Abstract: Disclosed is a pumpdown, retrievable, subsurface, safety valve for use in a well. The valve comprises a valve section including a valve member to control flow through the well tubing and one or more force exerting sections urging the valve member to a position blocking flow. The valve section and force exerting sections are interconnected. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

Abstract: A method and apparatus for cementing well conduits in a well which is particularly advantageous when used in cementing wells having a subsea wellhead.

Abstract: A cementing head for use in the cementing of casing in a wellbore, wherein means are provided internally of a tubular housing for normally directing drilling fluid or mud through the cementing head prior to introducing cement therethrough, and wherein cement control means are also disposed internally of the tubular housing for regulating and controlling the introduction of a first cementing plug in advance of cement, followed by a second cement plug, and with means for thereafter pumping drilling fluid or mud down to wash out the cement from the cementing head while forcing the second cementing plug down the casing above the cement.

Abstract: Cementing plug launching apparatus for use in cementing a casing string in a well in which a casing closure is releasably attached to the upper end of the casing string, the closure having a cement conduit opening therethrough and in which a cementing plug is releasably supported below the closure by the cement conduit, the plug being separable from the cement conduit upon introduction of a ball into the cement flowing into the casing through the conduit.