Research On Rock Resistivity Measurement System Based On Embedded Platform

Formation resistivity is an important parameter for well logging interpretation and oil and gas reservoir evaluation.With the gradual deepening of fine oil and gas exploration,conglomerate formations,thin sand and mudstone interaction layers,tight formations and other anisotropic reservoirs have become one of the important research directions of the petroleum industry today.The relationship between tensor resistivity and oil and gas evaluation parameters is particularly important to provide a theoretical basis for oil and gas reservoir evaluation.This paper completes the design and implementation of a rock tensor resistivity measurement system based on an embedded platform.The main research content includes the following parts.The first part uses COMSOL finite element numerical simulation software to study the numerical calculation method of rock resistivity.Based on the actual measured rock samples,three physical models of uniform medium formation model,vertical interlayer model and dip angle interlayer model are established.The technique of meshing and the influence of the interlayer under different resistivity on the overall resistivity of the rock sample are studied to lay a theoretical foundation for anisotropic measurement and analysis.The second part is the measurement scheme and the circuit design of the rock resistivity measurement system with S3C2440 A as the core.The traditional four-electrode resistivity measurement method is improved,and a method of measuring 9 components of rock sample tensor resistivity is proposed,and the design of the ring-shaped measurement electrode is used to effectively reduce the influence caused by electrode polarization;the circuit design includes Power circuit,conditioning filter circuit,A / D conversion circuit,serial communication circuit,system Flash storage circuit,and complete the production of hardware modules.The third part is the design and implementation of the system software platform.Build the embedded cross-compilation environment of the system,complete the transplantation of the kernel bootloader Bootloader,the cutting and compilation of the embedded Linux operating system,the production of the root file system and the transplantation of the SQLite database.Data correction method of multiplication principle;to improve the accuracy of the system.Finally,use the graphical interface development software Qt to make the hostcomputer software.The fourth part uses the designed and manufactured rock resistivity measurement system to conduct the actual rock sample resistivity measurement experiment.The comparison and analysis of the experimental data with the COMSOL numerical simulation results show that the overall change laws of the two are consistent,but because the measurement experimental environment belongs to non-ideal conditions,there are some differences between the actual measurement data and the numerical results under ideal conditions.The rock resistivity measurement system basically meets the design requirements.