Sergipe-Alagoas
Petroleum System of the Onshore and Shallow Offshore Sergipe-Alagoas Basin based on Geological, Geochemical and 2D Petroleum System data
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Atlas
Volume I
The study is a complete work for the Sergipe-Alagoas offshore basin providing geoscientists with different approaches to decipher the petroleum systems, where the elements and processes (source, oil, trap, reservoir and generation, migration and accumulation) are considered today critical for petroleum E&P companies.
High-resolution geochemical technology was applied to 51 selected oil samples and rock extracts from 39 wells (for source rocks) containing organic-rich sediments with the objective to characterize the present hydrocarbons and outline the active petroleum systems. The integration of the geochemical data with geological and seismic information indicates the presence of at least three main well-recognized petroleum systems in the basin: the Barra de Itiuba/Coqueiro Sêco (!), Muribeca (!) and Riachuelo-Calumbi (!).
2D compositional modeling along regional representative cross sections were performed in order to integrate all the geochemical data with the geological evolution of the area. The results show that the most important petroleum system of the Sergipe/Alagoas Basin is the Muribeca(!). Although it has produced more than 90% of all the oil found so far, it still has not been much explored in the deep water areas. The presence of overcharged pods of generation in the Mosqueiro and Alagoas lows opens up an entirely new way of looking at oil generation, migration and accumulation within Sergipe Alagoas Basin. This petroleum system must be considered as one of the most important ones due to charging of deep-water turbidites in the Sergipe/Alagoas Basin.
Volume II
A 2D modeling study is presented based on a selected and interpreted geological cross section of the Sergipe-Alagoas basin. Based on the geochemical information of source rocks units and respective spatial distribution, their present thermal maturity and genetic characteristic (oil/gas prone type) and the geological setting of the basin throughout the tectonic events of the basin, the main hydrocarbon kitchens are highlighted and periods of hydrocarbon expulsion & migration are described. The 2D modeling results take into account all aspects of migration with consideration to the salt, ramp and diaper domains and includes an in depth analysis of the fluid accumulations, multi charges to reservoirs and fluid preservation with respect to possible biodegradation risk.
The volume II is presented as a set of slides from main modeling results and includes relevant petroleum system insights.
Full references of all images are listed in the reports
- Volume I
- Introduction
- Regional Geology and Tectonic Network
- Exploratory History
- Elements of the petroleum systems
- Source rocks and hydrocarbons
- Petroleum systems of the Sergipe-Alagoas Basin
- Barra de Itiuba/Coqueiro Seco (!)
- Muribeca (!)
- Riachuelo/Cotinguiba (!)
- Exploratory implications and risks
- Volume II
- Geological characteristics of the cross section
- Source rock characteristics
- Maturity analysis
- Migration analysis
- Analysis of the fluid system
- Biodegradation risk
- Conclusions
- Simplified tectonic framework and main petroleum fields of the Sergipe-Alagoas Basin (after Figueiredo, 1985 and Van der Ven et al., 1989).
- Regional Bouguer anomaly map for northeastern Brazil, integrating data from onshore and offshore regions. The onshore rifts (Recôncavo and Tucano) are marked by regional lows in the Bouguer anomaly (less than –100 mGal), and the continental margin is associated with gravity lows onshore and on the platform (particularly in the Mosqueiro Low in the southern Sergipe subbasin). Seaward, the Bouguer anomaly rises rapidly to over +100 mGal beyond the shelf break. Contour interval is 10 mGal. (Mohriak et. al., 2000).
- Schematic cross section (Dip) in the southern Sergipe-Alagoas Basin (see location in the above map – after Van der Ven et al. 1989).
- Schematic geologic section of the tNorthern Sergipe-Alagoas basin (modified from Cainelli, (1987).
- Simplified stratigraphic chart of the Sergipe-Alagoas Basin (modified from Feijó, 1994). Black-Barra de Itiúba (!); Green-Muribeca (!); Yellow-Cotinguiba-Calumbi (!).
- Regional deep seismic profile A in the Sergipe subbasin. (See Figure 2 for location of profiles A and B.) Basinward of the shelf edge, the seismic section shows a strong reflector from about 6.5 to 9.0 sec two-way traveltime. (Mohriak et al., 2000).
