摘要
西湖凹陷中央背斜带北部油气突破已经引发渐新统花港组深层成藏模式新思考,而气源分析是成藏模式的一个重要环节,此文将中央背斜带北部新探钻井的天然气样品与三潭深凹及保傲斜坡北部天然气样品对比分析,从组分、轻烃指纹两方面探讨了母质类型,并用多种指标论证天然气成熟度问题,认为中央背斜带北部花港组天然气来自构造西侧三潭深凹同期地层,其成熟度明显低于三潭深凹南部花港组及保傲斜坡北部平湖组天然气,但分馏蒸发作用所造成的重烃含量异常低的假象容易误判为高成熟裂解气。气源判别的新认识为该地区花港组成藏提出了新的思路。
The exploration break through from Huagang Formation in the north segment of central anticline belt of Xihu Sag initiates geologists to re-think about the accumulation model in the deep Oligocene Huagang Formation.The analysis of gas source is one of the important aspects in the accumulation.The authors made a comparison among gas samples from the north segment of central anticline belt,Santan subsag and the north segment of Baochu slope,respectively,discussed the types of kerogen from the gas components and light hydrocarbon fingerprints,and demonstrated the gas maturity by a variety of indicators.It is concluded that the gases from Huagang Formation in the north segment of central anticline belt came from the same formation of Santan subsag which is located to the west of the central anticline,their maturity are inferior to those of gases from Huagang Formation in the south segment of Santan subsag and from Pinghu Formation in the north segment of Baochu slope.The false appearance,abnormal low content of heave hydrocarbon caused by fractionation and evaporation,can be easily mistaken for highly matured gas.The new idea about the gas origin put forwards a new method for the study on the accumulation model in Huagang Formation in the study area.
出处
《海洋石油》
CAS
2017年第1期21-29,共9页
Offshore Oil
关键词
天然气特征
气源
中央背斜带
西湖凹陷
Characteristics of natural gas
gas source
central anticline belt
Xihu Sag
