Abstract：The main geologic difficulties faced with the risk exploration in central block of eastern margin of Pre-Caspian basin are recognition and elimination of false subsalt structural image resulted from the giant thickness of Permian salt dome(greater than 3000m) and non-homogeneous reservoir prediction of matrix porous carbonate reservoir buried near 4000m.Starting from the cases of influence of giant salt dome on subsalt structure,the paper discussed the issues of false subsalt traps and faults resulted from the influence and considered that the size of pull-up amplitude of subsalt strata by salt dome in time domain mainly depends on the thickness of salt dome and the fault of subsalt events is mainly relative to the thickness of salt dome and steepness in limb of salt dome,and tried to eliminate the influence by velocity model and combining interpretation with multiple seismic data,restoring real feature of subsalt strata;meanwhile,the developing zone of non-homogeneous carbonate reservoir was successfully predicted by the aid of such seismic technology as seismic inversion and fracture detection.Application of above mentioned techniques to the exploration of subsalt targets in central block of eastern margin of Pre-Caspian basin achieved ideal effects.
