Borehole intersections

Control the gas. Keep mining.

The Proflow Gas Bypass System seals an intersected drainage hole at the face as soon as it can be safely accessed. The gas is under control in seconds. Mining carries on with minimal delay and the hole is treated properly when it suits.

  • Sealed in secondsThe unit seals the hole itself at the face. Once it's in position the installer inflates the airbag in under 10 seconds.
  • No waiting on treatmentMining carries on once the hole is sealed. Final treatment happens when it suits the crew, within the time or distance the site's borehole intersection process sets.
  • Minimal delaysA simple install that's the same every time. The flexible hose gets into tight spots off the miner.
  • Effective treatmentThe sealant cures without the pressure differential working against it. No leakage paths form so holes don't need re-treating.

The problem

It's the small leaks that stop a panel.

Some intersected holes are dead. Many are not. Gas pressure pushes out of the hole or suction draws air into it.

Treat a hole with that pressure differential on it and the positive or negative pressure works on the sealant as it cures. Air paths form between the sealant and the wall of the hole and wet holes are the worst for it. Once the sealant sets those paths stay and the hole keeps leaking gas or drawing air.

Gas in the roadway raises background levels at the face and slows or stops mining. Air drawn into the range triggers O2 and CO TARPs and holes get shut off. Crews are sent back to re-treat holes and replace leaking standpipes.

Across a panel it compounds. Development slows and at times stops. Mines with little float often cut the panel short so the face roads can be driven, and the coal inbye is sterilised.

How it works

Seal the hole first. Treat it once it's sealed.

The airbag on the standpipe controls the pressure differential. It forces all gas pressure, positive or negative, through the centre of the standpipe. That leaves the annulus between the standpipe and the strata free of pressure so the sealant forms an effective seal there.

  1. 01

    Clear the hole

    Scrape the hole out with the grout tamp once it's under supported ground.

  2. 02

    Insert and inflate

    Push the standpipe into the rib and inflate the airbag to 60 psi with the regulated inflator.

  3. 03

    Hose over

    Seal the other side the same way. Then join the two standpipes with the hose-over.

  4. 04

    Treat the hole

    Use the sealant your site's borehole intersection process calls for.

Designed for development

Built around the way development runs.

The system came out of development operations. Every part of the install is aimed at keeping production delays to a minimum.

  • Room to parallel task

    Some sites may take the chance to pump grout around the standpipes while cable bolts are being grouted. The hole is still treated within the time or distance the site's borehole intersection process sets.

  • Use the sealant your site has approved

    The airbag is internally ported and inflates through the standpipe itself. The choice of sealant stays with the site. Hand grout and pumped grout both work. So does Silent Seal.

  • Nothing to pull out

    Gas bags are no longer needed to stop the flow for a while, only to be popped later so a standpipe can go in. The standpipe goes in at the face and its airbag seals the borehole in one step. Popping the bag and the gas it releases are gone.

Availability

In testing. Not on sale yet.

Both hoses have passed fire resistance and antistatic testing to AS 2660 at BPI. The airbag is still being tested. The system won't be sold until it passes.

Get in touch for updates or to talk about how it would suit your site.