GB851036A - Drill collar stabilizer - Google Patents

Abstract

851,036. Drilling oil wells. DRILCO OIL A drill collar stabilizer comprises a metal TOOLS Inc. July 2, 1959 [July 11, 1958], barrel 10 disposed around a mandrel 12 of a No. 22786/59. Class 85. sub 11, and metal strips 32 resiliently attached to the barrel. The attachment is by a rubber or like layer 20 which is bonded to the barrel 10 and to the strips, an inner rubber or like layer 18 connected to the outer layer through holes 22, being bonded to the barrel to form a bearing for the mandrel 12. The stabilizer is secured between a shoulder 16 on the sub 11 and a screwed subshoulder 14, and the lower part of the barrel is formed with clutch teeth 28 to co-operate with formations 30 on the sub 11 during wash-over operations on the drill collar. The strips 32 are made from a metal which is easily millable and drillable, e.g. aluminium, and are shaped at top and bottom to facilitate the flow of well fluid through the channels between them, and minimize the forcing of abrasive particles between the strips 32 and the walls of the bore. The inner layer 18 has vertical grooves 40 for well fluid to lubricate the relatively rotating surfaces of the mandrel 12 and the layer 18. The stabilizer is of substantially the same diameter as the drill bit, the resilient attachment of the strips 32 permitting them to yield when irregularities in the bore are met.