辽东湾地区下第三系地震速度—岩性预测模型研究

地震速度－岩性预测模型由四个子模型组成：即（１）砂泥岩压实模型；（２）地震层速度转换模型；（３）速度校正模型；（４）砂岩指数转换模型。辽东湾地区的实际资料证明，上述四个子模型不但决定了岩性预测的具体方法，而且严格控制岩性预测的精度。

RESEARCH ON SEISMIC VELOCITY-LITHOLOGY PREDICTION MODEL FOR EOCENE OF THE LIAODONG BAY

This paper presents a set of seimic velocity-lithology prediction models on the basis of velocity-lithologic analysis, which consists of four sub-models: (1) sandstone-shale compaction model, (2)conversion model of seismic interval velocity (3)velocity correcting model, and (4) conversion model of sandstone index. The author divided the sandstone-shale compaction models of the Liaodong Bay into four types: 1) normal type , 2) abnormal type,3)waveshaped,and 4)equal-velocity type,and analyzed the geological origin and different usage for every type. Furthermore, the paper discusses the application and error-enlarging effect of classical Dix formula,and suggests that a drift correcting of compaction curve by VSP data,systematic error correcting of internal velocity from velocity spectrum,and 2-D filtering for interval velocities can be used to increase precision of lithologic interpretation. These models are very successful in lithologic prediction of Eogene at north sag in Liaoxi depression and soutli part of Liaozhong depression.