Dual Motor Bidirectional Drilling

Abstract

The present invention discloses methods and apparatus for utilizing a downhole electric motor or motors for drilling in a well casing using a combination retrieval/electric conduit cable capable of reliability supplying sufficient electric power to drive the electric motor(s) and other components or a separate retrieval cable and electric conduit where the electrical conduit in attached to or disposed in the casing pipe wall. The electric motors may be combined with mud motors. The casing may be a combination drill pipe/casing in which the combination drill/casing pipes is rotated to rotate the drill bits, preferable in combination with downhole drive motors.

1 . A system for drilling a well comprising:
 a) a well casing consisting of pipe joints connected together in a way to allow rotation of the joints in clockwise or counterclockwise direction;   b) a bottom hole assembly disposed in the connected pipe joints having a drill bit that is effective for rotation in a clockwise or counterclockwise direction;   c) an electric motor or motors of sufficient power to drive the drill bit and which can be operated to rotate the drill bit in a clockwise or counterclockwise direction; and   d) means for supplying sufficient electric power to the electric motor or motors to drive the drill bit.   
     
     
         2 . The system of  claim 1  wherein the system is suspended from a cable having electrical conduits releasably connecting the electric motor and components of the bottom hole assembly. 
     
     
         3 . The system of  claim 2  wherein the cable is constructed of discrete lengths of different diameters, the smallest diameter cable being the cable nearest the bottom hole assembly. 
     
     
         4 . The system of  claim 1  wherein the means for supplying electric power is electrical conduits disposed in or attached to the pipe joint with means to electrically connect the conduits electrically at each joint connection. 
     
     
         5 . The system of  claim 4  wherein the pipe joints are composite polymer pipe. 
     
     
         6 . The system of  claim 1  comprising a mud motor in addition to the electric motor or motors. 
     
     
         7 . The system of  claim 1  wherein the pipe joints are connected together with a connection comprising a first pipe joint having a top end and bottom end and in which the bottom end is tapered with a shoulder on the taper configured to fit into the top end of second pipe joint having a top end and bottom end that has a side walls describing an annular space to receive the taper bottom end of the first joint and which has a shoulder configured to mate with the shoulder of the first joint when the first and second pipe joints are pressed together. 
     
     
         8 . The system of  claim 1  wherein the pipe joints are connected together with a connection comprising a first pipe joint having a top end and bottom end and a second pipe joint having a top end and bottom end that has a side walls describing an annular space with an inside wall to receive the bottom end of the first joint and which has a retractable lock pin in an inside wall of the annular space of the second pipe that is configured to engage an opening in a wall of the first joint. 
     
     
         9 . The system of  claim 1  wherein the pipe joints are connected together with a connection comprising a first pipe joint having a top end and bottom end and a second pipe joint having a top end and bottom end that has a side walls describing an annular space with an inside wall to receive the bottom end of the first joint and which a fast-drying adhesive is placed between the annular space of the second pipe and the bottom end of the first pipe. 
     
     
         10 . The system of  claim 7  comprising means to connect an electrical conduit in the first pipe joint to an electrical conduit in the second pipe joint to make a secure electrical connection. 
     
     
         11 . The system of  claim 8  comprising means to connect an electrical conduit in the first pipe joint to an electrical conduit in the second pipe joint to make a secure electrical connection. 
     
     
         12 . The system of  claim 1  wherein the connected pipe joints are connected to the bottom hole assembly and configured in a manner to allow rotation of the connected pipe joint to rotate the drill bit disposed in the bottom hole assembly. 
     
     
         13 . A method of drilling wells comprising:
 1) providing
 a) a well casing consisting of pipe joints connected together in a way to allow rotation of the joints in clockwise or counterclockwise direction; 
 b) a bottom hole assembly disposed in the connected pipe joints having a drill bit and retractable under reamer that is effective for rotation in a clockwise or counterclockwise direction; 
 c) an electric motor or motors of sufficient power to drive the drill bit and retractable under reamer and which can be operated to rotate the drill bit in a clockwise or counterclockwise direction; and 
 d) means for supplying sufficient electric power to the electric motor or motors to drive the drill bit and retractable under reamer; 
   2) providing electric power to the electric motor to rotate the drill bit and retractable under reamer in a clockwise direction;   3) periodically changing direction of rotation of the motor to rotate the drill bit in a counterclockwise direction.   
     
     
         14 . The method of  claim 13  wherein:
 the bottom hole system is suspended from a cable having electrical conduits releasably connecting the electric motor and components of the bottom hole assembly and wherein the cable is constructed of discrete lengths of different diameters, the smallest diameter cable being the cable nearest the bottom hole assembly or wherein the means for supplying electric power is electrical conduits disposed in or attached to the pipe joint with means to electrically connect the conduits electrically at each joint connection. 
 
     
     
         15 . The method of  claim 13  wherein the pipe joints are composite polymer pipe. 
     
     
         16 . The method of  claim 13  comprising a mud motor in addition to the electric motor or motors. 
     
     
         17 . The method of  claim 13  wherein the connected pipe joints are connected to the bottom hole assembly and configured in a manner to allow rotation of the connected pipe joint to rotate the drill bit and retractable under reamer disposed in the bottom hole assembly and the bottom hole assembly is reversibility attached to the drill pipe and the drill rotated in a clockwise or counterclockwise direction 
     
     
         18 . The method of  claim 17  wherein the drill bit and retractable under reamer is rotated by an electric motor, a mud motor and rotation of the connected pipe joints.