- Detail of a regional seismic profile showing multiple cut-and-fill episodes associated with erosion by canyons in the deep-water region. The channels tend to deflect to the southwest, as indicated by progradation in the canyons (Cainelli, 1992). An important horizon (base of Calumbi Formation, Santonian) is characterized by a continuous reflector at 6.0 sec two-way traveltime. Below a nearly transparent seismic sequence underlying the base of the Calumbi reflector, the profile shows strong subhorizontal discontinuous reflectors and a main unconformity at about 6.5 sec and a large-amplitude anomaly near the middle of the profile. Below a layered reflective sequence with its top at 6.5 sec is a subtle deeper seismic reflector at 8.5 sec that may occur at 9–10 sec in other profiles. Alternative geologic interpretations are proposed in the text to explain these features (Mohriak et al., 2000).
- Segments of regional deep seismic profiles from the Sergipe–Alagoas Basin showing (a) a volcanic plug and (b) a possible salt diapir near the crustal limit. Seaward-dipping reflectors (SDR) are interpreted basinward of the salt diapir, and the seismic Moho is interpreted to be present at 9–10 sec, toward the oceanic crust. Modified from Mohriak et al. (1998).
- Interpretation of the regional deep seismic reflection line (profile A, in Figure 10) in southern Sergipe–Alagoas Basin. Important features of the deep seismic profile are discussed in the text. Abbreviations: BC = unconformity at the base of Calumbi Formation (Santonian); LT/UK = Upper Cretaceous–lower Tertiary sequences; SDR = seaward-dipping reflectors; LDR = landward-dipping reflectors. Modified from Mohriak et al. (1998).
- Alternative interpretations for regional profile A in the Sergipe subbasin. (a) This interpretation (Pontes et al., 1991) assumes that deep reflectors on regional seismic lines correspond to basement. (b) Another interpretation (Mohriak & Rabelo, 1994; Mohriak et al., 1995a; 1998) assumes that the deep seismic reflectors in the deep-water region actually correspond to lower crustal detachment horizons or the top of underplated rocks near the seismic Moho. Abbreviations: BC = unconformity at base of Calumbi Formation (Santonian); LT/UK = Upper Cretaceous–lower Tertiary sequences; SDR = seaward-dipping reflectors; LDR = landward-dipping reflectors (Mohriak et al., 2000).
- Drilled exploratory and development wells in the Sergipe-Alagoas Basin.
- Total oil and gas reserves of the Sergipe-Alagoas Basin.
- Production history of the Sergipe-Alagoas Basin.
- Map of the Sergipe-Alagoas Basin showing the location of the 39 wells from where rock samples were selected for this study.
- Stratigraphic column of the Sergipe-Alagoas Basin, showing the main source rocks intervals as well as oil accumulations, (Modified from Feijó, 1994).
- Geochemical log showing the organic-rich facies of the Barra de Itiúba Formation in the Sergipe-Alagoas Basin.
- Generic synsedimentary tectonic framework and reconstituted isopachs (in meters) of the rift sequence (after Van der Ven et al., 1989).
- Generic synsedimentary tectonic framework and reconstituted isopachs of the rift sequence (after Van der Van et al., 1989)
- Reference section of the Morro dos Chaves Member in well CS-1-AL (modified from Schaller, 1969).
- Geographic map with the location of well 1-RJ-1-AL and seismic lines A-B and C-D close to Atol quarry (Azambuja Filho et al., 1980).
- Well 1-RJS-1-AL drilled by Petrobras at the vicinity of the Atol quarry. See seismic sections A-B and C-D locations at figure above (Azambuja Filho et al., 1998).
- Seismic sections A-B and C-D in the vicinity of the Atol quarry (Azambuja Filho et al., 1998).
- Morro do Chaves Member of the Coqueiro Sêco Formation at the Atol Quarry. Thick coquina carbonate banks interbeded with thin black and greenish shales (Azambuja Filho et al., 1998).
- Blackshales and greenish shales interbedded with thick coquina carbonate banks of Morro do Chaves Mb. of the Coqueiro Seco Fm. at the Atol Quarry (Azambuja Filho et al., 1998).
- Detail of the blackshales and greenish shales. Observe the presence of fish fossils within the black shales (Azambuja Filho et al., 1998).
- Photomicrography of a black shale thin section. Observe the presence of a normal grading of the ostracodes and the enrichment in organic matter at the top (darker) indicative of storm activity (Azambuja Filho et al., 1980).
