Ventil og fremgangsmåte derav for bruk i brønnhull

摘要

A valve for use in a downhole tool The valve has an inlet communicating with the work string from which it is anchored. The inlet provides a flow path of a first cross-sectional area. A sealing assembly comprising a spring biased seal cap moves within an outer tubular body to open and close a number of ports arranged through the body. The ports provide a flow path of a combined cross-sectional area greater than the first cross-sectional area and the valve is arranged such that fluid flow through the inlet moves the seal cap to open the valve and create an unimpeded flow path between the inlet and the ports with negligible pressure drop. An embodiment including a shear ring is described to facilitate pressure testing above. A further embodiment includes a load adjuster to assist in closing the valve. The valve can be a high lift injection valve.