German Creek Gas

Management

Presentation to ACARP

Gas & Outburst Workshop

16th Sept 2005

Bruce Robertson

German Creek Gas Management History

Central Colliery

Pre-drainage, Goaf Drainage late 1980s

Southern Colliery

H2S management, CH4 drainage for frictional

ignition hazard

Grasstree Colliery

Outburst threshold content from start

Gas Utilisation

German Creek Location

Central Colliery Pre-Drainage Plan (typical)

Central - Gassiness

Central Colliery Gassiness

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

May-

85

May-

86

May-

87

May-

88

May-

89

May-

90

May-

91

May-

92

May-

93

May-

94

May-

95

May-

96

May-

97

May-

98

May-

99

May-

00

May-

01

May-

02

May-

03

May-

04

CH4 - m3/hr

Predrained Goafdrained Goafblow Ventilation

In Seam Drainage Plant

Goaf Drainage Systems - Central

Connection goaf hole to range

Free vent holes

Goaf drainage plant

Goaf fan site

Central – Panel Avg. Specific Emission

Total SE values for Central Longwall Panels

0

5

10

15

20

25

30

35

200 201 202 203 204 205 206 207 208 209 210 301 302 303 304 305 306 307 308 309 310 311

Panel

SE

Central - Goaf Drainage Efficiency

Goaf Drainage Efficiency(Goaf drainage gas/Total Longwall Gas)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

19/0

5/1

985

18/0

5/1

986

17/0

5/1

987

15/0

5/1

988

14/0

5/1

989

13/0

5/1

990

12/0

5/1

991

10/0

5/1

992

9/0

5/1

993

8/0

5/1

994

7/0

5/1

995

5/0

5/1

996

4/0

5/1

997

3/0

5/1

998

2/0

5/1

999

30/0

4/2

000

29/0

4/2

001

28/0

4/2

002

27/0

4/2

003

25/0

4/2

004

Weekly

10 wk mav

Outburst site in gate road heading

80 tonnes, 1500m3 CH4

Southern Gas Drainage

• Drain to 5.75 m3/t

for Frictional

Ignition prevention

• Steered inseam

holes vented

through risers

• Good drilling &

drainage conditions

• H2S drainage in

places

Grasstree Gas Drainage• Pre-drainage of shaft bottom

(TRD)

• Pre-drainage from shaft

bottom – inseam drilling

• Mains extension

• Flank drilling with MRD

• Optimised spacing

• Increasing length holes

• Compliance drilling

confirmed successful

drainage

• Retaining options for MRD or

cross-panel

• Goaf drainage for longwall

GT#2 TRD Surface Pre-drainageTRD #2 – PLAN OF LATERALS DRILLED BETWEEN SEPTEMBER 2001 AND APRIL 2002

Stage 1

Stage 2

Stage 3

Mine workings as planned

TRD Holes intersected in heading

150mm

NB Heading excavated by grunching

GC - Gas Utilisation

Goaf gas flared in past

Electricity generation planned for 2006 Energy Developments Limited (EDL)

32MW (16 units), start-up mid 2006

consume 2.5 – 3 PJ/yr

sourced from Grasstree (plus Central goaf?)

abates 1.1 Mt/yr of CO2 equiv(= 1.6 mill trees or 250,000 cars)

66kV exported to National Grid

revenue from electricity, NGACs, GECs, GGAP

Gas to liquids opportunity ?