CUTTING TOOL LAYOUT FOR CASING SECTION MILLING IN HORIZONTAL WELLS USING BOTTOM TO TOP METHOD Russian patent published in 2023 - IPC E21B7/28 E21B29/06 

FIELD: oil and gas industry.

SUBSTANCE: invention can be used in the construction and renovation of wells. The layout of the cutting tool is designed for milling a section of a cemented casing string in horizontal as well as in slanted wells with large zenith angles. The assembly of the cutting tool is attached to the lower end of the drill string and consists of two or more housing centralizers, a cardan-hinged assembly, an installation nozzle, a cardan-articulated assembly, two or more sliding hydraulic centralizers and a sliding hydraulic expander. The cardan-articulated assembly consists of two shaped coupling halves, between which a ball-shaped bushing with a central axial channel is installed. On the outer surface of the bushing, evenly along its circumference, pins are fixed, the axes of which lie in the diametrical plane of the bushing, perpendicular to its central axial channel, and intersect with the axis of the latter. Shaped half-couplings have the form of a hollow cylinder with a stepped outer side surface and a central axial channel, in which a connecting thread is made on one side, and on the opposite side, there is an internal annular bore for placing a disk spring and a seat in it, as well as two racks with coaxial through channels. The saddles are pressed against the outer surface of the sleeve by Belleville springs. The axis of the through channels in the stands of the shaped coupling half is perpendicular to the axis of its central axial channel and intersects with it. The sleeve is pivotally connected to the stands of two shaped coupling halves by means of trunnions, which are placed in the through channels of the stands with the possibility of free axial rotation. Connecting threads are made at the ends of the installation pipe, corresponding to the connecting thread on the shaped half-couplings.

EFFECT: increased reliability and efficiency of the cutting tool assembly when milling a section of the casing string using the bottom to top method in the horizontal area of the wellbore.

1 cl, 4 dwg