A good loop installation is mostly preparation. By the time the borehole is drilled, the decisions about loop, weight and grout should already be made — so the crew can focus on getting the loop down cleanly and safely.
Before you get to site
- Confirm the loop specification Pipe diameter, SDR, single or double U, and the loop manufacturer’s guidance on attaching weights.
- Confirm borehole depth and expected fluid Water, mud and grout densities all change how much weight you need.
- Calculate the weight per borehole Fluid displaced, versus water in the loop plus loop weight — then add a margin for friction and pipe memory. See Why Geothermal Loops Float.
- Choose your sizes Pick the combination of 20kg, 40kg and 56kg units that hits your target. See Choosing the Right GeoWeight.
- Order with margin A spare unit or two per rig costs far less than a stood-down crew. UK orders before midday arrive next day.
- Check your hardware Suitably rated shackles for combining units, and lifting equipment for the heavier sizes.
At the wellhead
- Inspect every weight Check each unit and its M10 lifting eyes for damage before use. Don’t use a unit with a damaged eye.
- Inspect the loop Look for cuts, scratches or crush damage from transport and storage before it goes anywhere near the hole.
- Protect the loop from the casing A casing top protector and a wellhead roller or loop reel help avoid shavings and scuffs as the pipe goes in.
- Handle with the lifting eyes The 40kg and 56kg units are above typical manual-handling guideline weights — use two people or mechanical lifting.
- Connect securely Attach weights to the bottom of the loop in line with the loop manufacturer’s guidance. When combining units, shackle them together and check every connection.
Lowering the loop
- Fill the loop with water Common practice, as a water-filled loop has much less upthrust than an empty one.
- Lower steadily and under control Don’t drop the loop. Let the domed and coned ends guide the weight down the hole.
- Watch for resistance If the loop stops short, don’t force it — forcing risks kinking or damaging the pipe. Stop, assess, and add weight or clear the obstruction.
- Confirm depth Make sure the loop has reached its design depth, and hold it there while you grout.
Grouting and testing
- Grout from the bottom up Tremie the grout from the base of the borehole so it displaces fluid upwards and fully fills the annulus.
- Pressure and flow test Test the loop in line with your standard and specification. In the UK, individual loops should be flow tested in both directions after insertion.
- Protect the loop tails Keep them capped and protected until they are connected.
Record it
Drilling logs increasingly record loop details — including the weight installed — alongside borehole depth, geology, water strikes, grout used and test results. Using standard GeoWeights sizes makes this easy: the weight on every loop is known and repeatable.
| Log entry | Example |
|---|---|
| Borehole ID and date | BH-03 · 14 Oct |
| Depth drilled / loop depth | 152m / 150m |
| Loop details | 32mm SDR11, single U |
| Weight installed | 1 × 56kg + 1 × 20kg = 76kg |
| Grout | Type and volume used |
| Tests | Pressure and flow results |
Illustrative entries — use the log format your scheme or client requires.
Need help on your next job?
We’re drillers too. If you’re unsure about weight, sizing or a custom spec, we’ll help you get it right before the rig arrives.