Abstract：In E13 formation，Hongliuquan Oilfield，thereare two sand sheet combinations:thin sand shaleinter-beds，and thick mudstone clamping flag-stone.Based on seismic velocity，thickness anddensity of single sand layer，lithological longitudi-nal combination, and well logging informationfrom Well Hong 118 and Well Hong 17，2D geo-logic model has been designed.With forward algo-rithm，three seismic response models with 40，60，80Hz are built.Based on sand sheet combinationcharacteristics and the forward modeling, the fol-lowing understandings are obtained:①In threeseismic response models，strong and weak reflec-dons appear on thin sand shale inter-beds，this isbecause of the interference from adjacent inter-faces;②Reflections on thick mudstone clampingflagstone appears as complex waves on the 40Hzsection，but as continuous strong events on the80Hz section;③There are two abnormal phenom-enon on the sections:continuous reflection on bro-ken sheets and discontinuous reflection on continu-ous sheets.The former may be due to waveletslide lobes of the adjacent sand bodies;the lattermay be because of accumulation effects of sand-stone concentrated pinch-outs;④Sand layers lessthan 5m cannot be identified on seismic sections，but geological reasons which cause waveform chan-ges can be analyzed on seismic sections comparedwith the 60Hz response model.Therefore sandbodies cross wells，its thickness，and its distribu-tion can be analyzed.
