Patent Publication Number: US-8118115-B2

Title: Method and system for installing geothermal heat exchangers, micropiles, and anchors using a sonic drill and a removable or retrievable drill bit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY 
     The present application is a Continuation-in-part of application Ser. No. 12/035,776, filed Feb. 22, 2008, now U.S. Pat. No. 7,891,440 the disclosures of which are incorporated by reference and to which priority is claimed. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to geothermal heat exchange systems and underground thermal energy storage systems and, in particular, to a method of installing geothermal transfer apparatuses and related underground support structures using a sonic drill and a removable or retrievable drill bit. 
     Geothermal heat exchange systems and underground thermal energy storage systems are environmentally friendly, energy efficient, heating and cooling systems. Accordingly, there is a rising demand for such systems for both commercial and residential buildings. There is therefore a need for a quick and efficient method of installing the geothermal transfer apparatuses used in many geothermal heat exchange systems and underground thermal energy storage systems. There is also a need for a quick and efficient method of installing underground support structures such as cast-in-place concrete piles, micropiles, and anchors which support the buildings housing the heating and cooling systems. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method and system which allows for cased holes to be drilled quickly, and in lithologies that are often difficult for conventional drill rigs to drill. It is also an object of the present invention to provide a method which allows for more accurate control and monitoring of the grouting process. 
     There is accordingly provided a method for drilling a cased hole and installing a geothermal transfer apparatus. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a drill string into the ground. A retrievable drill bit is operatively connected to the drill string. The cased hole is drilled to a desired depth by rotating and vibrating the drill string into the ground. The retrievable drill bit is retrieved from the cased hole following the drilling of the cased hole to the desired depth. A geothermal transfer apparatus is lowered into the cased hole following the retrieval of the retrievable drill bit. Grouting material may be discharged into the cased hole before or after the drill string is removed from the ground. 
     There is also provided a method for drilling a cased hole and installing a cast-in-place concrete pile. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a drill string into the ground. A retrievable drill bit is operatively connected to the drill string. The cased hole is drilled to a desired depth by rotating and vibrating the drill string into the ground. The retrievable drill bit is retrieved from the cased hole following the drilling of the cased hole to a desired depth. Concrete may be discharged into cased hole before or after the drill string is removed from the ground. Alternatively, a geothermal transfer apparatus may be lowered into the cased hole, prior to concrete being discharged into the cased hole, to form an energy pile. A reinforced steel structure may also be used to 
     There is further provided a method for drilling a cased hole and installing a micropile. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a drill string into the ground. A retrievable drill bit is operatively connected to the drill string. The cased hole is drilled to a desired depth by rotating and vibrating the drill string into the ground. The retrievable drill bit is retrieved from the cased hole following the drilling of the cased hole to the desired depth. A micropile is lowered into the cased hole following the retrieval of the retrievable drill bit. Grouting material may be discharged into the cased hole before or after the drill string is removed from the ground. 
     In any of the above described methods a removable drill bit may be used in place of a retrievable drill bit. For example, a sacrificial drill bit which is removed from the drill string prior to the cased hole being grouted may be used. 
