A tunable wellbore pulsation valve reduces drillstring friction in a wellbore. An upper valve plate and a lower valve plate, and upper valve plate orifice and lower valve plate orifice enabling throughflow. A Moineau motor rotates the upper valve plate while the lower valve plate remains stationary. Fluid flow causes a first fluid state of fluid passing through both the upper valve plate and the lower valve plate when the fluid passing causes rotation of the upper valve plate to align the upper valve plate orifice with the lower valve plate orifice. Increased flow efficiency produces more powerful fluid pressure pulsations and axial vibrations without increasing pump pressure at the surface of the wellbore, yielding increased wellbore friction reduction while expending the same or less energy at the surface pump than would be expended in the absence of the reduced turbulent and shear conditions and increased laminar conditions.

A gas-lift valve in a wellbore may include a valve housing and a flow restrictor. The valve housing may at least in part define a chamber for receiving an actuation fluid. The flow restrictor may have a position that is controllable by adjusting a downhole pressure to change a density of the actuation fluid in the chamber. The gas-lift valve may be positioned on production tubing in an annulus of a wellbore. Controlling the position of the flow restrictor may restrict an opening in the production tubing through which gas may flow.

A gas-lift valve in a wellbore may include a valve housing and a flow restrictor. The valve housing may at least in part define a chamber for receiving an actuation fluid. The flow restrictor may have a position that is controllable by adjusting a downhole pressure to change a density of the actuation fluid in the chamber. The gas-lift valve may be positioned on production tubing in an annulus of a wellbore. Controlling the position of the flow restrictor may restrict an opening in the production tubing through which gas may flow.

A single trip casing cutting and pulling assembly which includes a casing spear (12), a mud motor (16) and a casing cutter (18), wherein a valve (14) is located between the casing spear (12) and the mud motor (16). The casing spear is operated by fluid flow from surface and the valve (14) prevents operation of the casing cutter (18) until the casing spear (12) is set and casing cutting is required. A method is described for cutting and pulling casing which does not require any rotation of the drill string to operate any part of the casing cutting and pulling assembly. An embodiment is described which includes retrieving the seal assembly (48) on the same trip. Further embodiments describe performing an integrity test and a circulation test on the same trip with the option of making further cuts at shallower depths on the same trip until a section of cut casing can be recovered.

A single trip casing cutting and pulling assembly which includes a casing spear (12), a mud motor (16) and a casing cutter (18), wherein a valve (14) is located between the casing spear (12) and the mud motor (16). The casing spear is operated by fluid flow from surface and the valve (14) prevents operation of the casing cutter (18) until the casing spear (12) is set and casing cutting is required. A method is described for cutting and pulling casing which does not require any rotation of the drill string to operate any part of the casing cutting and pulling assembly. An embodiment is described which includes retrieving the seal assembly (48) on the same trip. Further embodiments describe performing an integrity test and a circulation test on the same trip with the option of making further cuts at shallower depths on the same trip until a section of cut casing can be recovered.

A method of pumping a non-Newtonian fluid includes pumping the non-Newtonian fluid into an interior of a tubular string, and autonomously controlling a flow resistance to the non-Newtonian fluid flowing from the interior of the tubular string to an exterior of the tubular string with an autonomous flow control device.

A method of pumping a non-Newtonian fluid includes pumping the non-Newtonian fluid into an interior of a tubular string, and autonomously controlling a flow resistance to the non-Newtonian fluid flowing from the interior of the tubular string to an exterior of the tubular string with an autonomous flow control device.

A coiled tubing heating head tool system includes a tool connected at a connector to a terminal end of coiled tubing, the tool having a tubular extending from the connector to a heating head having a heater, a fluid passage extending from a discharge port in the tubular through the connector into the coiled tubing, and a one-way valve in the fluid passage between the discharge port and the connector, and a power cable electrically coupled to the heater and extending through the tubular, the connector, and the coiled tubing, to an electrical power source.

A coiled tubing heating head tool system includes a tool connected at a connector to a terminal end of coiled tubing, the tool having a tubular extending from the connector to a heating head having a heater, a fluid passage extending from a discharge port in the tubular through the connector into the coiled tubing, and a one-way valve in the fluid passage between the discharge port and the connector, and a power cable electrically coupled to the heater and extending through the tubular, the connector, and the coiled tubing, to an electrical power source.

A toe valve to control the injection of fluid into a toe of an oil or gas well and including: a body with a bore, the body having a port adapted to permit fluid flow between the bore and an outlet on an external surface of the toe valve when the port is open; a closure member adapted to move from an initial closed position in which the port is closed, to an open position in which the port is open; and an actuating mechanism which can be actuated to urge the closure member from the initial closed position toward the open position, and which can be reset when the closure member is moving between the closed and open positions to return the closure member to the initial closed position.