Multi-basin area presents more challenges than the pre-salt
recently explained why the Brazilian equatorial margin
the new exploratory frontier where the company is preparing to invest heavily
presents challenges that are even more interesting and defying than the discovery of oil in the South Atlantic pre-salt layers
The equatorial margin is formed by the Foz do Amazonas (mouth of the Amazon River)
and Potiguar (offshore) basins on the northeast coast of Brazil
“The existence of a dynamic petroleum system which generated
and accumulated oil in the equatorial margin is already proven,” said the director
“We have samples of extremely light oil from the PAS-11 block
During three months we produced oil and gathered concrete evidence of a petroleum system
But the great challenge is to interpret the geology of the area in order to choose places to drill with the probability of discovering natural gas and/or oil in commercial quantities and which can be produced in an economically viable manner.”
There are fewer than 30 blocks under concession in the deepwaters of the equatorial margin
in the last four years a little more than five wells were drilled and no more than nine seismic surveys undertaken
ANP will offer the 11th bidding round in late September or October this year
Out of nine basins included in the auction
The Foz do Amazonas basin is situated at the western portion of the equatorial margin
alongside the coast of the Amapá and Pará states
It occupies an area of approximately 261,170 sq km (100,838 sq mi)
to the boundary between continental and oceanic crust
Estrella explained that the cycles of exploration at the mouth of the Amazon River are related to the renewed interpretation of data and an increased knowledge that leads to new alternatives in the identification of commercial opportunities
These are the main reasons why Petrobras is now returning to that area
China's Sinopec teamed with Petrobras in April to develop offshore areas of the Pará-Maranhão basin
Petrobras informed the ANP of the discovery of traces of oil and gas after drilling a 2,060 m (6,759 ft) well in the deep waters of the BM-PAMA-3 block (833.28 sq km or 321.7 sq mi)
The accord also includes exploration under the BM-PAMA-8 concession contract which includes three blocks totaling 2,307 sq km (891 sq mi)
The Pará-Maranhão basin is offshore Pará and Maranhão states
At present there are 13 offshore blocks under concession
The companies operating in the area are: Petrobras; Petrobras in association with Ecopetrol and Vale; and OGX
“The equatorial margin's coastal geology is much less known than the geology of the South Atlantic basins
especially due to interpretation difficulties caused by shear faults that resulted in a far more complex model for these sedimentary basins
“When separating from the African continent
the movements at the South Atlantic coast were more of distention and not of dragging of one over the other
This created a very complex situation and is still interfering in the definition of the dynamics of the region's petroleum system
even after producing in the PAS-11 block.”
He also explained: “The prospectivity is considered high because we already identified a generation module of oil and gas
We should also say that in the same latitude
thus confirming the potential of the region.”
The type of oil discovered in these basins offshore West Africa is very light
Jubilee holds reserves estimated at 1.8 Bbbl of oil; and Tweneboa/Owo/Ntomme
the situation in the Amazon River delta is completely different than what happens in the Niger River delta in Nigeria
The Niger has a much smaller load of sediments and its drainage basin discharges through a massive delta to the Gulf of Guinea
That gulf does not have as much circulation at the bottom as the Amazon River delta
thus preserving the organic material in deposition,” he added
is not matched anywhere in the world and is the largest in terms of sedimentary load,” Estrella continued
“The river loses only to the Nile in terms of extension
and sediments it has by far a much larger load than other great rivers
When such a large load of sediments originated from land arrives at the mouth of the river
mixes with organic material which is quickly oxidized and destroyed.”
He also noted another difference: “With the rotation of the Earth
the surface maritime currents run from east to west
These currents run in the opposite direction from the Earth's rotation
creating an interesting phenomenon: at the Brazilian coast
as in all oriental coasts of the continents
the surface maritime currents pressure surface waters offshore these continents because they push these waters
The surface currents coming from West Africa to Latin America leave behind
a sub-pressure; and because the pressure is lower
it creates a phenomenon called ‘upwelling'.”
