Тип бассейна:
Подтип бассейна:
Класс бассейна:
Возраст бассейна:
Тип полезных ископаемых:
Геологический возраст начало:
Геологический возраст конец:
Площадь: 161432.08 км²
Saline Basin:It is characterized by the presence of different deformation styles related to compressive tectonic events and salt tectonics, whose effects are printed on the sedimentary sequence as a structural front trending south-southeast to north-northwest, mainly developed from the Paleogene to Miocene time. The structural style reflects the strong influence of mass salt intrusions that originated the development of a series of structures in the form of large anticlines cored by salt, fauled blocks with high dip angles, as well as expulsed blocks and extruded salt canopies up to surface levels which may affect, in some cases, the topography of the seafloor. In this area, nine plays with prospective resources are identified and documented. In the Cenozoic, the Pliocene-Pleistocene and Miocene turbiditic sandstones. In the Paleogene the turbiditic sandstones of the Eocene-Oligocene and Paleocene are included. In the Mesozoic the plays known as Upper Cretaceous Breccia, Fractured Cretaceous carbonates and Upper Jurassic, are identified.
Discoveries
Recent discoveries in the Perdido Fold Belt confirmed the oil potential of the Tertiary rocks in the North Marine Region. Good quality reservoirs and promising resources in place were found in recently drilled wells (e.g.Trion-1 and Supremus-1), as well as in the known fields located to the north of the border (e.g. Trident-1), indicating the existence of active petroleum systems with significant resources in place. On the other hand, the new discovery done by Vespa-1 well, found hydrocarbon accumulations ins Miocene sandstones, proving another active petroleum system in the mini-basins sector. This confirms the existence of active petroleum systems with significant resources in place on a trend of structures extending from the Alaminos Canyon in the United States through the Mexican territory. On the other hand, new discoveries of the well (Vespa-1) with accumulations in the Miocene sands, prove the existence of additional active petroleum system in the slope of the mini-basin area. On the other hand, the previous discoveries such as Tamil-1 and Nab-1 wells, located in the eastern part of the Salina Basin, prove the existence of extra-heavy oil in Cretaceous rocks.
Emanations
There are numerous evidences of oil and gas emanations on the seafloor, proving the presence of active petroleum systems in deepwater. Most of these emissions are located mainly in the Perdido Fold Belt, in the Subsalt Belt front, in the mini-basin area related to salt diapirism, and in the distal compression system front with detachment level within the Eocene shales. In the South sector, emanations are mainly located at the central part, in the Saline Basin, related to the salt tectonics.
Stratigraphic and Sedimentological Framework
Neogene: The terrigenous sediments filled the basin and are represented by interbedded sandstones; mainly turbidites and shales. There is no conclusive evidence about important erosion in this area. Paleogene: At the beginning of the Cenozoic age, a change in the basin tectonic regime from passive margin to a foreland basin setting causes a marked change in the sedimentation, represented by the lithological contrast between Cretaceous carbonate sedimentation and the thicker terrigenous Cenozoic column.
Cretaceous: The development of a passive margin setting during the Cretaceous time is represented by basinal carbonates in most part of the area, and slope related carbonates at the eastern side, with benthic clays and chert interbedded horizons.
By the end of the Cretaceous time, a decrease in the sea level caused the deposition of calcareous debris flows and turbidites at the continental slope margin, on the eastern flank, represented by dolomites, shaly limestone and dolomitized breccias.
Tithonian: During the Tithonian time, the maximum marine transgression occurred, related to the Late Jurassic anoxic events registered worldwide. A mixture of fine terrigenous and laminated organic-rich carbonates, without bioturbation, were deposited.
Kimmeridgian: The same marine conditions continued during the Kimmeridgian time. These deposits are represented by significant thicknesses of carbonate and terrigenous rocks in some parts of the basin, changing gradually to partially dolomitized oolitic banks carbonates.
Oxfordian: The sediments of this age consist in shallow marine clastics, evaporites and organic-rich carbonates, whose distribution has not been specified. Upper Middle Jurassic : It is characterized by the deposition of salt layers associated to the Gulf of Mexico opening processes. During the Callovian and at the beginning of the Oxfordian time, marine conditions were gradually extended across the basin. Paleozoic: This sequence represents the "economic basement“, constituted by Middle Paleozoic continental sedimentary rocks (red beds) derived from the erosion of older crystalline and metamorphic basement rocks, similar to the crystalline rocks reported in Chiapas.
