Livro de Resumos - Dinossauros do Maranhão

Paleontologia 268
High Resolution Palynological Studies in Hydrocarbon Exploration in Indian
Perspective: Present Status in West Coast and East Coast Basins and
opportunities in Late Neo-Proterozoic of Rajasthan
Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow – 226007, India
E-mail: mahrotrabsip@rediffmail.com
Naresh C. Mehrotra
With the rapid growth of hydrocarbon exploration in India, a good amount of subsurface
data is continuously being generated from the various prospective sedimentary basins.
Most of the exploration activities have been centered around Oil & Natural Gas
Corporation Ltd., India's National Oil Company. However, with the opening of exploration
activities to private operators in the last decade a lot of geoscientific information has been
generated. Palynological studies related to hydrocarbon exploration have been published
mainly from K.D. Malviya Institute of Petroleum Exploration (ONGC) by Mehrotra and
colleagues in the last decade. A comprehensive account of stratigraphic palynology in the
commercially producing basins of India – Cambay, Mumbai Offshore, Cauvery, Krishna-
Godavari (K-G) and Assam Arakan has been given by Mehrotra et al. (2002). This is
quickly followed by publication of good amount of information on palynological
biostratigraphy, source rock evaluation, palaeoenvironment and sequence biostratigraphy,
particularly from the Western Offshore and K-G basins. It includes Atlas of dinoflagellate
cysts from Mesozoic (Mehrotra & Aswal, 2003) and Tertiary (Mehrotra & Singh, 2003) of
Krishna-Godavari Basin. Another major publication dealing mainly with stratigraphic ranges
of significant palynofossils from various Indian petroliferous basins and their significance in
hydrocarbon exploration was published (Mehrotra et al., 2005). Mehrotra et al. (2002b)
and Kapoor & Swamy (2007) published lot of significant palynological data from several
exploratory wells in Mumbai Offshore. Recently Mehrotra et al. (2008) reviewed the status
of high resolution biochronostratigraphy of petroliferous basins of India based on
dinoflagellate cysts and spore-pollen data. The present work deals with an updated
account of palynostratigraphic, source rock evolution and palaeoenvironment information
from the Western Offshore and Krishna-Godavari (K-G), the two most prospective
hydrocarbon bearing basins. Forty-three dinoflagellate biohorizons have been identified in
the subsurface Tertiary sediments of Mumbai Offshore, facilitating a high resolution
correlation of Oil bearing horizons. Integrated palynostratigraphic data from the Mesozoic
and Cenozoic has been compiled in a table. Eighty-two dinoflgellate biohorizons have been
identified. A very fine dinoflagellate based stratigraphic resolution has been achieved at
most levels making it effective in geological modeling for hydrocarbon exploration research
in both Western Offshore and Krishna-Godavari Basin. Potential source rock facies in
Panna Formation (Ypresian) in Western Offshore and Cretceous of Krishna-Godavari Basin
have been identified and their distribution mapped in several promising areas. Limitations
of present biostratigraphic studies in Western Offshore and K-G Basin and future areas of
focus have been identified. First record of Type I matured, Liptinite organic matter facies
from Late Neoproterozoic of Rajasthan is considered significant. This throws open an
entirely new basin for hydrocarbon exploration from Neoproterozoic sediments in
Rajasthan and other similar prospective basins in India.
Palestras Magistrais