A nozzle for a drill bit such as may be used to drill for oil or natural gas. The nozzle includes a generally-cylindrical body having a longitudinal axis, a proximal end for insertion into a drill bit body, and a distal end opposite the proximal end. The nozzle body defines a longitudinal bore through the nozzle along the longitudinal axis. The nozzle further includes one or more lobes extending radially from the nozzle body near the distal end. Each of the lobes is displaced axially from the distal end such that a cylindrical portion of the nozzle body is disposed between the distal end and the lobe. The nozzle further includes a fitting in the distal end configured to engage a tool for imparting rotational torque to the nozzle about the longitudinal axis. Such a nozzle is preferably insertable into a drill bit body from outside the body.

A nozzle for a drill bit such as may be used to drill for oil or natural gas. The nozzle includes a generally-cylindrical body having a longitudinal axis, a proximal end for insertion into a drill bit body, and a distal end opposite the proximal end. The nozzle body defines a longitudinal bore through the nozzle along the longitudinal axis. The nozzle further includes one or more lobes extending radially from the nozzle body near the distal end. Each of the lobes is displaced axially from the distal end such that a cylindrical portion of the nozzle body is disposed between the distal end and the lobe. The nozzle further includes a fitting in the distal end configured to engage a tool for imparting rotational torque to the nozzle about the longitudinal axis. Such a nozzle is preferably insertable into a drill bit body from outside the body.

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 pressure generating device for use in downhole drilling operations includes a rotating valve portion having a first body with at least one first flow channel, and a stationary valve portion having a second body with at least one second flow channels and at least one bypass channel. A flow restrictor is positioned within the at least one bypass channel for adjusting a total flow area of the at least one bypass channel. During rotation of the rotating valve portion relative to the stationary valve portion, a total flow area of a passage defined by the first flow channel(s), the second flow channel(s), and the at least one bypass channel varies according to a uniform closure pattern to provide uniform pressure pulses within a single revolution of the rotating valve portion. A method of generating uniform pressure pulses in downhole drilling operations is also disclosed.

A pressure generating device for use in downhole drilling operations includes a rotating valve portion having a first body with at least one first flow channel, and a stationary valve portion having a second body with at least one second flow channels and at least one bypass channel. A flow restrictor is positioned within the at least one bypass channel for adjusting a total flow area of the at least one bypass channel. During rotation of the rotating valve portion relative to the stationary valve portion, a total flow area of a passage defined by the first flow channel(s), the second flow channel(s), and the at least one bypass channel varies according to a uniform closure pattern to provide uniform pressure pulses within a single revolution of the rotating valve portion. A method of generating uniform pressure pulses in downhole drilling operations is also disclosed.

A drag bit includes a blade extending from the bit body and supporting inner cutters proximate the longitudinal axis and outer cutters spaced from the longitudinal axis. The inner cutters are rotationally offset from the outer cutters. During operation the inner cutters deposit cut material in a channel that is contiguous with a channel that receives material cut by the outer cutters. The cutters and the contiguous channels flush agglomerating material from the slots.

A drag bit includes a blade extending from the bit body and supporting inner cutters proximate the longitudinal axis and outer cutters spaced from the longitudinal axis. The inner cutters are rotationally offset from the outer cutters. During operation the inner cutters deposit cut material in a channel that is contiguous with a channel that receives material cut by the outer cutters. The cutters and the contiguous channels flush agglomerating material from the slots.

A nozzle for a drill bit such as may be used to drill for oil or natural gas. The nozzle includes a generally-cylindrical body having a longitudinal axis, a proximal end for insertion into a drill bit body, and a distal end opposite the proximal end. The nozzle body defines a longitudinal bore through the nozzle along the longitudinal axis. The nozzle further includes one or more lobes extending radially from the nozzle body near the distal end. Each of the lobes is displaced axially from the distal end such that a cylindrical portion of the nozzle body is disposed between the distal end and the lobe. The nozzle further includes a fitting in the distal end configured to engage a tool for imparting rotational torque to the nozzle about the longitudinal axis. Such a nozzle is preferably insertable into a drill bit body from outside the body.

A nozzle for a drill bit such as may be used to drill for oil or natural gas. The nozzle includes a generally-cylindrical body having a longitudinal axis, a proximal end for insertion into a drill bit body, and a distal end opposite the proximal end. The nozzle body defines a longitudinal bore through the nozzle along the longitudinal axis. The nozzle further includes one or more lobes extending radially from the nozzle body near the distal end. Each of the lobes is displaced axially from the distal end such that a cylindrical portion of the nozzle body is disposed between the distal end and the lobe. The nozzle further includes a fitting in the distal end configured to engage a tool for imparting rotational torque to the nozzle about the longitudinal axis. Such a nozzle is preferably insertable into a drill bit body from outside the body.