Fluid Geodynamics of Deeply Buried Zones of Oil and Gas Accumulation in Sedimentary Basins

2021 ◽  
Vol 62 (08) ◽  
pp. 878-886
Author(s):  
L.A. Abukova ◽  
Yu.A Volozh
Keyword(s):  
Water Exchange ◽  
Oil And Gas ◽  
Hydrodynamic Instability ◽  
Sedimentary Cover ◽  
Sedimentary Basins ◽  
Earth’S Crust ◽  
Void Space ◽  
Gas Generation ◽  
Gas Accumulation ◽  
Earth's Crust

Abstract —We substantiate certain ideas concerning the key role of fluid-geodynamic processes in the evolvement of hydrocarbon accumulations at great depths, in the Earth’s crust. The presented geodynamic model of oil and gas accumulation is based on updated ideas of the structure of the Earth’s tectosphere, which includes plate, preplate, and folded complexes, and the model makes clearer the spatial scale of the organic matter transformation into hydrocarbons of the oil series. In the bottom layers of the Earth’s crust, we predict the existence of a special stagnation type of water-drive systems with the following distinguishing features: (a) different scales of manifestation, from local to regional; (b) a limited nature of processes of water exchange with the external environment; (c) absence of persistent drainage horizons (beds and interbeds); (d) alignment of hydrodynamic potentials in terms of depths and laterals; and (e) increasing importance of lithohydrochemical and organic-chemistry factors in the development of the void space of the fluid host medium. In their inner space, systems with difficult water exchange can exercise control over the evolvement and preservation of autoclave hydrocarbon systems for a long time, the key feature of the autoclave systems being spatial coincidence (localization) of the processes of oil and gas generation and accumulation. We assume that, in the settings of all-round compression, hydrodynamic instability, and no drainage, occurrence of productive zones is controlled by foci of low pore (reservoir) pressures rather than by local hypsometric highs. We present results of prediction of the development of water-drive stagnation systems occurring in the subsalt deposits of the Caspian depression within the unpenetrated areas of the subsalt profile. For the sedimentary cover at large (and ultralarge) depths, a prediction of reservoir pressures was made, which can be regarded as a necessary component in any prediction of oil and gas potential, since it makes it possible to contour some new (previously unknown) industrially significant zones of hydrocarbon accumulation.

Methodological and technological aspects of exeption of the gravitational effect of the lower part of the earth's crust in study of sedimentary cover of oil and gas-bearing areas

2020 ◽  
pp. 38-45
Author(s):  
V.A. Spiridonov ◽  
◽  
N.N. Pimanova ◽  
Keyword(s):  
Gravitational Field ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
A Priori ◽  
Sedimentary Basins ◽  
Gravitational Effect ◽  
Earth’S Crust ◽  
Density Model ◽  
Crust And Upper Mantle ◽  
Earth's Crust

In the case of seismic density modeling of sedimentary basins, it is necessary to exclude from the observed gravitational field the effect created by inhomogeneities of the lower part of the crustal section. The article offers one of the approaches to the geological field reduction, implemented through the construction of a 3D density model for the entire thickness of the earth's crust and upper mantle. A fragment within the study area is selected from the constructed 3D model and its gravitational effect is calculated. Various options for implementing this approach are considered, depending on the amount of a priori information. The technological base of the method is GIS INTEGRO. Keywords: Gravitational field, geologic reduction, density model, GSS profiles, inversion, structural framework of the model.

scholarly journals ORE, OIL-AND-GAS REGIONS OF THE SOUTH OKHOTSK SEA PROVINCE AND DEEP GEODYNAMICS

2020 ◽  
Vol 39 (6) ◽  
pp. 3-24
Author(s):  
V.G. Khomich ◽  
◽  
N.G. Boriskina ◽  
Keyword(s):  
Oil And Gas ◽  
Sea Water ◽  
Mineral Resources ◽  
Fluid Flows ◽  
Sedimentary Basins ◽  
Earth’S Crust ◽  
Okhotsk Sea ◽  
The South ◽  
Hydrocarbon Gases ◽  
Earth's Crust

