North Goonyella Fire MRE 14th September 2018. “It Was Discovered that the New Hole Being Drilled into the Goaf was the Wrong Hole”

MRE – North Goonyella – 14.09.2018.pdf

There are a number of paragraphs I have highlighted in the MRE.

I was going to make comments on each one but it would have being longer than the MRE itself.

How many more things can the Management get wrong in 24 hours?

Note Borehole for foam injection being drilled on wrong side of TG Chute road.

Boreholes being opened and closed to drain methane off the goaf.

Decisions made to alter point of Floxal Nitrogen injection.

No measurements of Floxal Unit flow rates conducted.

Indications there is a significant error in the ventilation quantity being used at one Tube Bundle 28 and 29 locations.

Alternate Plan ventilation changes discussed for Longwall. (I will do a separate post about this element)

 

Today, 14 Sep 2018 1, Inspector Les Marlborough, attended a meeting at North Goonyella Mine to discuss the status of the high CO in 9N TG. I was met by Mr Mike Carter.

Meeting

Attending the meeting was;

Mr Marek Romanski, UMM;

Mr Mike Carter;

Mr Peter Baker, Peabody Operations manager;

Mr Nev Impson, Compliance Manager;

Mr Dennis Black, Ventilation Officer

Mr Charles Lilly, Peabody Senior Director of Engineering;

Mr Rick Sewell, GM South Project Manager;

Mr John Pearson, SSI-IR;

Mr Jeff Perks, HST Superintendent (Scribe).

In addition, the meeting was joined by video conference by;

Mr Darren Brady;

Mr Michael Brady;

Mr Martin Watkinson (SIMTARS).

Meeting

Last 24 Hours

Continued monitoring gases and injection of inert gas as per plan;

Continued inspections and critical work underground as per the re-entry plan;

Foam going down Hole 2690 shut down at Mid-Day;

It was discovered that the new hole being drilled into the goaf was the wrong hole. It was not the hole being drilled on the MG side of the Tailgate Chute Road (as noted in the MRE of the site meeting dated 12 Sep) but the hole on the TG Side of the Chute Road; I requested that the Mine provide copies of the Permit to Drill documentation for the hole drilled in error.

• The Mine had again opened up the surface borehole behind MG9 North 5 CT seal. The hole was breathing out and allowed to purge the Methane. This hole then showed over 80% Nitrogen;
• As a result of this, the Mine altered the Floxal input into the MG seals to close off MG 4 CT Floxal input and diverted the Floxal gas into 3 CT Seal, utilising the water drainage pipe to take the additional Floxal gas;
• The Mine also ran a pipe round to the Maingate and ran it behind the Maingate Shield to put Floxal gas into the goaf at this point;

I asked whether the Mine had taken measurements of the Floxal gas now being injected into the MG seals and was informed that they had not taken measurements. I stressed that they must measure whenever they introduce Floxal gas into the goaf so that the quantity of inert gas being injected is known; o New borehole #2 is now underway following the error and is now at 93 m Depth. Should be completed Mid-Day 14 Sep.

Current Status;-

• Gas readings for the previous 24 hours were provided and discussed. Tube 24 Stable and inert;

Tube 29 showed an increase in CO in the TG Chute Road. The CO now, according to the

Gas Chromatograph in the TG Chute Road was 430 PPM;

• It appears that the modified Graham’s ratio is varying with the barometer;
• Tube 28 reflects the results shown in the TG Chute Road. However, there is still a significant difference in CO make when calculated between tube 28 and 29. This indicates there is a significant error in the ventilation quantity being used at one of these points. This should be investigated by the Mine.

Plan for the next 24 Hours;-

Continue Floxal injection as per current status; e Continue inspections, monitoring and essential work as per the re-entry plan;

Continue drilling of new hole #2 at MG side of TG Chute Road. This is expected to hole through on Saturday Mid-Day. I recommended that the Millennium Floxal units be repositioned onto this hole at this time.

• When the Narrabri Unit arrives and is commissioned it can be used to replace the Millennium Units and the excess available can be shared between the New Hole and the MG Seals. This will probably occur on Sunday.

The Mine discussed the proposed ventilation change required for the alternate plan, This involves cutting down the quantity across the face to 2 m3/s by using the vehicle doors at 57 CT C-B to increase the leakage through. This takes air off the Longwall face and if the doors are fully opened will reverse the air across the face. I did note there were errors in the Ventilation Model being used and stated that these must be rectified to ensure the model is validated before the work is undertaken.

Copies of the current gas data spreadsheets, the Incident Action Plan and a plan showing the injection points being used and the quantities of inert gas being injected were provided.

I thanked the people for their time and explained that Inspector Marlborough would return to the Mine at 8:30 AM on Saturday 15 September to review progress and to discuss plans going forward.