     Also provided is a system for drilling the cased holes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is an elevation, partially in section, view illustrating a sonic drilling rig drilling a cased hole; 
         FIG. 2  is an elevation, cross-sectional, view illustrating pressurized fluid being discharged into the hole of  FIG. 1 ; 
         FIG. 3  is an elevation, cross-sectional, view of a retrievable drill bit operatively disposed in the hole of  FIG. 1 ; 
         FIG. 4  is an elevation, cross-sectional, view illustrating a retrieval tool being lowered into the hole of  FIG. 1 ; 
         FIG. 5  is an elevation, cross-sectional, view illustrating the retrieval tool engaging the retrievable drill bit in the hole of  FIG. 1 ; 
         FIG. 6  is an elevation, cross-sectional, view illustrating the retrieval tool and the retrievable drill being removed from the hole of  FIG. 1 ; 
         FIG. 7  is an elevation, cross-sectional, view of a removable drill bit operatively disposed in the hole of  FIG. 1 ; 
         FIG. 8  is an elevation, cross-sectional, view illustrating a removal tool removing the removable drill from cased the hole of  FIG. 1 ; 
         FIG. 9  is an elevation, cross-sectional, view illustrating a geothermal transfer loop being lowered into the hole of  FIG. 1 ; 
         FIG. 10  is an elevation, cross-sectional, view illustrating a co-axial geothermal transfer apparatus being lowered into the hole of  FIG. 1 ; 
         FIG. 11  is a fragmentary, partially in section, view of the co-axial geothermal transfer apparatus of  FIG. 10 ; 
         FIG. 12  is an elevation, partially in section, view illustrating a grouting rig grouting the hole of  FIG. 1 ; 
         FIG. 13  is another elevation, partially in section, view illustrating the grouting rig grouting the hole of  FIG. 1 ; 
         FIG. 14  is an elevation, partially in section, view showing a geothermal transfer loop in the grouted hole of  FIG. 1 ; 
         FIG. 15  is an elevation, partially in section, view illustrating a downhole hammer drilling a hole into a bedrock formation; 
         FIG. 16  is an elevation, partially in section, view showing a geothermal transfer loop in the grouted hole of  FIG. 15 ; 
         FIG. 17  is a perspective view of a heat pump coupled to the geothermal transfer loop of  FIG. 9 ; 
         FIG. 18  is a perspective view of an underground thermal energy storage system; 
         FIG. 19  is an elevation, partially in section, view of a cement truck discharging concrete into the hole of  FIG. 1  during the installation of an energy pile; 
         FIG. 20  is view taken along line A-A of  FIG. 19 ; 
         FIG. 21  is a perspective view of an energy pile; 
         FIG. 22  is an elevation, partially in section, view of a cement truck discharging concrete into the hole of  FIG. 1  during the installation of a cast-in-place concrete pile; 
         FIG. 23  is a perspective view of a cast-in-place concrete pile; 
         FIG. 24  is an elevation, partially in section, view of a grouting rig discharging grout into the hole of  FIG. 1  during the installation of a micropile and anchor; 
         FIG. 25  is a perspective view of a micropile and anchor; and 
         FIG. 26  is a perspective view of a micropile. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings and first to  FIG. 1 , a drilling rig  10  is shown drilling a cased hole  12  into the ground  14 . The drilling rig  10  generally comprises a drilling apparatus  20  mounted on a movable vehicle  50 . The vehicle  50  is at a desired drilling location on the ground surface  15  and the drilling apparatus  20  is in a desired drilling position. A drill pipe  22  is operatively connected to the drilling apparatus  20 . A proximal end  23  of the drill pipe  22  is threadedly connected to the drilling apparatus  20 . A distal end  24  of the drill pipe  22  is connected to a ring bit  26  which is concentric with the drill pipe  22 . The combination of the drill pipe  22  and the ring bit  26  form an open ended drill string  30 . There is a cavity, or inner space  35 , defined by the drill string  30 . A retrievable centre bit  28  is releasably connected to the drill string  30  at the ring bit  26 . 
     In this example, the drilling apparatus  20  is a rotary and vibratory apparatus in the form of a sonic drill. Sonic drills are well known in the art and examples of sonic drills are described in my earlier U.S. Pat. Nos. 5,027,908 and 5,409,070, the complete disclosures of which are incorporated herein by reference. Accordingly, the drilling apparatus  20  is not described in more detail herein. The drilling apparatus  20  rotates and vibrates the drill string  30  into the ground  14 . A hose  42  hydraulically connects a pump apparatus  40  to the drilling apparatus  20 . During the drilling process, pressurized fluid is pumped by the pump apparatus  40  along the hose  42 , through the drilling apparatus  20 , and into the inner space  35  of the drill string  30  as indicated by arrow  44 . 
     As best shown in  FIG. 2 , pressurized fluid flows through passageways  27  and  29  in the retrievable drill bit  28  as indicated by arrows  45  and  46 . The diameter of the hose  42 , shown in  FIG. 1 , is less than the diameter of the inner space  35 , thereby preventing the pressurized fluid from being pushed back through the hose in response to high pressure spikes. The vibrating drill string  30  causes the pressure in the fluid column to oscillate at the same frequency that the drill string is vibrated at. The pressure spikes  38   a ,  38   b , and  38   c  thus created cause the fluid column to act in a manner similar to a water hammer, thereby adding an additional drilling force. 