Middle Jurassic: It is mainly characterized by salt layers deposition related to the Gulf of Mexico opening. During the Callovian and early Oxfordian time, marine conditions were gradually extended across the basin.
Upper Jurassic: Is characterized by period of marine transgression from the Oxfordian to Tithonian.
Oxfordian is represented by coastal plain, fluvial and dunes environments at the east, changing transitionally to inner and middle floodplain environments to at west during the Lower Oxfordian. Upper Oxfordian is represented by a middle to outer ramp platform environments, with oolitic banks development forming well defined bands. In general, Oxfordian sediments consist of shallow marine clastics, evaporites and organic-rich carbonates whose distribution has not been well specified.
Kimmeridgian time is characterized by rocks deposited in inner to middle marine ramp platform environments during the Lower Kimmeridgian time, changing transitionally during the Upper Kimmeridgian outer marine ramp environments. Geological models suggest the presence of oolitic banks facies, which are considered an extension of those identified in the shallow water Southeast marine Basins.
During the Tithonian the maximum marine transgression occurred, related to Late Jurassic anoxic events registered worldwide. A mixture of fine-grained terrigenous and organic-rich laminated carbonates, were deposited.
The main reservoir rocks are represented by Lower Oxfordian sandstone systems at East, carbonate rocks (packstones-grainstones) and the Upper Jurassic re-deposited oolites from Upper Jurassic Oxfordian to Kimmeridgian.
Middle Jurassic. It is mainly characterized by salt layers deposition related to the Gulf of Mexico opening. During the Callovian and early Oxfordian time, marine conditions were gradually extended across the basin.
Upper Jurassic. Is characterized by period of marine transgression from the Oxfordian to Tithonian. Oxfordian is represented by coastal plain, fluvial and dunes environments at the east, changing transitionally to inner and middle floodplain environments to at west during the Lower Oxfordian. Upper Oxfordian is represented by a middle to outer ramp platform environments, with oolitic banks development forming well defined bands. In general, Oxfordian sediments consist of shallow marine clastics, evaporites and organic-rich carbonates whose distribution has not been well specified.
Kimmeridgian time is characterized by rocks deposited in inner to middle marine ramp platform environments during the Lower Kimmeridgian time, changing transitionally during the Upper Kimmeridgian outer marine ramp environments. Geological models suggest the presence of oolitic banks facies, which are considered an extension of those identified in the shallow water Southeast marine Basins.
During the Tithonian the maximum marine transgression occurred, related to Late Jurassic anoxic events registered worldwide. A mixture of fine-grained terrigenous and organic-rich laminated carbonates, were deposited.
The main reservoir rocks are represented by Lower Oxfordian sandstone systems at East, carbonate rocks (packstones-grainstones) and the Upper Jurassic re-deposited oolites from Upper Jurassic Oxfordian to Kimmeridgian.
Cretaceous
During Cretaceous time open sea basin conditions were developed, sometimes oxic, where shaley carbonates interbedded with calcareous debris flows were deposited. Halokinetic lense-shaped clastic breccias were deposited as well, composed by carbonate fragments removed from the salt-cored anticlines at their flanks in basin environments, together with calcarenitic turbidite flows coming mainly from the Yucatan Platform. At the Eastern portion, slope dolomitized breccia facies are identified, related to a destabilization of the Yucatan Platform slope, corresponding to the continuity of Sonda de Campeche deposits. The Cretaceous main reservoir rocks in deepwater are comformed by slope and basin-floor breccias located at the edge of the Yucatan Platform, changing transitionally westward to basinal fractured carbonates, where halokinetic breccias and related local debris flows can be found.
Paleocene
The Paleocene time is represented by bathyal environments, showing a sedimentological composition dominated mostly by shales interbedded with some channel sandstones. The source of the sedimentation came from Southwest. The presence of some carbonate rocks at Northeast, could be due to the re-worked debris flows, through some distal gravity flows from the Yucatan Platform. The shale dominant Paleocene rocks, act mainly as a seal for the Cretaceous reservoir rocks, having a wide regional distribution and great thickness. As reservoir rocks, slope and basin sandstone deposits distributed through submarine channels within the area could be interesting.
