NARMADA, KUTCH &
B.TECH 2’ND YEAR
RAJIV GANDHI INSTITUTE OF POETROLEUM
What is a sedimentary basin?
• A low lying area in the earth crust
• Basically tectonic in origin
• Sediments get deposited and accumulated
► Areal extent of about 1.79 million sq. km.
► So far 26 basins have been recognized.
► In the deep waters beyond 200m isobaths, the sedimentary area has been
estimated to be about 1.35 million sq.km.
► The unexplored area has come down to 15% which was 50% in 1995-1996
and the credits goes to DGH
► On the basis of geological prospectivity, the basins of india have been
divided into 4 categories
Category 1: Proven commercial productivity
Category 2: Identified prospectivity
► Sedimentary basin with proved occurence of hydrocarbons but from which
no commercial production of hydrocarbon has been occurred.
Category 3: Prospective basins
► Sedimentary basins with no significant oil and gas shows but which on
geological considerations are considered as prospective.
Category 4: Potentially prospective
► Petroliferous basins with uncertain prospects which require basic data to be
generated for prognosis. It includes the basins which bear an anology with
similar hydrocarbon producing basins in the world and may be prospective.
► It forms the north-western part of the western continental margin of India.
► It is bounded by the Nagar- Parkar fault in the North, Radhanpur-Barmer arch in the
east and North Kathiawar fault towards the south.
► The basin extents between Latitude 22 30' and 24 30' N and Longitudes 68 and
72 E covering entire Kutch district and western part of Banaskantha (Santalpur
Taluka) districts of Gujarat state.
► The total area of the basin is about 71,000 sq. km of which onland area is 43,000
sq.km and offshore area is 28,000 sq.km. upto 200 bathymetry.
► The basin is filled up with 1550 to 2500m of Mesozoic sediments and 550m of
Tertiary sediments in onland region and upto 4500m of Tertiary sediments in
offshore region (Well GKH-1).
► The basin is located in the northern part of western continental margin of
► The onland part of the basin is also known as Saurashtra Peninsula.
► This basin lies north of commercially proven Mumbai Offshore and south of
highly prospective Kutch basin.
► The onland part of the basin borders with the commercially proven Cambay
Basin on its eastern flanks.
► The deeper offshore Saurashtra borders with the Indus fan (to the abyssal
plain of the Arabian Sea)
► It is the southern-most of the three marginal basins embayed into an arrow
graben along the Narmada-Songeo fracture.
► The narmada rift basin crosses it in the Gulf of Cambay region at the widest
part of the shelf, south of kathiawar bulge.
The evolution of the western continental-margin basins of India is related to the breakup of
eastern Gondwanaland from western Gondwanaland in the Late Triassic / Early Jurassic and
the subsequent spreading history of the Eastern Indian Ocean
The western margin evolved through early rift and post rift phases of divergent margin
development. A series of regional and local horsts and grabens resulted in response to rifting
along the dominant basement tectonic trends (NNW-SSE, NE-SW and ENE-WSW).
The northernmost part of the western continental margin was the first to be subjected to
continental rifting and crustal subsidence in the Late Triassic
The opening of the Kutch basin to the north of Saurashtra peninsula coincided with the
transgressive phase of the sea onto the coastal areas of other parts of Gondwanaland
including the western margin of Indian plate during Jurassic-Cretaceous time (Krishnan, 1960).
Rifting along the Delhi trend and consequent subsidence of the block between the Nagar Parkar
hills and the Saurashtra Peninsula in the Late Triassic initiated development of the Kutch Basin.
The basin formed the site for westerly deepening epi-continental sea, probably an extension of
the Tethys, in which thick pile of sediments, ranging in age from Middle Jurassic to Early
Cretaceous, were deposited in shallow marine to deltaic environments. The sediments were
deposited in two major cycles - a Middle Jurrasic transgressive cycle and a Late Jurassic - Early
Cretaceous regressive cycle
The Kutch basin is a pericratonic rift basin situated in the western margin of India. Nagar Parkar
uplift in the north and Kathiawar uplift (Saurashtra horst) in the south respectively along Nagar
Parkar and North Kathiawar faults delimit the E–W rift
GEOLOGY AND TECTONIC EVOLUTION:
The Kutch basin has a comprehensive Mesozoic package. It has about 3000m of sediments
ranging in age from the Late Triassic to Lower Cretaceous. The basin was inundated by sea
by the Middle Jurassic (Bajocian) times.
The sediment package is predominantly siliciclastic with the carbonate sediments being
mostly confined to the Bathonian.
