Minutes from the second Wollombi Sydney Gas Meeting
Date: 15-Jul-08
Author: Peter Firminger
These are independent minutes from the Wollombi Valley Chamber of Commerce Meeting with Sydney Gas.
Notes from the 2nd Wollombi Sydney Gas Meeting - 14-July-2008
Peter Hamshere welcomed attendees and Sydney Gas Representatives.
Presentation entitled "Sydney Gas Exploration in the Hunter" by Mark Harper (with [largely undocumented] interjections from Dana Hollis).
A map showing PEL 4 and PEL 267
An explanation of Coal Seam Gas Exploration
"What we need to find is sufficient coal that has sufficient gas and that the gas can be extracted in sufficient amounts for viable production."
Exploration: Seismic Study - Core holes - Test wells
Production and Sales: Produce Gas - Sell Gas
Core holes: 4 inches in diameter taking ground samples
Core hole site uses tanks rather than cellars (plastic-lined ponds)
A liquid is used to propel and lubricate the drill-head. Drilling remains and liquids are taken away for processing.
The drilling rig is approx 30 feet high running from 7am to 7pm Mon-Fri and 7am to 1pm Sat.
Core hole lined with metal tubing. Aquifers are not affected, if a second deeper aquifer is found, the core hole will be sealed off and abandoned.
Some aquifers must not be disturbed by law.
Slides showing core hole samples and a rehabilitated core hole site.
Core holes are filled and sealed in concrete
Test wells: similar in structure to a core hole, encased to prevent leakage. Some wells have significant CO2 and may be sealed off and abandoned.
A test well is to test the flow of gas, filtering impurities, CO2, water etc.
The gas is flared (burnt) on-site rather than taken away.
A test well is only 5 feet high with a visible tank and a 10 foot fence. In the case of a lot of water, the water is piped away with the gas [which makes no sense when the gas is being burnt].
A production well is sealed (encased) down to the coal seam.
Pipelines are small pipes from the wells growing to larger pipes as more wells join the pipeline along it's length to the Compressing station.
Odorant is added at the Compressing station [meaning the gas is odourless along the pipelines]. The gas is lighter than air. Coal seam methane will ignite in a 5-15% air-gas ratio. (LPG ignites in a 5-30% ratio and Petrol 3-95%)
Questions from Sean Gough
- Why did Sydney Gas stop exploring for methane gas in the Wyong area?
Mark Harper (MH): I wasn't with the company back then. Management decided not to continue with it for some reason.
- How long has Sydney Gas been operating as a company?
MH: Not sure, probably 6 to 8 years, I'll find out for you (looks towards Peter Hamshere).
- Has Sydney Gas conducted any seismic surveys of the immediate area around Wollombi or Paynes Crossing? If not when will they, over what area and will separate access agreements be required?
MH: Yes we conducted seismic surveys here.
Dana Hollis (DH): Actually, not in Wollombi, but in the Hunter.
MH: Seismic surveys would show the same thing across the entire region. We know what the strata [or structure] is and it wouldn't show anything we don't know.
- Who are the joint venture partners with SGL?
MH: AGL in a 50/50 partnership
- Does Sydney Gas/AGL JV receive funding from the State Government?
MH: No, nothing from th
