A wellbore drill bit assembly includes a drill bit that includes a drilling fluid pathway that has an inlet fluidly connected to a drilling fluid entrance of the drill bit and an outlet fluidly connected to a drilling fluid exit of the drill bit; and a nozzle positioned in the drilling fluid pathway, where at least a portion of the nozzle includes a removable material configured to dissolve or erode in contact with a drilling fluid additive.

A wellbore drill bit assembly includes a drill bit that includes a drilling fluid pathway that has an inlet fluidly connected to a drilling fluid entrance of the drill bit and an outlet fluidly connected to a drilling fluid exit of the drill bit; and a nozzle positioned in the drilling fluid pathway, where at least a portion of the nozzle includes a removable material configured to dissolve or erode in contact with a drilling fluid additive.

A wellbore drill bit assembly includes a drill bit that includes a drilling fluid pathway that has an inlet fluidly connected to a drilling fluid entrance of the drill bit and an outlet fluidly connected to a drilling fluid exit of the drill bit; and a nozzle positioned in the drilling fluid pathway, where at least a portion of the nozzle includes a removable material configured to dissolve or erode in contact with a drilling fluid additive.

A wellbore drill bit assembly includes a drill bit that includes a drilling fluid pathway that has an inlet fluidly connected to a drilling fluid entrance of the drill bit and an outlet fluidly connected to a drilling fluid exit of the drill bit; and a nozzle positioned in the drilling fluid pathway, where at least a portion of the nozzle includes a removable material configured to dissolve or erode in contact with a drilling fluid additive.

The invention relates to a device (10) for producing a cavity in a soil from a starting point to a target point along a drilling line for introducing timbering for holding the cavity open having a tunneling head (11), at the outer end of which at least one cutting element (12) for Stripping the soil is provided, wherein the tunneling head (11) has a receiving Chamber (15) which has an opening (16), to which a face conveyor line (17) is connected, and in which at least a first nozzle (21) for discharging a liquid for transporting the stripped soil away from the receiving Chamber is provided, which first nozzle (21) is provided in such a way that the discharge opening thereof is oriented substantially in the direction of the face conveyor line, wherein the advancing drive takes place via an advancing device. It is provided here that at least one second nozzle (23) is provided which is arranged in such a way that the discharge opening thereof is directed substantially onto the soil to be stripped.

The present disclosure describes various embodiments, as well as features and aspects thereof, of an improved drill bit assembly for a percussion boring system. More specifically, one non-limiting embodiment of an improved drill bit assembly for a percussion boring system comprises a bit and a product engagement member. The bit comprises a slant faced head and at least one exhaust port. The product engagement member comprises a product coupling portion and at least one fluid restriction portion. This improved drill bit assembly is such that, when the product engagement member is detachably engaged with the slant faced head of the bit, a first portion of the fluid stream expelled from the bit is directed substantially forward of the slant faced head and a second portion of the fluid stream is directed substantially rearward from the slant faced head.

The present disclosure describes various embodiments, as well as features and aspects thereof, of an improved drill bit assembly for a percussion boring system. More specifically, one non-limiting embodiment of an improved drill bit assembly for a percussion boring system comprises a bit and a product engagement member. The bit comprises a slant faced head and at least one exhaust port. The product engagement member comprises a product coupling portion and at least one fluid restriction portion. This improved drill bit assembly is such that, when the product engagement member is detachably engaged with the slant faced head of the bit, a first portion of the fluid stream expelled from the bit is directed substantially forward of the slant faced head and a second portion of the fluid stream is directed substantially rearward from the slant faced head.

A hydrojet rotary drill bit (10) is provided for drilling a hole in a subsurface formation. The bit body (12) includes a plurality of axially extending ribs (16a, b, c, d, e, and f) and a flow channel between adjacent ribs. A plurality of cutting elements are fixedly mounting on a respective one of the plurality of ribs. A plurality of flow nozzles (20a, b, c, d, e, and f) made on respective one of the plurality of ribs to direct fluid (mud) to a respective one of the plurality of cutting elements to clean and cool the cutting elements.

A hydrojet rotary drill bit (10) is provided for drilling a hole in a subsurface formation. The bit body (12) includes a plurality of axially extending ribs (16a, b, c, d, e, and f) and a flow channel between adjacent ribs. A plurality of cutting elements are fixedly mounting on a respective one of the plurality of ribs. A plurality of flow nozzles (20a, b, c, d, e, and f) made on respective one of the plurality of ribs to direct fluid (mud) to a respective one of the plurality of cutting elements to clean and cool the cutting elements.

Systems and methods for acid tunneling within a wellbore include a whipstock and a steerable acid tunneling arrangement which is run into the wellbore. The acid tunneling arrangement is azimuthally and angularly oriented by the whipstock. Information relating to the direction of tunnel development is sensed and provided to a controller at surface and can be used to map the tunnel.