Cased Hole Logging Technology Application Research In Deep-well Formation Detection System

For a long time, electric well-logging is always an important branch of stratum exploration technology. Nowadays, minable hydrocarbon resource in the world is less and less. Plenty of oil wells have been mining for many years, and very long steel casing had been runed in them. Therefore, how to search for remanent oil layer and other deposits through steel casing? The formation resistivity measurement method through steel casing gets the unique edge in this aspect. The method, as one of electric well-logging ways, has some advantages such as comparatively mature technology and lower measurement cost. However, the method has some inherent limitation due to the limited technological condition. With the development of electronic technology, some problem of the method had been solved at the end of the last century.By researching the known measuring technologies of cased hole formation resistivity, combining with existing advanced designing experience of logging tool, using available measurement and controlling technique and related device, a set of design thought and scheme are put forward in the dissertation. The content includes the introduction about the resistivity measurement method through steel casing, the structural design of the whole system, the software and hardware design and realization and so on.A remote measurement and control system, which adopts one PC as master, multi MCUs as slaves, RS485 as the field bus, has been designed. The host computer PC is used as the main calculating and controlling device. The ground and underground measurement equipment adopted the embedded system based on AVR serial high-speed SCM in order to control cost and size effectively. Because of very long transmission distance, a kind of encoding and decoding digital transmission method are used to assure the accuracy and efficiency of data transmission. Furthermore, functional modules and data transmission method mentioned in the dissertation will provide references for the development of cased hole formation logging instrument.