System for running tubular members

Abstract

The present invention relates to a wiper plug and internal drop ball mechanism that may be used in conjunction with a downhole surge reduction tool to run, hang, and cement casing liners in a wellbore. The apparatus of the present invention comprises a wiper plug assembly removably attached to the drill string within the casing liner, a drop ball sub attached below the wiper plug assembly which releases a float valve actuator ball having a diameter larger than the drill string, and float equipment having a plurality of flapper valves. The apparatus of the present invention may further comprise a diverter tool connected between the drill string and the casing liner.

What is claimed is:  
     
         1 . A drop ball mechanism for holding and releasing a drop ball within a tubular member being run on a drill string in a wellbore containing drilling fluid, said drop ball connected to the lower end of a wiper plug assembly for arrangement within the tubular member, and said drop ball having a diameter greater than the inside diameter of the drill string.  
     
     
         2 . The drop ball mechanism of  claim 1 , wherein the wiper plug assembly is releasably connected to the drill string within the tubular member near the top of the tubular member, said wiper plug assembly having an axial bore therethrough, and said wiper plug assembly including a receptacle in the axial bore for receiving a drill pipe dart.  
     
     
         3 . The drop ball mechanism of  claim 2 , wherein the tubular member includes float equipment attached near the bottom of the tubular member, said float equipment having an axial bore with a diameter greater than the inside diameter of the drill string, said float equipment including a plurality of flapper valves which are activated by the drop ball after it is released from connection with the wiper plug assembly.  
     
     
         4 . The drop ball mechanism of  claim 3 , further comprising a drop ball housing for releasably connecting the drop ball to the wiper plug assembly.  
     
     
         5 . A wiper plug assembly for use in pumping down a tubular member connected to a drill string, said wiper plug assembly comprising: 
 a wiper plug having an upper end, a lower end, and an axial bore formed therethrough, said wiper plug having a receptacle formed within the axial bore for receiving a drill pipe dart; and    a drop ball having a diameter greater than the inside diameter of the drill string, said drop ball releasably connected to the lower end of the wiper plug.    
     
     
         6 . The wiper plug assembly of  claim 5 , further comprising a drop ball housing for releasably connecting the drop ball to the lower end of the wiper plug.