In the South Okhotsk Sea province – on the islands of Sakhalin, Kunashir, Iturup, Urup and surrounding sea areas – many occurrences of rare, noble metal and other mineralizations as well as of oil-and-gas fields, gas hydrate accumulations, and isolated areas of active emission of water-hydrocarbon gases are known. Occurrences and deposits of solid, liquid and gaseous mineral resources are controlled by hidden deep fault transform zones: Nosappu (Tuscarora), Iturup, and Urup. These long-lived extended (more than 1000 km) zones are distinguished at the N-W Pacific megaplate margin near the S-E flank of the Kuril-Kamchatka trogue. Using the seismotomographic methods we have established their extension to the west from the seismic focal zone in the oceanic slab that subducted into the transition zone of the mantle. In the areas of strike-slip extension the faults accounted for the active formation of the drainage channels for the penetration of the sea water in the lithosphere with the following serpentinization of its ultramafites, and for decompressional generation of ascending mantle-derived abiogenic fluid flows. The latter penetrated from the underslab asthenosphere in the oversubduction mantle wedge and beneath the lithospheric mantle, where they accounted for the development of the processes of metasomatism. The subsequent migration of flows initiated the creation of primary magma reservoirs in the lower parts of the continental lithosphere, and intermediate and peripheral chambers in the Earth’s crust. The injection of melts from the chambers in the consolidated Earth's crust led to the formation of abyssal, hypabyssal intrusive massifs, arch-dome uplifts and magmatogenic-ore (ore-magmatic) systems predominantly among the rocks of the pre-Pliocene basement. The concentration of oil and gas accumulations mainly from the mantle-derived abiogenic hydrocarbons containing mercury, gold, rhenium, and PGE in the Cenozoic sedimentary basins amidst the reservoirs under the impermeable beds also resulted from deep under- and overslab fluid flows.

scholarly journals RING STRUCTURES IN THE SOUTH TORGAI BASIN AND THE FORECAST FIELDS OF HYDROCARBONS

Neft i gaz ◽  
2020 ◽  
Vol 3-4 (117-1118) ◽  
pp. 54-68
Author(s):  
B.S. ZEYLIK ◽  
◽  
R.T. BARATOV ◽  
Keyword(s):  
Oil And Gas ◽  
New Technology ◽  
Sedimentary Basins ◽  
Wide Distribution ◽  
Earth’S Crust ◽  
The South ◽  
Tension And Compression ◽  
Ring Structures ◽  
Earth's Crust ◽  
Hydrocarbon Deposits

A new technology for forecasting hydrocarbon deposits is proposed, which is based on the principles of shock and explosive tectonics (ShET) and the use of Earth remote sensing data.The shock-explosive tectonics (ShET) paradigm has been advanced in Kazakhstan and developed over 40 years. The new technology is fundamentally different from traditional prognostic constructions due to the indispensable and constant use of the latest space information. Data from scanner, photo and radar space surveys reveal a wide distribution of previously not studied ring and linear structures. A study of ring structures, carried out in Kazakhstan for half a century, indicates a clear predominance of cosmogenic, asteroid-meteorite and cometary structures among them. The data of deciphering satellite images, taking into account the spatial position of known oil and gas fields, make it possible to identify concentric zones of tension and compression of the earth’s crust that accompany cosmogenic ring structures. An analysis of long-term data revealed the confinement of most hydrocarbon deposits and their geological reserves to concentric zones of extensiondeconsolidation of the earth’s crust. Concentric extension zones alternate with the compression zones separating them, in which a small number of mineral deposits are found. The proposed new technology for forecasting hydrocarbon deposits can be applied in many sedimentary basins of the World. Specifically, on the basis of the new technology, a forecast of new hydrocarbon deposits in the South Tоrgai oil and gas basin was based on two cometary ring structures: Chelkar-Aral and Baikonur

scholarly journals Role of elision water exchange in formation of the Yamalo-Kara depression hydrodynamic field

