Abstract: A downhole system having a chemical injection valve assembly configured to inject at least one chemical from a chemical injection line into a downhole tubing. The chemical injection valve assembly includes a passive access control mechanism configured to reveal a first port to the tubing in a first condition and block the first port in a second condition. The passive access control mechanism including a movable piston, wherein in the first condition the piston is exposed to a first pressure source on a first side of the piston and to a second pressure source on a second side of the piston. The first pressure source is from within the tubing and the second pressure source is from outside of the chemical injection line and the tubing. Also included is a method of chemical injection in a downhole system.

Abstract: Apparatus for diverting fluid flow out of a working string, having a primary sub housing defining an axial bore and one or more primary sub housing circulation ports; a valve within the housing and defining one or more valve circulation ports. The valve ports are in fluid communication with the housing ports when the valve is in an open circulation position. One or more fluid-impinged surfaces are included and disposed within the primary sub housing and in operative connection with the valve. Fluid flowing through the primary sub housing impinges upon the fluid-impinged surfaces and, at a sufficient flow rate, causes the valve to move so as to actuate the valve in opposition to a biasing force operating on the valve and into open circulation position to cause flow of fluid out of the valve and primary sub housing through the aligned valve and primary housing ports.

Abstract: A downhole system having a chemical injection valve assembly configured to inject at least one chemical from a chemical injection line into a downhole tubing. The chemical injection valve assembly includes a passive access control mechanism configured to reveal a first port to the tubing in a first condition and block the first port in a second condition. The passive access control mechanism including a movable piston, wherein in the first condition the piston is exposed to a first pressure source on a first side of the piston. To a second pressure source on a second side of the piston and the first pressure source from within the tubing and the second pressure source from outside of the chemical injection line and the tubing. Also included is a method of chemical injection in a downhole system.