Numerical simulation of the heat and fluid flows for the standing column well (SCW) and porous medium around the borehole of the ground source heat pump has been investigated. The finite difference technique was used. Parametric study for several variables has been developed. For example, different bleed ratios of 0.10, 0.20 and 0.30 and far-away temperatures ranging from 15 degrees C to 60 degrees C were investigated. An increase in bleed ratio and the far-away temperature will increase the outlet water temperature from the SCW, retuning back to the heat pump. The effect of porosity, ranging from 0.05 to 0.275, was also considered. Increasing porosity decreases the water outlet temperature. Similarly, the effects of Nusselt and Reynolds numbers in the ranges of 15-500 and 1000-11,000, respectively are reported in this paper. Nusselt and Reynolds numbers decrease with the water outlet temperature. The SCW can be employed as a good ground heat exchanger in a geothermal assisted heat pump system. A polynomial correlation of Nusselt number in terms of Reynolds number has been developed. (c) 2007 Elsevier Ltd. All rights reserved.