Earth heat exchange system

An earth wellbore heat loop system has been developed which ash, in certain aspects, a heat loop wellbore in the earth extending from an earth surface down into the earth to a bottom of the wellbore, a heat loop disposed in the heat loop wellbore and extending down to a position near the bottom thereof, the heat loop including a heat loop comprising pipe and a bottom member, the pipe extending down to the bottom member (300) on one side thereof and up from the bottom member on another side thereof, the bottom member comprising a body (302), a first bore through the body extending from a first opening (305) of the body to a second opening (306) of the body, the first opening and the second opening each sized and configured for receipt therein of an end of a heat loop pipe, a second bore (308) having at least a one opening on the body, the second bore sized and configured for securement thereat of an end of coil tubing. Filler material has been developed for use in a heat loop wellbore that has, in certain aspects an amount of water, and an amount of a gel material, such as a polymer. An amount of thermally conductive solids may be used with the polymer and the water.