11. WORLD PRIMARY ENERGY
CONSUMPTION
Million Oil Natural Coal Nuclear Hydro Total
tonne oil Gas Energy electric
equivalent
USA 895.6 554.6 555.7 183.2 48.3 2237.3
China 231.9 24.9 520.6 4.0 58.3 839.7
India 97.1 23.7 173.5 4.4 16.1 314.7
Russia 122.3 335.4 114.6 30.9 39.8 643.0
Japan 247.2 71.1 103.0 72.7 20.4 514.5
Germany 131.6 74.6 84.4 38.7 5.8 335.2
WORLD 3510.6 2164.3 2255.1 601.2 594.5 9124.8
India is the 3rd largest coal consumer of the world
R/P : 246 years
Underground Coal Gasification
12. • COALIFICATION PROCESS
• GASIFICATION PROCESS
• UNDERGROUND (IN SITU) PROCESS
Underground Coal Gasification
13. CARBON/COAL GASIFICATION
REACTIONS
Partial Combustion C + O2 = 2CO exothermic
Combustion C + O2 = CO2 exothermic
C + CO2 = 2CO endothermic
Water-Gas C + H2O = CO + H2 endothermic
Hydrogasification C + 2H2 = CH4 exothermic
Shift CO + H2O = CO2 + H2 exothermic
Reformation CO + 3H2 = CH4 + H2O exothermic
Underground Coal Gasification
20. • COALIFICATION PROCESS
• GASIFICATION PROCESS
• UNDERGROUND (IN SITU) PROCESS
Underground Coal Gasification
21. UNDERGROUND COAL
GASIFICATION
A process to convert
unmineable under-ground
coal/ lignite into
combustible gases by
gasifying the coal insitu
Underground Coal Gasification
22. ESSENTIAL STEPS IN UCG
• Drill wells into coal seam
• Create a permeable link
path
• Ignite coal at bottom
• Inject air (or oxygen) to
sustain fire
• Remove product gas
through production well
• Clean product gas in
surface facilities for end
use
Underground Coal Gasification
23. .. where we STAND..
.. what we SEE..
.. what we FACE..
.. what we SEEK..
Underground Coal Gasification
24. .. where we STAND..
Underground Coal Gasification
25. UCG REACTORS - WORLD
Site Depth (m) Year Gas Produced
(Million m3)
Podmoskovna 30-80 1947-62 4700
Lissichamskaya - 1948-62
Angren 120-200 1962-current 14000
Juzno-Abinskaja 50-300 1955-current 6700
Schatska - 1965-74
*Russian Fields
Underground Coal Gasification
26. UCG REACTORS - WORLD
Site Depth (m) Year Gas Produced
(Million m3)
Hanna 85 1973-79 63.56
Hoe Creek 50-120 1976-79 12.18
Price Town 270 1979 1.39
Rawlins 30 1979-81 17.35
Centralia 75 1983 1.78
Hanna ( Rocky 110 1987-88 13.10
Mt.1)
USA fields
Underground Coal Gasification
27. UCG REACTORS - WORLD
Site Depth (m) Year Gas Produced
(Million m3)
Bruay-en- 65 1978-81
Artois (France)
La aute Deule 60 1979-85
(France)
Thulin 860 1986-87 0.55
(Belgium)
Alcorisa 500-700 1990 -
(Spain)
European fields
Underground Coal Gasification
28. .. What we SEE..