2019 ◽  
pp. 248-261
Author(s):  
D. A. Novikov
Keyword(s):  
Water Exchange ◽  
Oil And Gas ◽  
Water Pressure ◽  
Hydrodynamic Characteristics ◽  
Gas Generation ◽  
Pressure System ◽  
Stage Of Development ◽  
Capacitive Properties ◽  
Unique Material

The unique material has been compiled on the hydrodynamics of oil and gas deposits of the Yamalo-Kara Depression for the first time in the last 30 years. The main feature of the region is the wide development of abnormally high formation pressures (Ka to 2.21) in both Jurassic and Lower Cretaceous horizons. Studying the filtration-capacitive properties and hydrodynamic characteristics of the Jurassic-Cretaceous reservoirs allows to established the predominate role of the elision water exchange in the formation of the modern hydrodynamic structure. At the depth of about 2–2.5 km elisional lithostatic system begins to acquire the features of elisional thermo-dehydration system. The extensive zones of piezomaxima (Bolshekhetskaya and Karskaya megasyneclise) at the present stage of development of the water-pressure basin system became internal areas of water pressure (supply) with a maximum degree of hydrogeological closeness. The vast zones of piezomaxima (the Bolshekhetskaya and Karskaya megasyneclises) became the inner regions of water pressuring (feeding) with the maximal degree of hydrogeological closeness of the interior at the current stage of the development of the water-pressure system in the basin. The areas of piezominima extending along the main sites of oil and gas generation are related to the largest zones of oil and gas accumulation (Vankoro-Suzunskaya, Bovanenkovskaya, Urengoyskaya and others). Currently, two types of natural water-pressure systems has been established in the region under investigation: elision in the inner regions (dominating within the Yamalo-Kara depression) and infiltration — in the basin margins of the West Siberian sedimentary basin.

COAL AS A SOURCE OF OIL AND GAS: A CASE STUDY FROM THE BASS BASIN, AUSTRALIA

2003 ◽  
Vol 43 (1) ◽  
pp. 117 ◽  
Author(s):  
C.J. Boreham ◽  
J.E. Blevin ◽  
A.P. Radlinski ◽  
K.R. Trigg
Keyword(s):  
Organic Matter ◽  
Oil And Gas ◽  
Middle Eocene ◽  
Vitrinite Reflectance ◽  
Mineral Resources ◽  
Sedimentary Basins ◽  
Source Rocks ◽  
Gas Generation ◽  
Australian Context ◽  
Effective Source

Only a few published geochemical studies have demonstrated that coals have sourced significant volumes of oil, while none have clearly implicated coals in the Australian context. As part of a broader collaborative project with Mineral Resources Tasmania on the petroleum prospectivity of the Bass Basin, this geochemical study has yielded strong evidence that Paleocene–Eocene coals have sourced the oil and gas in the Yolla, Pelican and Cormorant accumulations in the Bass Basin.Potential oil-prone source rocks in the Bass Basin have Hydrogen Indices (HIs) greater than 300 mg HC/g TOC. The coals within the Early–Middle Eocene succession commonly have HIs up to 500 mg HC/g TOC, and are associated with disseminated organic matter in claystones that are more gas-prone with HIs generally less than 300 mg HC/g TOC. Maturity of the coals is sufficient for oil and gas generation, with vitrinite reflectance (VR) up to 1.8 % at the base of Pelican–5. Igneous intrusions, mainly within Paleocene, Oligocene and Miocene sediments, produced locally elevated maturity levels with VR up to 5%.The key events in the process of petroleum generation and migration from the effective coaly source rocks in the Bass Basin are:the onset of oil generation at a VR of 0.65% (e.g. 2,450 m in Pelican–5);the onset of oil expulsion (primary migration) at a VR of 0.75% (e.g. 2,700–3,200 m in the Bass Basin; 2,850 m in Pelican–5);the main oil window between VR of 0.75 and 0.95% (e.g. 2,850–3,300 m in Pelican–5); and;the main gas window at VR >1.2% (e.g. >3,650 m in Pelican–5).Oils in the Bass Basin form a single oil population, although biodegradation of the Cormorant oil has resulted in its statistical placement in a separate oil family from that of the Pelican and Yolla crudes. Oil-to-source correlations show that the Paleocene–Early Eocene coals are effective source rocks in the Bass Basin, in contrast to previous work, which favoured disseminated organic matter in claystone as the sole potential source kerogen. This result represents the first demonstrated case of significant oil from coal in the Australian context. Natural gases at White Ibis–1 and Yolla–2 are associated with the liquid hydrocarbons in their respective fields, although the former gas is generated from a more mature source rock.The application of the methodologies used in this study to other Australian sedimentary basins where commercial oil is thought to be sourced from coaly kerogens (e.g. Bowen, Cooper and Gippsland basins) may further implicate coal as an effective source rock for oil.