- GC and GC-MS data for a typical extract of the shales of Morro dos Chaves Member at Atol quarry. (Azambuja Filho et al., 1980).
- Schematic section of the evolution of the Morro do Chaves facies at the Atol quarry (Azambuja Filho et al., 1980).
- Schematic log of the Morro dos Chaves facies at the Atol quarry (Azambuja Filho et al., 1980).
- Schematic evolutionary model for the deposition of the Morro do Chaves Member (Azambuja Filho et al., 1980).
- Natural series from organic-rich sediments of the Barra de Itiúba/Coqueiro Seco formations analyzed in this study.
- Map of the thicknesses variations of Barra de Itiuba/Coqueiro Seco sediments analyzed in this study.
- Map of the TOC contents of the Barra de Itiuba/Coqueiro Seco sediments analyzed in this study.
- Map of the Hydrocarbon Source Potential (S2) values of the Barra de Itiúba/Coqueiro Seco sediments analyzed in this study.
- A geochemical log of 1-SES-15-se well showing the organic-rich sediments of Muribeca Formation.
- A geochemical log of 6-ALS-36-SE well showing the organic-rich sediments of Muribeca Formation.
- Generic synsedimentary tectonic framework and reconstituted isopachs (in meters) of the Alagoas Stage (transitional sequence) – after Van der Ven et al., 1989.
- Geochemical log of the Muribeca Formation.
- Natural series of sediments of Muribeca Formation recovered in the Sergipe-Alagoas basin from organic-rich sediments analyzed, showing the onset of hydrocarbon generation below 3,000m.
- Map of thickness of organic-rich sediments of the Muribeca/Maceió formations from Sergipe-Alagoas Basin.
- Map of the average TOC values for the Muribeca/Maceió formations.
- Map of average S2 values for the Muribeca/Maceió formations.
- Geochemical log showing an organic-rich section of the Riachuelo Formation.
- Geochemical log (1-CAU-3-SE) showing characteristics of the Late Albian-Cenomanian/Turonian marine source rocks of the Riachuelo/Cotinguiba formations (adapted from Koutsoukos et al., 1991).
- Natural series from organic-rich sediments of the Riachuelo Formation (Taquari Member) analyzed in this study.
- Map of thickness of organic-rich sediments of the Taquari Member, Riachuelo Formation from Sergipe-Alagoas Basin.
- Map of the TOC (%) of organic-rich sediments of the Taquari Member, Riachuelo Formation from Sergipe-Alagoas Basin.
- Map of S2 of organic-rich sediments of the Taquari Member, Riachuelo Formation from Sergipe-Alagoas Basin.
- Simplified tectonic framework and main petroleum fields of the Sergipe-Alagoas Basin (after Figueiredo, 1985 and Van der Van et al., 1989). The oils fields from SES-92, Guaricema, Dourado, Caioba, Siririzinho and Carmópolis had contributions from oils sourced from the Muribeca and Riachuelo Formations (Mello, 1988; Trindade, 1992).
- Schematic dip cross-section in the southern Sergipe-Alagoas Basin showing the migration pathways, in which the oils migrated from the deep offshore pods to the nearshore and onshore oil accumulations.
- Shows the location of the oils samples selected for the geochemical analyses of this study.
- Map of oil types identified in this study corresponding to each petroleum system known from the Sergipe-Alagoas Basin.
- API degree versus Saturates content of the Sergipe-Alagoas oils. Note that oil mixtures and biodegradation do affect the bulk data and does not allow any differentiation among the oil types from the Sergipe-Alagoas Basin.
- Map displaying the API gravity data of the oils analyzed in this study. Note the increase of API data close to the deep offshore pods. By contrast, the onshore oils showed the lower values (biodegraded or longer distance from the pods).
- Sulfur versus whole oil carbon isotopes from the oils analyzed for the Sergipe-Alagoas Basin. Note that the lacustrine oils, as reported by Mello, 1988, present low carbon isotope and sulfur data when compared with the marine ones.
- Map displaying the Sulfur data for the oils analyzed. Note a good correlation with the API degree map from figure 56.
- Carbon isotopes from the oils analyzed for the Sergipe-Alagoas Basin. Note that the lacustrine oils, as reported by Mello, 1988, present low carbon saturate and aromatic isotopes when compared with the marine ones.
- Gas chromatograms of the main oil types of the Sergipe-Alagoas Basin. Note the presence of B-carotane in the hypersaline oil.
