Earth storage structural energy system and process for constructing a thermal storage well

An earth coupled structural energy system comprising:

• an energy distribution system for selectively supplying thermal energy within a building structure;
• earth storage means for communicating thermal energy with the earth, the earth storage means having an integrated earth interface generally defining an earth interface surface area, the earth storage means comprising an array of wells disposed within the earth;
• fluid transport means disposed within the earth storage means for circulating a thermal transfer fluid through the earth storage means;
• the fluid transport means comprises longitudinal first tube means within each well, the first tube means defining an external surface at the fluid transport means interface;
• the earth storage means comprising an intermediate particulate volumetric mass surrounding the tube and extending radially to the integrated earth interface;
• the fluid transport means having an interface with the earth storage means, the fluid transport means interface defining a surface of substantially smaller area than the earth interface surface area;
• means for maintaining a high thermal conductivity at the fluid transport means interface;
• and
• means for thermally communicating with the thermal transfer fluid to effect thermal changes in the energy distribution system;
• the earth storage means having a high thermal permeability, whereby thermal energy is readily conducted between the earth and the fluid transport means with minimum thermal radiation.

An earth coupled thermal storage arrangement comprising:

• a generally longitudinal well defining a well depth and having a substantially moisture impervious integrated earth interface generally defining an earth interface surface area;
• fluid transport means for communicating thermal energy with the earth, comprising first conduit means for circulating a thermal transport fluid and thermally communicating with the earth, the first conduit means disposed within the substantial depth of the well and having an end defining an interior region, and second conduit means for circulating thermal transport fluid to and from the first conduit means, the second conduit means disposed within the first conduit means;
• the first conduit means surrounded by an intermediate volumetric particulate mass comprising a sand/gravel mixture;
• and
• means for maintaining moisture within the particulate mass at the fluid transport means interface.

The process for constructing a thermal storage well, comprising the steps of:

• drilling a shallow surface hole with a dry auger bit at an angle to the vertical;
• placing surface pipe in the hole;
• cementing the surface string to the surface;
• running in hole a drilling string;
• drilling to a well depth, while rotating pipe and circulating fluid down the center of the pipe and up the exterior;
• pulling up from the hole a short distance to allow the circulation of mud;
• circulating water base drilling mud to stabilize the hole;
• pulling out of the hole the drilling string, while filling the hole with mud;
• running in hole an outer tube with centralizers;
• running in hole a slotted pipe;
• circulating down outside of the outer tube and up center a water base drilling mud;
• stopping the circulation and measuring the fluid loss from the surface pipe and continuing until fluid loss is small;
• mixing gravel and sand slurry with a drilling mud;
• and
• reverse circulating the slurry down the well to pack the space between the outer tube and the rock face, at a slow rate.

The process for constructing a thermal storage well comprising the steps of:

• drilling a well;
• circulating mud through the hole to establish a filter cake;
• running a thermal transfer conduit in the hole;
• running a drill string within the hole while circulating mud;
• measuring moisture loss from the well;
• and
• reverse circulating a sand/gravel slurry through the thermal transfer conduit to establish an intermediate particulate mass extending adjacent to the filter cake.