     At minimum, sufficient pressurized fluid is pumped into the inner space  35  to form a fluid column  37 . This impedes the entry of ground materials through the passageways  27  and  29  in the retrievable drill bit  28  and into the inner space  35 . However, additional pressurized fluid may be pumped into the inner space  35  in order to carry cuttings up the annulus  13 , between the drill string  30  and the ground  14 , to the ground surface  15 . This is illustrated in  FIG. 2 . Arrow  44  indicates the direction of the flow of pressurized fluid into the ground  14  through the inner space  35  of the drill string  30 . The excess pressurized fluid is pushed down and around the retrievable drill bit  28  and up an annulus  13 , towards the surface as indicated by arrows  45  and  46 . The pressurized fluid acts as a cutting fluid and carries cuttings as it moves up the annulus  13  to the ground surface  15  where the pressurized fluid and cuttings are expelled from the cased hole  12  as indicated by arrows  47  and  48 . In this example, the pressurized fluid is water, but water with added components such as polymer or clay may also be used. The pressurized fluid has a pressure range of between 100-5000 psi, with the preferred pressure range being between 500-2000 psi. 
     Additional drill pipes (not shown) may be added to the drill string  30  in sequence. Each additional drill pipe has a first end and a second end. The additional drill pipes are hollow and open at both ends. First ends of the additional drill pipes are threadedly connected to the drilling apparatus  20  and second ends of the additional drill pipes are threadedly connected to the drill string  30 . The additional drill pipes may then be rotated and vibrated into the ground to increase the depth of the cased hole  12 . The additional drill pipes may be added manually or with an automated drill pipe handling apparatus. 
     Referring now to  FIG. 3 , the ring bit  26  and the retrievable drill bit  28  are shown in greater detail. The ring bit  26  is threadedly connected to the drill pipe  22  and has an annular inner wall  41 . An annular recess  43  and annular shoulder  49  extend about the annular inner wall  41  of the ring bit  26 . The recess  43  and the shoulder  49  are generally parallel to and spaced-apart from one another. The retrievable drill bit  28  is disposed within the ring bit  26  and is releasably connected to the ring bit  26 . The retrievable drill bit  28  includes a sleeve portion  51  which rests on the shoulder  49  of the ring bit  26 . A protrusion extends longitudinally outward from the sleeve portion  51  and defines a button bit portion  53  of the retrievable drill bit  28 . Passageways  27  and  29  extend through the button bit portion  53  and allow fluid to flow through the retrievable drill bit  28  as described above. A plurality of dogs, only two of which  54   a  and  54   b  are shown in  FIG. 3 , reciprocatingly extend through corresponding radial openings  55   a  and  55   b  in the sleeve portion  51  of the retrievable drill bit  28 . An annular spring  65  retains at least a portion of the dogs  54   a  and  54   b  within the openings  55   a  and  55   b , and in communication with the sleeve portion  51  of the retrievable drill bit  28 . 
     A frustoconical detent  56  is disposed within the sleeve portion  51  of the retrievable drill bit  28 . There is a flange  57  near a tapered end of the detent  56 . As best shown in  FIG. 3 , when the retrievable drill bit  28  is releasably connected to the ring bit  26 , the detent  56  urges the dogs  54   a  and  54   b  radially outward of the sleeve portion  51  of the retrievable drill bit  28 , and into engagement with the annular recess  43  in inner wall  41  of the ring bit  26 . A shaft  58  with a knob  59  at a remote end thereof extends from the detent  56 . It will be understood by a person skilled in the art that the shaft  58  may be pulled to actuate the detent  56  upwardly from the position shown in  FIG. 3 . When the detent  56  is moved upwardly from the position shown in  FIG. 3  the frustoconical shape of the detent  56  will cease urging the dogs  54   a  and  54   b  into engagement with the recess  43  in the ring bit  26 . The spring  65  then biases the dogs  54   a  and  54   b  into the sleeve portion  51  of the retrievable drill  28  through radial openings  55   a  and  55   b.    
     As shown in  FIGS. 4 to 6 , once the cased hole  12  has been drilled to a desired depth, the drill string  30  is disconnected from the drilling apparatus  20 . As shown in  FIG. 4 , a retrieval tool  61  tethered to a cable  63  is lowered into the drills string  30 . The retrieval tool  61  includes a latch (not shown) which is for engaging the knob  59  on the remote end of the shaft  58  that extends from the detent  56  disposed within the sleeve portion  51  of the retrievable drill bit  28 . As shown in  FIG. 5 , when the retrieval tool  61  engages the knob  59  at the remote end of the shaft  58 , an upward force may be applied to the cable  63  causing the detent  56  to move upwardly and cease urging the dogs  54   a  and  54   b  into engagement with the recess  43  in the ring bit  26 . The spring  65  then biases the dogs  54   a  and  54   b  into the sleeve portion  51  of the retrievable drill  28  through radial openings  55   a  and  55   b . The retrievable drill bit  28  may then removed from the ground  14 , as shown  FIG. 6 , leaving a cased hole  12 . 
