norte basin onshore exploratory potential norte

norte basin onshore exploratory potential norte

ONSHORE EXPLORATORY POTENTIAL - NORTE BASIN
URUGUAYAN BASINS
LITHOSTRATIGRAPHIC COLUMN
SOURCE ROCKS
Mangrullo Fm.
Cordobés Fm
Fm.
Unit
Facies
TOC %
Kerogen type
Cordobés Fm.
(Early Devonian)
Marine shales
3.6
I and II
Cerro Pelado Fm.
(Early Permian)
Marine shales
1.5-2/
0.5-1.5
I and II /
II and III
Fraile Muerto Fm
Fm.
(Early Permian)
Marine shales
0 5-2
0.5-2
III
Mangrullo Fm
Fm.
(Early Permian)
Marine oil shales
10-12
I
RESERVOIR ROCKS
EXPLORATORY WELLS & SEISMIC SURVEYS
The Paraná Basin is a large intracratonic basin which extends over
1 400 000 km2 in several South American countries.
1.400.000
countries In Uruguay,
Uruguay it is known
as the Norte Basin,
Basin and crops out in an area of more than 90.000
90 000 km2. The
Early Devonian to Late Cretaceous sedimentary fill has a maximum drilled
thickness of 2.500
2 500 m.
m
Ø
San G
S
Gregorio
i F
Fm.
(Late Carboniferous)
Fluvio-glacial
Fl
i
l i l
diamictites and
sandstones
18 25%
18-25%
Tres IIslas
T
l F
Fm.
(Early Permian)
D lt i sandstones
Deltaic
d t
20 30%
20-30%
Buena Vista Fm.
(L t Permian)
(Late
P
i )
Aluvial, ffluvial and
aeolian
li sandstones
d t
and conglomerates
12-18%
%
Tacuarembó
T
bó Fm.
F
(L t J
(Late
Jurassic)
i )
Fluvial,
Fl
i l llacustrine
t i and
d
aeolian
li sandstones
d t
12 18%
12-18%
Cuaró Fm.
(E l Cretaceous)
(Early
C t
)
Basic dykes and sills
3-30%
Mercedes Fm.
(Late Cretaceous)
Aluvial and fluvial
sandstones and
conglomerates
l
t
18-27%
- Gas shale potential of the Devonian Cordobés Formation. In February
2010, the North American company
p y Schuepbach
p
Energy
gy LLC was
granted a 10,000
g
,
km2 p
prospection
p
permit in central Uruguay.
p
g y
- Devonian sequence, including braided-delta and sandy litoral plain
(Cerrezuelo Fm.), shallow shelfal (Cordobés Fm.), and sandy litoral plain
deposits
p
((La Paloma Fm.).
)
- Permian
P
i
sequence, comprising
i i
glacial
l i l to
t glacio-fluvio-lacustrine
l i fl i l
ti
(S
(San
G
Gregorio
i Fm.),
F ) glacio-marine
l i
i
(C
(Cerro
P l d Fm.),
Pelado
F ) deltaic
d lt i (Tres
(T
I l Fm.),
Islas
F )
marine (Fraile Muerto Fm.), restricted marine-lagoon (Mangrullo Fm.),
shelfal to transitional (Paso Aguiar Fm. and Yaguarí Fm.) and fluvio-aeolian
deposits
p
((Buena Vista Fm.).
)
- Late Cretaceous sequence,
sequence comprising fluvio-aeolian
fluvio aeolian deposits (Guichón
Fm ) and aluvio-fluvial
Fm.)
aluvio fluvial deposits (Mercedes Fm.).
Fm )
Facies
Recent exploratory efforts in the Norte Basin are centered in:
Four sequences are recognized:
- Juro-Cretaceous
J
C t
sequence, including
i l di
b
basaltic
lti flows
fl
(G
(Gaspar
F ) fluvioFm.),
fl i
l
lacustrine
ti
and
d aeolian
li
d
deposits
it (Itacumbú
(It
bú Fm.
F
and
d Tacuarembó
T
bó Fm.)
F ) and
d
finally huge volumes of basaltic flows (Arapey Fm.).
Unit
BOUGUER GRAVIMETRY
Seismic line
(see below)
Early Cretaceous basic dykes and sills of the Cuaró Fm. cut units of all but
the later secuence.
secuence
Deep depocenter
(not drilled yet)
- Coal
C l potential
t ti l off the
th Permian
P
i Tres
T
I l Formation
Islas
F
ti (correlated
(
l t d with
ith the
th
Brazilian Rio Bonito Formation). ANCAP and the Facultad de Ciencias
are performing a detailed mapping of the facies of the upper third of the
Tres Islas Formation, and will p
perform a few exploratory
p
y drills in order to
assess thickness,, lateral extent and q
qualityy of the coal beds. The closest
example is the Candiota Coal Mine, in Rio Grande do Sul, 40 km north of
the national boundary.
boundary The Uruguayan coal is expected to have similar
properties to the Brazilian coal.
coal
- Oil shales of the Permian Mangrullo
g
Formation ((correlated with the
Brazilian Rio Bonito Formation).
) The Uruguayan
g y
company
p y CENESTE
S.A. has been granted two small exploration permits in NE Uruguay.
COAL PROSPECTIVITY
2D seismic (1.600 km), gravimetric (24.600 km2) and magnetometric
surveys
y were p
performed in the Norte Basin. Between the 1950s and 1980s
ten exploratory
p
y drills were made ((16.900 m drilled in total).
) Although
g all were
declared dry wells, some levels with interesting source rock potential were
encountered These source rocks are thermally immature,
encountered.
immature unless in the
vicinity of Cretaceous dykes and sills,
sills where is often correlated with gas
shows.
shows
In the late 1970s and early
y 1980s and evaluation of the oil shale resources
was accomplished. As a result of the Fischer assay, it was calculated that
the mineable oil shale bed would yield 277 million barrels of shale oil and 30
million tons of sulphur.
sulphur
INTERPRETED SEISMIC LINE
GAS SHALE & OIL SHALE PERMITS
SCHEMATIC WSW-ENE
WSW ENE CROSS-SECTION
CROSS SECTION
CENESTE S
S.A.
A