Abstract: A packer valve for regulating the fluid flow rate and pressure within a fluid conduit such as a well, includes a housing, and an inflatable packer element mounted on an elongated mandrel. The inside diameter of the housing is formed with an arrangement of annular grooves which circumscribe the inflatable packer element. The inflatable packer element is adapted to adjust an annulus between the housing and the inflatable packer element to provide complete shutoff of fluid flow or to provide a tortuous flow path for fluid flow within the annulus. The tortuous flow path causes a frictional pressure loss. The amount of the pressure loss is controlled by the inflation pressure of the inflatable packer element, by the shape of the annular grooves, and by the length of the inflatable packer element.