A bottom hole assembly comprising a downhole tool known as a cutting tool is provided for use within a subterranean well for severing tubulars. The cutting tool comprises a fluid source, a gas-driven rotatable motor and a cutting head including one or more cutters. The fluid source supplies pressurized fluid and thereby energy to the gas-driven rotatable motor which is disposed to generate thrust to set the gas-driven rotatable motor in motion. The cutting head is coupled to the gas-driven rotatable motor and rotates while cutting the tubular. The cutting tool can be deployed in a subterranean well by a variety of deployment methods, and the pressurized fluid may be supplied from a surface system, generated inside the cutting tool or bottom hole assembly, or input within the cutting tool or bottom hole assembly prior to deployment.

The invention further relates to associated methods.

Disclosed herein are downhole landing assemblies including a downhole landing assembly for an oil or gas well, downhole landing assembly may include: an upper seat cylinder capable of being coupled to an upper portion of a tubular string; a lower seat cylinder capable of being coupled to a lower portion of the tubular string, wherein the lower seat cylinder may be coupled to the upper seat cylinder; a landing seat coupled to the lower seat cylinder, the landing seat may have two inner surfaces; and a landing mandrel having two outer surfaces, wherein one outer surface of the two outer surfaces may be capable of being abutted against one inner surface of the two inner surfaces.

Downhole cutting tool positioning assemblies and methods to cut a tubular are presented. The assembly includes a drive screw, a drive nut coupled to the drive screw and configured to shift from a first position to a second position as the drive screw rotates in a first drive screw direction, a pressure piston configured to shift from a first position to a second position in response to force applied to the pressure piston, a chamber having a pressure fluid that is pressurized by the pressure piston as the pressure piston shifts from the first position towards the second position, a sleeve configured to slide from a first position towards a second position in response to pressure from the pressure fluid, and a latch key having a profile configured to shift radially to engage a tubular groove as the sleeve shifts from the first position towards the second position.

A casing removal system includes a flow diversion valve. The flow diversion valve includes a flow switch that engages an upper end of an inner casing. When the flow switch engages the upper end of the inner casing, the flow diversion valve opens and at least a portion of the fluid flow through the casing removal system exhausts to the annulus. The remaining fluid flow below the flow diversion valve is insufficient to operate a mud motor that drives a casing cutter. In other embodiments, when the flow switch is not engaged with the inner wall of casing, the flow diversion valve prevents fluid flow to components that are downhole of the valve and when the flow switch is engaged with the inner wall of casing, the flow diversion valve allows for fluid flow to components that are downhole of the valve.

A wireline cutting tool. The wireline cutting tool comprises an elongated tubular body. A knife housing resides within the tubular body proximate an upper end, while a plunger resides within the tubular body proximate a lower end. An electric wireline passes through a bore of the knife housing and the plunger en route to an electrical connection sub. The electrical connection sub includes a pin that transmits signals from the electric wireline down to a downhole tool. The plunger is configured to slide up the bore of the lower sub in response to a first upward shear load applied by the wireline. This causes the plunger to act against knives residing within the knife housing. The knives are configured to travel up the bore of the upper sub in response to a second upward shear load applied by the plunger, pinching the wireline until severed. The second shear load is greater than the first shear load, creating a two-stage cutting tool.

A casing mill including a first milling configuration having a first blade for milling a first casing section, and a second milling configuration having a second blade, the second blade being an ultra-high expansion blade for milling a second casing section. A wellbore system including a borehole in a subsurface formation, two nested casings disposed within the borehole, a string disposed within the casings, a casing mill disposed within or as a part of the string and including a first milling configuration having a first blade for milling a first casing section, and a second milling configuration having a second blade, the second blade being an ultra-high expansion blade for milling a second casing section, the second casing section being radially outwardly disposed of the first casing section, and a stroking tool disposed between the first milling configuration and the second milling configuration.

A mill for a single casing string including a housing, a first blade section having a blade of a first profile disposed in the housing and positionable to axially mill the single casing string, a second blade section having a blade of a second profile disposed in the housing and positionable to axially mill the single casing string, the first and second blades deployable simultaneously, the second blade configured to ride on an inside diameter surface of the single casing string while the second blade in the deployed position.

A method of recovering casing from a wellbore in which: a logging tool is run to an estimated stuck point of the casing through the central bore of the casing spear and casing cutter; the casing spear is attached to the casing and tension applied so that logging can be performed over a length at an estimated stuck point both with and without tension to provide the verified stuck point; and the casing cutter is positioned relative to this to cut the free casing; and the spear used to remove it. The method can be performed on a single trip. Embodiments include incorporating a packer to circulate fluid during casing cutting; a disconnect, anchor mechanism and motor to allow use of a motor to operate the cutter; and a Down Hole Power Tool with a method of establishing the required force to recover a length of stuck casing.

A wellbore system includes method of cutting a casing in a wellbore. A string is disposed in the casing, the string including a cutting tool and an activation sub coupled to the cutting tool. The cutting tool includes a ball seat and a cutter. The activation sub includes a control piston disposed therein. The control piston has a ball at an end thereof. The control piston is configured to move within the activation sub to engage the ball to the ball seat when a flow rate of a fluid through the control piston is above a flow rate activation threshold, wherein engaging the ball to the ball seat creates a pressure differential across the ball seat that moves the ball seat to extend the cutter from the cutting tool.

A method of separating a downhole tubular includes running a tool into a wellbore to a predetermined location on a work string and actuating flow actuated slips. The method also includes maintaining slips in a set position by providing a first upward force on the work string. The method further includes rotating the work string to separate an upper portion of the tubular from a lower portion using a cutter assembly disposed on the work string below the slips and pulling the upper portion of the tubing and the tool from the wellbore.