Design Of Excitation Signal Source For3D Induction Logging

3D induction logging is a modern logging technology. Induction logging, as theconventional logging method, is one of the main methods in resistance measuring. Theresistivity of the oil and gas formations are anisotropy. which is just the characteirstic thedesign of3D induction logging bases on. The3D induction instrument can measure of thevertical and hoirzontal formation resistivity which represent the electircal anisotropv of theformation, dip angle, azimuth and the interface position of the layer in horizontal wells, candefine the “low resistivity reservoir in thin interaction layers, can detect the angles of faultsand layers, can be applied to the measurement of highly deviated and even hoirzontal wells.And that is the developing trend of the3D induction logging nowadays. However themeasurement theory, instrument design and data processing and interpretation are extremelycomplicated. As the problem needs to be solved piling up. the design of signal generator andprocessing method of3D induction logging in this paper provide theoretical guidance andhave theoretical and practical significance.The excitation signal source of3D induction logging is developed in this paper. Firstly, thebasic theory of3D induction logging is discussed. and the project design is brought out?Secondly’ the hardware system including main control module. DDS waveform generatingmodule, power amplifier module and power collecting module of the excitation signal sourceof3D induction is designed basing on ADSP21992. Also, the working pirnciples of eachmodule are expressed. Basing on module design, the software system achieves the design ofmain control program, control command and AD collecting system. Each part of the softwaresystem is analyzed, and provides block diagrams. Finally^the signal generating board is testedwith laboratory equipment, and the design of the excitation signal source of3D inductionlogging is verified.