Discovery of seismites in the Upper Cretaceous Yaojia Formation in Daqing Placanticline of Songliao Basin and its geological significance
Shao Chen1 Fan Tailiang1 Guo Yajie2 Cheng Peng3 Sun Yu1 Wang Hairong1
1 School of Energy Resources，China University of Geosciences（Beijing），Beijing 100083
2 No.2 Seismic Interpretation Department，Daqing Oilfield Exploration and Development Institute，Daqing 163712，Heilongjiang
3 Northwest Petroleum Company，SINOPEC，Urümqi 830011，Xinjiang
A great deal of seismites，which are related with earthquakes，were found in the Yaojia Formation of the Upper Cretaceous，Daqing Placanticline.By observation of cores，two major categories of seismites are identified，which are deformational structures of soft sediments(including liquefaction sand dyke，ball-and-pillow structure，vibration-induced liquefaction structure and load structure)and hard rock(including step micro-fault，autoclastic brecciated structure and structure).These deformational structures can be divided into 7 subclasses.Based on the data of core observation(Well DQ-N1，DQ-N2，DQ-N5，DQ-N7)，the vertical sequence of seismites was drawn，at the same time，different development of seismites in the sedimentary system of delta was discussed.The oil trace，which was found in the step micro-fault(Well DQ-N2)and formation breakdown(Well DQ-N5)，shows that the seismites themselves were a kind of potential reservoir，and seismic activity can efficiently enhance the porosity and permeability of the reservoir and increase new pathways for oil and gas migration.It will provide a breakthrough point to analyze the exploration and development of oil and gas resource.
Shao Chen,Fan Tailiang,Guo Yajie et al. Discovery of seismites in the Upper Cretaceous Yaojia Formation in Daqing Placanticline of Songliao Basin and its geological significance[J]. JOPC, 2012, 14(6): 719-726.
