Keen to harness the benefits of geothermal energy for heating their historical buildings, staff at Emmanuel College, Cambridge began to research boreholes and ground source heating solutions. 

Sand ingress affects boreholes in Cambridge

The problem they were faced with however, was the fact that the vast majority of boreholes drilled around Cambridge are unsuccessful due to sand ingress.  This is because much of Cambridge is underlain by water saturated, running greensand. 

This is incredibly difficult to successfully drill a borehole through.

Despite this challenge, staff at Emmanuel College decided to commission a test borehole for an open loop ground source heat system. 

Drilling a test borehole through Cambridge’s greensand

The college’s main geothermal energy contractor was so concerned by the issues anticipated however, that they made it a stipulation to find a specialist drilling contractor capable of drilling sand.

The Igne team was subsequently awarded the contract to drill the test borehole because of their extensive experience drilling large diameter boreholes in difficult conditions.

The Morgan’s team mobilised to site and began drilling a test abstraction well. 

Successfully drilling boreholes in difficult conditions 

The borehole drilled was 60meters deep, and it started at a 20inch diameter; permanent casing was installed and grouted into place and the borehole was extended to full depth with a finished diameter of 200mm. 

Drilling was completed on time, to budget with no issues encountered from the running sand.  A test pumping phase was then initiated, and the borehole yielded the quality and quantity of water expected. 

Owing to the carefully engineered and packed installation, there was no sand ingress. 

Open loop ground source heat pump installation 

Emmanuel College staff are content that the water quantity is high enough, and so the project is now moving to phase two with the installation of additional wells for the final open loop ground source heat pump installation. 

The test well drilled by Igne will form part of the final installation.

Overcoming complex challenges to successfully drill boreholes

With its inhouse borehole geophysics expertise and its extensive experience in overcoming serious water abstraction obstacles – from artesian pressure to running sand – Igne is the only choice for those who need to drill boreholes in difficult ground conditions.

Even if you’ve been told by other drilling companies that you cannot have a borehole for water or ground source heating, we recommend giving our experts a call for a second opinion: 01544 267 980.