Method and apparatus for heating drilling and/or completion fluids entering or leaving a well bore during oil and gas exploration and production

A system for pre-heating downhole fluids returning from a well bore, the system comprising:

• a. a principal heat exchange vessel;
• b. an inlet for allowing a heat transfer media to circulate through the vessel through a plurality of heating fluid flow lines;
• c. a first outlet for flowing the heat transfer media from the vessel;
• d. a second inlet for introducing fluids returning from the well bore for receiving heat from the heat transfer media within the fluid flow lines in the vessel for pre-heating the downhole fluids to a desired temperature;
• e. an outlet for flowing the heated downhole fluids from the vessel to a solids removal system;
• f. means for flowing the downhole fluids from the solids removal system to the principal heat exchange vessel to be post-heated before returning down the well bore;
• and
• g. heating means for heating the heating fluid to a desired temperature before returning the heating fluid to the heat exchange vessel.