Occurrence and Nature of Overpressure in the Sedimentary Section of the South Caspian Basin, Azerbaijan

2009 ◽  
Vol 27 (5) ◽  
pp. 345-366 ◽  
Author(s):  
A. A. Feyzullayev ◽  
I. Lerche
Keyword(s):  
Sedimentary Basins ◽  
Tectonic Stress ◽  
Depth Interval ◽  
Caspian Basin ◽  
Hydrocarbon Generation ◽  
The South ◽  
South Caspian Basin ◽  
Gas Generation ◽  
Mud Volcanism ◽  
Zone Depth

Two basic factors are identified that contribute to overpressure in different sedimentary basins of the world, including the South Caspian Basin (SCB): tectonic stress and subsurface temperature. Two overpressure zones are identified in the SCB: 1. An upper zone (depth interval 600–1200 m), conditioned by disequilibrium rock compaction (undercompaction) and 2. A lower zone (zone of decompaction) conditioned by hydrocarbon generation (depth below 5 km). The lower overpressure zone is the most intense and depends on the thickness of the shale sequence, the content and type of organic matter, and the temperature conditions of kerogen transformation to hydrocarbons. In this zone the greatest risk is associated with gas generation at depths greater than 9 km, due to both more intense thermal breakdown of kerogen and the cracking of liquid hydrocarbons generated earlier. Overpressure is a major cause of diapirism and mud volcanism in SCB.

Geologic-geochemical and modelling studies of hydrocarbon migration in the South Caspian basin

2020 ◽  
pp. 4-15
Author(s):  
M.F. Tagiyev ◽  
◽  
I.N. Askerov ◽  
◽  
◽  
...  
Keyword(s):  
Sedimentary Cover ◽  
Geochemical Data ◽  
Caspian Basin ◽  
Hydrocarbon Generation ◽  
The South ◽  
South Caspian Basin ◽  
Hydrocarbon Migration ◽  
Upward Migration ◽  
Modelling Studies ◽  
Hydrocarbon Charge

Based on pyrolysis data an overview is given on the generative potential and maturity of individual stratigraphic units in the South Caspian sedimentary cover. Furthermore, the pyrolysis analyses indicate that the Lower Pliocene Productive Series being immature itself is likely to have received hydrocarbon charge from the underlying older strata. The present state of the art in studying hydrocarbon migration and the "source-accumulation" type relationship between source sediments and reservoired oils in the South Caspian basin are touched upon. The views of and geochemical arguments by different authors for charging the Lower Pliocene Productive Series reservoirs with hydrocarbons from the underlying Oligocene-Miocene source layers are presented. Quantitative aspects of hydrocarbon generation, fluid dynamics, and formation of anomalous temperature & pressure fields based on the results of basin modelling in Azerbaijan are considered. Based on geochemical data analysis and modelling studies, as well as honouring reports by other workers the importance and necessity of upward migration for hydrocarbon transfer from deep generation centers to reservoirs of the Productive Series are shown.

scholarly journals Organic matter in rock–water systems of petroliferous basins: interrelationships (a case study: South Caspian Basin)

2019 ◽  
Vol 74 ◽  
pp. 74
Author(s):  
Akper A. Feyzullayev ◽  
Ian Lerche
Keyword(s):  
Organic Matter ◽  
Sedimentary Cover ◽  
Water System ◽  
Underground Water ◽  
Depth Interval ◽  
Caspian Basin ◽  
Hydrocarbon Generation ◽  
Mud Volcanoes ◽  
South Caspian Basin ◽  
And Migration

