Context:
Mumbai high turns 50.
Mumbai High:
- Mumbai High – India’s flagship and largest oilfield
- Type of Petroleum Trap – Anticline Traps
Petroleum Traps:
- Petroleum trap – An underground rock formation that blocks the movement of petroleum and causes it to accumulate in a reservoir that can be exploited.
- Reservoir rock – Would be porous and permeable and usually composed of sedimentary rock such as sandstones and dolomites.
- Composition –
- Top of the trap is occupied by natural gas and is underlain by the oil and then the water.
- Cap Rock – A layer of impermeable rock that prevents the upward or lateral escape of the petroleum.
- Petroleum Reservoir – Part of the trap occupied by the oil and gas
- Classification of traps – Structural traps and Stratigraphic traps.
- Structural traps – Formed by tectonic events, such as folding or faulting of rock units.
- 3 types of Structural Trap – Anticline Traps, Fault Traps and Salt Domes
- Anticline Traps – Most common type of structural trap, created through the created through the folding of rock strata into an arch-like shape.
- Fault Traps – Formed when reservoir rock is split along a fault line.
- Salt Dome Traps – Formed as a result of below ground salt, which is less dense than the rock above it, moving upwards slowly which deform and break up the rock along the way.
- Stratigraphic traps – Related to sediment deposition or erosion and is bounded on one or more sides by zones of low permeability.
Sedimentary basins in India:
- There are 26 sedimentary basins in India, covering a total area of 3.4 million square kilometer.
- Composition –
- 49% of total sedimentary area is located on land
- 12% in shallow water
- 39% in the deep-water area.
- Divided into – 3 categories (based on maturity of hydrocarbon resources)
| Category | Feature | Area | Regions |
| Category-I | Basins which have reserves and already producing. | 30% of total basin area | Krishna-Godawari Mumbai Offshore Assam shelf Rajasthan Cauvery Assam-Arakan Fold belt Cambay |
| Category-II | Basins which have contingent resources pending commercial production | 23% of total basin area | Saurashtra Kutch Vindhyan Mahanadi Andaman Nicobar |
| Category-III | Basins which have prospective resources awaiting discovery | 47% of total basin area | Kerala-Konkan Bengal-Purnea Ganga Punjab Pranhita Godavari Satpura-S.Rewa-Damodar Himalayan foreland Chhattisgarh Narmada Spiti Zanskar Deccan Syneclise Cuddapah Karewa Bhima Kaladgi Bastar |
Source: Economic Times
Previous Year Question
Consider the following heavy industries:
1. Fertilizer plants
2. Oil refineries
3. Steel plants
Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries?
[UPSC Civil Service Exam – 2023 Prelims]
(a) Only one
(b) Only two
(c) All three
(d) None
Answer: (c)
