Low headroom confined space geoexchange drilling system and method

Abstract

A low headroom confined space drilling system is disclosed, comprising a low headroom drilling apparatus, a drilling fluid supply system, a drilling fluid collection system, and a drilling fluid recycling apparatus for supplying a recycled drilling fluid to the drilling apparatus. A method of installing a geoexchange borehole in an interior space of a building is also disclosed, comprising installing a borehole access chamber in a floor slab of a building, positioning a low headroom floor mounted rotary drilling apparatus over the borehole access chamber, providing a pressurized drilling fluid to the drill rod string and powering a rotary downhole drilling device attached to the drill rod string to advance the borehole to a desired depth, recovering a drilling fluid and drill cuttings from the borehole, removing drill cuttings from the recovered drilling fluid using the drilling fluid recycling apparatus and returning a recycled drilling fluid to the drilling apparatus.

What is claimed is: 
     
         1 . A method of installing a geoexchange borehole in an interior space of a building, comprising:
 installing a borehole access chamber in a floor slab of said building at a desired borehole location;   positioning a low headroom floor supported rotary drilling apparatus comprising a drill rod string over the borehole access chamber at the desired borehole location;   providing a pressurized drilling fluid to said drill rod string of said drilling apparatus with a drilling fluid supply system and powering a rotary downhole drilling device attached to said drill rod string to advance said borehole to a desired depth;   recovering a drilling fluid and drill cuttings returned from said borehole during drilling and removing said drilling fluid and drill cuttings from at least one of:
 said borehole; 
 said borehole access chamber and; 
 a drilling fluid splash pan installed over said borehole access chamber; 
 and conveying said drilling fluid and drill cuttings to a drilling fluid recycling apparatus using a drilling fluid recovery system; 
   removing at least a substantial portion of said drill cuttings from said recovered drilling fluid and drill cuttings using said drilling fluid recycling apparatus; and   returning a recycled drilling fluid substantially cleaned of said drill cuttings to said drilling apparatus using said drilling fluid supply system.   
     
     
         2 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 1 , additionally comprising:
 automatically providing and handling threaded drill rod sections from an automated drill rod loading apparatus to said drill rod string of said drilling apparatus.   
     
     
         3 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 1 , additionally comprising:
 installing at least one return loop of geoexchange piping in said geoexchange borehole.   
     
     
         4 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 1 , wherein positioning said rotary drilling apparatus additionally comprises securing said rotary drilling apparatus to said floor slab. 
     
     
         5 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 1 , wherein said drilling fluid comprises water and said rotary downhole drilling device comprises a pressurized water downhole hammer drill. 
     
     
         6 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 1 , wherein said drilling fluid recycling apparatus comprises at least one primary shaking screen particle separator and at least one primary cyclonic particle separator. 
     
     
         7 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 6 , wherein said drilling fluid recycling apparatus further comprises at least one drill cuttings holding hopper and at least one drill cuttings disposal container. 
     
     
         8 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 5 , wherein said drilling fluid supply system comprises a polishing filter, at least one holding tank, and a high pressure drill water supply pump. 
     
     
         9 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 1 , wherein said drilling fluid collection system comprises at least one drilling fluid collection tank, and at least one sludge lift pump fluidly connected to said drilling fluid recycling system. 
     
     
         10 . The method of installing the geoexchange borehole in the interior space of the building according to  claim 3 , additionally comprising:
 grouting said loop of geoexchange piping in said geoexchange borehole.   
     
     
         11 . A low headroom confined space drilling apparatus comprising:
 a floor supported base frame;   a drill mast rotatingly mounted to said base frame for elevation to a substantially vertical drilling position;   a rotary drill head motor axially extendably mounted to said drill mast for rotating a drill rod string; and   an automated drill rod loading apparatus attached to said base frame and comprising:
 a drill rod caddy containing at least one threaded drill rod section; and 
 at least one extendable pivoting arm operable to automatically retrieve and handle a threaded drill rod section for attachment to said drill rod string. 
   
     
     
         12 . The low headroom confined space drilling apparatus according to  claim 11 , additionally comprising
 a pressurized water powered water hammer drill attached a lower end of said drill rod string; and   a high pressure water pump fluidly attached to said water hammer drill through said drill rod string.   
     
     
         13 . The low headroom confined space drilling apparatus according to  claim 11 , additionally comprising a vertical ceiling jack mounted to a top end of said drill mast for forceably engaging a ceiling surface above said floor slab. 
     
     
         14 . A drilling fluid recycling system for removing at least a substantial portion of drill cuttings particles from a drilling fluid, the recycling system comprising:
 an inlet for receiving a drilling fluid and drill cutting particle mixture;   at least one primary shaking screen particle separator for separating a portion of said drill cuttings particles from said received mixture;   at least one primary slurry pump and primary cyclonic particle separator for separating a further portion of said drill cuttings particles from said mixture;   at least one secondary shaking screen particle separator for separating yet a further portion of said drill cuttings particles from said received mixture;   at least one secondary slurry pump and secondary cyclonic particle separator for separating a final portion of said drill cuttings particles from said mixture and for discharging a recycled drilling fluid stream cleaned of said substantial portion of said drill cuttings particles;   at least one drill cuttings hopper for receiving said separated portions of said drill cuttings particles from said primary and secondary shaking screen separators and said primary and secondary cyclonic separators; and   at least one disposal container for accumulating said separated drill cuttings particles for disposal.   
     
     
         15 . The drilling fluid recycling system according to  claim 14 , wherein said recycling system is enclosed in a standard modular metal shipping container.