Eocene
Lower and Middle Eocene is represented by shale-dominated bathyal environments and some siliciclastic turbiditic systems, with a South – Southwest proveneance. At north of the area, deposits culminate in huge lobes related to amalgamated channeled fans. Some carbonate-dominated channel and fan complexes exist to the East, originated by the erosion of the Yucatan Platform and probably developed in slope environments. During the Upper Eocene the dominance of bathyal environments and the presence of siliciclastic turbiditic systems continues; at the Eastern side, sandstone fan complexes with proximal and distal amalgamated channels continue spreading to the deepest parts of the basin to finally form confined channel systems and fans toward the central part of the area. The Eastern portion, may present channel systems and carbonate-dominated fans with associated mud flows. The reservoir rocks in the Deepwater South Sector are represented mainly by basin-floor fans and slope sandstone facies, which are expected to be more abundant and thicker to the North. On the other hand, the Eastern portion may contain calcarenites at the proximity of the carbonate platform.
Oligocene
Taking into account the specific study area in the Deepwater South Sector, most of the area corresponds to shale-dominated basin-floor facies; to the Eastern portion, a calcareous influence it is observed due the proximity to the carbonate platform. The Oligocene is characterized by the presence of turbiditic systems in amalgamated channel and overbank facies with a SW - NE trend, as a continuity of the Eocene depositional systems and culminating as basinfloor fans at North, where salt influence is lower. The Oligocene reservoir rocks are sandstones and shales related to channel and fan facies.
Miocene
From the Miocene, salt barriers plays an important role in the sedimentation distribution. Deepwater environments, channel lobes and fans at basinal conditions prevails. In the Southern portion, minibasins are confined by the salt movement. Sediment input came from the South and Southeast and provenance may vary locally within the Saline Province. On the other hand, at West and along the Saline and Catemaco Fold Belt borderline, the sediment influx mainly bypass directly to the Gulf’s Abyssal Plain. Miocene is the most prolific stratigraphic level in the area, up today, with production mainly in the Catemaco Fold Belt. The reservoir rocks in the Deepwater South Sector are turbiditic sandstones with variable thickness, with a Southwestern volcanic source influence, combined with a mainly quartz-feldspatic contribution from the South.
Upper Seal rock for Cretaceous reservoir rocks
In this area, Paleocene has characteristics of being very clay-rich shales and thicker, so it works as a good regional seal rock for Cretaceous reservoir rocks.
Upper seal rocks of Tertiary reservoir rocks
In Upper Paleogene (Eocene and Oligocene) and Neogene, thinner regional seal rocks exist due to interbedding sandstones and shales related to siliciclastic turbiditic systems. These seal rocks can be interrupted by faults of variable displacement (tens to hundreds of meters of vertical displacement). At the top of the stratigraphic column (Upper Pliocene and Pleistocene), seal rock quality is uncertain, due to its shallower position and inferred by the presence of hydrocarbon seeps on the seafloor.
Tectonic and Structural Framework
Upper Miocene - Lower Pliocene
Increasing of gravitational tectonics related to thesedimentary load and salt movement. Mini-basins generation. Development of salt canopies and tongues. Closure of diapiric structures, creating salt weld faults (Lower Pliocene).
Middle - Upper Miocene
Correspond to a couple of compressional events: Laramide and Chiapanecan Orogenies. Development of prominent salt-cored anticlines. Beginning of salt bodies intrusion due to halotectonic effects. Thrust fault detachments above the salt layers creating “pop up” structures.
Cretaceous - Middle Miocene
Thermal subsidence period, passive margin settings with subtle structuring of the geological units. Early salt movement by flotation, differential charging and gravitational sliding generating pads and salt domes structures (halokinesis).
Jurassic
Corresponds to the Gulf of Mexico opening processes. Horst and graben systems infilled by red beds and Callovian salt layers. Weak drapping structuring related to the salt units and differential subsidence. First halokinetic movements. Upper Jurassic units sedimentation, with lateral and thickness variations in the paleo-structural highs.