scholarly journals Accelerated non-linear destruction of the earth's crust

2001 ◽  
Vol 6 (4) ◽  
pp. 281-290
Author(s):  
E. V. Artyushkov
Keyword(s):  
Lower Crust ◽  
Sedimentary Basins ◽  
Earth’S Crust ◽  
Mountain Ranges ◽  
Crustal Rocks ◽  
The Earth ◽  
Lithospheric Plates ◽  
Temperature And Pressure ◽  
Earth's Crust ◽  
Major Hydrocarbon

The upper part of the Earth—the lithospheric layer,∼100 km thick, is rigid. Segments of this spherical shell–lithospheric plates are drifting over a ductile asthenosphere. On the continents, the lithosphere includes the Earth's crust,∼40 km thick, which is underlain by peridotitic rocks of the mantle. In most areas, at depths∼20–40 km the continental crust is composed of basalts with density∼2900kg m−3. At temperature and pressure typical for this depth, basalts are metastable and should transform into another assemblage of minerals which corresponds to garnet granulites and eclogites with higher densities 3300–3600 kgm−3. The rate of this transformation is extremely low in dry rocks, and the associated contraction of basalts evolves during the time≥108a. To restore the Archimede's equilibrium, the crust subsides with a formation of sedimentary basins, up to 10–15 km deep.Volumes of hot mantle with a water-containing fluid emerge sometimes from a deep mantle to the base of the lithosphere. Fluids infiltrate into the crust through the mantle part of the lithosphere. They catalyze the reaction in the lower crust which results in rock contraction with a formation of deep water basins at the surface during∼106a. The major hydrocarbon basins of the world were formed in this way. Infiltration of fluids strongly reduces the viscosity of the lithosphere, which is evidenced by narrow-wavelength deformations of this layer. At times of softening of the mantle part of the lithosphere, it becomes convectively replaced by a hotter and lighter asthenosphere. This process has resulted in the formation of many mountain ranges and high plateaus during the last several millions of years. Softening of the whole lithospheric layer which is rigid under normal conditions allows its strong compressive and tensile deformations. At the epochs of compression, a large portion of dense eclogites that were formed from basalts in the lower crust sink deeply into the mantle. In some cases they carry down lighter blocks of granites and sedimentary rocks of the upper crust which delaminate from eclogitic blocks and emerge back to the crust. Such blocks of upper crustal rocks include diamonds and other minerals which were formed at a depth of 100–150 km.

Active faulting, recent deformation and displacement of earth surface of large sedimentary basins of the earth's crust

1979 ◽  
Vol 52 (1-4) ◽  
pp. 347
Author(s):  
A.T. Donabedov ◽  
V.A. Sidorov ◽  
A.S. Grigoriev ◽  
A.V. Michailova ◽  
Z.E. Shachmuradova
Keyword(s):  
Sedimentary Basins ◽  
Earth’S Crust ◽  
Earth Surface ◽  
Active Faulting ◽  
Earth's Crust
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