The cold waters of the bottom rise and these currents from the bottom are highly loaded with organic nutrients
That is why the oriental coasts of the continents are richer in fish than the western coasts
nutrients and organic material were deposited and eventually formed petroleum source rocks
in Nigeria a great share of the petroleum is of marine origin and is in the post-salt
rather than source rocks of lacustrine origin such as can be found in Brazil's pre-salt
Africa also has petroleum from lacustrine origin because Africa
the Amazon River originated as a transcontinental river and took its present shape approximately 2.4 million years ago
These are the most significant results of the study on two boreholes drilled near the mouth of the Amazon River by a team from Petrobras
the Institute for Biodiversity and Ecosystem Dynamics (IBED) of the University of Amsterdam
scientific drilling expeditions such as the Ocean Drilling Program could only reach a fraction of a sediment column around 10 km (6 mi) thick from the Amazon deep-sea fan (a sort of underwater delta)
New exploration efforts by Petrobras plus sedimentological and paleontological analysis on samples from the two boreholes (one of which was 4.5 km [about three miles] below the sea floor)
gave deep insight into the history of both the Amazon River and the Amazon deep-sea fan
This data was published in the scientific journal Geology in July 2009
and is very important to understand South America's paleogeography and the evolution of aquatic organisms in Amazonia and the Atlantic coast
the basin was the target for a 2D spec seismic survey
93 exploration wells have been drilled in the basin
60 by Petrobras and 33 by companies within risk contracts
This exploration effort resulted in the discovery of two sub-commercial gas accumulations: Pirapema and the area of well APS-51A
Petrobras has 100% interest in two blocks in the exploration phase (FZA-M-217 and FZA-M-252) at Foz do Amazonas basin totaling approximately 38,000 sq km (14,672 sq mi)
Technical hurdles may be quite simply described by a geologist such as Estrella
who has been involved in the discovery of huge amounts of oil worldwide
“To exemplify the challenge that we face in the mouth of the Amazon River
one needs to address a curious characteristic that is technically complex: the surface currents running towards the north by the coast of Amapá state are so strong that pollen from the Amazon forest plants were identified in British beaches
in order to place a blow out preventer at the bottom of the ocean to begin drilling at 1,000 m (3,280 ft) water depth
we have to move the snubbing rig dozens of kilometers against the current
before starting to lower the BOP to land it where it was planned
lighter equipment has to be released even further away
but the distance must be calculated according to the weight of the equipment.”
the Barreirinhas basin is found offshore starting north of the Parnaíba River mouth
Although there have been no significant oil discoveries
the occurrence of hydrocarbons traces in several wells that were drilled leads to the expectation of light oil and condensates
There are four blocks under concession in the exploration phase totaling 3,268 sq km (1,262 sq mi)
Petrobras has 100% interest; it has partnerships with international operators in the others
“Barreirinha is an onshore basin which has an extension offshore
There were non--commercial discoveries onshore but the offshore part is more or less related to PAS-11
We believe that both are part of the same petroleum system.”
Ceará basin has four offshore petroleum producing fields: Xaréu (1977)
Early estimates for these fields are of 71.8 MM cu m (451.6 MMbbl) of oil and 5.8 MM cu m (204 MMcf) of gas
Besides these fields Petrobras has two exploration blocks totaling 1,216 sq km (470 sq mi) with dozens of well drilled and numerous traces of oil and gas
Potiguar basin is in the extreme northeast of Brazil's continental margin and includes onshore and offshore areas
Most of it spreads throughout Rio Grande do Norte state
It is one of the 10 oil and gas producing basins in the country
14 fields are either producing or are being developed; and 67 are producing onshore
Current offshore production of 44,000 b/d of oil and 12 MMcm/d (424 MMcf/d) of natural gas comes from Dentão
The three fields being developed are Salema Branca
Petrobras operates two blocks in shallow waters and four in deepwaters of the Potiguar basin
the volumes in situ are estimated at 1.18 Bbbl of oil and 60 bcm (2,118 bcf) of natural gas
Offshore proven reserves are of 105 MMbbl of oil and 8.3 bcm (293 bcf) of natural gas
Estrella noted that “the Portiguar basin is important because very often
the chances for finding oil in the basin's offshore extension are good
when you cannot find oil onshore it does not mean that you will not be able to find it offshore
It is always possible to find oil offshore
there is a very good chance to find it offshore as well.”
