Abstract: A power swivel particularly adapted for downhole cementing operations. The power swivel includes a housing having a fluid passageway therethrough and a stem assembly mounted for rotational movement with respect to the housing and having a fluid passageway communicating with the housing passageway. A hollow bore motor mounted with the housing receives the stem assembly through a central bore of the motor and rotates the stem assembly with respect to the housing.

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.