Source potential of the Mesozoic–Cenozoic rocks in the South Caspian Basin and their role in forming the oil accumulations in the Lower Pliocene reservoirs

Abstract

The source potential and organic maturity of the shales alternating with the reservoir beds in the Lower Pliocene Productive Series -the major oil-bearing unit in the South Caspian Basin -are inadequate to have formed the observed petroleum accumulations. A geochemical study of rocks collected from wells and outcrop localities has been carried out to assess the oil-and gas-generative properties of the Middle Jurassic to Lower Pliocene sediments of the basin. On the whole the section under review is characterized by poor to good organic richness and low hydrogen index, suggesting type 2 and 3 kerogens. Organic-rich sediments are relatively frequent in parts of the Oligocene-Miocene interval. Source-to-oil correlation based on carbon isotope signatures points to a largely epigenetic origin for the oils reservoired in the Lower Pliocene. Isotopically, the oils in these Productive Series reservoirs are best correlated with organic matter contained in the Miocene sediments.

On the Origin of Hydrocarbons in the Main Lower Pliocene Reservoirs of the South Caspian Basin, Azerbaijan

“…correlation: isotopic composition of carbon (ICC) in organic matter and oils (Bailey et al, 1996;Guliyev and Feyzullayev, 1996;Feyzullaev et al, 2001). The profile of Fig.…”

“…In recent years a number of publications have discussed thoroughly the results obtained (Bailey et al, 1996;Guliyev and Feyzullayev, 1996;Wavrek et al, 1996;Abrams and Narimanov, 1997;Inan et al, 1998;Кatz et al, 2000;Feyzullaev et al, 2001;Gurgey, 2003).…”

Deep-rooted piercement structures in deep sedimentary basins — Manifestations of supercritical water generation at depth?

“…In deep-water, deep sedimentary basins, such as the abyssal Gulf of Mexico, Mediterranean Sea, Black Sea, the Caspian Sea, and Atlantic Ocean, amongst others, mud volcanoes are known to penetrate very deep into the sub-stratum, even deeper than the limits of reflection seismic detection (i.e., N10 km, see Feyzullayev et al, 2001). Planke et al (2003) found that terrestrial mud volcanoes in Azerbaijan emitted brines with various degrees of enrichment factors, indicating net additions of B, Na, Al, Cr, Fe, Mn, Ni, Cu, Zn, As, Cd, Ba, U, Cl, and Br and a net removal of Ca, Mg, K, and SO 4 , compared to seawater.…”

“…A conceptual sketch, based on recent mud volcano studies in Azerbaijan (includingFeyzullayev et al, 2001;Planke et al, 2003). (a) Inferred section through a ca.…”

Geochemical constraints on the Palaeocene–Miocene evolution of eastern Azerbaijan, with implications for the South Caspian basin and eastern Paratethys

“…Palaeocene–Miocene strata of onshore eastern Azerbaijan represent a thick interval (minimum 200–500 m) of mainly low total organic carbon (TOC), low‐sulphur, microfossil‐poor, lithologically homogeneous claystone, with a much thicker (up to 1200 m) correlative section in the more distal South Caspian basin to the east (Ali‐Zadeh et al , 1975; Feyzullayev et al , 2001). Because of their homogeneous, fine‐grained character, it traditionally has been very difficult to subdivide these strata for regional correlation.…”