Design And Simulation On Rigid-Flexible Walking Mechanism Of Downhole Robot For Oil Wells

This paper raises a theory that the direction of donwhole tractor’s development is to be smart as a donwhole robot, and presents a walking program of downhole robot which has rigid-flexible walking mechanisms. The walking mechanism uses a flexible spring lamination coupling with two rigid links instead rigid links which is used in the traditional stretch downhole tractor, and it can possesses more adaptability in the downhole environment than the traditional downhole tractor.The main content of this paper is the structure design and parameter design. The static model of the flexible spring lamination is established by the 2R pseudo rigid model and then the relation equation between force and deformation as well as the relation equation between the driving force and the contact force are obtained. The adaptability of the walking mechanism for many kinds of downhole environments is researched and simulated through RecurDyn. At last, the experimental prototype of the donwhole robot is tested to confirm the passing-ability whose experimental results are compared with the simulation results.This paper introduces how to import the model, add constraint, create contacts, and create drivers in the RecurDyn. It makes the simulation about the walking mechanism’s motion with constraint of the casing or not. That can verify the 2R pseudo rigid model of the flexible spring sheet, and makes simulations about the walking mechanism of the downhole robot to verify it’s suitability in necking, bulge and dislocation which are often happened in the oil well., and gets the suitability of the downhole robot which is in the size of this paper introduced.At the last of the paper, it introduces the experimental devices of contact force of walking mechanism and the passing-ability of the downhole robot, and makes some experiments with them. Through those experiments, we make sure that the robot can give enough force in the general oil well and the walking mechanism can give enough contact force as well. That verifies the model of simulation can reflect the true situation of the system of downhole robot of oil well.