- M/Z 191 Fragmentograms of oils from Sergipe-Alagoas Basin. Note the high abundance of gammacerane in the hypersaline oil.
- M/Z 217 Fragmentograms of oils from Sergipe-Alagoas Basin. Note the high abundance of 4-methyl steranes in the lacustrine oil.
- M/Z 259 Fragmentograms of oils from Sergipe-Alagoas Basin showing the high relative abundance of lacustrine marker TPP polyprenoids, in the 1-SES-108 well.
- M/Z 231 and M/Z 245 Fragmentograms of oils from Sergipe-Alagoas Basin. Note the small differences in the abundance of C29 and 3mthyl/ 4methyl triaromatics steranes between the hypersaline and marine anoxic oils.
- M/Z 231 and M/Z 245 Fragmentograms of oils from Sergipe-Alagoas Basin. The lacustrine oil show higher abundances of C29 triaromatic steranes
- Mass chromatograms from metastable ion monitoring of C27 to C30 steranes compounds of oils from Sergipe-Alagoas Basin. Note the absence of C30 steranes in the lacustrine oil.
- Mass chromatograms from metastable ion monitoring of C27 to C30 steranes compounds of oils from Sergipe-Alagoas Basin. Note the absence of C30 steranes in the lacustrine oils.
- Gas chromatograms of the main oil families of the Sergipe-Alagoas Basin. Note the presence of B-carotane in the hypersaline oil. Observe the bimodal n-alkane envelope of the marine hypersaline and anoxic oils and the presence of high molecular weight n-alkanes in the lacustrine sample.
- Plots of Hopane/ Sterane versus Pristane/ Phytane ratios from the oils analyzed for the Sergipe-Alagoas Basin. Note that the lacustrine oils, as reported by Mello, 1988, presents the highest ratios when compared with the marine ones that agglutinated themselves showing similar values. It is also important to mention the difficulties in differentiating the Aptian marine hypersaline from the Albian-Cenomanian marine anoxic oil types.
- Carbon isotopes versus Pristane/ Phytane ratio from the oils analyzed for the Sergipe-Alagoas Basin. Note that the lacustrine oils, as reported by Mello, 1988, present low whole oil carbon isotope and higher Pri/Phy ratios when compared with the marine oils. It is also important to mention the difficulties in differentiating the Aptian marine hypersaline from the Albian-Cenomanian marine anoxic oil types.
- Plot of Hopane/ Sterane versus Gammacerane index from the oils analyzed for the Sergipe-Alagoas Basin. Note that the Aptian marine hypersaline oils, as reported by Mello, 1988, present the highest Gammacerane data when compared with the lacustrine and the Albian-Cenomanian marine anoxic oil types.
- Plot of Ts/ (Ts + Tm) versus C29 αββ/(αββ + ααα) steranes from the oils analyzed for the Sergipe-Alagoas Basin. Note that there is a good correlation between the two-biomarker maturity parameters suggesting the absence of any control of thermal maturity in the oil types identified. However, oils with higher thermal evolution appears to occur around the Mosqueiro and Cururipe low, showing a close distance from the deep active pods of generation.
- Map of C29 αββ/(αββ + ααα) steranes from the oils analyzed for the Sergipe-Alagoas Basin. Note that there is a good correlation between the increase of the thermal evolution of the oils with the Mosqueiro and Cururipe Lows, where the active pods of generation are located (see above). Green stars represent the new oil samples analyzed.
- Map of Ts/ (Ts +Tm) ratio maturity parameter for the oils analyzed (red dots) for the Sergipe-Alagoas Basin. Note that there is a good correlation between the increase of the thermal evolution of the oils with the Mosqueiro and Cururipe Lows, where the active pods of generation are located. Green stars represent the new oil samples analyzed.
- Gas chromatograms and M/Z 191 mass fragmentograms of oils from Sergipe-Alagoas Basin showing the presence of paleobiodegradation. Note the coexistence of n-alkanes and C25 norhopanes. Observe the n-allkane bimodal envelops in all the oil samples.
- Map of C25 norhopane index for the oils analyzed for the Sergipe-Alagoas Basin. Note that there is a good correlation between the increase of the paleobiodegradation of the oils with the presence of the São Francisco River, suggesting that percolation of meteoric water into the reservoirs occurred in the geologic time. Green stars represent the new oil samples analyzed.
