用声波测井资料计算剥蚀量的方法改进

作者提出了用声波传播时间与深度关系的指数模型来计算剥蚀量的一种改进方法。该方法同时考虑了声波在岩石基质中传播时间的物理范围和声波在地表的传播时间,从而在浅部和大深度上都能较好地反映地质真实和预测压实趋势,提高了剥蚀量估计。文中应用这一改进方法对东海西湖凹陷第三系地层作了压实趋势拟合和主要不整合面的剥蚀量计算,得出的东海1井中新世末的T₁0界面剥蚀厚度达1750m。 

AN IMPROVED METHOD TO CALCULATE DENUDED AMOUNT BY SONIC WELL LOGS

An improved method to calculate denuded amount by the exponential model of sonic propagation time vs. depth is suggested in this paper. The method considered the physical range of sonic propagation time in rock matrix and the sonic propagation time in Earth's surface, and can well reflect geologic reality and predict compaction trend in shallow and great depths so as to improve the estimation of denuded amount. The improved method is applied to the Triassic strata of the Xihu Depression, the East China Sea by the authors to fit compaction trend and to calculate the denuded amount of major unconformity planes. The estimated denuded thickness of T₁0 interface at the end of the Miocene in well Donghai-1 is about 1750m.