靖边气田陕181—陕400井区奥陶纪古地貌研究

Study on Ordovician ancient landform in Shan 181~400 well bock of Jingbian gas field

靖边气田是一个与奥陶系海相碳酸盐岩有关的风化壳型气田,陕181-陕400井区是靖边气田扩边建产的重点区,由于前期钻井较少,对古地貌形态尚缺乏详细认识,制约了区块扩边建产进程。结合近年来最新钻井资料,采用残余厚度法对奥陶系古地貌进行刻画,分析了地貌单元与油气富集关系。研究表明,该区存在剥蚀区、台丘、斜坡、沟槽4类地貌单元,其分布规律呈现西部剥蚀区-中部斜坡-东部台丘的特征,台丘和斜坡区是下一步产能建设有利区。

Jingbian gas field is a weathering crust gasfield,which is related to the Ordovician marine carbonate.Its distribution is strictly controlled by ancient landform.Located in southwest of Jingbian gas field,Shan181-400 well block is the key target of Jingbian gas field extension productivity construction in recent years.However,due to the lack of drilling data and unclear recognition of ancient landform characteristics in early stage,the progress of extension productivity construction has been restricted.Combined with the latest drilling data in recent years,the residual thickness method has been used to describe the Ordovician ancient landform and then the relationship between geomorphic unit and oilgas enrichment has been analyzed.Research results show:this area has 4 kinds of geomorphic units,namely denudation area,hill,slope and groove;its distribution pattern is western denudation area →middle slope →eastern hill;and the hill and slope are the potential productivity construction areas.The research achievements can directly guide the extension productivity construction,and provide reference for similar ancient landform areas.