Patent ID: 9556693
Date: 2017-01-31
CPC Classifications: E21B

Claim:
1. A disconnecting tool for disconnecting a drill pipe from a lower casing in a borehole and having an axial extension along a centre line, the disconnecting tool comprising: an axial force generator comprising a first part and a second part and providing an axial movement of the second part in relation to the first part along the axial extension, a wireline powering the axial force generator, and an element comprising a leading part and a trailing part, the trailing part being connected with the second part, wherein a fluid channel extends from the leading part to the trailing part, the fluid channel being configured to permit fluid to flow from a front area in front of the element to a rear area between the trailing part and the first part of the axial force generator when the second part is moved away from the first part of the force generator during disconnection, thus equalizing fluid presssure across the element during disconnection, and wherein the fluid channel has an inlet in the leading part and an outlet leading to the rear area.