Abstract: For gas lift, gas lift valves install on a completion in a wellbore. The gas lift valve has a pressure-sensitive valve and a check valve configured to control communication in the valve. A piston is held closed with a first connection relative to the valve's outlet exposed to tubing pressure, while the check valve is held open in the valve with a second connection. Pressure testing can be performed on the integrity of the tubing and casing by increasing the tubing and annulus pressures while the piston stays closed. The gas lift valve is then actuated for operation by increasing the tubing or annulus pressure beyond a predetermined limit of the first connection to release the piston to move open relative to the outlet. The movement of the piston releases the hold of the second connection on the check valve so the check valve can function normally as a one-way valve.

Abstract: A chemical injection valve can include a valve stem reciprocably disposed relative to a primary seal, and a variable flow restrictor upstream of the primary seal relative to a direction of flow through the chemical injection valve. The variable flow restrictor restricts the flow when the valve stem is disengaged from the primary seal. A chemical injection system can include a chemical treatment pumped through a chemical injection valve and into an interior of a tubular string in a well, the chemical injection valve including a valve stem, a primary seal sealingly engaged with the valve stem in a closed position and disengaged from the valve stem in an open position, and a flow restrictor that restricts the flow of the chemical treatment downstream from the primary seal in the open position.

Abstract: For gas lift, gas lift valves install on a completion in a wellbore. The gas lift valve has a pressure-sensitive valve and a check valve configured to control communication in the valve. A piston is held closed with a first connection relative to the valve's outlet exposed to tubing pressure, while the check valve is held open in the valve with a second connection. Pressure testing can be performed on the integrity of the tubing and casing by increasing the tubing and annulus pressures while the piston stays closed. The gas lift valve is then actuated for operation by increasing the tubing or annulus pressure beyond a predetermined limit of the first connection to release the piston to move open relative to the outlet. The movement of the piston releases the hold of the second connection on the check valve so the check valve can function normally as a one-way valve.

Abstract: A method is disclosed of manufacturing a side pocket mandrel for use with a gas lift valve downhole on a tubing string. A plurality of separate components of the mandrel are manufactured. A face on at least one end of each of the separate components is configured for solid-state joining with a face on another of the separate components. Joints are then formed between the separate components by moving the face of at least one of the separate components in a solid state joining process relative to the face of at least one other of the separate components. For example, linear friction, rotary friction, or spin friction welding can be used by moving one of the faces against another. Also, an induction heater can preheat the ends to a suitable temperature to reduce the need for friction heating.

Abstract: A chemical injection valve can include a valve stem reciprocably disposed relative to a primary seal, and a variable flow restrictor upstream of the primary seal relative to a direction of flow through the chemical injection valve. The variable flow restrictor restricts the flow when the valve stem is disengaged from the primary seal. A chemical injection system can include a chemical treatment pumped through a chemical injection valve and into an interior of a tubular string in a well, the chemical injection valve including a valve stem, a primary seal sealingly engaged with the valve stem in a closed position and disengaged from the valve stem in an open position, and a flow restrictor that restricts the flow of the chemical treatment downstream from the primary seal in the open position.