黄河口凹陷中洼古近系火山岩发育特征及其对油气成藏的控制作用

选择黄河口凹陷中洼南部斜坡带为靶区,以井筒、三维地震资料为核心,建立了地质与地球物理互馈的研究模式,对该区古近系火山机构的形成、演化进行了精细解剖,并结合地球化学资料探讨了火山活动期次、强弱对(准)同沉积期碎屑岩油气成藏的控制作用.结果表明,研究区火山活动划分为两大旋回、6个期次,整个火山活动演化过程呈现断裂活动强烈、...

Development characteristics of Paleogene volcanic rocks in the middle subsag,Huanghekou sag and their control on hydrocarbon accumulation

Taking the southern slope zone of the middle subsag of Huanghekou sag as the target area,and the borehole and 3D seismic data as the core,a study model of mutual feedback between geology and geophysics is established to precisely dissect the formation and evolution of Paleogene volcanic apparatus in this area,and to discuss the control of volcanic activity stage and strength on(quasi)synsedimentary clastic rock hydrocarbon accumulation in combination with geochemical data.The results show that the volcanic activity in the study area is divided into two major cycles and six stages,with the whole evolution process characterized by strong fault activity,frequent magmatic activity,and gradual westward migration of the activity center from the early Eocene,showing a basic pattern of being strong in the east and weak in the west.Volcanic activity has a constructive effect on hydrocarbon source enrichment and oil&gas generation in the study area.It will not significantly change the enrichment law of organic matter in the sag,but the high-temperature stove heat source it carried will accelerate the evolution process of organic matter,and make the hydrocarbon generation threshold of source rocks become shallower,which is conducive to the large-scale generation of oil and gas.The peak period of volcanic activity in the study area is the period of large-scale development of volcanic apparatus.The associated crater,associated flood basalt and dike intrusion can form lateral traps,and may change the enrichment law of sediments.A thick sand layer is formed on the side facing the provenance in volcanic apparatus enrichment areas,and it can be used as a high-quality exploration target area.Moreover,minerals such as chlorite coating and zeolite produced by volcanic activities are conducive to the preservation of primary pores and the development of secondary pores in synsedimentary clastic reservoirs,which is of positive significance to the development of high-quality reservoirs.