     It will be understood by a person skilled in the art that the retrievable drill bit described above is only one example of a drill bit which may be used to install a geothermal transfer apparatus according to the method disclosed herein. Other suitable types of drill bits may also be used. For example, as shown in  FIG. 6 , a removable drill  128  bit may be used. In this example, the removable drill bit  128  is a sacrificial bit which is stitch welded to the drill string  30  as indicated by welds  130   a  and  130   b . However, other means of coupling the removable drill bit  128  to the drill string  30  may be used, for example, a roll pin. Passageways  127  and  129  extend through the removable drill bit  128  to allow fluid to flow through the removable drill bit  128 , as discussed above for the retrievable drill bit  28 . As shown in  FIG. 7 , once the cased hole  12  has been drilled to a desired depth, a removal tool  161  is dropped down the hole. The removal tool  161  knocks the removable drill bit  128  out of the drill string  30  leaving the removable drill bit  128  in the ground  14  when the drill string  30  is removed from the ground  14 . Preferably the removal tool  161  is a metal bar and in some examples it may be tethered to allow for retrieval. 
     Furthermore, variations may be made to the drilling process without departing from the scope method disclosed herein. For example, as shown in  FIG. 15 , in situations where bedrock  114  impedes the drilling process, a downhole hammer apparatus  98  with a downhole drill bit apparatus  99  may be used to hammer into the bedrock  114  in order to drill the hole  12  to the desired depth. 
     Once the hole is drilled, a geothermal transfer apparatus, which is capable of transferring heat to and from the ground  14 , is lowered into inner space  35  of the drill string  30 , i.e. into the cased hole  12 . The geothermal transfer apparatus may be a geothermal transfer loop  70  as shown in  FIG. 9 . Preferably, the geothermal transfer loop  70  is filled with fluid prior to being lowered into the cased hole  12 . In this example, the geothermal transfer loop  70  is a high density polyethylene tube filled with water. The fluid adds weight to the geothermal transfer loop  70  and prevents the geothermal transfer loop  70  from collapsing in any fluid column that may remain in the hole  12 . 
     Weights  75  may also be attached to the geothermal transfer loop  70  to facilitate the lowering of the geothermal transfer loop  70  into the cased hole  12 . A lead portion  71  of the geothermal transfer loop  70  may further be straightened to facilitate the lowering of the geothermal transfer loop  70 , and aid in keeping the geothermal transfer loop  70  at the bottom of the cased hole  12  during the grouting process and withdrawal of the drill string  30 . In this example, the weight  75  is an elongated piece of steel bar that has been attached to the lead portion  71  of the geothermal transfer loop  70  with wiring  76 . The steel bar performs the dual function of a weight and a means for straightening the lead portion  71  of the geothermal transfer loop  70 . Once the geothermal transfer loop  70  has been completely lowered into the hole  12 , the hole  12  is grouted. The hole  12  may be grouted with the drill string  30  remaining in the ground  14  or after the drill string  30  has been removed from the ground. 
     It is known to use geothermal transfer loops in geothermal heat exchange systems as is disclosed in my co-pending U.S. patent application Ser. No. 11/067,225, the complete disclosure of which is incorporated herein by reference, and in which a geothermal transfer loop is coupled to a heat pump. Accordingly, the present method provides an improved means for installing geothermal transfer loops. 
     Alternatively, the geothermal transfer apparatus may be a co-axial geothermal transfer apparatus  77  as shown in  FIGS. 10 and 11 . The co-axial geothermal transfer apparatus  77  shown in  FIGS. 10 and 11  is similar to the type disclosed in U.S. Pat. No. 7,347,059 to Kidwell et al., the complete disclosure of which is incorporated herein by reference. As shown in  FIG. 11 , the co-axial geothermal transfer apparatus  77  comprises an outer, thermally-conductive, conduit  112  and an inner conduit  114  disposed within the outer conduit  112 . The inner conduit  114  has a plurality of connected fins  116   a ,  116   b  and  116   c  which form a spiral annular flow channel between the inner conduit  114  and the outer conduit  112 . In operation, fluid is pumped from the ground surface down the inner conduit  114  where it exits at a distal end of the inner conduit  114  as indicated by arrows  111  and  113 . The fluid then flows along the annular flow channel back up to the ground surface as indicated by arrows  115  and  117 . The circulating fluid allows for heat transfer between the ground and an ambient environment. 
