Experimental Study on the Impingement Characteristics of Self-Excited Oscillation Supercritical CO2 Jets Produced by Organ-Pipe Nozzles

Supercritical carbon dioxide (SCO2) jets are a promising method to assist drilling, enhance oil–gas production, and reduce greenhouse gas emissions. To further improve the drilling efficiency of SCO2 jet-assisted organ-pipe nozzles were applied generate self-excited oscillation jet (SEOSJ). The impact pressure rock erosion capability SEOSJs under both supercritical gaseous CO2 (GCO2) ambient conditions experimentally investigated. It was found that characteristics produced by dramatically affected chamber length. optimum range dimensionless length highest peak strongest is within 7–9. ratio decreases gradually with increasing difference, whereas intensity increases difference rate gradually. dominant frequency observed decrease monotonically but increase difference. Moreover, comparison impingement different showed values similar two conditions, SEOSJ achieves higher in at same breaking ability closely related its axial pressure. depth mass loss sandstone caused nozzle best performance than those other nozzles. results deeper narrower crater GCO2 reported provide guidance for applications design an used drilling.