High Resolution Biostratigraphy and Litho-Micro Facies Analyses of Paleogene Sequences of Tapti-Daman Sector, Mumbai Offshore, India
Beerpal S. Pundeer1, R. A. Thakur1, R. S. Rawat1, Raju Grover1, S. Uppal2, P. K. Tirky2, and Sujay Sinha3
1Palynology Div., KDMIPE, ONGC, Dehradun, India
2Sedimentology Div., KDMIPE, ONGC, Dehradun, India
3Paleontology Div., KDMIPE, ONGC, Dehradun, India
Integrated sedimentological, biostratigraphic and paleoenvironmental studies on Panna, Belapur, Diu, Mahuva and Daman formations helped in attempting high resolution biostratigraphy and understanding depositional set up in the Tapti-Daman Block. Ninteen dinoflagellate biohorizons are recognized in the Panna, Belapur, Diu, Mahuva and Daman formations in ten wells. These are: LAD Impagidinium dispertitum, 26Ma (Top of Chattian, Late Oligocene) to LAD Palaeoperidinium pyrophorum, 58Ma (Thanetian-Late Paleocene), based on the globally recognized dinoflagellate biohorizons. Two Hiatuses, one Ca. 48-51Ma between Panna and Belapur formations (Early and Middle Eocene) and another Ca. 36-39.4Ma between Diu and Mahuva formations (Middle - Late Eocene and Early Oligocene) are identified. Micropaleontological studies were integrated for determination of age and environments based on Foraminiferal bioevents.
Facies analysis of conventional cores enabled interpretation of reservoir characters. In the wells U-2 and N-1, Panna Formation is with moderate to poor reservoir quality, while the limestone facies in Belapur and Diu formations indicate good reservoir quality. In Mahuva and arenaceous Daman formations the reservoir facies is with moderate to good porosity.
Fluvial environment mainly prevailed during the deposition of Panna Formation in the areas of U-2, N-1 and T-1. During the deposition of Belapur, Diu and Mahuva formations, the area was under sub-tidal to inner neritic conditions. Daman Formation experienced marine transgressive phase.
Paleogeographic maps at the top of Panna, Diu, Mahuva and Daman formations revealed the transgressive and regressive phases of the basin.
Presentation GEO India Expo XXI, Noida, New Delhi, India 2008©AAPG Search and Discovery