     It is known to use coaxial-flow geothermal transfer apparatuses in geothermal heat exchange systems as is disclosed in U.S. Pat. No. 7,363,769 and continuations thereof to Kidwell et al., the complete disclosures of which are incorporated herein by reference, and in which a co-axial geothermal transfer apparatus is coupled to a heat pump. Accordingly, the present method provides an improved means for installing coaxial-flow geothermal transfer apparatuses. 
     In other examples, the geothermal transfer apparatus may be a superconduting heat transfer device similar to the type disclosed in U.S. Pat. Nos. 6,132,823 and 6,911,231 to Qu, the complete disclosures of which are incorporated herein by reference. Superconducting heat transfer devices allow for bi-directional heat transfer to and from the ground. The superconducting heat transfer devices disclosed by Qu generally includes a substrate, in the form of a conduit, which carries a superconducting heat transfer medium. The superconducting heat medium is applied to an inner surface of the conduit in three basic layers, the first two being prepared from solution and the third being a powder. 
     The first layer of the superconducting heat medium comprises at least one compound selected from the group consisting of sodium peroxide, sodium oxide, beryllium oxide, manganese sesquioxide, aluminum dichromate, calcium dichromate, boron oxide, and a dichromate radical. The first layer of the superconducting heat medium is absorbed into the inner surface of the conduit and is an anti-corrosion layer which prevents etching on the inner surface of the conduit. In theory the first layer also causes re-alignment of the atomic apparatus of the material comprising the conduit so that heat may be more readily absorbed. A further function of the first layer is to prevent the inner surface of the conduit from producing oxides as oxidation of the inner surface of the conduit will cause heat resistance. 
     The second layer of the superconducting heat medium comprises at least one compound selected from the group consisting of cobaltous oxide, manganese sesquioxide, beryllium oxide, strontium chromate, strontium carbonate, rhodium oxide, cupric oxide, β-titanium, potassium dichromate, boron oxide, calcium dichromate, manganese dichromate, aluminum dichromate, and a dichromate radical. The second layer of the superconducting heat medium prevents the production of elemental hydrogen and oxygen thus restraining oxidation between the oxygen atoms and the atoms of the material comprising the conduit. In theory the second layer conducts heat across the inner conduit surface. A further function of the second layer is to assist in accelerating molecular oscillation and friction associated with the third layer of the superconducting heat medium so as to provide a heat pathway for conduction. 
     The third layer of the superconducting heat medium comprises at least one compound selected from the group consisting of denatured rhodium oxide, potassium dichromate, denatured radium oxide, sodium dichromate, silver dichromate, monocrystalline silicon, beryllium oxide, strontium chromate, boron oxide, sodium peroxide, β-titanium, and a metal dichromate. The third layer of the superconducting heat medium is believed to generate heat once the superconducting heat medium is exposed to a minimum activation temperature. Upon activation, atoms in the third layer of the superconducting heat medium begin to oscillate in concert with atoms in the first and second layers of the superconducting heat medium. Experimentation has shown when such a superconducting heat medium is properly disposed on a substrate it has a thermal conductivity that is generally 20,000 times higher than the thermal conductivity of silver. 
     It is known to use geothermal transfer apparatuses comprising a thermal superconducting medium in geothermal heat exchange systems as is disclosed in co-pending U.S. Pat. No. 7,451,612 to Mueller et al., the complete disclosure of which is incorporated herein by reference, and in which a geothermal transfer apparatus comprising a thermal superconducting medium is coupled to a heat pump. Accordingly, the present method also provides an improved means of installing geothermal transfer apparatuses comprising a thermal superconducting medium and which are used in geothermal heat exchange systems. 
