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Overview
In 2007 Chilean Ministry of Mines and
Energy tendered a bid for 36.000 km2 of prospective territory within
the Magallanes Basin in the southern part of Chile. This tender included
10 exploration blocks in which state owned ENAP (Empresia Nacional del
Petroleo-Chile) has variable rights to continue its production depending
on its level of interest. Considerable interest existed in this bid
because of the oil and gas production history by super Majors BP (Pan
American Energy), Total and US independent Apache, on the Argentina
side of the basin.
Manas together with partner IPR (Independent
Petroleum Resources, a Texas based independent) won the bid for the
Tranquillo block which was evaluated as the most prospective block on
offer. BP's Pan American won the block directly east,
Total won the adjacent southern block and Apache won two blocks to the
South East.
The most significant points regarding
Manas Petroleum's Tranquilo block are as follows:
- The Tranquillo block is in
a thrust belt environment and has a considerable number of target structures
of both shallow and moderate depth, with potential for significant GIIP
figures; including the possibility of finding giants fields.
- Tranquilo has a proven petroleum
system
- Some fields can be identified
in them and early production can be easily achieved.
- The block contains prospects
and leads with an estimated undiscovered potential of more than 4 Tcf
(recoverable) of natural gas
- Although the main potential
is gas, based on discoveries on the Argentina side of the basin, there
is a serious chance of liquids production.
- Vast exploration potential
which can be conveniently staged in three exploration periods.
Location
The block's southern boundary begins in the North coast of Skyring Sound and it has 1,428 Km of 2D seismic and 33 wells. The Magallanes basin has a well-developed 417 Km network of gas pipelines connecting the main fields to market, such us Methanex,
the world largest methanol plant. In addition the state oil company
ENAP has four plants in the basin, the largest of which, Cabo Negro
produces LPG from natural gas and has a capacity of 2,930 m3 per day.
Cumulative production in the Magallanes totals (m3) 63,934,010 oil and
(million m3) 232,416 natural gas. The Tranquilo block is in the foreland
of the Magallanes basin which is part of the same geological formation
as Argentinas Austral Basin. This has historically produced over 500
million barrels of oil and more than 10 TCF of natural gas. According
to the Chilean government in this region of Chile the production of
hydrocarbons has proved commercially viable.
Partner
Manas has built a bidding consortium
with IPR (Independent Petroleum Resources, www.iprgoc.com)
on a 50% / 50% basis. IPR is the designated operator of the project.
Manas and IPR won the tender and the consortium was awarded the Tranquilo
block on November 15th.
Manas has opened a Chilean company and
is an active and constructive partner within the consortium.
Work Commitment
The contract with the government of Chile
is finalized during Mai 2008 and comprises of three exploration periods
of 3, 2 and 2 years, respectively. The production period is 25 years.
IPR is the designated operator of the block.
Exploration work commitments
First Exploratory Period:
- 370 Km 2D Seismic
- 160Km2 3D Seismic
- 6 Exploration Wells of 600,
600, 800, 1000, 1700 and 2300 m.
Second Exploratory Period:
- 140 Km 2D Seismic
- 220 Km2 3D Seismic
- 4 Exploration Wells of 600,
700, 2000 and 2200 m.
Third Exploratory Period:
- 150 Km 2D Seismic
- 150 Km2 3D Seismic
- 3 Exploration Wells of 600,
2000 and 2500 m.
Total Investment: USD 33,240,000
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Geology
The Tranquilo Block is located in the
foreland of the Magellan's Basin where Cretaceous and Tertiary basin
are the main components of the oil system with a Lower Cretaceous source
rock.
The Petroleum System is proven in the
gas field Tranquilo and in Esperanza 3 and 4 wells containing gas and
condensate shows. In Manzano 5 through 9 there are shallow objectives
with gas.
In the western half of the block, there
are deltaic system of Upper Cretaceous (mainly fracture plays) as well
as conventional tertiary plays. Traps are created by faults propagation
folding and inversion of the external thrust belt. In the Eastern half
of the block, Tertiary stratigraphic traps, CBM Tertiary play and leads
and prospects in deltaic phases of Oligocene-Miocene platform.
