Abstract: The present invention is a surface controlled subsurface safety valve (SCSSV) for use in a well, preferably a hydrocarbon producing well. The SCSSV comprises a valve body having a longitudinal bore for fluid to flow through, a bore closure assembly, a pressure balanced drive assembly, and a fail safe assembly. The bore closure assembly is positioned and normally biased to close the bore to fluid flow. The drive assembly is coupled to the bore closure assembly for driving the bore closure assembly to an open position. The fail safe assembly is positioned and configured to hold the bore closure assembly in the open position in response to a hold signal and to release the valve to return to the safe, closed position upon interruption of the hold signal.

Abstract: A wellhead union and associated methods provide enhanced safety in operations involving access to, and/or fluid communication with, a wellhead. In a described embodiment, a wellhead union has a housing structure which includes a fluid conduit and a plug. A safety interlock prevents removal of the plug from the fluid conduit when fluid pressure is present within the wellhead. As a warning that such fluid pressure is present within the wellhead, the safety interlock additionally provides an externally visible indication when the fluid pressure is present.

Abstract: A wellhead union and associated methods provide enhanced safety in operations involving access to, and/or fluid communication with, a wellhead. In a described embodiment, a wellhead union has a housing structure which includes a fluid conduit and a plug. A safety interlock prevents removal of the plug from the fluid conduit when fluid pressure is present within the wellhead. As a warning that such fluid pressure is present within the wellhead, the safety interlock additionally provides an externally visible indication when the fluid pressure is present.