Reliability Design And Experimental Research On The Hydraulic Drive System Of Oil Well Logging Instrument Mechanical Arm

In oilfield exploration and development process, well logging is an importantmeans to identify and evaluate oil and gas reservoir. It is also an important means tosolve a series of geological problems. It can directly provide the information and data ofpetroleum geology and engineering and technical personnel. Well logging tool isdesigned to be able to drive the mechanical arm. With mechanical arm stick to well wall,the instrument in the well logging tools can measure parameters in the working depth.The performance of the logging tools used in the logging process is a precondition toensure the accuracy and validity of logging information and data. The drive system ofthe mechanical arms is an important component to ensure the effectiveness of loggingparameters, and it is also a restricting factor of logging depth. Because of foreign policyof limiting logging equipment exportation,logging tool drives with the capacity of hightemperature in China are weak and the function is simple. So independent research anddevelop highly reliable drive system of well logging tools which working under deepwell are particularly important.In this thesis, firstly, the design difficulties of hydraulic system workingenvironment was analyzed, which include high temperature, high pressure, vibration,shock and mud, low leakage, miniaturization. A design method of the closed hydraulicsystem with pressure balance device was analyzed. An AMESim Simulation of thehydraulic system was conducted, which proves that the hydraulic system design methodis feasible.Secondly, under the guidance of reliability design, reliability of the hydraulic drivesystem was predicted and analyzed. Weak links in the system was analyzed, and then animprovement plan was proposed. Key structural components such as manifoldcomponent，hydraulic cylinder，balance piston were designed. In addition，the effect ofthermal stress produced by environmental temperature on the system structure wasanalyzed.At last, an experiment program including environmental stress experiment andreliability testing experiment is proposed for the early development stage. With theprocess of “design-experiment-improvement-experiment”, flaws in the design processwere found and then improved. Ground load simulation experiment shows that theexperimental prototype meets the requirements of technical indicators and systemreliability for development stage, which lay foundation for the well logging experiment.