Abstract: A well drilling sub has a body with a threaded upper end for connection into a drill pipe string and a threaded lower end for connection and rotation with an earth boring bit. An axial passage in the body conveys drilling fluid to an outlet in the earth boring bit. Diverting nozzles in the body are in fluid communication with the axial passage. Each nozzle diverts and discharges a portion of the drilling fluid being pumped down the axial passage. Each diverting nozzle has a nozzle axis that points upward and outward and also at a oblique angle. The oblique angle lags a radial plane considering a direction of rotation of the body.

Abstract: A casing shoe secured to a lower end of a casing string is positioned a selected distance from a bottom of the well, defining an open hole portion in the well below the casing shoe. Cement is pumped through the casing shoe and back up an annulus surrounding the casing string, while leaving at least part of the open hole portion free of cement. The annulus and the open hole portion are isolated from an interior of the casing string while the cement is uncured. The casing shoe has a timer that opens the interior of the casing string to the open hole portion after a selected time sufficient for the cement to cure. The operator may then pump a tool down the casing string while displacing fluid in the casing string below the tool through the casing shoe and into the open hole portion of the well.

Abstract: Described are drilling subs that may be connected in a drill string for reducing the accumulation of debris on the exterior of the drill string or otherwise facilitating the return of drilling fluid during drilling operations. A plurality of radially spaced stabilizing blades protrude from an exterior surface of the drilling subs to define exterior flow channels therebetween through which drilling fluid returning to the surface may is directed. Diverting nozzle passages are provided that extend between an inner axial passage of the drilling subs and the exterior surface of the drilling subs. The diverting nozzle passages exhibit a radial spacing corresponding to a radial spacing of the exterior flow channels such that drilling fluid discharged from the diverting nozzle passages is directed toward the exterior flow channels.

Abstract: A casing shoe secured to a lower end of a casing string is positioned a selected distance from a bottom of the well, defining an open hole portion in the well below the casing shoe. Cement is pumped through the casing shoe and back up an annulus surrounding the casing string, while leaving at least part of the open hole portion free of cement. The annulus and the open hole portion are isolated from an interior of the casing string while the cement is uncured. The casing shoe has a timer that opens the interior of the casing string to the open hole portion after a selected time sufficient for the cement to cure. The operator may then pump a tool down the casing string while displacing fluid in the casing string below the tool through the casing shoe and into the open hole portion of the well.

Abstract: A well drilling sub has a body with a threaded upper end for connection into a drill pipe string and a threaded lower end for connection and rotation with an earth boring bit. An axial passage in the body conveys drilling fluid to an outlet in the earth boring bit. Diverting nozzles in the body are in fluid communication with the axial passage. Each nozzle diverts and discharges a portion of the drilling fluid being pumped down the axial passage. Each diverting nozzle has a nozzle axis that points upward and outward and also at a oblique angle. The oblique angle lags a radial plane considering a direction of rotation of the body.

Abstract: A fluid injection sub for a well creates eduction to draw well fluid into a mixing chamber and discharge the well fluid mixed with an injection fluid pumped down a string of tubing to the sub. The injection sub has a well fluid intake passage leading from an exterior of the housing to the mixing chamber. The injection sub also has a mixed fluid discharge passage extending from the mixing chamber to the exterior of the housing for discharging the mixed fluid exterior of the housing. A nozzle at the lower end of the mixing chamber discharges the injection fluid into the mixing chamber.