辽河油田大洼地区中生界基性火山岩油气成藏特征

Hydrocarbon accumulation characteristics of Mesozoic basic volcanic rocks in Dawa area of Liaohe oilfield

辽河油田大洼地区中生界基性火山岩的形成和分布受构造背景和断裂系统共同控制,呈北薄南厚的分布特征;首次认为水下喷发型玄武质火山角砾岩为基性火山岩良好储层,呈北部尖灭、南-东部相变、整体呈东西向鼻状分布的特征;该区发育构造-岩性复合型油气藏,具有断层-不整合面“接力式”立体输导体系,形成整体含油、立体成藏、构造和有效储层控制油气富集的成藏模式,为进一步拓展辽河油田基性火山岩油气藏勘探提供了依据.

The formation and distribution of Mesozoic basic volcanic rocks in Dawa area of Liaohe oilfield are controlled by the tectonic background and fracture system,which presents the distribution characteristics of thick in north and thin in south.For the first time,it is considered that the basaltic volcanic breccia of the underwater eruption type is a good quality reservoir of basic volcanic rock,and its distribution is characterized by pinch-out in the north,phase transition from the south to the east,and east-west nose distribution.There are tectonic-lithologic complex oil and gas reservoirs in this area,and there is‘relay’three-dimensional transmission system of fault—unconformity surface,forming a reservoir formation model of overall oil bearing,three—dimensional accumulation,hydrocarbon accumulation is controlled by structure and effective reservoir,which provides a basis for further exploration of basic volcanic rock oil and gas reservoirs in Liaohe oilfield.