The siliciclastic sediments range from nearshore coarse-grained sands and conglomerates to
storm-influenced shallow shelf silts and clays.
The Kutch basin got rifted along this trend. Kutch rifting was initiated in the Late Triassic as
indicated by continental Rhaetic sediments in the northern part of the basin(Koshal, 1975). In
the early stages of India's northward drift away from Gondwana land, during Jurassic time, the
Kutch basin was formed by subsidence of a block.
GEOLOGICAL SETTING OF AN AREA:
The Saurashtra peninsula is located in the western periphery of India in the state of Gujarat.
Saurashtra is a pericratonic rifted passive margin basin comprising an onshore area of 52,000
km2 and a 20,000 km2 offshore extension into the Arabian Sea.
The peninsula developed by rifting along the three intersecting Precambrian orogenic trends,
the ENE–WSW Narmada Son lineament, the west coast fault with the NNW–SSE Dharwar
trend and the NE–SW Delhi Aravalli trend,at different stages of evolution of the Indian sub-
continent and their subsequent reactivation during the Mesozoic and Tertiary times. Bounded
by major faults and rift basins, the northern limit of Saurashtra is marked by the faulted margin
of Kutch and the southern coast runs parallel to the extension of Narmada geo-fracture.
The Wadhwan Formation occurs as a marine tongue within an overall deltaic system. The
Deccan Trap Formations occupy most of the exposed area of the Saurashtra.
Expected reservoirs :
(i) Cretaceous sandstone.
(ii) Eocene-Miocene shelfel carbonates / reefal build up.
(iii) Tertiary deep water sands (Indus Fan).
Expected source rocks :
Paleocene to Oligocene shales
Expected cap rocks :
Eocene to Early Miocene shales.
CATEGORY OF THE BASIN:
Category III (Prospective Basin).
AGE OF THE BASIN & SEDIMENT-THICKNESS:
The oldest phanerozoic rocks in this basin are the Mesozoic rocks exposed in the north
eastern part (Dharangdhara Formation) of this basin.
However major part of the Saurashtra Basin (both on land& offshore) is covered by
Deccan Traps which have hindered the exploration of Mesozoic Hydrocarbon targets.
Rocks of Early Cretaceous are exposed in the on land part of the Saurashtra Peninsula
(north eastern part of the basin). Late Cretaceous – Early Paleocene Deccan Volcanics
cover most of the Saurashtra Peninsula and the Tertiary sediments are exposed only on
the periphery of the Peninsula.
Tectonic movements in the Tertiary were milder and cyclic.
After the early Middle Miocene, the western margin as a whole experienced heavy influx of
clastics and manifests basinward rapid shift of the shelf over considerably long distance to
its present position.
The principle tectonic elements in the offshore region are:
Shelfal Horst-Graben Complex:
lies between the coast and shelf margin trough. The shelf structural assemblage
consists of a number of horsts & grabens.
Shelf Margin Trough:
This Is a narrow linear trough elongated parallel to the shelf edge. It lies between shelfal
horst-graben complex to the east and Laccadive ridge to the west.
This Is located between Laxmi ridge and Laccadive ridge. Consists of a series of
pronounced linear magnetic anomalies.Total sedimentary cover in the Laxmi basin
varies from 1250m on basement highs to 3000m in the depressions.
It is considered as a continental remnant rifted away from the continental margin
and reworked by hotspot volcanism. The ridge has a complex system of
grabens, half grabens& normal faults.
This Is a narrow elongate ridge in the deep offshore part west of Laxmi Basin.
Arabian Abyssal Plain:
Is a typical oceanic depression in Cenozoic times through the sea-floor spreading
along the Carlsberg ridge. It is consistent with a set of well-pronounced magnetic
anomalies characteristic of seafloor spreading.
Narmada is the southern-most of the three marginal basins embayed into an arrow graben
along the Narmada-Songeo fracture.
In the Early Cretaceous,fluvialsedi-ments of the Nimar Formation were deposited by a
river system flowing along the Narmada lineament.
The valley opened into a rift basin in Late Cretaceous time, and marine sediments were
deposited in a progressively deepening environment until the end of the Cretaceous.
Then sedimentation ended abruptly as a result of regional uplift followed by activity that
deposited the Deccan Trap in early Paleocene time.
The marine sediments were mostly carbonate and less than I,000ft (300m) thick. This
section indicates a slow rate of basin subsidence and uplift of the adjacent horsts.
