The Seismic Sedimentology Research About E₃d₂Formation In East Sag Of Tanhai Area

The east area of Tanhai is in the south of Dawa Rongxingtun sag,in Lianning province,which in a shallower sea area. It,s a fault-depression basin which as a result of extensional andstrick-slip stresses in time of Meso-Cenozoic. The research of seismic sedimentology aboutE3d2in the researching region is amied at solving the problem of thin reservoir prediction anddistribution of sedimentary facies of E3d2in Liaohe Tanhai.Referring to the previous research, and rock date, logging date, we set up a sequenceframework about E3d2which divided the E3d2strata into two third-order sequence, includesupper E3d2and deeper E3d2. Through a systemic analysis, we consider that there are threesedimentary facies, delta facies, fluvial facies and lacustrine facies. The strata sequence reflicta regressive processes of lake from the bottom to top. There are delta-front facies sand bodyand delta plain facies sand body in the deeper E3d2, and delta plain facies sand body andfluvial facies sand body in the upper E3d2.On the basis of the understanding mentioned above, we use the technology of seismicsedimentology, includes90°phasing of seismic data, frequency division processing, andstratal slicing, to research the sediment of E3d2strata. First, we identified four inner layer forstratal slice analysis, with the contains of isochronous stratigraphy framework, combined theseismic resolution and the characteristics of seismic reflection. As well know that manydepositional surfaces cut across seismic events lead to the stratal slice not follow geologictime well. At the same time, we carried out a interlayer attribute analysis to resolve thisproblem. Compared of those two methods, the cut across seismic events phenomenon is wellreduced while using interlayer attribute analysis. At last, we make a sedimentary microfaciesanalysis and the sand body preview about E3d2strata, combined these two methods above,and logging and well logging data.During the seismic reversion we use the seismic, well logging, and velocity spectrumdata to make sure the accuracy of previewing. By using the result of seismic reversion and theunderstanding of seismic sedimentology, we make the sand body in upper E3d2and deeperE3d2more implement. Finally, we proposed two exploration target in Gaibei tectonic area andLongbei tectonic area, composite the strata, tectonic, sedimentary reservoir, and hydrocarbonaccumulation characteristics.