Open-Loop Chalk Wells
London

CLIENT CONFIDENTIAL                          DURATION 12 MONTHS       
VALUE £600,000


SCope
  • Drilling
  • Borehole acidisation
  • Pumping testssdu

INTRODUCTION

The company was appointed by the client to install and test new Chalk wells as part of a open-loop ground source heating and cooling system for the a prestigious  development in central London. The system is designed to provide renewable heating and cooling to the property using circulated water from the Chalk aquifer of the London Basin.


THE WORKS
4 No. 115 m deep chalk wells were drilled using direct circulation techniques at 500 mm diameter. A permanent steel casing of 340 mm diameter was installed and sealed into the top of the Chalk aquifer at depth of approximately 80 m, with the remainder of the borehole left as an open-hole section through the competent Chalk. 

The direct circulation drilling ensured both increased borehole stability during drilling and improved cuttings removal leading to a better developed final product.

Each well was acidised by our specialist borehole development crew by the controlled injection of hydrochloric acid into the sealed borehole. A programme of airlift development and intermittent development pumping was carried out to ensure the wells met strict criteria, specifically that the abstracted water would have a low fouling potential when passed through a  plate heat exchanger and then re-injected back to the aquifer. A pumping test regime included individual step tests, constant rate tests and abstraction-recharge testing on multiple wells.

Contact us at info@subsurfacehydro.co.uk

© Subsurface Hydro Limited, 2021