EnLink has a dramatically better way to drill holes for large-scale EHXs. EnLink's
fit-to-purpose drill rig, using proven technologies and optimized for large scale GHP projects, enables EnLink to efficiently drill small-diameter holes several hundred feet deep in a wide variety of soil conditions — even under challenging conditions where casing would be required.

EnLink stands out as a trailblazer in GHP technology, and with 13 patents to its credit, has made a significant contribution to the industry.

Historically, the most difficult and costly task in installing a GHP system has been drilling the vertical bore holes and inserting the closed-loop tubing that makes up the EHX. EnLink’s innovative technology addresses both of those issues.

Drilling service contractors on GHP projects typically use equipment developed for other applications, mainly water well drilling. These drilling technologies are not optimal for high production rate requirements (i.e., several hundred wells on a single site) associated with GHP installations for commercial/institutional projects. This often leads to drilling difficulties, cost overruns and significant delays.

After decades working in oilfield and geotechnical services, the founders of EnLink saw an opportunity in the GHP industry if key obstacles could be overcome. They met those challenges designing a "fit-to-purpose" drill rig specifically optimized for high production of GHP boreholes in any soil condition.

The EnLink Drill

The patented EnLink Drill employs an innovative integration of components, including a multifunction drill head and automated rod/pipe handling and casing methods. Each of these components has been expertly demonstrated over many years in challenging applications. With EnLink's proprietary design, the drill operator simply selects the correct features and tools for the job at hand and consistently achieves maximum production rates, no matter the soil condition.

The drill is just one part of a process that has evolved into an integrative design philosophy, complemented by a suite of technologies exclusively focused on efficient installation of EHXs.

EnLink's highly efficient loop insertion and grouting systems have been successfully utilized for over five years. In commonly encountered unstable soil or overburden conditions, the EnLink Drill prevents the borehole from collapsing on itself by simultaneously inserting casing into the hole as the drill penetrates the earth — ensuring that the bored hole will remain open for the looping and grouting steps.

From the beginning, EnLink has relentlessly focused on developing and employing technological innovations that reduce the installed cost and improve the performance of EHXs. We can efficiently complete EHXs where many other drillers cannot easily or economically perform. EnLink has a dramatically better way to drill holes for large-scale EHXs.

EnLink's fit-to-purpose drill rig uses proven technologies optimized for large-scale GHP projects. This enables EnLink to efficiently drill small-diameter holes several hundred feet deep in a wide variety of soil conditions — even under extremely challenging situations where casing would be required.

EnLink's holistic approach to EHX design and implementation involves far more than just a specialized drill rig. Our technical innovations include…

• The development of a custom drill rig that uses five drilling technologies: mud rotary, air rotary, downhole air hammer, sonic and mud sonic. The drill rig is also optimized to handle the challenges of drilling many holes for a large-scale EHX -- predictably, rapidly, and under a variety of geologic conditions.
  
  
• A coiled tubing unit (CTU) for quickly and easily inserting polyethylene pipe loops -- all the way to the bottom of pre-drilled holes less than four inches in diameter.
  
  
• A grout mixing process for uniformly blending any type of thermally enhanced grouts in large quantities. Additionally, a bottom-up pumping process helps ensure that the grout gets dispersed evenly and thoroughly throughout the vertical depth of a completed borehole.
  
• An energy metering system to accurately measure the quantity of heat transferred between the earth and the building to verify EHX performance.

Innovative Materials

Grout: One of the most important determinants of an EHX's performance - and hence its required size and its associated cost - is the quality of the grout used to seal each ground loop within its borehole to the adjoining earth. EnLink's grouting system is compatible with all major grout types.

U-bend: At the bottom of every EHX ground loop is a U-bend. EnLink has designed a special U-bend to work in conjunction with its CTU loop insertion rig. The U-bend quickly and easily slides down a borehole.

EnLink also uses polyethylene pipe of the highest quality from leading manufacturers for its EHX systems.

EnLink Technology