Design And Implementation Of Simulated Downhole Logging Instrument Based On DSP

With the rapid development of well logging technology, a lot of new well logging instrument have been proposed, the combination of the downhole logging instrument function is rapidly increased, and the amount of well logging data is becoming larger and larger. Additionally, coupled with the hostile operating environment on well site, it put forward higher requirements for the development of a logging data transmission system with high reliability, good stability, wide transmission bandwidth and good real –time performance.In the process of the research and development of the logging system, detecting ground system and telemetry system usually requires mounting the downhole logging instrument. But there are many types of downhole logging instruments with different principle which are mounted complicatedly that resulted in low efficiency. Therefore, it is needful urgently to design a device which can simulate many different kinds of downhole logging instrument for system detection and commissioning.In view of this situation, combining embedded technology with network logging, this thesis designs and implements an embedded simulated downhole logging instrument with DSP F28335 and FPGA as the main framework. This simulated instrument is mainly used to simulate the functions of different downhole logging instrument for performance test of the logging data transmission system. Furthermore, it could be used for functional test of new logging instrument on earlier stage of development.This thesis proposes a data acquisition method based on time-deep-driven to try to simulate the logs as closely as possible. Moreover, once the logging instrument is designed and turned over to production, its interface, transport format and other parameters are fixed. In response to this situation, the thesis uses several commonly used logging data transfer bus including industrial Ethernet, CAN, RS-485 to maximally simulate logging instrument based on different bus.This thesis elaborates the design thought and implementation process of the simulated downhole logging instrument, including solution design, software and hardware implementation, test platform construction and result analysis, the main work of this thesis are as follows.1. This thesis researches and analyzes the functional requirements of simulated downhole logging instrument, then formulates a solution of the simulated downhole logging instrument based on F28335.2. This thesis uses EDA tools such as Or CAD16.3 and PADS2007 for schematic design, PCB drawing, and completes hardware platform of simulated downhole logging instrument. In order to work in the high temperature environment, all chips are high temperature industrial level model.3. This thesis writes the underlying driver code and application code, transplants SD driver and FATFS file system, designs the solutions to three bus interfaces.4. This thesis constructs the test platform based on the existing set of logging data transmission system, then conducts related tests and studies scheduling algorithm.Indicating by the field test, the simulated downhole logging instrument has reached the anticipated demand, and provides a reference for simulated logging and test.