Patent ID: 6834722
Filing Date: 2004-12-28
Classification: E21B

Abstract:
A cyclic check valve for regulating downhole fluid flow in a coiled tubing string comprising:an outer housing adapted to be connected to a coiled tubing string, the outer housing having a fluid passageway therethrough; a shiftable, spring loaded sleeve located in the fluid passageway, wherein the sleeve is shiftable by a pressure induced force to cycle the check valve between an activated mode and a de-activated mode, wherein in the activated mode a flapper is biased to close the fluid passageway to prevent fluid flow up through the check valve and into the coiled tubing string and in the de-activated mode, the flapper is held open by the extension of the sleeve through the flapper; and a pressure indicator means for producing a recognizable pressure response when the check valve is cycled between the activated and de-activated modes.