Design And Simulation Of Flexible Expanding Brake For Downhole Tractor Experiment Device

With the growing number of oil wells in recent years, there are many oil wells faced with the problems of maintenance and the oil pipeline detection every year, which need to delivery the maintenance of equipments or detective equipment to the specified location. There are mainly two feed-in of downhole instruments, one is cable into and another is coiled tubing into. The vertical well depends mainly on the cable to sent equipments, which relies on the instrument’s own gravity to pass the instrument down to the designated location. The large displacement well and horizontal well mainly relies on lower flexible tube to sent the instrument to the specified location by coiled tubing. But the ground facilities of the way needs is complex and its operation cost is high.This article puts forward a design scheme of flexible expanding brake type downhole tractor by the comparative analysis of various forms under the condition of drawing on and assimilating the existing downhole tractor technology at home and abroad. The scheme adopts the modular design that divided into the centralizer module, expanding brake module and walking module. Expanding brake module use the design of the flexible arm, making the flexible arm contact with the borehole wall fully, provide enough expansion force and adapt to the complex underground environment very well. On the basis, it analyzes the function principle of downhole tractor and state the work process. At the same time, it designs overall structure of downhole tractor and the hydraulic system of the device detailed. What’s more, it uses SolidWorks software 3 d entity modeling of downhole tractor to complete the assembly.The article adopts the method of finite element analysis, using the SolidWorks Simulation to emulate the flexible arm of expanding brake mechanism. According to the result of the simulation experiment, it designs a reasonable size of flexible arm. Not only that,it is also simulate the flexible arm’s stretching process, the obstacle-surmounting course, the swelling process and the contact stress for flexible arm of expanding brake mechanism in Ansys. It uses the SolidWorks Simulation for the working process of the centering mechanism of flexible arm and the simulation of flexible arm’s obstacle ability under the condition of embossment and reducing. Finally, the analysis of flexible arm fatigue by using Simulation can validate the reliability of the flexible arm.