过套管电阻率测井仪机械系统优化设计

Optimum Design of Mechanical System for Casing Resistivity Logging Tool

为了解决以往过套管地层电阻率测井仪器在生产测井中的局限性,通过对电阻率测井原理以及技术特点的研究,设计新一代测井仪机械系统。仪器利用四连杆式机械推靠装置,通过建立具有最大测井直径和最小需求驱动力推靠装置的力学与优化设计模型,并结合复合形法有效地对推靠装置进行了优化设计,实现电极探针与套管内壁的良好接触和脱离,保证了探针采集信号的准确性和稳定性;最后,通过对仪器的性能参数、耐温耐压性能等进行了实际测试,验证仪器设计与分析的合理性。

In order to solve the previous casing formation resistivity logging instrument of logging limitation,through the study of the resistivity logging principle and technology characteristics,combining with the logging instrument design experience of domestic and overseas,we research and design a new generation instrument.In the process of the detailed design and analysis of the pushing assembly’s main structure,an electrode assembly is designed,which has the advantages of easy installation,disassembly,replacement and insulation,and has the characteristic that electrode can be withdrawn in the fault state.At the same time,the mechanics and optimization design models of pushing device are established,with the maximum logging diameter and minimum demand driving force,and the pushing device is optimized effectively based on complex method.In addition,hydraulic transmission system is designed on the premise that the pushing assembly’s working condition is analyzed in detail,which has the advantages of simple structure,complete function,pressure balance,position indicator and double safety overflow.And it can be simulated and analyzed with AMESim.Finally,the main performance parameters of the prototype are practically tested,including the force loaded by measuring electrode on casing,insulation among measuring electrodes,closing and opening consuming time of pushing device and temperature and pressure resistant performance of pushing assembly.As a result of the test,pushing assembly’s defect is discovered and design is improved.At the same time,the rationality of design and analysis of pushing assembly are fully validated by the test.