Development Of Measuring Instrument On Rock And Ore Materials Porosity

With the rapid development of China's modernization construction, the growing problem of energy shortage is becoming apparent. Especially, Oil and gas resources in occupy important positions the energy sector. The oil-gas exploration has become relates the national livelihood, the national security important matter is also suspends at scouts' difficult problem. The reservoir has been developed the vast majority of sedimentary rocks such as sandstone and carbonate. Sandstone porosity depends mainly as storage and seepage paths, carbonate reservoir are mostly with double porosity medium and reservoir by the pore, treat the fractured rock permeability as channels. Master reservoir porosity and permeability is the base of understanding of reservoir storage conditions, measuring up main layer, the boundary between effective thickness and interlayer, and estimate reserves. So, the porosity is the fundamental constant which the oil field exploration and the development must grasp. In one word, it is essential to develop an intelligent rock and ore porosity measurement.This design has adopted advanced sensor, chip microprocessor techniques and embedded system. In this way, it has solved the problem of the measurement of irregularly shaped solid. And this design has the advantages of high degree of intelligential, measure accurately, convenient operation, showing the degree of porosity automatically at real time and data statistics.This thesis choose three projects to illustrate the main idea, and in the end we choose project 3; Using the USB communication interface and integrated amplifiers A / D converter.As for the porosity of the system hardware, the thesis describes the microcontroller, A / D converter, LCD selection and design, detailing the A / D converter and the microcontroller interface and principle and AD7706 low-pass filter and notch treatment.In software system design, the thesis describes the transplant of UC / OS-II in the MSP430, and gives the porosity measuring instrument software design seven tasks (self-task, the task menu, measurement tasks, data query tasks, sample statistics, system calibration task and Data transfer )We have debugged ADC AD7706, SB equipment modules FT245BL and the operating system and analyzed the results. To test the accuracy of measuring instrument, we have had the test according the actual measurement of several samples of rocks and minerals in a laboratory environment (temperature 20℃, relative humidity 50%). The results show that in Table 1, porosity measurement accuracy better than 0.5%, standard deviation less than 0.2%, the relative error is less than 1%, good reproducibility. In Table 2, for different samples, the porosity measurement accuracy better than 0.5%, the relative error is less than 2%, the instrument is stable and normal, but when the measured sample porosity is small, the error is larger, which should caused by the non-linear sensor, it can be reduced by software algorithms. The overall effects can meet the preset specifications.At the end of this thesis, I have summarized the thesis and some problems in the design.