Abstract: A stabilizing mechanism for guiding drill direction of a flexible drill string when drilling the straight portion of a deviated well bore. The stabilizing mechanism comprises a tubular mandrel adapted for connection between the flexible drill string and a drill bit. The mandrel has at least two, reduced diameter areas spaced apart and disposed axially along its length. A non-rotating type stabilizer sleeve is positioned on each of the reduced diameter areas. Bearing means is provided at each end of each of the sleeves to reduce wear. The mandrel is capable of traversing a short radius curve of a deviated well.

Abstract: A flexible drill pipe adapted for connection in a drill string, having sufficient wall thickness in order to withstand forces imposed by drilling a well. The flexible pipe has a plurality of cuts defining interlocking teeth and recesses on axially adjacent segments of the pipe, the teeth in one segment being positioned in the recesses of, and interlocking with the teeth of, the adjacent segment. Each of the teeth includes a generally semicircular crown section, two essentially flat shoulders and a tapered base portion, with the curved, tapered sides of circumferentially adjacent bases forming the semicircular recesses for receiving the crowns of axially adjacent interlocking teeth.