基于声波测井资料的川西地区深层岩石单轴抗压强度预测

Prediction of Uniaxial Compressive Strength of Deep Rock in Western Sichuan Based on Acoustic Logging Data

由于川西地区地层情况复杂、地层砂岩和泥页岩频繁交替出现,造成机械钻速低的钻井难题一直未得到解决,其主要原因之一是缺乏原始条件地层岩石的强度参数,缺乏钻头合理选型的科学依据。因此,对川西地区须家河组的24块岩心进行了单轴抗压强度试验,并应用试验结果对比分析了11种预测岩石单轴抗压强度的经验模型,认为2种基于声波时差的指数型经验模型对川西地区须家河组地层岩石单轴抗压强度预测结果较好,并对这2种经验模型进行了校正,校正后的预测模型预测误差在15%内,认为该模型能够用于川西地区须家河组岩石单轴抗压强度预测。

The problem of low ROP in the western Sichuan Basin was not solved because of complex geological conditions and sandstone and shale alternating frequently.One of the major causes was lacking of parameters of original geological rock strength and without scientific basis of rock bit selection.Therefore uniaxial compressive strength of 24 cores from the Xujiahe Formation of western Sichuan Area was tested,and then 10 empirical equations were summarized and compared.It indicated that,two empirical equations were used to forecast uniaxial compressive strength of rock from the Xujiahe Formation with good result,the,two empirical equations were calibrated with predicted error less than 15% after calibration.So,two empirical equations can be used to forecast the uniaxial compressive strength of from Xujiahe Formation of western Sichuan Area.