储层中阵列感应测井响应负差异机理研究

Study on Negative Differential Response Characteristics for MIT in Reservoir

利用多孔介质中两相渗流模型和阵列感应测井理论,建立了阵列感应测井(MIT)时间推移模拟方法。以实际测井数据为基础,计算分析发现储层中阵列感应测井响应产生负差异的主要因素除了束缚水饱和度、地层含水饱和度、泥浆滤液与地层水矿化度比值外,还有水相相对渗透率。提出了用水相相对渗透率识别负差异油层的方法。详细分析了这些参数变化时的一般响应规律。用时间推移模拟得到的径向电阻率分布特征说明了油层产生负差异的机理。以实际测井数据为例给出了阵列感应测井(MIT)时间推移模拟方法在识别负差异油层中的有效性。

A time-lapse simulation method of multi-array induction logging（MIT） is set up using the equations of two-phase fluid flow in porous media and array induction logging theory.Based on the field logging data,it is found that MIT＇s negative differential response of reservoir is not only due to traditional three facts（the saturation of bound water,water saturation,the salinity difference between formation water and mud filtration）,but also the water relative permeability.Proposed is a new method to identify negative differential reservoir using the water relative permeability.The general response characteristics at different parameters are analyzed.Radial resistivity distribution,which is obtained from the time-lapse simulation,explains reasons of the negative difference in oil zone.An example of field logging data shows the method＇s validation,i.e.,the time-lapse simulation identifies the negative differential reservoir.