Development And Application Of Digital Induction Logging Tool

With the constant development of exploration and exploitation of the oil and gas fields,the increasing demand for well logging technology comes from discovery and development of complex oil and gas fields,especially subtle oil and gas reservoirs.In terms of performance of electronic devices,technical indicators,measurement accuracy and ability to combinate with new logging platform,early induction logging instrument can not adapt to the needs of oilfield production.Based on the Electromagnetic Induction principle,digital induction logging tool made by the current advanced electronic technology and devices can solve the above problems.With the unified data acquisition circuit and signal processing technology,the instrument can complete stratigraphic information collection and signal control,simplify the circuit,improve the reliability and measurement accuracy.The main content of study includes circuit design,the design of coil system and research of communication.With integrated circuit,modular design and the thick film technology,digital induction lgging tool can prevent signal from interference of transmission circuit.The tool can put up with 175? and 140 mpa.In the 0.2~100?·m formation,the measurement accuracy can reach ±2mS/m.Designed on the base of the geometrical factor theory,coil syetem can improve the detection characteristic of instrument.Because of using the standard CAN Bus,the tool can communicate fast.Its rate is 1Mbps.The logging speed can reach 1500 m/h,improving the tool's logging combination ability.Using magnetic separation technology,communication circuit guarantee the independence of each instrument.The testing results from the standard wells and production wells located in different regions show that the tool is reliable and stable.It can complete well logging task with high quality in the bad environment,such as high temperature and high pressure.The data of tool acquired meet the quality control standards.The tool has a very good consistency compared with some similar tools at home.Moreover,this paper has also carried out research about the application in reservoir evaluation,identification of oil and gas layer and so on.All these examples show that this tool can solve complex reservoir problems,reduce the discovery cost of oil and gas fields and enhance the efficiency of exploration.The tool will play an important role in the process of exploration and exploitation of oil and gas fields,and have a broad application prospects.