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Amu-Darya basin showing political boundaries, gas fields, and major geologic and geographic features discussed in text. Dark shade, portion of basin with sedimentary rocks below 4.5 km.
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High resolution images of crustal structure across the San Andreas Fault (SAF) were obtained by using the common conversion point stacking of teleseismic P-to-S converted waves recorded during the Los Angeles Region Seismic Experiments (LARSE-I and II). In the upper crust, several sedimentary basins were delineated in the images, including the San...
This paper is a synthesis of a preliminary litostratigraphical and structural study finalized to improve the deep aquifers knowledge in Piemonte (northern Italy). In detail the work concerns the Piemonte plain sector, that is the most important water reserve in the region. In this moment most wells take water in the first 200 m of aquifer; therefor...
Se ha realizado el análisis polínico en muestras de musgos desarrollados
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cuenca sedimentaria terciaria de la comarca de Maceda, Orense (NW de España). Los
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Understanding the kinematic processes around the formation of sedimentary basins is central to quantifying their resource potential. Building accurate kinematic models is a subjective and time-consuming process which requires incorporation of both vertical and lateral motions within sedimentary basins. Majority of plate reconstruction studies mostl...
Citations
... Vendian and Riphaen shales are proven thick source rocks in East Siberia, with most reservoirs within Cambrian age stromatolitic limestones or shallow water sandstones sealed by widespread Cambrian evaporites and salts (Clarke, 1985;Dyman et al., 2001;Ulmishek, 2001a, b;Nakashima, 2004). ...
... The Precaspian Basin is one of the largest basins in the world, with deep sedimentation reaching more than 20 km in central parts (Dyman et al., 1999). Precaspian Basin has an area of 500 000 km 2 of which more than three-quarters lie in Kazakhstan and the rest area lies in the Russian territory ( Fig. 3) (Bakirov et al., 1990;Brunet et al., 1999). ...
... The porosity is higher than 20 % and permeability varies from 30 mD to several hundred millidarcies. Reservoir quality decreases with increasing depth in Triassic and Upper Permian sequences due to substantial porosity loss (Dyman, et al. 1999). Combined reservoir-seal parameters of postsalt clastic reservoirs indicate a good target for geologic CO 2 storage. ...
The terms of the Paris Agreement oblige Kazakhstan to decrease its Greenhouse Gas (GHG) emissions by 2030. Annual GHG emissions of the country already went beyond the limit set by the Paris agreement in 2014 and this number is expected to increase with a growing economy showing that current measures of GHG mitigation in the country are insufficient. Despite the energy sector of the country being heavily dependent on its coal and substantial land resources, CCS was not featured in the “Green Economy” plan of the country. To investigate the applicability of this technology, six selected Kazakhstan sedimentary basins (the Precaspian, Mangyshlak, South-Torgay, Ustyurt, Chu-Sarysu, and Zaysan basins) were evaluated and ranked for geologic CO2 storage deployment in terms of containment, capacity, and feasibility. The effective CO2 storage capacities in oil reservoirs, gas reservoirs, and saline aquifers were estimated for each basin using the Carbon Sequestration Leadership Forum (CSLF) and USDOE methods. The evaluations revealed that the Precaspian Basin is the most suitable for geological CO2 storage, followed by the Mangyshlak, South Torgay, and Ustyurt basins. The total effective CO2 storage capacity of the country is estimated to be ∼583 Gt, of which ∼539 Gt corresponds to the abovementioned four suitable basins where most of injected CO2 is expected to be stored in the hydrodynamic traps. The results suggest that four sedimentary basins identified in this study have prospectivity to reduce GHG emissions of Kazakhstan significantly and thus enable the decarbonization of national economy to achieve the goals set by the Paris Agreement.
... The Amu-Darya Basin has been extensively studied as a result of its economic importance. Several papers give an overview of the stratigraphy and tectonics of the basin (Clarke 1988;Dyman et al. 1999;Thomas et al. 1999;Brookfield & Hashmat 2001;Ulmishek 2004;Brunet et al., this volume, in press). ...
