混合泥质砂岩粘土包裹颗粒电阻率模型

砂岩油气层的低电阻率可能是由于富含分散粘土、层状泥质、高束缚水、高矿化度水、骨架导电等因素综合引起的，因此有必要建立一种适用于骨架导电且同时含分散粘土和层状泥质砂岩解释的通用电阻率模型，以提高复杂泥质砂岩储层含水饱和度的解释精度。基于层状泥质与分散粘土砂岩并联导电的观点，而分散粘土砂岩的导电可用粘土包裹颗粒电阻率模型进行描述,从而建立了考虑分散粘土和层状泥质同时存在的含油气泥质砂岩粘土包裹颗粒通用电阻率模型；通过2组分散泥质砂岩岩样实验测量数据和1组层状泥质砂岩测井资料的测试,表明该模型既适用于分散粘土砂岩地层解释又适用于层状泥质砂岩地层解释；利用建立的混合泥质砂岩粘土包裹颗粒电阻率模型，对海拉尔盆地高泥地区的苏1、苏3井进行处理，并将模型计算的含水饱和度与试油结果进行对比，结果表明模型计算的含水饱和度是合理的，故本模型适用于含油气复杂泥质砂岩地层解释。

A GENERALIZED CLAY COATING GRAIN RESISTIVITY MODEL FOR LAMINATED AND DISPERSED SHALY SAND

Low resistivity of hydrocarbon bearing sand reservoirs may be caused by several coexisted factors, such as rich dispersed clay, laminated shale, high-irreducible water saturation, high formation water salinity, and conductive grains. Therefore, a generalized resistivity model that takes both conductive grain and interpretation of dispersed clay and laminated shaly sand into consideration is needed to more accurately interpret water saturation of complex shaly sand reservoirs. Based on the concept of parallel conductance of laminated shale and dispersed shaly sand, and considering that clay coating grain resistivity model can be used to describe the conductance of dispersed shaly sand, this paper presents a generalized clay coating grain resistivity model for oil/gas-bearing shaly sand containing both dispersed clay and laminated shale. Verification with the experimental data of dispersed shaly sand samples and well logging data in laminated shaly sands shows that this model can be applied to both dispersed shaly sands and laminated shaly sands. The model has been used in Su-1 and Su-3 wells with high shale content in the Haila'er Basin. Comparison with formation testing results shows that the calculated water saturation is reasonable, so the model proposed in the paper is applicable to interpretation of complex hydrocarbon-bearing shaly sands.