感应电阻率测井侵入校正方法

在钻井过程中,井筒泥浆柱压力和地层压力的不平衡使得泥浆滤液不断渗入地层.由于泥浆滤液和地层水矿化度(电阻率)的不同,这种泥浆滤液渗入的结果使得侵入带地层电阻率发生了变化,从而影响了地层感应电阻率的测量结果.分析了测井环境对感应电阻率测井曲线的影响,论述了对感应电阻率测井曲线作侵入校正的基本原理,提出了一种实用的感应电阻率测井曲线侵入校正方法.经现场多口井的数字处理试验,证明效果良好.

An Invasion Correction Method For Induction Resistivity Logging

During the drilling procedure, the mud filtrates continuously penetrate into the formation because of the unbalance between the mud column pressure in the borehole and formation pressure. Because of the difference between salinity (resistivity) of the formation water and the mud filtrate, the mud filtrate invasion results in the resistivity changes of the invaded zone, thus affecting the measuring result of the formation induction resistivity. Analyzed is influence of the logging environments on induction resistivity. The basic principle of invasion correction for the induction resistivity is discussed. A practical method of invasion correction for induction resistivity logging is introduced. Log data processing of several wells shows this method is better.