Downhole Robotic Micro-Drilling System

Abstract

The invention relates to the completion and enhancement of oil and gas wells. The invention provides for a downhole tool which: enters vertical or horizontal wells located adjacent to the oil and gas bearing formation, parts the casing and extends outward forming micro-boreholes necessary to remove residual oil and gas which remain in place. After the initial fluid production has been harvested, the invention can be employed on new or old wells and can operate in all conditions which wells encounter during the standard drilling process. The process of micro-holes can replace the process known as “fracking”. Fracking is being employed; however the process is being reviewed due to safety of human life. The invention employs special alloys and procedures to form the extended reach micro-boreholes.

1 . A downhole drilling system for drilling micro-holes in earth formations comprising: a surface control unit which programs the action of the downhole tool and provides high-pressure fluid pressure to the downhole tool which in turn, by robotic action, parts the casing and drills a micro-hole to a general location, which is pre-programmed from the surface for the enhancement of oil and gas production. 
     
     
         2 . A method of  claim 1  to extend a micro-borehole outward into an oil and gas formation allowing the general attitude of the borehole to be as planned and to rotate the vertical borehole to a horizontal borehole in a distance less than 30′-0″. 
     
     
         3 . A system of  claim 1  of casing inserts which are mounted into the standard protective casing allowing the inserts to be placed in a planned location allowing the casing string to be parted employing a mill/bit, which, due to the insert material, allows many cycles to occur without replacement of the mill/bit downhole. 
     
     
         4 . A method in which a hex-shaped guide tube is allowed to exit the casing into the formation cased into the formation allowing a pre-determined radius to be formed by the mill/bit, which extends into the oil and gas formation and the radius is formed via the bent section located at the end section of the extension tube. 
     
     
         5 . A guide tube as set forth in  claim 4 , which is constructed of a carbon fiber material or the like, which has strength qualities in torsion resistance of a high magnitude and the axial bending is of very low resistance thereby allowing the guide tube to retain its tolerance when loaded by torsional forces and will bend an axial load at a very low magnitude of force. 
     
     
         6 . The extension tube is equipped with a disconnect assembly which allows the tube to assist in providing a 90° turn and by a robotic event allows the drilling string to go forward into the formation at a given angle to a pre-determined distance and return to the guide tube all allowing retraction of the guide tool into the downhole tool. 
     
     
         7 . A mill/bit to be employed for the purpose of parting the casing and extending outward into the formation causing a micro-borehole to be found at a specific distance from the protection casing. 
     
     
         8 . A mill/bit extension tube as set forth in  claim 6  is provided to allow the rotating assembly to bend to the shape and direction of the guide tube by employing a special alloy such as NiTi material having a small tube diameter resulting in a small section modulus and having mounted along the axis spherical guides which supports the small diameter tube and provides lateral stability of the extension tube which is loaded by compression forces. 
     
     
         9 . A system which allows the extension tube as set forth in  claim 6  to be disconnected from the guide tube in an automatic and robotic fashion and once the guide tube is disconnected, the extension tube is allowed to travel to the designated distance and once the extension tube has completed its travel, it is extracted causing the extension tube to reenter the tool casing causing the guide tube to also be retracted into the tool casing. 
     
     
         10 . A system which allows the downhole tool to be located at different intervals along the axis of the casing employing the landing nipples to be engaged thereby locating the micro-hole formation and to anchor the tool to avoid any axial movement. 
     
     
         11 - 13 . (canceled) 
     
     
         14 . A drilling system, which provides completion fluids to be cleaned from solids at a level lower than 5 microns thereby allowing the formation to be clear of any particles, which are introduced from the completion fluids. 
     
     
         15 . A drilling system, as set forth in  claim 8  which indicates the cycle milestones, which have been completed, and identifies the completion of the drilling event. 
     
     
         16 . (canceled) 
     
     
         17 . A drilling system as described in  claim 9 , which allows the placement of clusters of micro-boreholes to replace oil and gas formation fracking process with a controlled and predictable program employing micro-boreholes.