High Resolution Sequence Stratigraphy in the Shelfal part of Bengal - - PowerPoint PPT Presentation

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

1

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Identification of Stratigraphic Play potential within Jalangi Formation using High Resolution Sequence Stratigraphy in the Shelfal part of Bengal Basin, India

Pinaki Basu*, H.S.Vachak, Kumar Vivek, A.Sai Kumar & Dr. Harilal GEOPIC, ONGC Ltd. India basupinaki72@gmail.com

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

2

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Scheme Of Presentation

 Introduction  Geology Background  Present study  Conclusions

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

• Bengal basin, a polycyclic basin, has evolved through

two distinct tectonic episodes. It was initiated as an intra-cratonic rifted basin within Gondwanaland.

• This phase of basin development ended with wide

spread volcanism during which continental flood basalts (Rajmahal Trap with intratrappeans) covered the Gondwana grabens and surrounding highs.

3

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Location map and area of study in Bengal Onland Basin

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

4

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Tectonic Map of Bengal Basin

• During this journey of the Indian

plate, the pericratonic part on the eastern margin (along with Gondwana sediments) continuously subsided and received colossal volume of sediments from Late Cretaceous through Tertiary to Recent times in a passive margin set-up.

• Second phase of basin formation

took place when Indian Craton separated out completely from Antarctica/Australia around 128 Ma and kept on moving northwards.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

5

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Ghatal Fm.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

6

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

(Source: Public domain)

Regional Geological Cross Section across Bengal Basin

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

7

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Petroleum system: Bengal Basin

Gondwana Petroleum System Paleogene Petroleum System

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

8

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Regionally correlated horizons

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

9

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Zone of Interest on Seismic section

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

10

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

RMS amplitude attribute map corresponding to 100ms window below Feature2_top Horizon showing high amplitude elongated features /geobodies aligned parallel to the paleo coastline.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

11

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Sweetness attribute map corresponding to 100ms window below Feature2_top Horizon showing high sweetness elongated features /geobodies aligned parallel to the paleo coastline.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

12

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

RGB Blending of the geobody

RGB blending done at level of 20ms below F2_Top horizon

25 (B)Hz) 15(R)Hz

20 (G)Hz

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

Ghatal Fm.Top Jalangi Fm.Top

13

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Impedance section showing the low impedance geobody within the Paleocene Fm.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

14

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

• A high resolution seismic chronostratigraphy approach was adapted to

assess the geometric relationships of depositional cycles and lithologic associations of these geobodies in response to relative sea-level changes.

• A 3D seismic chronostratigraphy cube was built to interactively assess the

basin history through the Paleocene sequence of Bengal Shelfal part, to assess the varied stratal architectures of the sequence.

• The main step entailed seismic interpretation using closely spaced semi

automatically generated seismic horizons from seismic reflection data.

• The auto tracked seismic horizons were further used to carry out 3D

“Wheeler transformation”. Methodology adopted for High Resolution Sequence Stratigraphy and identification of Stratigraphic plays

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

15

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Ghatal Fm.Top Jalangi Fm.Top Feature_2 Top

Seismic section showing the Correlated Horizons

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

16

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Ghatal Fm.Top Jalangi Fm.Top Feature_2 Top

Inline showing the Truncated Horizons

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

17

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

High resolution Horizon Cube and Wheeler transform generated on Inline in 3D vol.

The stratigraphic features are best understood when studied simultaneously in the “Wheeler domain” and in the depositional /structural domain. This integrated technique represents a unique methodology for exploration of stratigraphic traps.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

18

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Identified isolated geobodies close to shelf edge

Basin ward Land ward

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

19

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Relief Map showing Barrier Bar and Tidal Inlet complex Clastic deposition in a Marginal Marine env.

(Source: Public domain)

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

20

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Systems Tracts Study on Seismic line (IL948).

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

Tidal Inlet Tidal Inlet 21

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Wheeler Similarity showing the Barrier Bar complex

Zoomed part

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

22

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

Model for Transgressive Barrier Bar complex

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

23

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

• These strike aligned geobodies mapped within the Jalangi Fm. are

wide spread along the paleo shelf margin in Bengal Basin

• Deposited during a transgressive-regressive sea level cycle.
• Thick marine shale packages, with thin coal seams were deposited in

the shelfal part.

• Jalangi Formation shale has good source rock enrichment over the

entire shelf part and possess greatest potential for oil generation in Bengal Basin.

• Hydrocarbon generation within this sequence is likely to charge these

intricately associated stratigraphic features/ geo-bodies which act as good reservoirs thus enhancing the stratigraphic play potential.

Conclusions

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

24

GEOPIC, ONGC Ltd, Dehradun

12/5/2017

ACKNOWLEDGEMENTS

We thank Director (Expl.),ONGC for giving permission to present and publish this paper in AAPG- GTW, Mumbai-2017. We wish to express our sincere thanks to Shri Anil Sood, ED-HOI-GEOPIC (Retired) for giving us the opportunity to carry out this project.

The views ews expres essed sed in in this paper er are solely ely those of

• f the authors
• rs and not necessari

essarily ly be be that of

• f ONGC

GC.

Oil and Gas Resources of India: Exploration and Production Opportunities and Challenges

Geosciences Technology Workshop; Mumbai, India, 6-7 December 2017

25

GEOPIC, ONGC Ltd, Dehradun

12/5/2017