Abstract: A process of manufacturing a well closure apparatus and using it downhole by releasing components contained within the apparatus. The well closure apparatus is an internal bidirectional tubing plug that is adapted for insertion into a tubing string for sealing the tubing string internally while running the tubing into a fluid filled well. The tubing plug is comprised of a body having an inner surface with a recess or passage extending through the body from one end to the other. The recess holds petals and a keystone petal that are held within the recess by a cork and the cork is held in place by a nut. At depth, the tubing is filled with well fluid, the tubing plug is released at a predetermined hydraulic pressure, and the pieces of the releasing components are pumped to the bottom of the well or are circulated out of the well.

Abstract: An internal bidirectional tubing plug for plugging a well to prevent well fluids from passing the plug in a well conduit until the internal components of the plug are pumped out of its body. The body of the plug connects to the well's tubing string. The body holds a petal assembly consisting of several petals and a tapered cork assembly located within an opening formed by the petals. Both assemblies are sandwiched between upper and lower pistons. Hydrostatic pressure on the bottom of the plug as it is lowered into the fluid filled well holds the petals within the body. The internal components of the plug are removed from the body by applying hydraulic pressure in the upper area of the plug. This causes the plug to fail at a recess provided in the cork, resulting in the two assemblies and the pistons being forced out of the body.