Herrenknecht HK 250T
Maxi rig, 250 ton pullbackOur heavyweight for long, large-diameter and sea channel crossings.
CAPABILITY 05 / 06 · Drilling fluid engineering
THE MUD DOES THE WORK.
Engineered bentonite and polymer programmes, mixed and recycled on site, matched to the sands, clays and caprock of the Gulf.
THE SCOPE
Drilling fluid engineering
Drilling fluid is the part of HDD nobody sees and everything depends on. It stabilises the bore wall, carries cuttings out, cools and lubricates the tooling, and reduces the pull load on the pipe. Get it wrong in loose Gulf sand and the bore collapses; get it wrong in reactive clay and the reamer balls up. Crossroad runs its own mixing and recycling plants and designs the fluid programme per crossing from the geotechnical data.
Bentonite concentration, polymer additives, viscosity and pH are set for the strata and adjusted as the bore progresses, with returns monitored at both pits. Recycling units separate cuttings and return cleaned fluid to the tanks, which cuts water consumption and disposal volumes on long crossings. Annular pressure is kept below the formation fracture limit so there are no inadvertent returns at the surface or into the channel bed.
WHAT WE DELIVER
IN SCOPE ON EVERY JOB
- 01Fluid programme designed from the geotechnical investigation
- 02Bentonite and polymer systems for sand, silt, clay, caprock and mixed strata
- 03On-site mixing tanks and recycling units on every crossing
- 04Viscosity, density, pH and sand-content testing through the bore
- 05Annular pressure management against hydrofracture
- 06Returns containment, cuttings disposal and water consumption reporting
HOW IT RUNS
SEQUENCE ON SITE
01
Programme design
Strata, bore length and pipe size set the base fluid and additives; volumes are estimated per pass.
02
Mix and condition
Fluid is mixed on site, tested and conditioned before the pilot bore starts.
03
Monitor and adjust
Returns, pressure and fluid properties are checked through every pass and the programme is tuned.
04
Recycle and dispose
Cuttings are separated, fluid is recycled, and residues are removed to the approved disposal route.
See the full four-stage bore animated on the home page, or size your own crossing with the HDD tools.
IRON ON THE JOB
EQUIPMENT WE BRING
Ditch Witch JT 100
Midi rig, 100k lbs pullbackThe workhorse for utility corridors and mid-range road crossings.
Mixing & Recycling Tanks
Drilling fluid systemsEngineered mud programs matched to UAE soil strata.
ON RECORD
CROSSINGS LIKE YOURS
STRAIGHT ANSWERS
QUESTIONS WE GET ASKED
Engineers answer every enquiry. If your question is not here, send it over.
01How much drilling fluid does a crossing use?
Between 1.5 and 3.5 times the reamed hole volume depending on the ground: reactive clay at the low end, clean sand and gravel at the high end. The fluid estimator on our tools page gives a planning figure.
02What happens to the used fluid?
It is recycled through solids-control units during the bore and the remaining slurry is removed by tanker to an approved disposal site. Nothing is discharged to the ground, drains or the sea.
03Can fluid escape to the surface?
Inadvertent returns happen when annular pressure exceeds what the ground can hold. We design the depth and fluid programme to stay under that limit and monitor pressure continuously, which is how it is prevented rather than cleaned up.