Geothermal: ACL Luttelgeest drilling triplet

Geothermal triplet LTG-GT-04 & LTG-GT-05 & LTG-GT-06

Start drilling: Mid april 2020
End drilling: December 2020

Target: Aquifer in the Slochteren Sandstone formation

Depth (AH): 1962m; 2286m; 2275m
Depth (TVD): 1851m; 1830m; 1821m

Project Summary

Client:Aardwarmte Combinatie Luttelgeest (ACL) B.V.
Triplet:Luttelgeest / ACL Triplet
Wells:LTG-GT-04 & LTG-GT-05 & LTG-GT-06
Start drilling:Mid April 2020
End drilling:December 2020
Target:Aquifer in the Slochteren Sandstone Formation
Result:Successfully drilled wells, disappointing test results
Power (thermal):14 MWTh
Depths (AH):LTG-GT-04: 1962m; LTG-GT-05: 2286m; LTG-GT-06: 2275m
Depths (TVD):LTG-GT-04: 1851m; LTG-GT-05: 1830m; LTG-GT-06: 1821m
Role of WEP:Drilling Supervision, HSE and subsequent support (on-site and office based) during the well delivery phase
Challenges:Execution during COVID-19 “intelligent lockdown”, Unconventional sizes in production well
New Technology:Not applicable

Project Description

Drillmec HH300 (contracted via GERF, operated by D&S) has been rigged up in Q1 2020. Mid-April 2020 drilling operations of the first well commence. WEP has been contracted by ACL to provide supervisional support on the well deliveries (both on site and back-office) and testing of the wells. Expectations are high, nextdoor of the Hoogweg Aardwarmte project (also a triplet: LTG-GT-01, 02 & 03) which is producing/exploiting geothermal heat since 2018.

Late October 2020 LTG-GT-06, the last of the three wells was drilled to TD and tested. Unfortunately, the thickness of the geothermal aquifer (Slochteren formation) was found to be significantly less as anticipated, resulting in disappointing test results. Rig to be demobilized before the end of 2020. It is investigated whether the output of the well(s) can be improved.