... The Jurassic-Cretaceous basin is underlain by several troughs, possibly rifts, filled with up to several thousand metres of poorly dated continental siliciclastic sediments and possibly volcanics, generally considered as Mid-Late Carboniferous to Triassic in age (Babadzhanov et al. 1986;Clarke 1988Clarke , 1994Shayakubov & Dalimov 1998;Dyman et al. 1999;Thomas et al. 1999;Brookfield & Hashmat 2001;Ulmishek 2004;Natal'in & Ş engör 2005;Zanchetta et al. 2013;Brunet et al., this volume, in press). The exact geometry and depths of these troughs are neither well known nor constrained. ...
... The Amu-Darya Basin has been extensively studied as a result of its economic importance. Several papers give an overview of the stratigraphy and tectonics of the basin (Clarke 1988;Dyman et al. 1999;Thomas et al. 1999;Brookfield & Hashmat 2001;Ulmishek 2004;Brunet et al., this volume, in press). ...
... The Jurassic-Cretaceous basin is underlain by several troughs, possibly rifts, filled with up to several thousand metres of poorly dated continental siliciclastic sediments and possibly volcanics, generally considered as Mid-Late Carboniferous to Triassic in age (Babadzhanov et al. 1986;Clarke 1988Clarke , 1994Shayakubov & Dalimov 1998;Dyman et al. 1999;Thomas et al. 1999;Brookfield & Hashmat 2001;Ulmishek 2004;Natal'in & Ş engör 2005;Zanchetta et al. 2013;Brunet et al., this volume, in press). The exact geometry and depths of these troughs are neither well known nor constrained. ...
The Bukhara-Khiva region forms the northern margin of the Mesozoic Amu-Darya Basin. We have
reconstructed several cross-sections across this margin from subsurface data. The objectives included
examining the structure of the Bukhara and Chardzhou steps, and determining the tectonicsedimentary
evolution during the Jurassic times. Subsequent to the Cimmerian collision in the Middle
Triassic, an extensional event controlled the deposition of the Early-Middle Jurassic-age siliciclastic
succession in the Bukhara-Khiva region. During this period the main Late Palaeozoic-age inherited
structures were reactivated as normal faults. Continental, coarse-grained siliciclastics are mainly
confined to the basal Lower Jurassic section, probably Pliensbachian-Toarcian in age, whereas marine
siliciclastics occur in the early Late Bajocian. In the Early-Middle Jurassic the Bukhara and Chardzhou
steps were predominantly sourced by areas of relief, the remains of Late Palaeozoic-age orogens,
located to the north. The rate of extension significantly declined during the Middle Callovian-
Kimmeridgian period. Deposition of the overlying Lower Cretaceous continental red-coloured clastics
was related to the interaction of basin subsidence, a fall in eustatic sea level, and sediment supply. Subsequent marine transgression in the Late Barremian, partially related to broad thermal subsidence
in the Amu Darya Basin, resulted in the deposition of an extensive Late Cretaceous clay-marl
succession.
... Besides the conventional exploration play types highlighted above, Ukraine appears to have significant unconventional resource potential as well. In particular, the Dnieper‐Donetsk basin may have a very large basin‐centered gas accumulation, based on the presence of overpressure and reported gas shows within the Carboniferous (Dyman et al., 2000). As to the shale gas potential in general, Ukraine has, for example, a very similar, if not identical, Silurian‐Lower Devonian black shale succession to that of Poland. ...
Context is everything. Not all thick sands pay out and not all thin sands are poorly productive. It is important to understand a basin's palaeogeographical drivers, the resultant palaeoenvironments and their constituent sedimentary architecture. Development of a depositional model can be predictive with respect to the magnitude of accessible pore space for potential development.
