초록 ▼

A rotary drill bit (10) has a jet pump device including a plurality of jet pump assemblies (26). Each jet pump assembly (26) has an outer housing (28) secured to the bit body (14) and receiving any elongate nozzle member (46) therein in concentric relation to form an annular chamber (48) therein. A

A rotary drill bit (10) has a jet pump device including a plurality of jet pump assemblies (26). Each jet pump assembly (26) has an outer housing (28) secured to the bit body (14) and receiving any elongate nozzle member (46) therein in concentric relation to form an annular chamber (48) therein. A flow restriction (38) is mounted within the outer housing (28) above the nozzle member (46). The elongate nozzle member (46) has a lower nozzle port (50) and an opposed upper nozzle port (52). Drilling fluid from the central bore (20) is directed to the nozzle member (46) where the drilling fluid is divided into two streams, one stream for flow through lower nozzle port (50) against the formation and the outer stream for flow through the upper nozzle port (52) and flow restriction (38) to create a low pressure area or suction in an annular chamber (48). A low pressure cross sectional area is formed at the bottom of the bore hole (B, FIG. 4) and drilling fluid with entrained formation cuttings is drawn upwardly through the annular chamber (48) and the flow restriction (38).

대표청구항 ▼

[ What is claimed is:] [1.] A rotary drill bit for drilling a well bore hole in a formation comprising:a bit body having a central bore to receive a pressurized drilling fluid;a jet pump device positioned on said bit body including a jet assembly having a lower jet nozzle directed downwardly toward

[ What is claimed is:] [1.] A rotary drill bit for drilling a well bore hole in a formation comprising:a bit body having a central bore to receive a pressurized drilling fluid;a jet pump device positioned on said bit body including a jet assembly having a lower jet nozzle directed downwardly toward the formation and a fluid flow restriction;flow diverter means communicating with said central bore to receive pressurized drilling fluid therefrom and to separate said pressurized drilling fluid into two streams for said jet assembly, one of said streams being directed to said lower jet nozzle for discharge against the formation in a downward direction and the other stream being directed through said flow restriction; anda discharge flow passage extending from a lower bore hole cavity adjacent the lower face of the drill bit through said flow restriction for said jet assembly for drawing a mixture of drilling fluid and entrained formation cuttings upwardly from said lower bore hole cavity for discharge from the well bore hole through said flow restriction.