in this ppt describe the offshore oil and gas field

1. A Seminar On
OFFSHORE OIL AND GAS FIELD
Jiwaji University, Gwalior
Under The Guidance By:- Submitted By:-
Dr. P.K.Jain Chinmay Kumar Pradhan
S.O.S Earth Science M.Sc. 3rd SEM

2. CONTENTS
• INTRODUCTION
• HISTORY
• OFFSHORE OIL AND GAS FIELD IN INDIA
• TECTONIC HISTORY
• STRATIGRAPHY STUDY
• LITHOSTRATIGRAPHY STUDY
• PETROLIUM ASPECT
• OIL AND GAS FIELD IN THIS BASIN
• CONCLUSION
• REFERENCE

3. • “Offshore” when used in
relation to hydrocarbons refers
to operations undertaken at,
or under the sea in association
with an oil, natural gas or
condensate field that is under
the seabed or to activities
carried out in relation to such
a field.
https:/delighttransport.com/
/

4.  U.S. offshore oil and gas history began in the
late 1880s because of high water at Grand Lake
St. Marys , according to some Mercer County
historians. In California, offshore oil wells were
drilled from piers beginning in 1896 at
Summerland in Santa Barbara County.
 In 1938, the first offshore well was constructed
in the Gulf of Mexico. Pure Oil and Superior Oil
Company built a freestanding drilling platform—
a 320-foot by 180-foot freestanding wooden
deck in 14-feet of water about a mile offshore
near Creole, Louisiana Offshore Oil & Gas History - American Oil & Gas Historical Society (aoghs.org)

5. • The largest offshore oil fields in India are
the Mumbai high field. It was formerly
called “the Bombay high field”.
• Bombay offshore field was discovered by a
Russian and Indian oil exploration team
during mapping of the gulf of Khambhat in
1964-67 followed by a detail survey in
1972
• The oil operations are run by india’s oil
and natural gas corporation(ONGC)
• Bombay offshore oilfield 160 km off the
coast of Mumbai , India, in about 75m of
water of the Arabian sea.
https://www.upstreamonline.com/exploration/ongc-lifts-lid-on-fresh-oil-and-gas-find-off-mumbai-coast/2-1-1168644

6. Continue…
• It is the largest continental terrace in the
world.
• It covers an area of about 116,000 km
square
• It supplied 14% of India’s oil requirement
and accounted for about 38% of all domestic
production as per data available till 2004.
https://www.ndrdgh.gov.in/NDR/?page_id=651

7. • The basin is bounded to north and east by
deccan trap out crops of Saurashtra
peninsula and western ghats respectively.
the southern limit is marked by east-west
trending Panjim arch and the western
limit is defined by the shelf edge
basement arch
• Five structural provenance with different
tectonic and stratigraphic events can be
identified with in the basin.
1.surat depression
2.Panna Basin - Heera block
3.Ratnagiri block
4.Mumbai platform
5.Shelf margin
PETROLIUM GEOLOGY OF INDIA PAGE NO-23

8. • It forms the southward extension of the
Cambey basin and to the west it is
separated from Saurashtra basin by Diu
arch.
• An arm of this depression extends far
south in to Panna-Bassein-Herra block
and further south in to Ratnagiri block.
• The Surat depression has numerous
structural features of different origins like
basement-controlled anticlines,
differential compaction over sand bodies
encompassed by shale, inversion and
growth fault related roll over features
PETROLIUM GEOLOGY OF INDIA PAGE NO-23

9. • This block located east of Mumbai
High/Platform and south of Surat
Depression has three distinct N-S to NW-
SE trending tectonic units which lose their
identity in Miocene.
• The western block is a composite high
block dissected by a number of small
grabens.

10. It is the southward continuation of the
Panna-Bassein-Heera block. This block is
differentiated into four distinct tectonic
units by three sets of NNW-SSE trending
echelon fault systems.
The western block is termed ‘Shrivardhan
Horst’ and to its east is ‘Vijayadurg Graben’
which is also a syn sedimentary sink during
Paleogene and Early Neogene.
• https://www.researchgate.net/figure/Tectonic-map-of-Western-Mumbai-Offshore-Basin-after-Pandey-et-al-1998_fig1_324587461

11. • It is bounded by Shelf Margin to its west
and south and by Saurashtra Basin and
Surat Depression to its north.
• Mumbai Platform includes Mumbai high
and DCS area.
• Its northern boundary with Saurashtra
Basin is indistinct and to its west lies Deep
Sea Basin with the western boundary
marked by part of a regional ridge ‘Kori
High’.
https://www.researchgate.net/figure/Location-of-Mumbai-Offshore-Basin-
showing-major-tectonic-and-geomorphologic-features_fig2_288208354

12. • The stratigraphic fill of the basin consists
only of tertiary sediments, which are in
place more than 5000m thick.
• It is classified 3 types-
1.Sands and lignitic clays (basal part)
2.Limestones and alternations of shales
(middle part)
3.Shales and clays forming (upper part)
PETROLIUM GEOLOGY OF INDIA PAGE25

13. • The entire Surat depression consists of
shale and claystone
• The middle section in the Bombay
platform area consists of alterations of
limestone and shale.
• The upper part of this section the
productive zones of the Bombay high field
are present
• The part of west Bombay high and south
of Ratnagiri block the shale sequence is
replaced the limestone section.
https://www.ndrdgh.gov.in/NDR/?page_id=651

14. • Bombay offshore basin which is the first oil discovery in carbonate reservoir in the country
• The major producing horizons are of middle Miocene age ,Eocene, Oligocene, and early Miocene
sequences are also oil and gas bearing in many structures.
1. Pre-mid Miocene shale in the Surat depression.
2. The shales in the shales margin basin.
3. Shales which alternate with the limestone of Bombay platform.
Basal clastic and fractured basement

15. • Shale is mainly cap rock in Mumbai high but somewhere carbonates are also present as cap rocks
whereever tight limestone is formed.
• Ex- Basin Reservoir
Limestone is the main reservoir . Limestone is the basically micrite,bio micrite and chalky type .
They posses mainly Primery and secondary porosity.
 Average porosity range-15-35%
 Average permeability-10 Md to 1 Darcy

16. • The Bombay offshore field is the largest
field in the basin with relativity smaller
fields being Panna Basin, Heera, Ratna, R9,
R7, South Tapti, Dahanu, B-57, B-55, B-58
and DCS.
PETROLIUM GEOLOGY OF INDIA PAGE NO-25

17. • ONGC envisages a total crude oil production of 202.42 MMT BY 2030
• It aim to improve the recovery rate by 40% by 2040

18. • The study of Geology gives an idea about the formation, stratigraphic
sequence and present condition of the bombay offshore basin
• Study of petroleum system also provides information about generation
and expulsion adjacent to the Bombay offshore basin which may have
occurred as dearly as middle Miocene and continued ,or began again,
in the pliocence
• Burial- history data indicate Peak generation most likely occurred during
the late Miocene and early pliocene

19. • PETROLIUM GEOLOGY OF INDIA JOURNAL BY ONGC
• NATIONAL DATA REPOSITOTORY(WWW.ndrdgh.gov.in)