New Telemetry Logging Tool Interface Circuit Design

Telemetry logging instrument (TLI) serves important function in computerized production logging system.It is used to uplink measure data of downhole such as temperature, pressure to surface instructions. Thinking the traditional telemetry tools' many barriers, great power waste on tool bus and inability to connect to the quart pressure transducer, a new kind of TLI have been developed in this paper.The design theory and data transmition method of the new TLI are explained in this paper, but interface design of the new TLI take a stress. For design of pressure measure interface, a new way is showed which uses quart pressure transducer to measure pressure and uses FPGA to handle output data of quart pressure transducer, it has enhance precision of pressure measure greatly. Again, some special means are take to deal with flux and other parameter.In the last, a new method is discussed in this paper, which could use FPGA to realize downhole system of data collection and management replace telemetry gage and measure interface circuit, this method make the whole TLI composed of FPGA, sensor circuit and other circuit, instead of MCU and complex exterior circuit, so bring briefness, high reliability and easy maintenance to the new TLI.Simulation test has proved that the design method of new TLI .is feasible, it is a betterment to conventional logging instrument.