Resistivity Logging While Drilling Medium Frequency Ensemble And Transceiver System Design And Realization Of The Circuit

LWD (Logging While Drilling) is an advanced logging techniques, it can achieve logging while drilling. Generally, we can olny put the wireline logging tool into the borehole after drilling completion. Wireline logging method is no longer applicable in the horizontal wells or the highly deviated well that its slope is over65degrees LWD tools are placed on the drill bit, it can obtain stratigraphic information while drilling, no matter what wells, especially horizontal wells, can be logging. The LWD data are otain under the condition that the strata is just-opened, the borehole is not yet apparent collapse and the mud on the formation penetrated very shallow even can be ignored. So, the LWD data are closest to the original strata and more conducive to estimate the percent of petroleum in complex wells and complex formation. LWD has become very popular for many oil service companies from all over the word.The LWD technology in our country is more backward than abroad. Although a few LWD systems are introduced from foreign country, it is far from meeting the needs of the actual engineering service and overseas competition. Therefore, the development of logging instrument using LWD which has independent intellectual property right has become an imminent task.LWD tool works at high temperature, high pressure, severe vibration and harsh environments. LWD system requires high reliability and it is extremely difficult to develop. A kind of frequency synthesizer and transceiver circuit system is designed in this paper which can measure and extract the relevant parameters of the formation. The circuit include:the generation of transmitting signal, local oscillator signal and sampling clock signal; power amplification of the transmitted signal; amplification, acquisition and procesing of the received signal; the communication between the different circuits boards or between the circuit and the ground system. The functions and performance of the instrument is determined by analysing its principle and structure. And a reasonable and viable solution is developed, which the TMS320F2810DSP controller is used as the core of the project. The related application software is developed as well. At last by system testing the design is proved feasible, which laied a solid foundation for further development of the logging instrument using with drilling azimuth resistively technology.