Press Release : Subhorizontal Geothermal Well Architecture A Proven Concept

A second subhorizontal well successfully completed and tested at Cachan (Paris Basin, France)

The second subhorizontal geothermal well has been completed on the Paris suburban Cachan site for its customer DALKIA (EDF Group).

The well, which will serve as the injection unit of the local Geothermal District Heating doublet, is similar in design to the production well achieved in late December 2017, recorded as a world premiere in geothermal well engineering.

It features an openhole drain, 8"1/2 in diameter and 1 005 m long (against 1 001 m for the first well).

Targeted at a nominal 450 m3/h productive/injective performance, the new doublet managed by a DALKIA/City of Cachan JV (DALKIA operator), will replace two existing, 34 years old, doublets, both cumulating 350 m3/h capacity.

The concept, pioneered by GPC IP, opens attractive perspectives for geothermal development in densely populated areas undergoing moderate to poor (by geothermal standards) reservoir performance.

Pierre UNGEMACH & Miklos ANTICS