【摘要】 石油钻井中由于井底压力略大于地层压力,使得钻井泥浆侵入到原始地层中,改变地层的电阻率,影响了电阻率测井的准确性.以油水两相流的渗流方程、对流扩散方程和阿尔奇公式为理论模型,采用有限差分方法对泥浆侵入过程进行二维数值离散,针对麻黄山西探区储层实际情况输入模型中有关参数,分别对侵入时间24h和48h,解得给定侵入时刻储层的压力、含水饱和度、地层水矿化度和电阻率在垂向和径向的分布,计算结果与实际情况相符,可用其对实际电阻率测井值进行校正.通过一个低侵算例验证,结果与理论分析相符合,因此该方法可以用于垂向上非均匀储层的泥浆侵入计算.更多还原

【Abstract】 Due to the pressure difference between borehole and reservoirs,drilling mud invades the original reserviors while drilling for petroleum,changing the formation resistivity,which has a negative effect on resistivity logging.Based on the theoretical model of two-phase flow equation,convection-diffusion equation and Archie formula,finite difference method is adopted to discretize mud invasion models in the way of two dimensions.Parameters of the reservoir in Mahuangshan area,Ordos basin,north-central China,with the mud invasion time of 24,48hours respectively are input for the model,and the vertical and radial distributions of pressure,water saturation,salinity and formation resistivity in the designated time are worked out.The computing results are consistent with fact instance,and can be used for correcting resistivity logging values for mud invasion reservoirs.A case of low invasion is computed and the results prove to conform to the theoretical analysis.This method can be used in mud invasion of vertical inhomogeneous medium.更多还原