辽河凹陷滩海区X潜山历经多期次构造改造作用,地层厚度与地层产状稳定性差,岩相岩性复杂多样,岩性识别困难。X潜山太古界地层岩性为一套变质岩体系,主要发育有混合花岗岩、混合片麻岩、片麻岩和角闪岩。为了对变质岩类岩性进行准确识别,在对变质岩测井响应机理分析,优选并构造出变质岩敏感测井响应参数的基础上,采用图版法、决策树(Decision Tree,DT)模型及支持向量机(A Library for Support Vector Machine,LIBSVM)模型三种岩性识别方法对研究区单井进行了岩性识别。经与钻井取心和录井分析得出的实际岩性对比结果表明,决策树模型与支持向量机模型识别符合率均高于图版法,为该区变质岩岩性准确识别提供了可行的方法。
The conductance of pyrite-bearing laminated and dispersed shaly sands is not well understood and resistivity models for pyrite-bearing shaly sands are nonexistent. Thus, we first synthesize clean pyrite-matrix samples, and quartz-matrix samples with variable laminated shale, dispersed shale, and pyrite content and then perform petrophysics experiments to assess the effect of pyrite content on the conductivity of pyrite-bearing shaly sands. Second, based on the differences in conductivity and conduction pathways and geometries because of the variable composition of the pyrite-bearing laminated and dispersed shaly sands, we divide the shaly sands into their components, i.e., laminated shale, quartz grains, pyrite grains, hydrocarbon, dispersed shale, microscopic capillary water, and mobile water. A generalized resistivity model is proposed to describe the conductivity of pyrite- bearing laminated and dispersed shaly sands, based on the combined conductivity differential equation and generalized Archie equation. In the generalized resistivity model, the conductivity differential equation is used to describe the conductivity of dispersed inclusions in a host, whereas the generalized Archie equation is used to describe the conductivity of two conducting phases. Moreover, parallel conductance theory is used to describe the conductivity of dispersed shaly sands and laminated shale. Theoretical analysis suggests that the proposed model satisfies the physical constraints and the model and experimental results agree. The resistivity and resistivity index of shaly sands decrease with increasing conductivity and pyrite. Finally, the accuracy of the resistivity model is assessed based on experimental data from 46 synthetic core samples with different oil saturation. The model can describe the conductivity of clean pyrite-matrix samples, and quartz-matrix samples with different volumes of laminated shale, dispersed shale, and pyrite. An accurate saturation model of pyrite-bearing laminated and dispersed shaly sands is thus obt
