-008HZ)
国家重点基础研究发展计划(973计划)项目(2005CB422107)
关键词
地层水化学
油气运移
油气聚集
文留地区
东濮凹陷
渤海湾盆地
hydrochemistry of formation water
hydrocarbon migration
hydrocarbon accumulation
Wenliu region
Dongpu sag
Bohai Bay Basin