徐家围子断陷徐南地区气藏超压成因  

The causes of overpressure in the gas reservoirs in southern area of Xujiaweizi fault depression

作　　者：狄嘉祥[1] 刘文龙[1] 吴世环[2] 

机构地区：[1]中国石油大庆油田有限责任公司勘探开发研究院 [2]中国石油大庆油田有限责任公司采油四厂

出　　处：《天然气工业》2009年第8期42-43,共2页Natural Gas Industry

基　　金：国家重点基础研究发展计划(973计划)(编号:2009CB219308)的资助

摘　　要：松辽盆地徐家围子断陷为受徐西、徐中两条断裂控制的箕状断陷,在徐南地区发现有超压气藏存在。利用地球物理和地质资料,从压实不均衡、生烃作用以及泥岩封闭等方面分析了该区的超压成因。研究结果表明,徐南地区地层为正常压实状态,不存在明显或可识别的欠压实沉积过程,地层压力在巨厚的泥岩封闭层下完好保存。生气作用是造成徐南地区气藏超压的主要原因,泥岩封闭为超压的保存提供了良好条件,压实不均衡作用对徐南地区的超压作用不明显。The Xujiaweizi fault depression in the Songliao Basin is a half graben bounded by the western fault and the middle fault,and overpressured gas reservoirs occur in the southern area.Geophysical and geologic data were integrated to study the causes of overpressure in aspects of under compaction,hydrocarbon generation and mudstone sealing.And the following understandings were obtained:①the formation in the southern area of Xujiaweizi fault(the so-called Xunan area)is normal in compaction without significant or recognizable undercompaction,and the formation pressure is well preserved due to the sealing of very thick mudstone;②gas generation is the major factor causing overpressure of the gas reservoirs in the Xunan area,the sealing of mudstone provides favorable conditions for the maintenance of the overpressure,and in contrast,the contribution of undercompaction to the overpressure is insignificant in the Xunan area.

关 键 词：松辽盆地 徐家围子断陷 异常超压 成因 压实不均衡 生气作用 泥岩封闭 

分 类 号：P618.13[天文地球—矿床学]