     Referring now to  FIGS. 12 and 13 , once the geothermal transfer loop  70  has been completely lowered into the drill string  30 , the hole  12  may be grouted. The hole  12  may be grouted with the drill string  30  remaining in the ground  14  or after the drill string  30  has been removed from the ground  14 . In this example, grouting is accomplished by the tremie line method. A tremie line hose  80  is lowered into the hole  12 . The tremie line hose is comprised of a steel pipe section  82  at a distal end and a flexible tube section  81  at a proximal end thereof. The steel pipe section  82  is the lead end of the tremie hose line  80  lowered into the hole  12 . A pump  86  pumps thermally conductive grouting material  120  from a reservoir  88  along the tremie hose line  80  to the bottom of the hole  12 . The grouting material  120  encompasses the geothermal transfer apparatus  70 . As the hole  12  is filled from the bottom up, a tremie line hose reel  87  pulls the tremie line hose  80  out of the hole  12 , so as to maintain the lead end of the tremie line hose  80  below the grouting material  120 . This process is continued until the hole  12  has been filled with grouting material  120  and the grouting material encompasses the portion of the geothermal transfer loop  70  which is below the ground surface  15  as shown in  FIGS. 14 and 16 . 
     In other examples, grouting may be accomplished by the pressure grouting method. Pressure grouting may be accomplished by attaching a grout line to the top of the of the drill string or a grout line can be attached to the swivel on the drill head. As the drill string is removed from the ground, grouting material is simultaneously pumped into the inner space of the drill string. The grouting is topped up once the casing has been removed. In some cases grouting may not be required, for example in silty or sandy soils which collapse about the geothermal loop when the drill string is removed. 
     As shown in  FIG. 17 , once the grouting process is completed, either by the tremie line method or the pressure grouting method, the geothermal transfer apparatus  70  may be operatively connected to the heat pump  100  disposed within in a building  101 , or other structure, housing an ambient environment, to form a geothermal heat exchange system. The geothermal transfer loop  70  may also be operatively connected below the ground surface  15 , in series, to additional geothermal transfer apparatuses below the ground surface  15 . The series of geothermal transfer apparatuses are then connected to a communal heat pump. 
     Alternatively, as shown in  FIG. 18 , the geothermal transfer apparatus  70  may be operatively connected to a heat pump  103 , which in turn is coupled to a thermal energy collector  105 , to form an underground thermal energy storage system. In the example shown in  FIG. 18 , the geothermal energy collector  105  is a solar energy collector disposed on a roadway  107 . Heat from solar radiation on the surface of the roadway  107  is collected by the thermal energy collector  105  during the summer. The heat is then pumped, by the heat pump  103 , into the ground  14  where it is stored. The stored heat may later be used to melt snow or ice on the surface of the roadway  107  during the winter. In another example, heat from the ground may be used to heat cold air during the winter. This causes a lowering of the ground temperature. The lowered ground temperature may later be used to cool an ambient environment during the summer. Accordingly, both heat and cold may be stored in underground thermal energy storage systems. 
     Referring now to  FIGS. 19 and 20 , in another application, a geothermal transfer apparatus, in the form of a geothermal transfer loop  70 . 1 , is fitted to a reinforced steel structure  92  and lowered into a cased hole  12 . 1  drilled according to the present method. In  FIGS. 19 and 20  like structure and environment have been given like reference numerals as in  FIG. 12  with the additional numerical designation “0.1”. In this example, the geothermal transfer apparatus is a geothermal transfer loop  70 . 1 . However, it will be understood by a person skilled in the art that any geothermal transfer apparatus capable of transferring beat to and from the ground may be used. In this example, once the combination of the geothermal transfer loop  70 . 1  and reinforced steel structure  92  are lowered into the hole  12 . 1  the hole  12 . 1  may be filled with concrete  93  by a cement truck  91  using the tremie line method, previously described herein, to form an energy pile  94  which is shown in  FIG. 21 . In other examples, the hole  12  may be filled with grout or other suitable matter. 
     In  FIG. 21  like structure and environment have been given like reference numerals as in  FIG. 17  with the additional numerical designation “0.1”. The energy pile  94  provides foundational support to a building  101 . 1  and is also operatively connected to a heat pump  100 . 1  disposed within the building  101 . 1  to form a geothermal heat exchange system. Accordingly, energy piles are a cost-effective way of installing geothermal heat exchange systems in ground conditions where foundation piles are required. Presently such energy piles are being installed by Cementation Foundations Skanska of Maple Cross House, Denham Way, Maple Cross, Rickmansworth, Herts, United Kingdom, WD3 9SW. 
