India is poised to emerge as a major source of hydrocarbon with its several prospective Neoproterozoic sedimentary basins, a top official of the Birbal Sahni Institute of Palaeobotany (BSIP) has said.
"Worldwide, Neoproterozoic successions are major hydrocarbon producers. In India also, the scientists have discovered several fossil indicators in the Gotan Limestone (late Neoproterozoic) in Rajasthan," BSIP Director Dr Naresh C Mehrotra told PTI.
Organic matter maturation studies for hydrocarbons were carried out recently by the Lucknow-based BSIP on a rich assemblage, comprising algae, acritarchs and larvae of the petroleum fly from the Gotan Limestone, Marwar subgroup in Rajasthan, revealed the micro fossil indicator Algae of Type I Liptinite, Mehrotra said.
"Since Gotan Limestone is the first record of matured Type I Liptinite in India, it is considered significant," Mehrotra said.
The sediments are evaluated to be of moderate source potential.
"However, the sediments in the down dip direction in the vicinity of the area, may have hydrocarbon source pool which may be rich in organic matter with higher Thermal Alteration Index (TAI)," Mehrotra, also the principal investigator of the project, said.
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Generation of subsurface data is also required to substantiate the studies and precisely map the potential 'source rocks' in the petroleum system," Mehrotra said.
Gotan Limestones divulges an entirely new basin for hydrocarbon exploration, he said.
"Initiation of similar source rock studies is required in other Neoproterozoic basins in the Indian subcontinent and positive data would significantly enhance the hydrocarbon potential in the country," he said.
Similar studies on other Neoproterozoic sediments are also being carried out by BSIP but an extensive and integrated geoscientific work on both the exposed and subsurface Neoproterzoic sediments are essential in the regions to determine the thickness and geographic extent of source rocks, Mehrotra said.
High impact studies on the source rock evaluation, palynostratigraphic and palaeoenvironmental data on Western offshore (including Bombay offshore) and Krishna Godavari (K-G) basins have also been carried out.
Forty three dinoflagellate (marine micro-organism) biohorizons have been identified in the Tertiary subsurface of Mumbai offshore, facilitating a high resolution correlation of Oil Bearing horizons, Mehrotra said.
In the K-G basin, 82 dinoflagellates biohorizons have been identified.
A very fine dinoflagellate-based stratigraphic resolution has been achieved by BSIP scientists at most levels making it useful in geological modeling for hydrocarbon exploration in both Western offshore and K-G Basin, Mehrotra said.
BSIP has recently proposed to the Oil Industry Development Board (Ministry of Petroleum & Natural Gas) to set-up a National Centre of Applied Palynology, Biostratigraphy and Source Rock Characterisation for Fossil Fuel Exploration and National Core Lab in consultation with the Directorate General of Hydrocarbons.
This proposed Centre is mainly to provide independent facility within the country for private operators to get quick results to enable them to take time-bound decisions in oil exploration.
"Currently, outsourcing is largely done to foreign laboratories. The proposed centre will also serve national oil companies like Oil and natural Gas corporation (ONGC) and Oil India (OIL) by providing alternate opinion and multiple data sets for reducing exploration risk, and also outsource their spill-over work," the BSIP director added.