Reservoir Inversion And Target Prediction Of Dongying Formation In The Eastern Tidal Zone, Liaohe Depression

Liaohe tidal zone, located in northern Liaodong bay, is the transition zone of Liaodong bay and Liaohe basin tectonic units, is the natural extensions to the sea of Liaohe basin, is a continental extension fault basin in Cenozoic. In recent years, with the improvement of exploratory level, the district shows good prospects for lithologic reservoir exploration.Taking the theories of Sequence stratigraphy, reservoir geology, exploration seismology as the guide, firstly perform the seismic sequence stratigraphic classification and correlation, establish the seismic sequence stratigraphic framework in the eastern of Liaohe tidal zone, then use geophysical techniques and computer means, perform the seismic attribute analysis along the layer, combine with the sedimentary facies analysis and the regional tectonic background, predict the favorable zones.The comprehensive analysis of drilling, logging and seismic data shows that the eastern of Liaohe tidal zone is divided into 7 three-order sequence （SQ1 - SQ7）. The Member 3 of Dongying Formation depositional period with east-west short axis in source, Member 2 of Dongying Formation depositional period into the long axis in the central source.On the basis of the interpretation of seismic sequence, through the extraction and contrast of seismic attributes along the layer, optimized sensitive seismic attributes for the study problems, root mean-square amplitude , instantaneous frequency and relative wave impedance. Combined with sedimentary facies, using the abnormal amplitude to identity delta and channel sand and the frequency to detect and analyze the fluid property, I consider that the east and west sides of depression may be developed fan delta and the the area of Gainan 1 may be developed gravity flow channel or sublacustrine fan in the Member 3 of Dongying Formation depositional period, the central depression mainly developed channel sand in Member 2 of Dongying Formation depositional period. The 3d visualization of seismic attributes along the layer can clearly reflect the layer distribution of depositional system.Select key sequence of Dongying Formation, establish geological model of sandstone reservoir in the sequence stratigraphic framework, and carry on the constrained sparse spike inversion of Well-Seismic, analyze the distribution characteristics and the evolution of sandstone reservoir in the section and plane. Through the identification of favorable reservoir and the trap prediction of favorable targets, I consider that the favorable zones of potential lithologic trap are the delta lobes in the northwest of depression and the area of Gainan 1 in the early period of Ed₃（SQ4）; the fan delta in the northeast of depression and the island of Kuihua in the late period of Ed₃（SQ5）; the delta peripheral zone in the northwest of Kuihua island in the early period of Ed₂（SQ6）; the river deposits in the middle of depression in in the late period of Ed₂（SQ7）.