Installation Of Ground Loops For Geothermal Heating And/Or Cooling Applications

Abstract

In order to install a ground loop for a geothermal heating and/or cooling system in ground material, a drilling machine having a drill bit connected to an end of first tubing may be used to create an borehole in the ground material. After the borehole is created, grout may be pumped into the borehole through the first tubing as the first tubing is removed from the borehole. This allows the borehole to be grouted from the bottom towards the top. Thereafter, second tubing may be inserted into the grout in order to create the ground loop. This eliminates the need for a “tremie” pipe to insert the ground loop and pump grout into the borehole, while still allowing for the borehole to be grouted from the bottom towards the top to reduce the likelihood of voids.

1 . A system for creating a borehole in ground material for installation of a ground loop, the system comprising:
 a drilling machine having first tubing at least partially wrapped around a reel; and   a support equipment apparatus including a first tank for holding and processing mud material, a second tank for holding a grout component, a pump configured to pump material to the first tubing, and a valve having a first configuration that allows the mud material to combine with grout component from the second tank in order to form grout such that the pump is configured to pump the grout to the first tubing, the valve further having a second configuration that allows the pump to pump the mud material without grout component from the second tank.   
     
     
         2 . The system of  claim 1 , wherein the pump is configured to pump the mud material or the grout to a first end of the first tubing, and a second end of the first tubing, opposite of the first end of the first tubing, includes a drill for creating the borehole. 
     
     
         3 . The system of  claim 2 , wherein the drill includes an attached mud motor configured to pump mud material and cuttings of ground material from the drill in the borehole towards a ground surface. 
     
     
         4 . The system of  claim 3 , wherein the drill is a mud hammer configured to be powered by the pump. 
     
     
         5 . The system of  claim 1 , wherein the drilling machine further includes a tubing injector configured to straighten the first tubing as the first tubing is deployed from the reel into the borehole. 
     
     
         6 . The system of  claim 1 , wherein the drilling machine further includes a drill bit attached to an end of the first tubing and a drive system configured to rotate the reel to deploy the first tubing into the borehole and to retract the first tubing from the borehole and coil the first tubing back onto the reel. 
     
     
         7 . The system of  claim 6 , wherein the pump is configured to pump the grout into the borehole while the drilling machine retracts the first tubing from the borehole. 
     
     
         8 . The system of  claim 1 , wherein the drilling machine includes two or more outriggers configured to stabilize the drilling machine relative to a ground surface. 
     
     
         9 . The system of  claim 1 , further comprising a pit pump configured to pump a combination of mud material and cuttings of the ground material from the drill from the borehole to the first tank. 
     
     
         10 . The system of  claim 9 , wherein the first tank includes a shaker system configured to filter ground material from the combination of mud material and ground material prior to the mud material passing through the valve. 
     
     
         11 . The system of  claim 1 , further comprising a heat exchanger insertion apparatus including a second reel and second tubing at least partially wrapped on the second reel, the heat exchanger insertion apparatus being configured to insert the second tubing into the borehole after the grout has been pumped into the borehole. 
     
     
         12 . The system of  claim 11 , wherein the heat exchanger insertion apparatus includes a drive system configured to force the second tubing into the borehole and through the grout in the borehole. 
     
     
         13 . The system of  claim 11 , wherein the heat exchanger insertion apparatus further includes a third reel and third tubing at least partially wrapped on the third reel, the drive system being configured to force the third tubing into the borehole and through the grout towards a bottom of the borehole. 
     
     
         14 . The system of  claim 13 , wherein the third reel is configured to retract the third tubing from the borehole after a predetermined length of the second tubing has been installed in the borehole. 
     
     
         15 . The system of  claim 13 , further comprising a pit pump configured to pump grout displaced by the second tubing as the second tubing is inserted into the borehole to the first tank. 
     
     
         16 . The system of  claim 13 , wherein the first tank includes a shaker system configured to filter the displaced grout prior to the grout reaching the valve. 
     
     
         17 . A method of creating a borehole in ground material for installation of a ground loop, the method comprising:
 using a drilling machine having a drill bit attached to a first end of first tubing to create an borehole in ground material;   inserting grout into the borehole through the first tubing; and   after inserting the grout, installing second tubing into the grout to create a ground loop.   
     
     
         18 . The method of  claim 17 , further comprising inserting the grout as the first tubing is removed from the borehole such that the borehole is grouted in a direction from a bottom of the borehole towards a ground surface. 
     
     
         19 . The method of  claim 17 , wherein using the drilling machine includes pumping a mud material through the first tubing and into the borehole while creating the borehole, and the method further comprises combining the mud material with a grout component to form the grout prior to inserting the grout. 
     
     
         20 . The method of  claim 19 , further comprising pumping grout displaced by the installation of the second tubing to a tank configured to hold the mud material prior to pumping the mud material through the first tubing. 
     
     
         21 . The method of  claim 20 , further comprising using a shaker system to filter the grout at the tank. 
     
     
         22 . The method of  claim 19 , further comprising pumping a combination of mud material and cuttings of ground material from the drill to a tank configured to hold the mud material prior to pumping the mud material through the first tubing. 
     
     
         23 . The method of  claim 22 , further comprising using a shaker system to filter the combination of mud material and cuttings of ground material at the tank.