Estimated Reserves: Unknown estimated
resources volume but using Tanquilo gas field as analogue may go from
0 to 2000 millions m3S
(Tranquilo had GOIS of 1200 million m3S,
9 wells)
Cretaceous (Skyring area)
- The Titonian - Aptian Erezcano/Zapata
fm. mainly hemipelagic black shales, siltstones and laminated sands
deposited in a platform and slope facies, 300 to 500 m. thick, organic
rich, across the block.
- Canal Bertrand fm., Aptian-Early
Coniacian, lower fan tubidites with submarine volcanics (La Pera Fm)
and La Torre fm., Coniacian-Santonian Sand rich turbidite complex, both
outcrping to the West of the block.
- Escarpada fm., Santonian-Campanian,
deep water, submarine channel conglomerates and levee/overbank sandstones
within the western most part of the block.
- Fuentes fm. Campanian Early
Maastrichtian hemipelagic muds grading upwards into slope and shallow
water platform facies to the Norh grade into Tres Pasos Fms. sandstones.
- Rocallosa fm., Maastrichtian-Danian,
mid to coarse, lower shoreface/stuarine deltaic sanstone that to the
North grade into Dorotea Fm.
Tertiary
- Chorrillo Chico Fm.: Early
Paleocene-Eocene, marine mudstones in part calcareous and glauconitic.
- Agua Fresca Fm.: Late Eocene
(470-776 m) mainly glauconitic clay stone some thin limestone beds with
fine to very fine glauconitic sandstones interbeds; deposited in a lower
neritic at the base, to shallower toward the top of the unit.
- Tres Brazos Fm.: Mid to Late
Eocene (450-700 m) deltaic clay stones and fine to very fine glauconitic
sandstones with thin limestone layers.
- Leņa Dura Fm.: Eocene (130-250
m) clay stones with minor fine to very fine glauconitic sandstones.
- Loreto Fm.: Oligo-Miocene
(630-945 m) deltaic facies with several litologies depending on the
environment of deposition marine through continental. Marine sandstones
partially conglomeratic and clays tones, with coal interbeds.
- El Salto Fm.: Late Miocene-Early
Pliocene (25-1080 m) interbeded sandstones and clay stones. The sandstones
are fine up to coarse conglomeratic. The fine fraction is mainly clay
stones and siltstones and tuff.
- Palomares fm. Mio-Pliocene
(75 m) volcanic breccias, tuff, conglomerates, sandstones and clay stones.
Structure:
The folded belt in the Skyring-Otway
and Peninsula Brunswick area is a basement involved deformation with
displacement transfer toward the sedimentary cover. It is subdivided
into three domains from west to east: Internal, Central and External,
that evolve by stages Coniacian, Maastrichtian-Eocene and Oligocene ,
respectively
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Oil System
Reservoirs
- Late Cretaceous units (Escarpada,
Rosa and Rocallosa) have thicker reservoir with more continuity, but
poorer petro physical characteristics than Tertiary reservoirs. Fractured
reservoir are expected
- Early Tertiary units Chorrillo
Chico, Agua Fresca formations have only a few reservoir bodies, generally
of reduced thickness and poorly defined areal extent. Petro physical
characteristics are regular to good quality for a gas reservoir. Has
a proven potential up to 60.000 m3/d.
- Loreto has two bodies of sand
depending on the location in the delta system generally the lower
is better than the middle sand.
Source Rock
- Early Cretaceous (Erezcano/Zapata
Formation) is the source rock.
- Late Cretaceous and Early
Tertiary rocks, lack of significant generating capacity with some exceptions
of some levels with regular to marginal organic content.
Timing, Migration and Trap
- Early Cretaceous source rock
expulsion began around 65 ma within the central structural domain.
- Primary migration fill structural
trap formed between 60 and 33 ma.
- Secondary migration occurred
after seal breach followed by entrapment toward late structures arround
23 ma. Anticline (gas in Chilenita).
- Migration pathways are mainly
vertical and may be fault assisted
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