Digital Circuits Of High Resolution Induction Logging Tool

Along with the oil field exploration and development of the in-depth, large ready-high sandstone reservoir has become increasingly difficult to find, both major oil field in the latter part of the development, the main force oil layer has seen water already all round , the development of thin reservoir to increase reserves can not be ignored as the main way.Since adopt the full symmetry coil and new data filtering synthesis methods, high resolution induction logging tool have the character that the depth of investigation is bigger, the vertical resolution is higher, and measured conductivity is closer to the real situation of formation, the reliable well logging data have provided to patition and identify the thin beds. The digital circuit is the core of high resolution induction logging tool, it produces the sequence controlling signals, and control the technological process of high resolution induction logging tool, and digitize the signal from the analog circuit in high-accuracy analog to digital conversion circuit, then encoded and uploaded it by telemetry circuit. Introduces the primary principles, circuital formation and the technological process working of high resolution induction logging tool. Study the data collection control circuit and telemetry circuit detailedly. The key circuit of the data collection control circuit is sequence control and high-accuracy analog to digital conversion. The signal from the analog circuit is digitize in high-accuracy analog to digital conversion circuit, an reference signal is led into to improve the measurement accuracy, the high-accuracy analog to digital conversion circuit counted this two signals at the same time, this has diminished error in instrument data digitization process, and improved measurement accuracy successfully. The telemetry circuit is a command-response system, it use the Manchester code. The command is downloaded and decoded, the data is encode and upload in this circuit. Introduces the primary principles and the function module circuital of telemetry circuit. Analyzes the field logging data and application results, finally give the conclusion that the performance of this tool is reliable and its well logging data is help for identify thin beds.