Research On Mechanism Of Wireline Tractor

Oil is a fundamental energy that sustains the development of industry and economy. With the develop of oil exploitation technology, the horizontal oil wells develop gradually as an important way to raise oil production. However, thelogging of horizontal oil well is very difficult. In vertical wells, and in those wells having only a few degrees of deviation, the axial thrust necessary to convey logging tools, is supplied by gravity. In these situations, the downward thrust applied to the string is equal to the weight of the string, minus any buoyancy force due to fluid downhole. The situation is more complex in highly deviated and horizontal wells.In horizontal wells the string will not move forward further without the input of additional forward axial thrust.This propulsion machines, often referred to as " Wireline Tractor". Most conventional tractors can be loosely grouped into two groups, namely, wheeled-powered and crawlers, this paper puts forward a type of Wheeled Wireline Tractor, which consist of a tubular housing and powered wheels that project from the housing and are designed to engage the inner walls of the casing or open hole, which operating diameter is 114.3mm-193.68mm. The over-obstacle mechanism for Wheeled Wireline Tractor include driving unit and flexible supporting unit. The robot has the adaptability to the change of well diameters, it can cross obstacles and convey the logging tools to the destination.The main content and contributions of this thesis are summarized as follows:On the basis of collecting and mastering a large amount of documents and references on Wireline Tractor,the differences and characters of existing Wireline Tractor and in-pipe robot locomotion modes are analyzed in detail.Considering the demands of horizontal oil wells environment and the exact locomotion mode,which is more suitable for horizontal oil wells environment is selected through comprehensive comparison,and proposed the related new locomotion mechanism of Wireline Tractor.On the basis of the selected locomotion mode and the proposed locomotion mechanism,some topics of in-pipe kinetic character of Wireline Tractor are analyzed and discussed deeply,including its in-pipe moving resistant, spatial motion equation, radial adjusting,capability over obstacle.The 3-D simulation model of the Wireline Tractor is designed by Pro/E, This paper uses ADAMS simulation technology deal with the problem of dynamics and kinematics analysis and proved its feasibility of over-obstacle.Although the major research project has been completed in this thesis,there still exists much research works to be done to make the system suitable for practical application. At the end of this thesis,the author makes a summary of the main research works and contributions,and give some suggests for further research.