Research On Key Technology Of Water Hammer Oscillator And Its Structural Design

The water hammer oscillator can generate periodic axial vibration under the action of high pressure drilling fluid,convert the friction between the coiled tubing and the borehole wall from static friction to dynamic friction,and increase the effective bit pressure at the drill bit.It's an important application tools.However,the domestic research on the water hammer oscillator is not yet mature,and the implementation of foreign technology blockade in China,in order to develop with independent intellectual property rights of water hammer oscillator,rich domestic water hammer oscillator type,this paper completes the research and design of the new water hammer oscillator.In this paper,the overall design scheme of water hammer oscillator is proposed,which includes the design scheme of the fluid commutation unit,the design scheme of the oscillation generating unit and the design scheme of the accumulator stabilizing unit.The structure of the internal flow channel of the jet element is designed in detail,and the flow channel model is established.The rationality of the flow channel structure in the jet element is verified by CFD.Completed accumulator calculation spring selection,design a sealing form and housing structure of the accumulator,using CFD theoretically verified reasonable flow passage configuration of the accumulator.The impact frequency and impact energy of the water hammer oscillator are calculated and the main components of the oscillator are analyzed.The constrained modal analysis of the water hammer oscillator is completed and the three-dimensional model of the internal flow path of the oscillator is established.The rationality of the flow channel structure in the water hammer oscillator is validated by CFD.Finally,this paper also designed the ground test scheme of water hammer oscillator,which laid the foundation for the experiment.Through the research,this paper has designed the reasonable structure of water hammer oscillator,which provides design ideas and methods for the development of continuous tubing downhole tools.