Patent ID: 7861781

Claim:
A well casing cement plug assembly, comprising: a receptacle for location at a lower portion of a string of casing, the receptacle having an axial passage therethrough; a wiper plug adapted to be pumped down the string of casing into engagement with the receptacle; a prong on the wiper plug that stabs into the axial passage, the prong having an axial passage seal that blocks the axial passage; the prong and the receptacle having cooperative latch members located in a lower portion of the receptacle to lock the wiper plug to the receptacle; wherein the receptacle comprises: a body through which the axial passage extends; a lower seal mounted to a lower end of the body and through which the axial passage extends; and wherein the latch members are located within the body and the axial passage seal is located within the lower seal when the prong is locked to the receptacle.