摘要
我国大中型气田已发现 6 8个 ,其中大部分分布于海相或海陆过渡相中 ,勘探实践证实海相层序富集大中型气田。 3大气区克拉通海相沉积层序 ,整体上经历了两次大的海侵和两次大的海退沉积 ,形成了纵向上多套优质的生储盖组合 ,而且经历了多期次的大型构造运动 ,形成震旦纪中晚期和志留、泥盆纪两次大的不整合和其他次级不整合 ,有利于地层 岩性风化壳天然气藏类型的发育。海相、海陆过渡相地层中 ,存在 4种天然气藏类型 ,即 (1)古隆起控气下的地层岩性天然气藏 ;(2 )古隆起控气下的受晚期构造运动调整的构造背斜气藏 ;(3)生物礁、鲕滩、河流相砂体等岩性气藏 ;(4)大型挤压背斜圈闭天然气藏。海相、海陆过渡相天然气的分布 ,受古隆起控制 ,同时各种沉积环境下形成的碳酸盐岩储集场所及河流相砂岩有利相带的分布也制约着天然气藏的富集 ,而且与多期次构造运动对原生气藏的破坏和调整有关。
Presently sixty-eight major natural gas fields have b ee n discovered in marine and transitional continental-oceanic sequences in China and marine sedimentary sequences are favorable for exploration of natural gas.T he marine sedimentary sequences in three cratonic basins are composed of two maj or cycles of transgression and regression,in which multiple combination of sourc e rocks,reservoirs and seals was formed.In addition,as a result of tectonic move ment many unconformities were formed and stratigraphic-lithological gas pools w ere developed.There are 4 kind of gas fields in marine sequences:(1) stratigraph ic-lithological gas traps related with old uplift ;(2) anticlinal gas pools re lated with old uplift and late tectonic movement;(3) lithological gas pools of r eef,oolite beach or sandbody;(4) large anticlinal gas pools under compressional background.In one word,distribution of natural gas is closely related with old u plift,reservoir conditions and tectonic activity.
出处
《石油实验地质》
CAS
CSCD
北大核心
2000年第4期325-329,共5页
Petroleum Geology & Experiment
基金
"九五"国家科技攻关项目(96-110-07-02)
关键词
天然气
海相层序
克拉通盆地
成藏模式
分布规律
natural gas
marine sequence
cratonic basin
formation model
distribution rule