- Oil X oil correlation between two lacustrine oils from Sergipe-Alagoas basin.
- Oil X oil correlation between two lacustrine oils from the Sergipe-Alagoas Basin, showing an identical M/Z 191 biomarkers distribution. The presence of C25 norhopane in the 1-SES-105 oils suggests a mixture of more than one migration pulse in the reservoirs.
- Plot of diamondoids and stigmastanes data of condensates and oils from Sergipe-Alagoas Basin.
- Main hydrocarbon occurrences of the Barra de Itiúba (!) petroleum system. The oil-kitchen (in green) is the area in which the source rocks – if present – are supposed to have attained a mature to overmature stage of thermal evolution (based on the integration of maps from Babinski & Santos, 1984, Van der Ven et al., 1989, and Bruhn, 1990).
- Events chart of the Barra de Itiúba/Coqueiro Seco (!) petroleum system, based on the integration of data of this study with published data.
- Structural map of the Fazenda Tomada, Furado, São Miguel, and Cidade de São Miguel fields (see location in the above map) at the top of the Serraria Formation (Dauzacker et al., 1984).
- Simplified geological cross-section across the Fazenda Tomada, Furado, São Miguel, and Cidade de São Miguel fields (Dauzacker et al., 1984).
- Schematic sedimentological model of the typical channel mouth bars reservoirs of the Barra de Itiúba at Tatu Quarry, near by Neópolis – SE (Azambuja Filho et al.,1980).
- Tatu Quarry – Barra de Itiúba Fm. – Channel mouth bars with scouring favoring the amalgamation of the reservoir facies.
- Tatu Quarry – Barra de Itiúba Fm. – Detail showing sigmoidal/tabular cross-stratification within the channel mouth bars.
- Penedo town – AL. Barra de Itiúba Fm. – Channel mouth bars, showing intense fluidization and deformation of the sigmoidal/tabular cross-stratifications.
- Penedo town – AL. – Barra de Itiúba Fm. – Detail of channel mouth bars, showing intense fluidization and deformation of the sigmoidal/tabular cross-stratifications (Modified from Azambuja Filho et al., 1980).
- Penedo town – AL – Barra de Itiúba Fm. – Detail of channel mouth bars, showing the toe of sigmoidal cross-stratifications with its typical climbing ripples (Modified from Azambuja Filho et al., 1980).
- Barra de Itiúba reservoirs from Furado oilfield, showing intense fluidization and deformation of the sigmoidal/tabular cross-stratifications. (Modified from Azambuja Filho et al., 1980).
- Barra de Itiúba reservoirs from Furado oilfield, showing two typical channel mouth bars starting with mudstones at the base, on the lower left side, to the distributary sandstones at the top, on the right upper side of the photo. Observe the typical intense fluidization and deformation of the sigmoidal/tabular cross-stratifications close to the top, which usually show the best porosities and permeability (Modified from Azambuja Filho et al., 1980).
- Barra de Itiúba reservoirs from Furado oilfield, core and thin section showing the best part of a typical channel mouth bar. Usually it presents good porosities and permeability (Modified from Azambuja Filho et al., 1980).
- Outcrop at the BR-101, Km of the Serraria Fm. Typical reservoirs. At this point it is possible to observe the tabular cross-stratifications of the fluvial sandstone bars. Flow direction towards the right (south), (Modified from Azambuja Filho et al., 1980).
- Outcrop of the Serraria Fm. Typical reservoirs. Detail of the coarse-grained fluvial sandstones with tabular cross-bedding. (Modified from Azambuja Filho et al.,1980).
- Serraria Fm. typical reservoirs. Detail showing coarse-grained fluvial sandstones with tabular cross-bedding. (Modified from Azambuja Filho et al.,1980).
- Vitrinite reflectance profile in the 1-FGT-1-AL well (see location in the map below) – based on data from Mello, 1988.
- Depth of the onset of oil generation in the Sergipe-Alagoas Basin (after Araújo et al. 1993).
- Main hydrocarbon occurrences of the Muribeca (!) petroleum system. The oil-kitchen (in orange) is the area in which the source rocks – if present – are supposed to have attained a mature to overmature stage of thermal evolution (based on the integration of maps from Babinski & Santos, 1984, Van der Ven et al., 1989, and Bruhn, 1990).
- Events chart of the Muribeca (!) petroleum system, based on the integration of data from this study and published data.