Generalizations and analyses are given of the data accumulated to date on the content of Organic Matter (OM) in formation waters of various stratigraphic complexes, as well as of mud volcanoes, and the correlation with OM in South Caspian Basin (SCB) sedimentary rocks. Results are based on about 300 analyses of formation waters and waters of mud volcanoes, as well as on more than 400 analyses of the content of OM in rocks (outcrops and wells from both onshore and offshore petroleum fields of the SCB). The stratigraphic interval covers the period from the Lower Pliocene to the Jurassic, and the depth interval from 73 m to 6043 m. In these intervals, the values of Dissolved Organic Matter (DOM) in reservoir waters vary from 4.1 mg/L to 271.2 mg/L, averaging (219 analyses) 48.9 mg/L. A good correlation has been established between the values of DOM and OM in rocks. Paleogene and Jurassic rocks have the highest correlations. DOM varies with depth with an increase in value from a depth of about 3.3 km, likely due to catagenetic transformation of OM into hydrocarbons in the rock–water system. The highest values of DOM are for waters with mineralization less than 50 g/L. Mud volcano waters are characterized by low levels of DOM and low mineralization, likely due to the condensate nature. The results of the studies show that underground water, as one of the components of a single rock–water system of the Earth’s sedimentary cover, together with the rocks, participates in the processes of hydrocarbon generation and migration.

Distribution and volume of rocks in sedimentary basins – unusual case of the South Caspian basin

2020 ◽  
pp. 7-13
Author(s):  
I.S. Guliyev ◽  
◽  
N.R. Abdullayev ◽  
Sh.M. Huseynova ◽  
◽  
...  
Keyword(s):  
Unusual Case ◽  
Sedimentary Cover ◽  
Sedimentary Basins ◽  
Caspian Basin ◽  
The South ◽  
South Caspian Basin ◽  
Lithospheric Thickness ◽  
The Earth ◽  
Unique Nature ◽  
Sedimentary Layer

The article gives a brief overview of the sedimentary cover of the Earth and summarizes volumes and mass of sediments contained in the Earth sedimentary layer (stratisphere). Using available data authors show unique nature of the South Caspian Basin and other rapidly subsiding basins with large amount of sediments and attenuated crust. Sedimentary, crustal and lithospheric thickness correlations are discussed.

scholarly journals Crustal density structure of the northwestern Iranian Plateau

2019 ◽  
Vol 56 (12) ◽  
pp. 1347-1365 ◽  
Author(s):  
Vahid Teknik ◽  
Abdolreza Ghods ◽  
Hans Thybo ◽  
Irina M. Artemieva
Keyword(s):  
High Density ◽  
Central Iran ◽  
P Wave ◽  
Arabian Plate ◽  
Scale Model ◽  
Moho Depth ◽  
Caspian Basin ◽  
The South ◽  
South Caspian Basin ◽  
Iranian Plateau

We present a new 2D crustal-scale model of the northwestern Iranian plateau based on gravity–magnetic modeling along the 500 km long China–Iran Geological and Geophysical Survey in the Iranian plateau (CIGSIP) seismic profile across major tectonic provinces of Iran from the Arabian plate into the South Caspian Basin (SCB). The seismic P-wave receiver function (RF) model along the profile is used to constrain major crustal boundaries in the density model. Our 2D crustal model shows significant variation in the sedimentary thickness, Moho depth, and the depth and extent of intra-crustal interfaces. The Main Recent Fault (MRF) between the Arabian crust and the overriding central Iran crust dips at approximately 13° towards the northeast to a depth of about 40 km. The geometry of the MRF suggests about 150 km of underthrusting of the Arabian plate beneath central Iran. Our results indicate the presence of a high-density lower crustal layer beneath Zagros. We identify a new crustal-scale suture beneath the Tarom valley between the South Caspian Basin crust and Central Iran and the Alborz. This suture is associated with sharp variation in Moho depth, topography, and magnetic anomalies, and is underlain by a 20 km thick high-density crustal root at 35–55 km depth. The high-density lower crust in Alborz and Zagros may be related to partial eclogitization of crustal roots below about 40 km depth. The gravity and magnetic models indicate a highly extended continental crust for the SCB crust along the profile. Low observed magnetic susceptibility of the Kermanshah ophiolites likely indicates that the ophiolite rocks only form a thin layer that has been thrust over the sedimentary cover.

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