Patent ID: 6755257
Filing Date: 2004-06-29
Classification: E21B

Abstract:
A drillpipe assembly comprising a drillpipe having secured at a downhole end thereof a delatchable latching sub containing an extendible running sub supporting a logging tool, the running sub being moveable between a first, retracted position, in which it supports the logging tool within one or more stands of drillpipe; and a second, extended position in which it supports the logging tool protruding from the drillpipe, the latching sub, when latched, retaining the running sub in its first position and the latching sub permitting extending of the running sub when delatched, wherein the logging tool is a compact diameter battery/memory tool, including an hydraulic actuator for extending the running sub wherein the hydraulic actuator includes one or more seals moveably sealingly interconnecting an outer periphery of the running sub and an inner wall of a drillpipe stand, whereby fluid pressure in the drillpipe acting on one side of a said seal tends to drive the running sub along the drillpipe.