渤海海域辽西构造带S型走滑转换带特征及控藏作用定量表征

S型走滑转换带是走滑环境下广泛发育的一类构造。以往的研究认识多集中在对走滑转换带类型划分的探讨上，缺乏对其控藏作用的精细研究。本次研究利用渤海海域辽东湾地区连片三维地震资料，结合油气田实例，运用统计学方法分析了辽西构造带S型走滑转换带的控藏作用。辽西带新生代构造变形总体表现为NE向伸展构造系统和NNE向右旋走滑构造系统的叠加构造变形，S型走滑转换带可分为增压段和释压段两大类。按照走滑转换带演化阶段的不同，将增压段进一步细分为压扭低凸起段、平缓增压段和强烈增压段等3个亚类。将释压段同样细分为纺锤形浅凹、平缓释压段和菱形释压段等3个亚类。将走滑断裂末端发育的转换带归纳为增压型或释压型马尾扇。应用S型走滑转换带“油气富集指数”的分析方法，论证了S型走滑转换带弯曲度与走滑调节断层活动性具有正相关性，并成功应用于辽西凹陷南次洼旅大5-2北油田成藏分析工作中，为勘探决策提供了定量化依据。

Characteristics of S-shaped strike-slip transfer zones and quantitative analysis of their influence on hydrocarbon accumulation in Liaoxi structural belt,Bohai Sea

S-shaped strike-slip transfer zone is widely developed structure in strike-slip strain background.However, previous researches are mainly focused on the classification of strike-slip transfer zones, but its control on hydrocarbon accumulation is poorly understood.Based on 3D seismic data and oil and gas fields analysis, this paper addresses the effects of S-shaped strike-slip transfer zone on hydrocarbon accumulation in the Liaoxi structural belt, Bohai Sea, by using statistical methods.Cenozoic structural deformation of the Liaoxi structural belt is characterized by deformation of NE-trending extension superimposed by NEE-trending dextral strike-slip activities.S-shaped strike-slip transfer zone can be divided into restraining bends and releasing bends.According to different evolution stages, restraining bends can be further divided into 3 subordinate classes, involving transpressional uplifting bend, gentle restraining bend and intense restraining bend.Similarly, releasing bends involve spindle-shaped pull-apart, lazy s-shaped pull-apart and rhomboidal pull-apart.In addition, the strike-slip transfer zones at the end of strike-slip fault zones contain restraining and releasing horsetails.The concept of oil and gas enrichment index (OGEI) is defined, and the positive correlation between master strike-slip fault curvature and intensity of adjusting strike-slip faults is proven.A mathematical model from OGEI is proposed to quantitatively predict oil and gas enrichment.It is a quantitative tool for exploration decision, and has been applied in analysis of LD5-2N oil field successfully.