Design for a Valve Port of a Reciprocating Valve that Rapidly Generates Continuous Wave Signals in Drilling Fluid

Due to the fact that cone-valve and rotary-valve signal generators have such characteristics as positive pulse signal with low frequencies,distribution space of valve port limited by radial size of drill string,insufficient fluid supply capacities,etc.,a reciprocating valve that can rapidly generate continuous wave signals has been designed.On the basis of introducing the composition of reciprocating valve and the mechanism of continuous wave signal generation,a mathematical calculation model of valve port shape curve was built,and the impact of valve port shape and distribution on the characteristics of generating continuous pressure wave was studied.The simulation and computation results showed that the correlation coefficient between the pressure wave generated by the designed valve ports(with 4 valve ports on each layer and with 3 layers along the axial direction) and the ideal sinusoidal pressure wave was up to 0.9657,with maximum frequency of 10 Hz.Research results indicated that the designed valve port could produce approximate sinusoidal continuous pressure waves,reduce the displacement of reciprocating motion of the valve cores,and shorten the cycle of the reciprocating motions to increase the generating frequencies of pressure wave signals.