This period of Late Cretaceous transgression is Synchronous with transgression on the
eastern continental margin and the final regression of the Mesozoic sea from Kutch and
HYDROCARBON POTENTIAL OF
• The Kutch Basin is a petroliferous basin where one oil and
two gas strikes have already been made.
• The gas pools were struck in GK-29A and GK-22C
structures in sandstone reservoirs of Palaeocene and
Late Cretaceous age at a rate of 1,24,332 m3/d and
2,39,930 m3/d respectively, whereas oil was struck in KD
structure in Middle Eocene limestone and siltstone
reservoirs at a production rate of 172 BPD at a depth of
• Kutch Basin is contiguous to the hydrocarbon-producing
Cambay Basin in the east and southeast, Mumbai
Offshore Basin in the south, and the South Indus Basin of
Pakistan in the North, where several discoveries of oil
and gas have already been made.
Study of source rock in Kutch basin:
► Source rock studies have been conducted on samples from outcrops, on land
wells Banni-2, Nirona-1, Lakhpat-1, Suthri-1 and most of the offshore wells
► The organic matter is of type II and III. The productivity index of the Mesozoic
outcrop samples indicates migrated hydrocarbons. The outcrop samples from
the western on land part of the basin indicate that Eocene and Oligocene
sediments contain type III and type II mixed Kerogens with TOC ranging from
0.54% to 3.45%.
► At present, the Upper Cretaceous sequence is in peak oil generation phase
and hence the major phase of oil migration is likely to have started only
around 1-2 Ma (Pliocene-Pleistocene). The argillaceous Jhuran Formation of
Late Jurassic age has been drilled in only one of the offshore wells i.e.
GK29A-1, where shale layers with adequate TOC are buried deep enough to
HYDROCARBON POTENTIAL OF KUTCH, SAURASTRA AND NARMADA BASIN:
HYDROCARBON PROSPECTS OF THE
► The Jamnagar sub-basin of Saurashtra, Gujarat is considered
geologically prospective for hydrocarbons by Directorate General of
Hydrocarbons (DGH), India. However the major part of the Jamnagar
sub-basin is covered by Deccan Traps, hindering the exploration of
Mesozoic hydrocarbon targets.
► Microbial analysis revealed high bacteria counts for methane
(1.32 106cfu/gm.), ethane (8.50 105cfu/gm.), propane
(6.86 105cfu/gm.) and butane oxidizing bacteria (5.70 105cfu/gm.) in
soil samples of Jamnagar sub-basin. The bacterial concentration
distribution maps show three distinct anomalies in the study
area, indicating hydrocarbon micro seepage at these places.
► Jamnagar sub-basin of Saurashtra has significant sediment thickness
below the Deccan Traps and can be considered for future hydrocarbon
exploration. The corroboration of adsorbed light gaseous hydrocarbons
and hydrocarbon oxidizing bacteria suggests its efficacy as one of the
potential tool in surface geochemical exploration of hydrocarbons.
► Two wells of reliance named Dhirubhai-27 and Dhirubhai-33 are
established and here gas production is tacking place.
Hydrocarbon prospects of Narmada basin:
► Major fields occur on north-south-trending, linear, fault-bounded ridges flanked by
narrow grabens. The reservoir rocks are mainly Eocene and Miocene limestone's.
► North of Narmada lineament, which is mainly a clastic basin, commercial hydrocarbon
resources are yet to be proved.
► Because of the short geologic history of the basin, the thinness of sediments, and the
complete exposure of the section from basement to top, the Narmada basin is not
► Of all the marginal rift basins, this basin has the longest history of deposition, with
about 12,000ft (3,600m)of sediments ranging in age from Jurassic to Holocene
► In the lower mid-Jurassic section, marine carbonate and shales were deposited.
1) GEOLOGICAL HISTORY AND TECTONICAL HISTORY OF KUTCH, NARMADA AND SAURASTRA BASIN-
2) HYDROCARBON PROSPECTS IN SUB- TRAPPEAN MESOZOIC DECCAN SYNCLINE, INDIA: EVIDENCE
FROM SURFACE GEOCHEMICALBY C. VISHNU VARDHAN1, B. KUMAR1, C.J. KUMANAN2, DEVLEENA MANI1,
AND D. J. PATIL.
3) GEOCHEMICAL ASSESSMENT OF LIGHT GASEOUS HYDROCARBONS IN NEAR
SURFACE SOILS OF KUTCH-SAURASHTRA: IMPLICATION FOR HYDROCARBON
PROSPECTS BY LAKSHMI SRINIVASA RAO*, P., MADHAVI, T., SRINU, D., KALPANA, M.S., PATIL, D.J. AND