普光气田飞仙关组层序地层划分

Sequence stratigraphic classification of Feixianguan Formation in Puguang Gas Field

朱永进 刘玲利 赵 睿 尹太举

长江大学油气资源与勘探技术教育部重点实验室，湖北 荆州 434023 长江大学地球科学学院，湖北 荆州 434023 新疆油田分公司勘探开发研究院，新疆 克拉玛依 834000

普光气田飞仙关组层序地层划分过程中，综合分析露头、地震、岩心、测井等资料，发现一些新的层序界面识别标志：野外露头上特征明显的岩性转化面及暴露侵蚀岩溶发育带；地震剖面上识别出具有弱振幅，中—低连续特征的退覆层序界面；沉积相序变化及沉积粒序特征反映出的海平面变化规律。能谱曲线上识别出Th－K占主导和U占主导的2种异常峰点，前者被认为一般代表较大规模的海侵。根据这些新标志，运用层序地层学原理，完成了层序划分工作，并以PG2井为例阐述了三级层序特征。

In the process of sequence classification of Feixianguan Formation, many new identification signs of sequcence interfaces are recognized after the analysis of outcrop, core, seismic and well logging data. The identification signs include the typical lithology conversion surfaces and karst zones observed on field outcrops, weak amplitude identified in seismic section and moderate-to-low continuous offlap sequence interfaces, change rules of sea level reflected by sedimentary facies sequence and sedimentary size grading
characteristics. Two types of abnormal peaks are observed in energy spectrum curves, which consist of the dominant potassium-thorium peaks and uraniumpeaks.The former usually represents a massive transgression.On the basis ofthese marks,the sequence classification of Feixianguan Formation was finished with the theory of sequence stratigraphy. Taking Well PG2 as an example, the characteristics of
third-order sequence was described inthispaper.