The Function Modularization Research Of The Logging Instrument In Oil Field

In this article, the reseach work is focused on design of modular instrument and a communication interface for the junction of logging instrument according to the requirements of production logging in oil field, so that the problems can be solved about the measurement of multiple parameters of logging instrument and the expansion of logging functions according to different needs. In this article, the main contents are as follows:1. Based on modular design idea of the instrument, define the instrument which can complete the acquisition or control function in accordance with uniform interface protocol as modular instrument. First design two modular instrument including the storage downhole camera and pressure meter. Then design CAN and RS232bi-directional communication interface which regards CAN bus as transport, Modbus as transport protocol to achieve the design of modular combination instrument2. By using CAN bus data transmission scheme which has fast transfer rate and large bus articulated node number, first develop hardware circuit of the CAN and RS232bi-directional communication interface which regards microcontroller PIC16F876A as the core chip. Secondly, design Modbus protocol which is suitable for data transmission to make the bid-directional data transmission between the serial port and CAN bus network stable.3.To complete the design of storage downhole camera, first build camera circuit, video storage circuit and other hardware circuits which regard S3C6410as the core chip. Then finish the software design of image acquisition making use of V4L2framework. Finally, realize H.264video encoding and SD card storage using S3C6410internal integrated hardware encoder under Linux system.4. First build signal acquisition circuit, amplification circuit, data storage circuit and other high temperature hardware circuits which regard microcontroller PIC16F73as the core controller. Then design the PCB board and the shell of the pressure meter. By using the method of acquiring instrument temperature to compensate the temperature drift, develop a storage pressure meter, whose pressure measurement ranges from0to60MPa, temperature measurement ranges from0to125℃and measurement accuracy is±0.2%FS and±1℃.5.First conduct experiments of heat-resistant, temperature drift and performance testing of the pressure meter’s circuit devices indoors. Then conduct experiments to test the effect of video acquisition of the storage downhole camera outdoor oil well. Finally, make use of the method of communicating with the host computer to verify the communication interface. Experimental results show that each module can work properly, the acquisition range and accuracy of the pressure meter can meet the requirements.