Magnetic bit sub

Abstract

A magnetic bit sub for collecting ferrous metal particles from oil wells, gas wells, and water wells during well drilling operations, well completion operations, and well maintenance operations provides tubular member with a threaded male connector on the upper end, for attachment to a drill string, and a threaded female connector on the lower end, for attachment to a drill bit, another portion of drill string, or another magnetic bit sub. Permanent magnets removably secured within recesses spaced along the outer surface of the tubular member collect ferrous metal particles coming into the proximity of the recessed permanent magnets for removal when the drill string is removed from the well.

1 . A magnetic bit sub for collecting ferrous metal particles from oil wells, gas wells, and water wells during well drilling operations, well completion operations, and well maintenance operations, the magnetic bit sub comprising:
 a tubular member having a threaded male connector on one end for attachment to a length of pipe, the tubular member further having a plurality of recesses spaced along the outer surface of the tubular member;   a plurality of permanent magnets, each magnet being disposed within one of the plurality of recesses;   securing means for securing the permanent magnets within the recesses; and   wherein ferrous metal particles coming into the proximity of the permanent magnets are attracted to the permanent magnets and held in place for removal when the length of pipe is removed from the well.   
   
   
       2 . The device of  claim 1 , wherein the tubular member further has a threaded female connecter at the other end for attachment to another length of pipe or to a drill bit. 
   
   
       3 . The device of  claim 2 , wherein the plurality of permanent magnets secured within the recesses spaced along the outer surface of the tubular member further comprises at least eight recessed permanent magnets arranged in an array along the outer surface of the tubular member, wherein the array consists of four sets of two recessed permanent magnets, wherein the recessed permanent magnets within each set of two recessed permanent magnets are aligned along the length of the tubular member, and wherein each set of two aligned recessed permanent magnets is located in a different quadrant around the circumference of the tubular member. 
   
   
       4 . The device of  claim 2  wherein the plurality of permanent magnets secured within recesses spaced along the outer surface of the tubular member further comprises at least twelve recessed permanent magnets arranged in a first array along the outer surface of the tubular member, wherein the first array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, and wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member. 
   
   
       5 . The device of  claim 4  wherein the plurality of permanent magnets secured within recesses spaced along the outer surface of the tubular member further comprises a second array of twelve recessed permanent magnets along the outer surface of the tubular member, wherein the second array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member, and wherein the sets of three recessed permanent magnets in the second array are shifted about 45 degrees around the circumference of the tubular member with respect to the sets of three recessed permanent magnets in the first array. 
   
   
       6 . The device of  claim 5  wherein the plurality of permanent magnets secured within recesses spaced along the outer surface of the tubular member further comprises a third array of twelve recessed permanent magnets along the outer surface of the tubular member, wherein the third array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member, and wherein the sets of three recessed permanent magnets in the third array are aligned with the sets of three recessed permanent magnets in the first array. 
   
   
       7 . The device of  claim 6  wherein the plurality of permanent magnets secured within recesses spaced along the outer surface of the tubular member further comprises a fourth array of twelve recessed permanent magnets arranged along the outer surface of the tubular member, wherein the fourth array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member, and wherein the sets of three recessed permanent magnets in the fourth array are aligned with the sets of three recessed permanent magnets in the second array. 
   
   
       8 . The device of  claim 7  wherein the plurality of permanent magnets secured within recesses spaced along the outer surface of the tubular member further comprises a fifth array of twelve recessed permanent magnets arranged along the outer surface of the tubular member, wherein the fifth array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member, and wherein the sets of three recessed permanent magnets in the fifth array are aligned with the sets of three recessed permanent magnets in the first and third arrays. 
   
   
       9 . The device of  claim 8  wherein the plurality of permanent magnets secured within recesses spaced along the outer surface of the tubular member further comprises a sixth array of twelve recessed permanent magnets arranged along the outer surface of the tubular member, wherein the sixth array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member, and wherein the sets of three recessed permanent magnets in the sixth array are aligned with the sets of three recessed permanent magnets in the second and fourth arrays. 
   
   
       10 . The device of  claim 2  wherein the permanent magnets are secured within the recesses by snap rings. 
   
   
       11 . The device of  claim 2  wherein the recesses are threaded and the permanent magnets are secured within the recesses by threaded retaining rings. 
   
   
       12 . The device of  claim 2  wherein the permanent magnets are secured within the recesses by an adhesive. 
   
   
       13 . The device of  claim 2  wherein the permanent magnets have a center counterbore, wherein each recess has a centered threaded radial bore, and wherein a threaded bolt through the center counterbore of each magnet mates with the centered threaded radial bore in each recess in the outer surface of the tubular member. 
   
   
       14 . The device of  claim 2  wherein the permanent magnets are alnico magnets. 
   
   
       15 . The device of  claim 4  wherein the tubular member is further characterized as having an upper portion, an intermediate portion, and a lower portion, and wherein the first array of recessed permanent magnets is located along the intermediate portion of the tubular member. 
   
   
       16 . The device of  claim 4  wherein the intermediate portion has an outside diameter less than the outside diameter of the remaining upper and lower portions, and wherein the first array of recessed permanent magnets is located along the intermediate portion of the tubular member. 
   
   
       17 . The device of  claim 16  wherein the outside diameter of the intermediate portion is about 2.75 inches and the outside of the upper and lower portions is about 3.75 inches. 
   
   
       18 . A magnetic bit sub for collecting ferrous metal particles from oil wells, gas wells, and water wells during well drilling operations, well completion operations, and well maintenance operations, the magnetic bit sub comprising:
 a member having a threaded male connector on one end for attachment to a length of pipe, the tubular member further having a plurality of recesses spaced along the outer surface of the tubular member;   a plurality of permanent magnets, each magnet being disposed within one of the plurality of recesses;   securing means for securing the permanent magnets within the recesses; and   wherein ferrous metal particles coming into the proximity of the recessed permanent magnets are attracted to the recessed permanent magnets and held in place for removal when the length of pipe is removed from the well.   
   
   
       19 . The device of  claim 18  wherein the plurality of permanent magnets secured within the recesses spaced along the outer surface of the tubular member further comprises at least twelve recessed permanent magnets arranged in a first array along the outer surface of the tubular member, wherein the first array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, and wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member. 
   
   
       20 . The device of  claim 19  wherein the plurality of permanent magnets secured within the recesses spaced along the outer surface of the tubular member further comprises a second array of twelve recessed permanent magnets along the outer surface of the tubular member, wherein the second array consists of four sets of three recessed permanent magnets, wherein the recessed permanent magnets within each set of three recessed permanent magnets are aligned along the length of the tubular member, wherein each set of three recessed permanent magnets is located in a different quadrant around the circumference of the tubular member, and wherein the sets of three recessed permanent magnets in the second array are shifted about 45 degrees around the circumference of the tubular member with respect to the sets of three recessed permanent magnets in the first array.