SEDIMENTARY BASINS OF INDIA : SEDIMENTARY BASINS OF INDIA Presented by:
Akhilesh Kumar Maury
4th Semester Introduction : Introduction Sedimentary basins refers to a geographical feature exhibiting subsidence and consequent infilling by sedimentation. On burial they are subjected to increasing pressure and begin the process of lithification.
The sedimentary basins of India occupy an area of 3.14 million sq. km. of which 3,20,000 sq. km. is in the offshore up to 200m isobaths.
There are total 26 sedimentary basins out of which 13 are important for Hydrocarbon reserves. Basin classification : Basin classification Category- I is the petroliferous basins with proved hydrocarbon reserves and where commercial production has already started.
These basins are:
Krishna-Godavari Slide 4: Category – II comprises basins with occurrence of hydrocarbons but from which no commercial production has been obtained yet .
Category – III comprises basins with no significant oil & gas shows but which on Geological considerations are considered to be prospective.
Category – IV comprises uncertain prospects. It includes the basins which bear an analogy with hydrocarbon producing basins in the world. Assam–Arakan Basin : Assam–Arakan Basin It includes Assam, Nagaland, Arunachal Pradesh, Manipur, Mizoram and Tripura. The Assam shelf has an extent of 40,000 sq.km. and includes the Shillong Plateau, the Garo, Khasi, Jaintia, Mikir Hills and the upper Assam valley. THE CAMBAY BASIN : THE CAMBAY BASIN The Cambay Basin occupies an area of approximately 56,000 sq.km.
The Cambay Basin can be divided into six tectonic blocks :
The Cambay Shale is the main source rock in this basin. CAUVERY BASIN : CAUVERY BASIN The Cauvery Basin, situated 160 to 460 km south of Chennai city, encompasses an area of 25,000 sq. km. falls in Indian territorial waters.
The basin is subdivided into six sub-basin:-
Ariyalur Pondicherry sub-basin.
Ramnad Palk Bay sub-basin
Mannar sub-basin BOMBAY OFFSHORE BASIN : BOMBAY OFFSHORE BASIN It lies in region of Western continental shelf of India and forms an important hydrocarbon bearing province. It is extending from Saurashtra Coast in the North to Vengurla arch near Goa in the South covering an area of about 1,20,000 sq.km. up to 200 m isobaths.
Tectonically the basin can be subdivided into Surat depression, Bombay High platform, Ratnagiri block, Shelf margin basin and the Shelf-edge basement arc.
Bombay Offshore Basin is producing nearly 70% oil and gas of India’s total hydrocarbon production KRISHNA GODAVARI BASIN : KRISHNA GODAVARI BASIN It an area of about 15,000 sq. km. of on land and the East- coast of India , West and North western limits are demarcated by Archaean outcrops. The basin is divided into six sub-basins.
West Godavari sub-basin
East Godavari sub-basin
K.G.Offshore sub-basin Slide 16: K.G. Basin is called the Middle-East of India as it has got such considerable amount of reserve that if properly utilized can serve the energy needs of not only the whole of India that also will make us more energy efficient so that we can even export crude and oil products to other nations. Conclusion : Conclusion India has 26 sedimentary basins with an area of 3.14 million sq. km.
The resource base of hydrocarbons is estimated to be about 29 billion tones of oil and oil equivalent gas (O+OEG).
Out of which 6.8 billion tones of in-place hydrocarbon has so far been established through exploration.
The sedimentary basins which has been explored constitute a total area of 0.52 million sq. kilometers i.e., about 17 per cent of the entire sedimentary area.
There is no commercial production in remaining 83% of total basin area. Bibliography : Bibliography http://www.mapsofindia.com
Drilling Operations Manual, Institute of Drilling Technology, ONGC Dehradun