In the sedimentary environment shaped by river-tidal bidirectional flow,thin coal seams are typically lo-cated within the oil-and gas-bearing strata of the Pinghu Formation in the PB area of the Xihu Sag.These coal seams significantly influence the seismic amplitude,phase,and frequency of the reservoirs.[Objective]To bet-terclarify the specific impact of coal seam development in the PB area on reservoir identification and effective identi-fication techniques,[Methods]this paper focuses on analyzing seismic and logging data to evaluate the prestack and poststack seismic response characteristics of the reservoirs.We then investigate the seismic response character-istics of the reflection coefficient after the coal seam is removed and perform poststack seismic forward modeling based on the wave equation.This analysis elucidates the influence of coal seams on seismic responses.Finally,rock physics multiparameter intersection analysis is employed to identify the sensitive parameters and establish the threshold values for reservoir lithology identification within the study area.[Results]When the reservoir thickness is less than the tuning thickness,the seismic data can be rotated by 90°,which reduces the impact of the coal seam on the reservoir diminishes.[Conclusion]For thin reservoirs with associated thin coal seams in the study area,we adopt a three-step high-quality reservoir prediction process that involves broadband spectrum inversion,specifically prestack Vp/Vs and prestack AVOG.This approach allows amore effective description of the distribution range of a-erated sand bodies in the study area.
关键词
PB地区/含煤薄储层/地震响应特征/储层预测/薄砂体分布/东海西湖凹陷
Key words
PB area/thin sand reservoir with coal/seismic response characteristics/reservoir prediction/distri-bution of the thin sand reservoir/Xihu Sag at East China Sea