Campos basin is responsible for around 80% of Brazil's total oil output
The most significant discovery made in the pre-salt area of the Campos basin was announced June 28 by a consortium formed by Repsol
190 km (118 mi) off the coast of Rio de Janeiro
The well was drilled by the latest-generationStena DrillmaxI drillship in 2,708 m (8,885 ft) water depth
reaching a final depth of 6,851 m (22,477 ft)
Brazil's deepwater oil production represents 25% of the country's output
Analysts say that new pre-salt provinces will increase this percentage significantly
Petrobras' enthusiasm offshore is expressed by its strategic planning which foresees 169 platforms
referring to the economic aspects that change the price of oil over long periods
“When planning to order a fleet of production ships for the company's projects
we depend on forecasts for the price of oil
we have no way of injecting more water in Marlim field
now that the field is producing more water and the water injection capacity installed in our ships has reached its limits
consider the hypothesis of a forecast of less than $40 per barrel in the project being planned for a field that we believe will be producing 60% of oil and 40% of water in 10 years
The ship is planned to work in that field and will be prepared to produce up to this financial limit
It is true that we depend on these forecasts
we based our ship-based projects on $35 oil
we could produce 60% water and 40% oil and it would still be worth it
But now the injection capacity of the ship is already set for the limits imposed by the other price
The result is that we have to offload the excess water in other ships instead of re-injecting in the well
because the ship doesn't have the injection capacity equivalent to the water the field is currently producing.”
Petrobras has a dominant position in the demand side for offshore rigs
plus a firm demand for several critical resources that are not yet contracted
The scale of future acquisitions is guaranteed by the 23 new production systems scheduled to start operating by 2014 and 36 more between 2015 and 2020
Estrella contends that the neither the local content requirements (goods and services produced in Brazil) nor the obligation that Petrobras operate blocks in the pre-salt area that have not been previously auctioned will diminish the interest of foreign companies
the pre-salt represents a spectacular amount of wealth which means utilization of resources in a large scale
We are offering unprecedented conditions for growth in the country's history
There are new companies coming to Brazil and the ones already installed here will surely expand their activities
the country will no longer play a supporting role
We are going through a geopolitical change to become one of the major players in the energy sector.”
Petrobras is seeking international partners as its production is expected to double oil production in the next 10 years to reach 4 MMb/d
The 11th bidding round includes 174 blocks (87 are offshore and 87 are onshore)
divided into 17 sectors in nine sedimentary basins
Brazil´s exploratory area will have a 40% increase
Peter Howard Wertheim is based in Rio de Janeiro
Geologists are increasingly finding that the hydrocarbon-bearing basins offshore South America are similar to those offshore West Africa
And the activity offshore West Africa is picking up
Petrobras E&P director Guilherme Estrella says that the equatorial margin will be the next challenge for Brazil's oil and gas industry after the pre-salt
particularly because there are so many oil and gas discoveries in West Africa
and there is much geological similarity between Brazil's equatorial margin and West Africa's
After decades of poor results in the exploration of oil and gas offshore Ghana
in 2007 Anadarko and its partners finally discovered the Jubilee field through the Mahogany-1 well
Since this well was drilled into a stratigraphic trap instead of a more easily identified structural trap
other companies also are trying to locate and map stratigraphic traps
Other important finds in Ghana are Mahogany Deep
The discovery Dzata is operated by Vanco Energy
the discovery Enyenra (Owo) is operated by Tullow
approximately 25 km (16 mi) offshore with estimated reserves of 700 MMbbl and expects to recover 200 MMbbl
Canadian Natural Resources (CNR) is the operator (57.6% interest)
in partnership with Svenska (27.4%) and Petroci (15%)
approximately 19 km (12 mi) offshore south of Jacqueville
and around 60 km (37 ft) southwest of Abidjan
Water depths range from 100 to 600 m (328 to 1,968 ft)
The Espoir field has estimated recoverable reserves of 93 MMbbl of oil and 180 Bcf of natural gas
Well Acajou-1x was drilled by theSovereign Explorer rig
The well on the Acajou South prospect (license CI-26) is approximately 24 km (15 mi) off the coast of Côte d'Ivoire in 3,050 ft (930 m) water depth
some 9 km (5.5 mi) distant from Espoir field
Both fields are operated by CNR (58.67%) in partnership with Tullow (21.30%) and Petroci (20%)
Côte d'Ivoire's largest natural gas producer is the Foxtrot field in offshore block CI-27
It is operated by Foxtrot International (24%) in partnership with Petroci (40%)
The other producing Lion and Panthère fields were discovered by Phillips in the 1980s
Other discoveries in the Ivory Coast beside: Lion; Panther are Belier; Kudu; Eland