Oil Well Plug Apparatus and Method

Abstract

An oil well plug apparatus and method for sealing oil and gas well casings has a plug assembly with an elongate plug body. A spinning knurled bit is attached by a shaft and bearing assembly to a first tapered end of the plug body. A seal disposed on the opposing second end of the plug body fills the clearance between the plug body and a well casing when the plug body is lowered into the casing. The plug assembly includes an anchor to which a chain and cable are attached for suspending and lowering the plug assembly into the casing of a blown out well. The chain reinforces concrete back-fill and a concrete mound capping the well. The cable is severed to release the tethered control of the plug assembly from above.

1 . An plug assembly for plugging the casing of a well comprising:
 an elongate plug body having a first end and an opposite second end with an intermediate elongate portion between the opposing first and second ends;   a bit attached to a first end of the plug body, said bit including a top portion with a broad shoulder adjacent to where the bit is attached to the plug body and including a base with a narrow tip extending away from the plug body;   a seal on the plug body disposed toward the second end of the plug body; and   an anchor attached to the second end of the plug body for suspending and lowering the plug assembly.   
     
     
         2 . A plug assembly for plugging the casing of a well as in  claim 1  in which said plug body includes a friction reducing coating. 
     
     
         3 . A plug assembly for plugging the casing of a well as in  claim 2  in which said friction reducing coating comprises at least three layers of epoxy. 
     
     
         4 . A plug assembly for plugging the casing of a well as in  claim 1  in which said first end of the plug body includes a tapered portion that includes a first narrowing. 
     
     
         5 . A plug assembly for plugging the casing of a well as in  claim 4  in which said tapered portion includes an additional second narrowing. 
     
     
         6 . A plug assembly for plugging the casing of a well as in  claim 1  in which said bit includes knurl blades. 
     
     
         7 . A plug assembly for plugging the casing of a well as in  claim 6  in which said knurl blades are arranged with the direction of each knurl blade curving upward from the narrow tip on the base to the broad shoulder on the top of said bit. 
     
     
         8 . A plug assembly for plugging the casing of a well as in  claim 1  in which said bit rotates and spins on the first end of the plug body. 
     
     
         9 . A plug assembly for plugging the casing of a well as in  claim 8  in which said bit is attached to the first end of the plug body by a bearing assembly and a shaft for spinning rotation of the bit. 
     
     
         10 . A plug assembly for plugging the casing of a well as in  claim 1  in which said seal includes three spaced rubberized members attached to the circumference of the plug body and said rubberized members are flexible and compressible. 
     
     
         11 . A plug assembly for plugging the casing of a well as in  claim 1  in which said plug body includes a guidance system for guiding the plug assembly to a mouth of the casing. 
     
     
         12 . A plug assembly for plugging the casing of a well as in  claim 11  in which said guidance system includes a global position satellite receiver for transmitting the location of the plug assembly to a remote control station. 
     
     
         13 . A plug assembly for plugging the casing of a well as in  claim 11  in which said guidance system includes a magnetic guidance sensor for locating the plug assembly within the mouth of the casing. 
     
     
         14 . A plug assembly for plugging the casing of a well as in  claim 1  including a chain and said chain attached to the anchor and being a length measured for reinforcement of a sealant back-fill material and a sealant mound material capping the well. 
     
     
         15 . A plug assembly for plugging the casing of a well as in  claim 1  including a cable attached to the chain for temporarily tethering the plug assembly to a platform, ship or boom. 
     
     
         16 . A method for plugging the casing of a well comprising the steps of:
 a. providing an elongate plug body with a bit on a first end and an anchor with a chain attached on a second end to form a plug assembly;   b. suspending the plug assembly with the chain and a cable attached to the chain;   c. lowering and guiding the plug assembly to a mouth of the well casing;   d. inserting the plug body into the well casing a determined distance with the chain extending upward through the mouth of the casing;   e. pouring sealant material into the casing above the plug body to fill the casing, said sealant material being reinforced by the chain extending through the sealant material;   f. pouring a mound of sealant material over the mouth of the casing; and   g. detaching the cable.   
     
     
         17 . A method for plugging the casing of a well as in  claim 16  including an additional step of providing said bit with knurled blades and a further step of spinning the bit as the bit moves through water. 
     
     
         18 . A method for plugging the casing of a well as in  claim 16  including an additional step of using a global position satellite receiver or magnetic guidance sensor to position the plug body into the mouth of the casing. 
     
     
         19 . A method for plugging the casing of a well as in  claim 16  including an additional step of sealing the plug body within the casing after the plug body is inserted using a rubber seal near the second end of the plug body to fill a clearance gap between the plug body and an interior wall of the casing. 
     
     
         20 . A method for plugging the casing of a well as in  claim 16  in which said sealant material is concrete or cement.