     Referring now to  FIGS. 22 and 23 , in yet another application, a cased hole  12 . 2  drilled according to the present method may be filled with concrete for the installation of cast-in-place concrete piles. In  FIGS. 22 and 23  like structure and environment have been given like reference numerals as in  FIGS. 12 and 17 , respectively, with the additional numerical designation “0.2”. There are many advantages to using cast-in-place concrete piles over traditional timber piles. For example, cast-in-place concrete piles are free from decay or attack by insect or marine borers. The load capacity of concrete is also greater than that of wood. As shown in  FIG. 22 , once the cased hole  12 . 2  is drilled to a desired depth, according the above-described method, a reinforced steel structure  92  is lowered into the hole  12 . 2 . A cement mixer  91  then discharges concrete  93  into the hole  12 . 2  using the tremie line method, previously described herein. When the hole  12 . 2  is full of concrete the drill string  30 . 2  is vibrated out of the hole. As the drill string  30 . 2  is vibrated out of the hole  12 . 2  the concrete  93  is forced to flow into a void created by the drill string  30  and intermingles with the surrounding soil particles creating a very strong bond after the concrete  93  has cured. The resulting cast-in-place concrete piles  95   a ,  95   b  and  95   c  are shown in  FIG. 23  and may be used to provide foundational support for a building  101 . 2 . 
     Referring now to  FIGS. 24 and 25 , in yet still another application, a cased hole  12 . 3  drilled according to the present method may be used for the installation of micropiles or minipiles. In  FIGS. 24 and 25  like structure and environment have been given like reference numerals as in  FIGS. 12 and 17 , respectively, with the additional numerical designation “0.3”. Micropiles are small diameter piles which can withstand axial and/or lateral loads. There are many advantages to using micropiles over concrete piles. For example, in concrete piles, most of the load capacity is provided by reinforced concrete. Increased load capacity is therefore achieved through increased cross-sectional and surface areas of the cast-in-place concrete piles. In contrast, micropiles rely on high-capacity steel elements to for load capacity resulting in small diameter piles which may be installed in restrictive environments. 
     Furthermore, as reported in Micropiles for Earth Retention and Slope Stabilization, Tom A. Armour P. E. as furnished by the ADSC: The International Association of Foundation Drilling, and the full disclosure of which is incorporated herein by reference, micropile installation allows for high grout/ground bond values along with the grout/ground interface. The grout transfers the load through friction to the ground in the micropile bond zone in a manner similar to a ground anchor. As a result, due to the small diameter of the micropile, any ending bearing contribution in micropiles is generally neglected. This provides for excellent underpinning to support structures. 
     As shown in  FIG. 24 , once the cased hole  12 . 3  is drilled to a desired depth, according the above-described method, a micropile  97  is lowered into the hole  12 . 3 . A pump  86 . 3  then pumps grouting material  120 . 3  from a reservoir  88 . 3  using the tremie line method, previously described herein. When the hole  12 . 3  is full of grouting material  120 . 3  the drill string  30 . 3  is vibrated out of the hole. As the drill string  30 . 3  is vibrated out of the hole  12 . 3  the grouting material  120 . 3  is forced to flow into a void created by the drill string  30 . 3  and intermingles with the surrounding soil particles creating a very strong bond. The grouting material  120 . 3  also bonds with the micropile  97 . 
     The resulting micropiles  97   a ,  97   b  and  97   c  are shown in  FIG. 23  and may be used to provide foundational support for a building (not shown). In this example, and as shown for one of the micropiles  97   a , each of the micropiles includes an elastic spacer  130 , a high capacity steel element  140 , and a torqued anchor plate  150  similar to the GEWI® Pile offered by DYWIDAG-Systems International Limited of Northfield Road, Southam, Warwickshire, United Kingdom, CV47 OFG. The GEWI® Pile functions as both a micropile and anchor. 
     Alternatively, as shown in  FIG. 26 , conventional micropiles  109   a ,  109   c , and  109   c  similar to the type offered by L. B. Foster of 6500 Langfield Road, Houston, Tex., United States of America 77092, may be installed to support a building  101 . 4  using the methods disclosed herein. In  FIG. 26  like structure and environment have been given like reference numerals as in  FIG. 12  with the additional numerical designation “0.4”. 
     It will be understood by someone skilled in the art that many of the details provided above are by way of example only and can be varied or deleted without departing from the scope of the invention as set out in the following claims.