"Un système géothermique en BOUCLE OUVERTE valorise l’énergie de l’eau souterraine et nécessite généralement DEUX FORAGES (DOUBLET). [...] [However, ] D’autres situations peuvent être qualifiées de "systèmes en boucle ouverte""
https://www.geothermies.fr/les-technologies-de-geothermie-de...

"OPEN LOOP BOREHOLES are most commonly used for large scale heat pump systems. They are comprised of at least one borehole which is drilled below the standing water table. A SUBMERSIBLE PUMP IS THEN INSTALLED IN THE BOREHOLE AND THIS PUMPS WATER TO THE HEAT PUMPS which then extract heat from the water. Once the heat has been extracted THE WATER IS PUMPED INTO A SECOND BOREHOLE (or boreholes) and discharged back into the ground. "
https://www.kensaheatpumps.com/boreholes/

Whether it is actually necessary to specify 'two' I leave up to you. There might be special cases in your doc, but as a rule 'doublet' means 'closed loop' (and vice versa) (see first extract above), i.e. up one borehole and down another.

DIFFERENCE between 'GROUND-SOURCE' and 'GEOTHERMAL':
"GEOTHERMAL HEATING uses heat directly from THE EARTH'S CORE, such as hot springs, geysers and volcanic hot spots. GROUND SOURCE HEAT PUMPS absorb the sun's energy stored in RELATIVELY SHALLOW GROUND and upgrade this for use in domestic and commercial applications."
https://www.kensaheatpumps.com/ground-source-heat-pump-compa...

Or maybe in your case, simply 'two sets of two boreholes for (ground-source) heat pumps'.