摘要
讨论砂岩和灰岩岩心电阻率、电容率参数与岩石含水饱和度之间的关系。对砂岩和灰岩岩心样品进行高压(30 MPa)真空(-0.092 MPa)驱替饱和,使岩心样品饱和某一矿化度的盐溶液,测量这些岩心电阻率和电容率参数。对所测量的数据分析发现,在4Hz^5 MHz的频率范围内,每种岩性电阻率和电容率均随频率的增加而减小,但在同等条件下,电容率随频率的变化幅度更明显,其频散度更大。不同的频率段,岩心电阻率和电容率参数频散度不同,低频段(小于100kHz)频散度大,在高频段(大于100kHz)频散度小。根据岩性电阻率和电容率参数,建立了一种新型的岩石含水饱和度的计算方法。相比于传统岩电实验,利用该方法计算饱和度不需要测量岩石的胶结指数、饱和度增大系数、地层因数等Archie公式的相关参数。通过岩心的电容率可以直接计算岩石含水饱和度,可减少多个不同参数实验测量带来的误差。
This paper mainly discusses the relationship of two parameters,which is resistivity and dielectricity, with water saturation of cores of sandstone and limestone. Through the displacement and saturation process for the cores of sandstone and limestone under the condition of high pressure(30 MPa)and vacuum(-0.092 MPa),each sample is saturated with NaCl solution of a certain salinity,and then we measure resistivity and dielectric constant of these cores.Through the analysis of the experimental data,it is found that in the range of frequency of4Hz^5 MHz,for either the sandstone or limestone,the resistivity and dielectric constant of them decrease with the frequency increasing,but under the same conditions,the frequency dispersion of permittivity is more obvious than that of the resistivity;that the dispersion degree of resistivity and permittivity of cores is not the same at different frequency ranges.There is a relative higher frequency dispersion in low-frequency(<100kHz),and lower frequency dispersion in high-frequency(>100kHz).Based on the experimental results,a novel formula to calculate water saturation of rocks is established with permittivity.Comparing with traditional litho-electric experiment,the method is more concise,and we do not need to measure rockcementation index,the saturation increasing coefficient,formation factor and other related parameters of Archie formula.Through the core of the permittivity of rock,water saturation can be calculated directly.This method not only simplifies the calculation,also eliminates the experimental errors of so much parameters from many different measurements.
出处
《测井技术》
CAS
CSCD
2015年第6期679-684,共6页
Well Logging Technology
基金
中国石油集团科技部"十二五"研究项目测井前沿技术与应用基础研究子课题全谱测井关键技术研究(编号2014A-3912)
关键词
岩石物理实验
电阻率
电容率
频散
含水饱和度
petrophysical experiment
resistivity
permittivity
frequency dispersion
saturation
