HJ断层的地震解释及其意义

Seismic interpretation of HJ fault and its significance

HJ断层位于冀中拗陷RY凹陷北部,是控制HJ洼陷的东边界正断层,长期以来解释为"一刀切",即纵切基底至新近系。综合研究地震时间剖面、水平切片后发现,HJ断层并不是"一刀切",而是被4条横断层切割为几段。结合储层分布特征,文中提出了一种特殊的油藏模式———断缝带油气藏,太古界花岗片麻岩上部是良好裂缝储层,盖层是覆于太古界花岗片麻岩储层之上的以泥岩为主的古近系砂泥岩段,断面是供油渠道。因此断缝带油气藏具备相应的生、储、盖等成藏条件,可以成为油气勘探的新目标。

HJ normal fault is located in the northern part of RY sag in Jizhong depression controlling the eastern boundary of HJ depression.It was interpreted as an 'across the board' fault for long time,which slit to the basement till Neogene.After a joint study of seismic time sections and horizontal slices,we have found that HJ is not an 'across the board' fault,but is cut into segments by four transverse faults.Combining reservoir distribution characteristics,we consider it as a special reservoir mode,viz.fractured reservoir.Good fractured reservoir develops in the upper part of the Archean granite gneiss,its cap rock is Paleogene mudstone shale section covered on the Archean granite gneiss,and the fault section is oil supply channels.Therefore,with the corresponding source rock,reservoir,cap rock and other conditions,fractured reservoir can become a new oil and gas exploration target.