Underground Coal Gasification
29. WHY UCG IN INDIA
• Exploitation of huge unmineable
coal reserves (123 billion tonnes) in
Gujarat alone
• Transportation of coal to existing
power station: Severe strain on
railways
• Environmentally clean technology
Underground Coal Gasification
30. WHY UCG IN INDIA
• Use of produced gas for power
generation or for chemical feed-
stocks
• Potential use of carbon di-oxide for
Enhanced Oil Recovery (EOR) exists
in the area
Underground Coal Gasification
31. UCG POTENTIAL IN INDIA
POTENTIAL AREAS SOBHASAN, KALOL AND
MEHSANA CITY
STRUCTURE OF NORTH
GUJARAT
ESTIMATED COAL/ 123 BILLION TONNES
LIGNITE RESERVES (700-1700 M DEPTH)
EXPECTED ENERGY EQUIVALENT TO ABOUT
15000 BILLION M3 OF
NATURAL GAS (Meh-Ahm
Block)
Underground Coal Gasification
32. UCG POTENTIAL
GSI ONGC
234 Bt coal >350 Bt (Unmineable depth)
(Around 150 Bt at 63 Bt in 60 Bt in >200 Bt in
unmineable depth) Mehsana- Patan- Bengal
Ahmedabad Tharad Basin
Block
Block
Equivalent to
15000 Billion m3 of Natural Gas
10%
Equivalent to 1.35 times of
O+OEG reserves of ONGC
Underground Coal Gasification
33. .. what we FACE..
Underground Coal Gasification
34. EXPERIENCE IN UCG PROJECT
In mid 80’s a UCG National Committee was set up
to look into the UCG project wherein ONGC was
the nodal agency
• Proposed site was in Mehsana city structure
• Two Information wells were drilled
• Hydrological studies conducted
• Core studies conducted
Underground Coal Gasification
35. EXPERIENCE IN UCG PROJECT
• 3-D Seismic survey carried out
• Prepared Geological model
• Design pilot wells
Underground Coal Gasification
37. GENERAL PROPERTIES FOR
FAVOURABLE UCG SITE
• Thickness of 3 to 10m
• Steeply dipping - (Flat lying acceptable)
• Strong, dry roof rock
• Coal seam shall not be major aquifer
• No major aquifer over coal seam at least twice of
stable cavity height
• Low natural permeability of formation
• No major faults or fractures
• Amenable topography
• Proximity to end user market
Underground Coal Gasification
38. UCG PILOT PROJECT IN INDIA
• PILOT PROJECT SITE : MEHSANA CITY
STRUCTURE
• TARGET COAL SEAM : SOBHASAN - III
• DEPTH OF COAL
SEAM : 900-1100 M
• THICKNESS OF COAL
SEAM : 6-14 M
• TYPE OF COAL : LOW RANK SOFT,
DARK BROWN
LIGNOBITUMINOUS
Underground Coal Gasification
39. UCG PILOT PROJECT IN INDIA
The objectives were:
• To demonstrate the feasibility of UCG at deeper
depth
• To demonstrate drilling of long in-seam holes and
to connect hole with vertical well
• To develop gasifier initiation and cavity growth
control techniques
• To monitor and measure gasifier development
• To know product gas quality and quantity
• To prove material capabilities and environmental
impact
Underground Coal Gasification
41. UCG PILOT PROJECT IN INDIA
The pilot could not be executed due to
• Limited expertise available then
• Non-availability of OIDB funds
Underground Coal Gasification
42. PHYSICAL REQUIREMENTS
• Characteristics of coal/lignite seams (Chemical
analysis, pyrolysis, through tube coal
experiments)
• Characteristics of roof and floor rocks
(Mechanical properties for prediction of cavity
formation and subsidence)
• Hydrological studies and gas migration studies
• Pollution studies (Air and Water) before and after
gasification
Underground Coal Gasification
43. TECHNOLOGICAL
REQUIREMENTS
• Drilling, Special cementing, Design and
Completion of Process wells
• Combustion process package ( Ignitor, Cavity
formation, Propagation)
• Process of CRIP (Controlled Retracting Injection
Point)
• Surface design for UCG
Underground Coal Gasification
44. .. what we SEEK..
Underground Coal Gasification
45. Participation Required
• Resource Characterisation
– Coal Seam Properties
– Hydrologic Characteristics
• Laboratory investigations of coal properties
• Laboratory Gasifier experiments
• Reaction Kinetics
• Subsidence studies
• Detailed Engineering design of pilot
• Development of process options for UCG product
Gas cleanup.
• Simulation of underground process
…… and lot more
Underground Coal Gasification