- Typical log response from the Muribeca Fm. with its members (Modified from Azambuja Filho et al., 1980).
- Composite reference section of the Oiteirinhos, Ibura and Carmópolis Members of the Muribeca Formation. Observe the unconformity at the base of the Carmopolis conglomerates (modified from Schaller, 1969).
- Location of the Carmopolis oil field in the Sergipe-Alagoas Basin.
- Simplified geological cross section across the Carmópolis field, located in the onshore Sergipe-Alagoas Basin (see map above) – after Schaller & Campos, 1985.
- Typical reservoir facies distribution of the Carmoplis Mb. reservoir (Modified from AzambujaFilho et al., 1980).
- Regional geoseismic section (based on a composite seismic profile) extending from onshore toward the plat-form of the Sergipe Basin, showing the rift architecture controlled by a number of synthetic and antithetic faults in shallow waters and by a major synthetic (seaward-dipping) fault near the eastern end of the profile. Borehole A, located onshore, was drilled through the pre-salt formations. A small hydrocarbon accumulation is located in a rift block near borehole B. Modified from Chagas et al. (1993).
- Reference section of the Maceió Formation in well 1-TM-1-AL at Tabuleiro dos Martins oil field (modified from Schaller, 1969).
- Idealized climatic curve showing the cyclicity caused by variations from arid to humid.
- Idealized paleogeography during the humid phase of the deposition of the Maceió Formation showing coarse sediments and turbidites. Terrestrial organic matter is present (Modified from Azambuja Filho et.al.,1980).
- Schematic sedimentological model to illustrate facies variations observed atoutcrops and at the Tabuleiro dos Martins field (Azambuja Filho, Arienti, Mello, 1980).
- Geological map of the outcrops near by São Luiz do Quiteunde-Al (Modified from Azambuja Filho et.al., 1980).
- Outcrops at the Morro do Camaragibe – Al (Modified from Azambuja Filho et.al., 1980). At this point can be observed thick massive channelized sandstones that have been deposited by high-density gravity flows.
- Outcrops at the Morro do Camaragibe – Al (Modified from Azambuja Filho et. al., 1980). At this point can be observed thick massive channelized sandstones cutting overbank deposits.
- Outcrops at the Morro do Camaragibe – Al (Modified from Azambuja Filho et.al., 1980). Contact of thick massive channelized sandstones with overbank deposits.
- Typical overbank facies at the Morro do Camaragibe outcrops (Modified from Azambuja Filho et.al., 1980).
- Schematic sedimentological model to illustrate facies variations observed in the Morro do Camaragibe outcrops. (Modified from Azambuja et.al., 1980). Similar facies are also observed at the Tabuleiro dos Martins field in cores (Arienti, 1997).
- Lateral facies variations observed in the Morro do Camaragibe outcrops. (Modified from Azambuja et. al., 1980). Similar facies variations were also interpreted at the Tabuleiro dos Martins field in cores (Arienti, et al., 1997).
- Schematic sedimentological model to illustrate facies variations observed in the outcrops of the region. (Modified from Azambuja et.al.,1980). Similar facies are also observed at cores of the Carmopolis field.
- Location of the Guaricema field.
- Schematic cross-section and type log of the Guaricema field, located in the offshore Sergipe-Alagoas Basin (see map above) – after Figueiredo, 1985.
- This map shows the structural framework of the platform and tectonic features in the deep-water region as inter-preted in the early 1990s. A large number of canyon channels and fans within the Calumbi Fm. (Cretaceous and Tertiary in age) were identified in the deep-water region. Several volcanoes and possible salt structures were also recognized. Modified from Pontes et al. (1991) and Lana (1993).
- Main hydrocarbon occurrences of the Cotinguiba-Calumbi (!) petroleum system. The oil-kitchen (in blue) is the area in which the source rocks are supposed to have attained a mature stage of thermal evolution (based on the integration of maps from Babinski & Santos, 1984, Van der Ven et al., 1989, and Bruhn, 1990).
- Events chart of the Riachuelo (!) petroleum system, based on the integration of all the published data.
- Location of the main petroleum occurrences of the Sergipe-Alagoas Basin, with the indication of their source rocks.
- Map displaying the main pods of Sergipe-Alagoas Basin, with their characteristics such as: origin, hydrocarbon quality and migration pathways. (Modified from Silva & Mendes, 1998).