Research On Digital Signal Acquisition And Software Implementation Of Deep-hole X-ray Fluorescence Well Logging

With the development of national socio-economic,the rigid demand for resources continues to increase.However,a lage number of surface and shallow mines have been gradually exploited exhausted to become crisis mines.Using new equipments and technologies to exploit the deep second space resources have been becomed a new strategic target of our country’s resource exploration.The X-ray fluorescence logging technology can be used to well sites in the field obtain real-time drilling of ore grade and ore reserves of stratum thickness and line,which has the remarkable advantages such as efficient,convenient and fast.In deep resource exploration,it is one of the current difficult problems how to apply the X-ray fluorescence well logging in deep high temperature environment.This thesis research topic originated from the sub-project ‘X-ray fluorescence logging research and development’(ZDYZ2012-1-07-01-03-02)of the major national scientific research and equipment development project ‘Core equipment research and development in deep resource exploration’.For the deep exploration of mineral resources under high temperature environment,the existing X-ray detector cannot operate normally,traditional analog circuits affected by temperature,energy spectrum measurements are not accurate,as well as the lack of systematized network structure of the existing X-ray fluorescence logging software,the main research is as follows:1.The design of excitation detection device of the deep-hole X-ray fluorescence logging.The design of the overall structure of the pipe probe and the excitation detection device.Selection and demonstration of the material for the shell of the probe for high temperature resistance and tensile strength.The selection of excitation source and Xray detector with the principle of low power consumption and less heat dissipation.Designing the probe parts active cooling device of the core components of the instruments,and selecting relevant heat insulation,heat conduction and refrigeration materials.2.The design of digital circuit system of deep-hole X-ray fluorescence logging under high temperature environment.Research on the selection of core components of digital circuits based on high temperature conditions.Design of the resistant circuit system under high temperature,includes analog front-end,digital multi-channel pulse amplitude analyzer,communication circuit and power circuit,etc.Making tests for the main circuit board in the simulated high temperature environment.The digital multi-channel pulse amplitude analyzer is be designed and implemented based on FPGA.Reaearch on the filter algorithm in the processing of nuclear signal,realization of a cusp-like algorithm based on flattop,and carry out the corresponding test experiment.3.Development of the X-ray fluorescence logging software platform based on DOA.The overall design of X-ray fluorescence logging software platform based on DOA.Defining the meta-data standard in data registration center and the markup language XFLML of the meta-data collection,design and implement the core functional modules;design the mechanism of data exchange for software platform;design the application cell library(DAUs)structure of the X-ray fluorescence logging software platform,design and implement the core function;design the security mechanism of platform operation.4.Performance test of deep-hole X-ray fluorescence logging.Using geological samples as the measuring object,the energy resolution,relative error and stability index of the instrument are tested.Tested the stability of the probe parts’ active cooling device of the core components of the instruments in high temperature environment;made the comparison tests of samples respectively at room temperature and high temperature environment;made the field tests of the instrument respectively in the test well and exploratory well.The main innovative achievements of this thesis are as follows:1.A new type of X-ray fluorescence logging excitation-detecting device under high temperature environment is be designed and successfully developed,A self-designed active cooling device is used to realize refrigeration and heat dissipation of the X-ray detector of fluorescence logging,solving the problem of normal stability of deep-hole X-ray fluorescence logging probe in high temperature environment.2.Design and develop a high temperature resistant digital X-ray fluorescence logging instrument circuit system,and it is implements digital acquisition and analysis of logging signals in high temperature environment.It is has solved the problems of the existing X-ray fluorescence logging circuit under the high temperature condition,such as the temperature is influenced greatly,the filtering forming effect is poor,and the ballistic loss is existing and so on.3.Design and implementation an X-ray fluorescence logging software platform architecture based on DOA,it solved the problems of the existing software of X-ray fluorescence logging which cannot realize the comprehensive management of log data,multi well multi point,asynchronous measurement,network synchronization and so on.By measuring the geological samples,the instrument resolution is 3.25%,the error values of the measurement is between-8%~14% and the spectral drift is <=2 channel.It proves that the instrument has good precision and stability.In the process of development,the reliability test of the refrigerating device of the probe and the stability tests of circuit board is be carried out in a simulated high temperature environment.The comparison tests of the samples carried out in room temperature and in the simulated environment of high temperature and so on,it proves that the instrument can work stably in high temperature environment.On this basis,the field measurement comparison tests is be carried out in the experimental well in Chongqing Geological Instrument Factory and in a regional geological #Z201 exploration well of Xinjiang.It was verified the X-ray fluorescence logging instrument which developed by this thesis can achieve the qualitative and quantitative measurement in the actual drilling.It is proves that the instrument can be applied to deep resource exploration activities.The results of this thesis will provide key technical support of deep-hole X-ray fluorescence logging for deep resource exploration in our country,it has important economic and scientific significance.