Research On High-speed Data Transmission System Of Logging Cable

As a crucial part of well logging system, the data transmission system of logging cable,namely, remote transmission’s transmission rate controls the development of well loggingdevices. The researching and developing of high eiffciency data transmission system oflogging cable has become a central issue concerned by well logging technology fields, and it isalso a key step of developing domestic imaging computerizing well logging devices. Thispaper aiming at the problems of current existing data transmission of well logging cable, suchas the slow speed of data transmission, containing less information, signal attenuation and lackfidelity proposed a new high speed data transmission system of well logging based on OFDM.In terms of hardware design, this object adopt DSP and FPGA as the processing core of thesystem, TMS320C6713of Spectrum Digital and EP1C12Q240C6N of Altera as hardwareplatform to manage the designing of modem, controller bus of down-hole instrument, theinterface of down-hole instrument and electric circuit of cable drive.When it comes to software design，it analyzed the data circuit of cable remote transmissionsystem according to the main request of cable remote transmission system and the requirementof many well logging devices. And based on which it designed a data protocol that meets therequirement of all the imaging well logging devices，what’s more, it gives the realizationprocedures. Meanwhile, by using Max+plusII and CCS as programming tools it wrote themodem program, CRC examine program and DSC controller program.It shows that the high speed data transmission system of well logging can compete datauploading and order transferring, improve the transmission rate of data effectively and is worthusing through the preliminary debugging of the lab.