徐家围子断陷安达地区火山岩有效储层预测方法

Methodologies for Predicing Effective Reservoir of Volcanic in Anda Area of Xujiaweizi Depression

针对火山岩岩性复杂,非均质性强,特别是深层地震资料信噪比相对较低,有效储层识别及预测难度大的问题,以营城组三段为目的层位,在分析火山机构地球物理特征和火山岩平面分布特征的基础上,运用地质统计学反演方法,通过GR反演预测酸性岩、中性岩和基性岩的分布。工区中性岩最为发育,厚度为400～800m;基性岩和酸性岩相对不发育。在岩性识别的基础上,运用密度反演分别圈定不同岩性的有效储层,本区有效储层主要以中性岩和基性岩为主,在火山锥、断裂和裂缝相对发育的地区,有效储层相对发育。

Because of the complex lithology and the heterogeneity of volcanic rocks,especially signal to noise ratio of deep seismic data being relatively low,it is difficult to identify and predict the effective reservoirs.In this paper,the 3rd member of Yingcheng Formation is the purpose of formation.On the base of studying the geophysical features of volcanic bodies and distribution of volcanic rocks on the plane,identifing persiliceous rocks,intermediate rocks and subsiliceous rocks use geostatistical inversion by GR ray.Intermediate rock is widespread in the research area,and the thickness of which is about 400-800 m.The subsiliceous rock and persiliceous rock are relatively undeveloped.On the base of identifing lithology,the effective reservoir,mainly of intermediate and subsiliceous rocks,can be delimitated by density inversion section.Therefore,the effective reservoir would be thicker with the development of colcaniccone,fracture and crack.