DOWNHOLE DRILLING ASSEMBLY

摘要

A downhole stabiliser (5), such as a drill motor stabiliser, comprises at least one reaming means and/or reinforcing means (10). The present invention also relates to an assembly (30), such as a downhole drilling assembly (31), comprising at least one such stabiliser (5) and/or a drill bit (40,41) comprising a gauge bit (42) at or near a drilling end (45) thereof, and a connection means (46) for connecting the drill bit (40,41) to a drill motor assembly (60), wherein the drill bit gauge (42) comprises a substantially cylindrical portion having a length less than or equal to approximately 1.0 times the nominal bit diameter. The present invention also relates to a novel locking mechanism (80), such as a lock and key mechanism, to allow locking of a shaft (70′), e.g. a motor drive shaft (71′), through or together with a stabiliser (5′).

主权项

1. A downhole stabiliser for use with a downhole drilling assembly comprising a drill bit, the stabiliser comprising at least one reaming means, wherein the shape of the stabiliser is acentric or eccentric in relation to a motor shaft and/or motor body portion of the downhole drilling assembly.