A reservoir evolution model of synrift lacustrine hyperpycnites, Barmer Basin (Rajasthan, India).

Autor: Majumdar, Pinaki, Konar, Shubhodip, Dolson, John, Dhanasetty, Archana, Bora, Ajoy Krishna, Kumar, Prem
Zdroj: Arabian Journal of Geosciences; Aug2022, Vol. 15 Issue 16, p1-18, 18p
Abstrakt: The Barmer Basin in northwest India is one of the largest hydrocarbon provinces in India with 38 discoveries declared by Cairn India and ONGC since the first discovery in 1999. The basin is 8000 km2 in area and accounts for about 20% of India's annual production of crude oil. This Palaeocene-Eocene lacustrine rift is the northern-most termination of the Cambay rift. Basinal hyperpycnites comprise important, but complex reservoirs, largely confined to the basin margins. This study details the BHT10 interval of the Palaeocene-Eocene Barmer Hill Formation in the Vijaya-Vandana field, which are large, complexly layered, low permeability submarine fan and channel-fill stratigraphic traps. The field consists of two mounded channel-fill and fan complexes. Four lithofacies dominate (1) reservoir quality sandstone in channel-fill complexes, (2) marginal quality conglomeratic and chaotic heterolithic clastics, (3) non reservoir porcellanites and diatomites and (4) mudstones. The best reservoir facies are confined channel-levee and fan deposits. Reservoir architecture is controlled by basin floor topography and structure. Climate-induced lake level fluctuations also impact stratigraphic architecture and channel avulsion with time. Although the primary trapping mechanism is an updip stratigraphic pinchout of the clastic fan facies, the reservoirs are interbedded with the source rock, and where thermally mature, very little water is recovered, making the trap partly unconventional in nature. Much of the sediment is texturally and mineralogically immature and has undergone burial diagenesis involving authigenic kaolinite and illite cementation. Diagenetic effects are more prominent closer to the basin bounding faults. Away from the faults, distal basin floor production is further complicated by interbedded layers of non-reservoirs which impede vertical connectivity. Integrated analysis of both diagenetic, thermal maturation and 3D seismic and geological facies analysis is essential in chosen favourable locations to develop this field. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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