Two-phase isolation methods and systems for controlled drilling

Abstract

There is provided a system and method for having multiple movable isolation zones within a borehole, to provide for zones having predetermined properties, such as pressure, flow or optical properties. These movable isolation zones provide advantages in downhole activities, such as, laser cutting and laser drilling to advance a borehole.

What is claimed: 
     
         1 . A method of advancing a borehole using a two-phase isolation drilling system, the method comprising:
 a. positioning a bottom hole assembly in association with a conveyance device in a borehole, the borehole having a sidewall surface, a bottom surface and a start, the conveyance device having an inflow path and a return path;   b. the bottom hole assembly comprising:
 i. an isolation means; 
 ii. a bit, and 
 iii. an inflow path and a return path; 
   c. wherein, the bottom hole assembly inflow path is in fluid communication with the conveyance device inflow path and the bottom hole assembly return path is in fluid communication with the conveyance device return path;   d. activating the isolation means into sealing engagement with the borehole sidewall surface, wherein the borehole is divided into a first and a second isolation zone, such that the second isolation zone includes the borehole bottom surface;   e. filling the first isolation zone of the borehole with a first medium, such that a predetermined pressure on the borehole surfaces in the first isolation zone is maintained by the first medium;   f. circulating a second medium through the input path of the conveyance device, the input path of the bottom hole assembly, through the bit, through the return path of the bottom hole assembly, and through the return path of the conveyance device; and,   g. engaging the bit against a surface of the borehole and while apply a pressure to the bit, rotating the bit against the borehole surface;   h. whereby, material is removed from the borehole surface and the removed borehole material is transported by the circulating second medium through the return path of the bottom hole assembly and the return path of the conveyance device, such that removed borehole material does not substantially contact the borehole surfaces of the first isolation zone.   
     
     
         2 . The method of  claim 1 , wherein a high power laser beam having at least about 15 kW of power, is directed through the bottom hole assembly and strikes the borehole surface. 
     
     
         3 . The method of  claim 2 , wherein the isolation means is a sealing engagement device. 
     
     
         4 . The method of  claim 2 , wherein the isolation means is an inflatable packer. 
     
     
         5 . The method of  claim 2 , wherein the isolation means is a slidable engagement device. 
     
     
         6 . The method of  claim 2 , wherein the first medium is a drilling liquid. 
     
     
         7 . The method of  claim 6 , wherein the drilling liquid is a drilling mud. 
     
     
         8 . The method of  claim 2 , wherein the second medium is a fluid transmissive to the laser beam. 
     
     
         9 . The method of  claim 2 , wherein the second medium is nitrogen. 
     
     
         10 . The method of  claim 1 , wherein thermal energy is direct by the bottom hole assembly toward the borehole surface. 
     
     
         11 . The method of  claim 1 , wherein a particle stream is directed by the bottom hole assembly toward the borehole surface. 
     
     
         12 . The method of  claim 2 , wherein the bit is rotated by an electric motor. 
     
     
         13 . The method of  claim 5 , wherein the bit is rotated by an electric motor. 
     
     
         14 . A method of controlled down hole cutting using liquids, gases and high power laser energy, the method comprising:
 a. providing a first isolation zone in a borehole, having a fluid;   b. providing a second isolation zone adjacent a surface in the borehole to be cut, the second isolation zone movably associated with the first isolation zone;   c. flowing a gas into the first isolation zone; and,   d. directing a high power laser beam along a laser beam path to the surface in the borehole, whereby material is cut from the surface by the laser beam; and,   e. moving an isolation zone in association with moving the laser cutting, so that the fluid does not substantially interfere with the laser beam.   
     
     
         15 . A system for advancing a borehole while simultaneously using a two-phase medium, the system comprising:
 a. a bottom hole assembly;   b. a bottom hole assembly housing;   c. a conveyance device affixed to the bottom hole assembly housing;   d. the bottom hole assembly comprising a rotating section and a non-rotating section;   e. a sealable engagement member; and,   f. the bottom hole assembly comprising at two isolated fluid paths.   
     
     
         16 . The system of  claim 15 , wherein the bottom hole assembly comprises high power laser optics and a high power laser beam path. 
     
     
         17 . A system for advancing a borehole while simultaneously using a two-phase medium, the system comprising:
 a. a laser bottom hole assembly;   b. a laser bottom hole assembly housing;   c. a conveyance device affixed to the laser bottom hole assembly housing;   d. the bottom hole assembly comprising a rotating section and a non-rotating section;   e. a sealable engagement member; and,   f. the bottom hole assembly comprising at least two isolated fluid paths.   
     
     
         18 . The system of  claim 17 , wherein the laser bottom hole assembly comprises an electric motor. 
     
     
         19 . The system of  claim 17 , wherein the laser bottom hole assembly comprises a mud motor. 
     
     
         20 . The system of  claim 17 , wherein the laser bottom hole assembly comprises a second sealable engagement member and a piston advancement means. 
     
     
         21 . A system for advancing a borehole comprising:
 a. a laser bottom hole a assembly having at least two portions;   b. a means for delivering a high power laser beam;   c. a means for convey high power laser energy to the bottom hole assembly; the conveyance means in optical association with the laser bottom hole assembly;   d. a means for rotating a portion of the laser bottom hole assembly;   e. a means for maintaining the relative position of the laser bottom hole assembly within the borehole;   f. the positioning means comprising a means for forming an isolation zone; and,   g. a means for advancing the laser bottom hole assembly.   
     
     
         22 . The system of  claim 18 , whereby the advancing means is selected from the group constitutes a tractor, a force from the weight of drilling collars, a piston means, or a force from the weight of a drilling fluid. 
     
     
         23 . A method of particle drilling to advance a borehole comprising the steps of:
 a. setting an sealable engagement member in a borehole to create a first and second isolation zone;   b. filling the first isolation zone with a drilling liquid; and,   c. circulating through the second isolation zone a drilling fluid comprising particles;   d. whereby the particle containing fluid impinges upon a borehole surface to in part advance the borehole, such that the particles are isolated from the second isolation zone.