Design Of Push-the-bit Support Mechanism For Autonomous Downhole Drilling Device

With the development of society,people put forward higher requirements for the technical level and advanced equipment of land exploration and deep sea exploration.Especially in the exploration and development of oil and gas resources,the current exploration equipment has been difficult to meet the production needs in the era of high efficiency,resource saving,manpower reduction and intelligence.Therefore,in order to get rid of the predicament of low efficiency and high consumption of oil and gas exploration,autonomous downhole drilling device.Autonomous downhole drilling device rely on telescopic push-back drilling robots,which are more intelligent in control system,more diversified in detection means,more timeliness in detection effect,and long-term monitoring of strata.Based on the present situation at home and abroad,some research achievements have been made on the autonomous downhole drilling device.According to the application environment and drilling depth of autonomous downhole drilling device,it can be divided into onshore/deep-sea shallow drilling and sampling drilling and deep drilling.The shallow drilling and sampling drilling structure of land/sea has low research and development cost and simple structure,and has achieved significant experimental results at home and abroad,and has a relatively mature application,while the deep drilling technology of land/sea is difficult,high research cost,and still needs to be solved in the aspects of cable retracting,cuttings migration,bearing traction,support crawling and other aspects.Among them,the push and support mechanism of the drill is the foundation of autonomous walking drilling.In this paper,based on the investigation of domestic and foreign drillers and pushthe-bit support mechanism,a push-the-bit support mechanism of downhole device is designed.Through the modeling,simulation,optimization and improvement of the mechanism,the motion principle is analyzed,and the body support and attitude adjustment of the drill are theoretically realized.In the structural design,two pairs of axial staggered hydraulic cylinders are used to increase the stroke of the piston rod in the supporting structure and ensure the strength of the supporting force.In the driving mode,push the support mechanism to hydraulic power source,and design the hydraulic system dominated by solenoid valve and servo system,to ensure the reliability of the support mechanism of electronic shrinkage operation and remote operation of the maneuverability;In the mechanical analysis,the software is used to analyze the structural stress status of the push-the-bit support mechanism,and the maximum push force and bearing capacity of the mechanism under the selected material are verified to reach 40 k N.Based on reasonable structural modeling,machining and prototype trial production,the motion experiment of the push mechanism was carried out to verify the feasibility of the structural design,and the motion defects of the mechanism were found in the experiment,and the optimization scheme of adding virtual constraints was given,which provided a reference scheme for the subsequent design of push-the-bit support mechanism.In conclusion,systematic analysis,design,optimization,trial production and experiment are carried out in this paper to achieve the research objectives,which is of great significance for the follow-up research and engineering application of the structural design of push-the-bit support mechanism of the autonomous downhole drilling device.