Structure optimization of a jet-type reverse circulation tool for horizontal hole

On the analogy of relevant design,a preliminary design and experimental prototype of jet-type reverse circulation tool was completed,which could be used for horizontal hole.Based on structural optimization experi-ments and researches,a series of optimized combinations of key components were derived,which were appropriate to in-situ conditions.According to experiment results,some conclusions were drawn as follows:the water absorp-tion rate was most influenced by the mode composed of jet tube and jet nozzle and little influenced by flow pa-rameter m and span S;and when the jetting rate exceeded 40m/s,the water absorption rate decreased sharply.