Electromagnetic drilling apparatus

A motor and bit combination for use in a drilling operation for forming boreholes, said motor having the form of an annular body, said annular body having an upper end opposed to a lower end, said upper end has means by which the motor annular body can be attached in supported relationship respective to a drill string;

• said bit has an annular body having a lower end opposed to an upper end, attachment means rotatably attaching said lower end of the motor annular body to said upper end of the bit annular body;
• said bit annular body has a cylindrical upper marginal end and vertical slots formed in the lower marginal end thereof;
• blades reciprocatingly received in the slots, an axial support member having a lower end and an upper end;
• said blades being attached to the lower end of said axial support member, means by which the upper end of said axial support member is captured respective to said bit annular body in a manner to reciprocate vertically respective thereto, and means by which said motor is attached to the upper end of said axial support member for imparting vibratory motion into said blades;
• means forming a primary and secondary electrical winding within said motor annular body, means forming a fluid flow passageway through said motor annular body, electrical conductor means by which a source of current can be connected to said primary winding;
• means arranged the primary and secondary windings within said motor annular body whereby current flow through the primary winding induces current flow through the secondary winding;
• and means including a repulsion coil associated with said secondary winding for vibrating said blades of said bit.

In an apparatus for forming a borehole that includes a drill string having an electric motor and a drill bit connected at the lower end thereof, an axial passageway formed through said string through which drilling fluid can flow through said motor and to a lower face of said bit;

• wherein said motor is connected to drive said bit;
• the improvement comprising:
• said drill string includes electric conducting members electrically insulated from one another and forming separate current flow paths for conducting current from the upper end of the string to the motor;
• said electric motor includes an eddy current plate and a pulse transformer having induction coils arranged to reciprocate said eddy current plate;
• means mounting said bit respective to said motor to cause at least part of said bit to vibrate in response to movement of said eddy current plate;
• said bit has a main body, means attaching said main body to said motor, a plurality of bit blades said means mounting said bit includes mounting the blades for reciprocation respective to said main body, and the last said means is connected to cause said eddy current plate to vibrate said bit blades.

A bit and motor for forming boreholes, said bit having a main body that has an upper opposed to a formation engaging end, and said motor has an upper end opposed to a lower end, means for removably connecting the upper end of the motor at the lower end of a drill string;

• means rotatably attaching said upper end of the bit body to said lower end of the motor;
• said motor includes an eddy current plate and a pulse transformer having induction coils arranged to vibrate said eddy current plate;
• cutter means mounted on said bit and connected to said eddy current plate to cause said cutter means of said bit to vibrate in response to movement of said eddy current plate;
• and electric conducting members electrically insulated from one another and forming separate current flow paths for conducting current to the motor;
• whereby, when the pulse transformer is energized, the eddy current plate vibrates and whereby imparts vibratory motion into said cutter means of the bit.

A motor and drill bit for use downhole in a borehole, said motor has an annular housing attachment means located on the lower end of said housing by which said drill bit can be attached thereto;

• attachment means located on the upper end of said housing by which said motor can be connected at the lower end of a drill string;
• said bit has a plurality of cutting members mounted for movement therein, a support member for moving said cutting members, and means connecting said support member to be moved by said motor;
• means forming a primary and secondary electrical winding within the motor housing, means forming a fluid flow passageway through said housing and bit, electrical conductor means by which a source of current can be connected to said primary winding;
• means arranging said primary and secondary windings within said motor housing whereby current flow through the primary winding induces current flow through the secondary winding;
• and means including a repulsion coil associated with said secondary winding for moving said support member and thereby vibrating said cutting members of said bit.