Petroleum Exploration -A Glimpse

1. PETROLEUM EXLORATION
-A GLIMPSE
by
S. K. De
GTC Session -11th Dec 2011
At Elita Promenade, Bangalore.

2. PETROLEUM EXPLORATION – A GLIMPSE
 Wealth of a Country consists of Forest,
Agriculture, Mineral and Human Resources.
 Mineral Wealth comes from Rocks of the
Earth.
 Rocks are of three types : Igneous,
Sedimentary and Metamorphic.
 Interior of the Earth consists of Crust, Mantle
and Core.
 Crust consists of Soil, weathered & sub
weathered layer and Rocks.

3. PETROLEUM EXPLORATION – A GLIMPSE
 Mapping of the surface of the Earth is done by
Survey of India. Top sheets are prepared by
Surveyors.
 Mapping of Rocks are done by Geological
Survey of India. Geologists are engaged in this
task. This leads to discovery of Minerals.
 Ground Water and Petroleum occur in the
sub-surface. Ground water mapping is done
by the Central Ground Water Board.

4. PETROLEUM EXPLORATION – A GLIMPSE
 Petroleum consists of Oil and Gas. First
discovered in India in 1886 at Digboi by
Britishers while laying the Railway Line in
Assam.
 Petroleum search started by Burmah Shell
and later by Oil India. Work remained
confined to Assam.
 In 1956 separate Oil Ministry was formed by
India under Mr. K. D. Malaviya. ONGC was
set up for Petroleum Exploration in India.

5. PETROLEUM EXPLORATION – A GLIMPSE
 Oil discovery game consists of
Exploration, Drilling and Production.
 Petroleum is found deep within the Earth.
Requires exploration by Indirect means and
found only in Sedimentary rocks.
 Subsurface mapping of the sedimentary
basins leads to discovery of Oil and Gas.
 Professionals involved in the exploration are
Geologists, Geo Physicists and Geo Chemists.

6. PETROLEUM EXPLORATION – A GLIMPSE
 Geological Mapping leads to locating areas of
sedimentary basins.
 Petroleum generally forms in Deep sea
conditions due to decomposition of micro
organisms under conditions of high
temperature and pressure over million of
years time. Source rocks are known as Shales.
 Geophysical methods of subsurface mapping
are Gravity – Magnetic, Electrical and Seismic.
Airborne , Land and marine surveys are
undertaken.

7. PETROLEUM EXPLORATION – A GLIMPSE
 Seismic methods are direct methods
viz., Reflection and Refraction. It measures
Rock properties of the Earth.
 Method involves data acquisition, Data
Processing and data Interpretation.
 Exploration leads to release of locations for
Drilling.
 Conditions necessary for Oil and Gas
discovery are Source rock, Reservoir rock
, Cap rock and Entrapment.

8. PETROLEUM EXPLORATION – A GLIMPSE
 Depth of burial and reserve estimation are
also important factors.
 After discovery, Oil and Gas fields are
delineated by Drilling more wells.
 Thereafter production starts from the field
and Crude Petroleum is sent to Refineries.
 Oil and Gas disovered in
Assam, Gujarat, Krishna – Godavari and
Cauvery basins and also at Bombay High.

9. PETROLEUM EXPLORATION – A GLIMPSE
 Till 1997, ONGC & Oil India did the
exploration work. Therafter, Government of
India offered the undiscovered areas for
exploration to bidding by National and
International Oil Companies.
 Main discoveries since has been the
discovery of Oil in Barmer area of Rajasthan
by Cairn Energy and Gas in East coast deep
waters and Godavari Offshore by Reliance
Industries Ltd.

10. PETROLEUM EXPLORATION – A GLIMPSE
 Oil constitutes over 35% of Primary energy
consumption.
 Present level of demand is about 120
million metric tons. Demand will be over
250 million tons by the end of 2011-12.
 India imports 70% of its requirement.
Import bill is huge. Present crude oil price is
around USD 125 per barrel.

11. THANK YOU.