Study On Reducing The Resistance Of Flexible Drill Pipe Feed In Radial Drilling In Casing

Radial horizontal drilling technology is the use of high pressure water jet in a formation reservoir or multiple layers along the radial drill a plurality of horizontal branch well drilling technology,and this technology can shift in 300mm radius in steering by vertical steering level,can effectively prevent the water cone and gas cone,and ensure sufficient drilling force,so it can be used in deep mining of hard bottom.However,in the actual production,there are many problems such as the large feed resistance of the drill pipe,which leads to the limitation of the feeding distance and even the occurrence of buckling and locking.The research is based on previous group to determine the optimization principle of the drill pipe without reaming on the orbital parameters of steering gear,for steering feed process,analyzing combined parameters of adding rollers and removing the straightening section and adding lever drag reducing mechanism,study on the drill pipe to reduce feed resistance when the steering resistance and straightening of the drill pipe at different stages.In this paper,the methods of theoretical analysis,numerical simulation and experimental research are combined.For drill pipe to process in original track,analysis to determine the place of the resistance increasing,for the first time put forward without reaming steering track to join the ideas of the roller and determine the layout of roller,furthermore,the influence of the parameters on drag force is analyzed.This paper first designed the lever reduction mechanism and analyzed its working principle for the significant increase in the resistance of straightening segment.Using ABAQUS to simulate the steering process after the drill pipe is added to the roller.The optimal roller spacing is 20.0 mm,and the roller is 1.8 mm high above the inner wall of the orbit,and the optimal parameters of 8 radius 9mm rollers.By changing the radius of roller and the spacing of rolling wheel,the influence law of the parameters such as rolling wheel spacing are found.The effect of the wheel spacing on resistance is not obvious;The turning radius increases from 6mm to 9mm.As the number of rollers increases,the steering resistance decreases first and the resistance is minimized at 8.The steering resistance is minimal when the optimal height of the roller is 1.8 mm above the inner wall of the track.Using ABAQUS to simulate the steering process of the drill pipe with the lever reduction mechanism.The best lever for reducing the drag is 55mm,left arm and the vertical Angle of 30~o,right arm and the vertical Angle of 60~o s55-30-60 lever reduction mechanism.In this paper,we find the influence law of the dimension Angle of the lever reducer mechanism to reduce the drag force,and obtain the better parameter combination.In the finite horizontal space,the larger,the greater the reduction of the deleveraging mechanism.The Q345b and304 stainless steel drill pipe were used in the improved orbit of the combined mechanism to be sent to the simulation.Compared with smaller elastic modulus of larger yield strength of304 drill pipe in favor of the to send into the experiment of the drill pipe and two kinds of drill pipe are conform to the requirements of the strength and deformation.Turn the drill pipe to the experiment after joining the roller.The results showed that drill pipe in the roller spacing is 20.0mm,beyond the orbit of roller wall height is 1.8mm,add 8 radius of 9mm rollers,steering resistance was reduced by 7.16%under the original orbit.The drill pipe turns to the experiment in the orbit of the lever reduction mechanism.The results show that Drill pipe in leveraged transverse size is 55mm,left arm and the vertical Angle of 30~o,right arm and the vertical Angle of 60~o S55-30-60 lever drag reduction mechanism in orbit steering resistance was reduced by 4.74%under the original orbit.The combination of the joining lever reduction mechanism and the roller will be combined to deliver the experiment.Combined mechanism of 8 radius 9mm rollers and S55-30-60 lever drag reduction mechanism is relatively better improve the ability of drill pipe than original orbit,steering resistance decreases by 8.37%,so lever drag reduction mechanism and rollers are feasible.