The present application relates to the technical field of through-the-bit
logging, and is a downhole
butt joint tool, a connecting male joint and a free catch release joint. The downhole
butt joint tool comprises a supporting cylinder, a
butt joint short section, a suspension short section, a suspension cylinder and a supporting
assembly. The connecting male joint comprises a male gun main body, a male joint connecting sleeve, a wiring column body, a catch cylinder, a
piston rod and the downhole butt joint tool. The free catch release joint comprises a joint shell, a driving motor, a transmission mechanism, a central joint, a slotted joint, a female joint body, a wiring ring body and the connecting male joint. The present application has a reasonable and compact structure and is convenient to use. The butt joint short section and the suspension short section are jointly connected and installed on a
drill pipe to be sent downhole in advance while drilling, so as to provide a suitable operation environment for a
pipe string provided with a through-the-bit
logging instrument, improve the stability and reliability of the release and catch operation of the through-the-bit
logging instrument, and facilitate the laying of a connecting cable of the through-the-bit instrument through the setting of a first threading channel. The present application has the characteristics of safety, labor saving, simplicity, convenience and high efficiency.