The deepwater zone corresponding to the South Sector is result of different tectonic events from the Middle Jurassic to Recent time.
Late Miocene - Recent
Gravitational tectonics, large sediment input to the basin and mobilization of autochtonous and allochtonous salt volumes; extensioncontraction combined systems.
Middle Miocene – Recent
Tectonic processes related to the Chiapanecan compressional event, redeformation of previous structures.
Eocene - Early Miocene
Continuation of the Gulf of Mexico evolution, lithostatic load related subsidence and by evacuation of salt bodies, influence of both Laramide and Chiapanecan Orogenies.
Late Jurassic - Cretaceous
Continuation of the evolution of the Gulf of Mexico, development of a extensionalgravitational system, formation of early salt related structures.
Middle Jurassic
Beginning of the Gulf of Mexico opening evolution, tectonic subsidence, horst-graben and half-graben structures development, formation of the rift basin, deposit of thick layers of salt.
Tectonic and Structural Framework - Typology of the traps associated with salt
Petroleum Systems
Cretaceous
Cretaceous rocks have relatively very rich organic matter intervals and probably within the the Kimmeridgian as well, however, there is not precise data about the real potential. Maximum estimated potential is about 2.5 T/m². There are samples with TOC values about 1% (in some areas up to 3-4%) dispersed in Miocene/Pliocene shales with mixed organic matter (types II/III) but its contribution to Cenozoic accumulations is unproven. According to geochemical interpretations, it has been established that the accumulations observed in the Cenozoic Rocks have a Jurassic origin. Features of Cretaceous source rocks Net Thickness: 20-200 m Organic content: ~2.5 % Organic Matter: Type II (HI~500-600)
Tithonian
Tithonian rocks are the main source of hydrocarbons of Mesozoic basins of the Southeast Marine Basins and probably in the Deepwater South sector. They are widely distributed, ranging in thickness between 100-400 m. From the sedimentological point of view, lithofacies are associated with deepwater carbonate environments ranging from external platform to deep basinal environments. In some areas, two horizons can be distinguished from the Tithonian rocks: A secondary thick horizon of low quality and a main thinner horizon of the highest source rock quality. Maximum estimated potential is about 3-4 T/m².
Features of Tithonian source rocks. Net thickness: 20-200 m Organic content : ~4% Organic Matter: Type II to II S (HI ~ 500-700) The regional Upper Jurassic source rock of marine origin (Type II) is proved in the area and is the source rock that fed the discovered accumulations of light and medium oil (by chemical analysis of the oil).
Oxfordian
The Oxfordian oil generator subsystem could be considered as secondary in the Southeast Marine Basins. Maximum estimated potential is about 3 T/m².
Features of Oxfordian source rocks. Net thickness : 20 to 200 meters Organic content: ~3% Organic Matter: Type II (HI~500-700) The Oxfordian oil generator system is considered as a closed system, since the accumulations in the Lower Oxfordian sandstones come only from the hydrocarbons expulsion from the Oxfordian source rock, and not migrate to Kimmeridgian or Cretaceous levels.
The initial potential in the area is determined based from over 1,500 pyrolysis data, with a detailed analysis. In the eastern part of the shallow water zone the Tithonian rocks have an average initial potential between 4.0 to 5.0 T/m², with significant lateral and vertical variations of the initial TOC and HI. Lateral and vertical variations of initial average HI from 250 mgHC/gR to 600 mgHC/gR were found.
Experiments with kinetical parameters were performed for the Tithonian, Cretaceous and Oxfordian rocks on some mature and immature samples
Figure A represents the diagram of the HI average in function of Tmax average per well on the Tithonian and the kinetic evolution curve.
Figure B. The Titonian rocks in the marine area is characterized by Tmax values greater than 430°C and a maturity value beyond 0.6% VRo.
The abundance anaylisis of n-non-1-ene, 2.3 dimethylthiophene and o-xylol in several samples confirms that the Tithonian level present lateral variations of Type II to IIS. In comparison, the Oxfordian seems clearly be Type II, Figure C.
Data source: Saline Basin. Petroleum geological synthesis. Gulf of Mexico –Deep water-South sector. Comisión Nacional de Hidrocarburos. 2015
Следующий Бассейн: Sabinas - Rio Grande