Research On Acquisition Circuit Of The Seismoelectric Logging Experimental System

Electronic technology has been widely used in the field of oil exploitation,which has promoted the development of petroleum exploration and mining technology. Seismoelectric effect is a mechanism of the interaction between mechanical wave and electromagnetic wave in fluid medium. This mechanism provides a special electrical logging method and has some advantages over other logging methods. Seismoelectric logging method can detect many properties of formation that contains fluid, such as permeability, conductivity, porosity, well liquid ion concentration and so on.The research on seismoelectric logging has been started since the 90s of last century, but logging instrument based on this method is still not available due to slow progress in engineering applications. The research content of this thesis is the seismoelectric signal acquisition system, which is the key component of the seismoelectric logging instrument. In engineering application,three problems need to be solved: Firstly, seismic signal acquisition system should be able to collect the weak seismic signal; Secondly, the seismoelectric signal acquisition system needs distributed measurement points to collect the seismoelectric signals of different position in the underground; Thirdly, the seismoelectric signal acquisition system needs to transfer a large amount of data generated in the logging process to the host computer in real time.In view of the above three problems, this thesis presents a design scheme of seismoelectric signal acquisition system. The system is based on SPI bus, which includes two parts: data acquisition boards and control board. The data acquisition boards are distributed at each measuring point, which are used to collect the seismoelectric signals of different depths. The control board transfers the data collected by the data acquisition board to the host computer in real time.After the debugging of the system, the function of the system is tested in the simulation environment.In this thesis, the seismoelectric signal acquisition system has 8 measuring points, which are used to collect the seismoelectric signals in different positions of the mine. The system can transfer all the data generated in the logging process to the host computer in real time. The passband of the system is 9.7kHz?37kHz,and the range of the seismoelectric signal can be collected is 0?16.7?V. At the same time,due to the use of SPI bus structure, the number of test points can be configured according to the actual needs. It has been proved that the seismoelectric signal acquisition system designed in this thesis meets the established design goals.The system in this theis lays a foundation for the development of seismoelectric logging tools.