We present a multi-field study of the Dneipr-Donets basin. Over 600 wells were studied with >4500 lithostratigraphical picks being made. Over 7500 sedimentological picks were made allowing mapping of facies bodies and charting shifts in facies types. A facies classification scheme was developed and applied. The Devonian-Permian sedimentary section records the creation, fill, and terminal closure of the Dneipr-Donets Basin:Syn-rift brittle extension (late Frasnian-Famennian): intracratonic rifting between the Ukrainian Shield and Voronezh Massif formed a NW-SE orientated trough, with associated basaltic extrusion. Basin architecture consists of rotated fault blocks forming graben mini-basins. Sedimentation is dominantly upper shoreface but sand packages are poorly correlatable due to the faulted palaeotopography.Early Post-rift thermal subsidence (Visean-Lower Bashkirian): the faulted palaeotopography was filled and thermal subsidence drove basin deepening. Cyclical successions of offshore, lower shoreface and upper shoreface dominate. Sands are typically thin (<10m) but can be widely correlated and have high pore space connectivity.Mid Post-rift: the Bashkirian (C22/C23 boundary), paralic systems prograde over the shoreface. Changes in vertical facies are abrupt due to a low gradient to basin floor. Deltaic and fluvial facies can produce thick amalgamated sands (>30m), but access limited pore space because they are laterally restricted bodies.Terminal post-rift (Mykytivskan): above the lower Permian, the convergence of the Kazahkstanian and Siberian continents began to restrict the Dnieper-Donets basin's access to open ocean. The basin approached full conditions and deposition was dominated by evaporite precipitation, with periodic oceanic recharge. Ultimately, this sediment records the formation of Pangea.
The successions examined were used to construct a basinal relative sea level curve, which can be applied elsewhere in the basin. This can be used to help provide palaeogeographical context to a field, which in turn controls the sedimentary architecture.
The seismic data have historically been utilized to perform structural interpretation of the geological subsurface. Modern approaches of Quantitative Interpretation are intended to extract geologically valuable information from the seismic data.
This work demonstrates how rock physics enables optimal prediction of reservoir properties from seismic derived attributes. Using a seismic-driven approach with incorporated prior geological knowledge into a probabilistic subsurface model allowed capturing uncertainty and quantifying the risk for targeting new wells in the unexplored areas.
Elastic properties estimated from the acquired seismic data are influenced by the depositional environment, fluid content, and local geological trends. By applying the rock physics model, we were able to predict the elastic properties of a potential lithology away from the well control points in the subsurface whether or not it has been penetrated.
Seismic amplitude variation with incident angle (AVO) and azimuth (AVAZ) jointly with rock-derived petrophysical interpretations were used for stochastical modeling to capture the reservoir distribution over the deep Visean formation. The seismic inversion was calibrated by available well log data and by traditional structural interpretation.
Seismic elastic inversion results in a deep Lower Carboniferous target in the central part of the DDB are described. The fluid has minimal effect on the density and Vp. Well logs with cross-dipole acoustics are used together with wide-azimuth seismic data, processed with amplitude control. It is determined that seismic anisotropy increases in carbonate deposits. The result covers a set of lithoclasses and related probabilities: clay minerals, tight sandstones, porous sandstones, and carbonates. We analyzed the influence of maximum angles determination for elastic inversion that varied from 32.5 to 38.5 degrees. The greatest influence of the far angles selection is on the density. AI does not change significantly. Probably the 38,5 degrees provides a superior response above the carbonates. It does not seem to damage the overall AVA behavior, which result in a good density outcome, as higher angles of incidence are included. It gives a better tie to the wells for the high density layers over the interval of interest. Sand probability cube must always considered in the interpretation of the lithological classification that in many cases may be misleading (i.e. when sand and shale probabilities are very close to each other, because of small changes in elastic parameters).
The authors provide an integrated holistic approach for quantitative interpretation, subsurface modeling, uncertainty evaluation, and characterization of reservoir distribution using pre-existing well logs and recently acquired seismic data.
This paper underpins the previous efforts and encourages the work yet to be fulfilled on this subject. We will describe how quantitative interpretation was used for describing the reservoir, highlight values and uncertainties, and point a way forward for further improvement of the process for effective subsurface modeling.
Abstract
Undiscovered potash resources in the Central Asia Salt Basin (CASB) of Turkmenistan, Uzbekistan, Tajikistan, and Afghanistan were assessed as part of a global mineral resource assessment led by the U.S. Geological Survey (USGS). The term “potash” refers to potassium-bearing, water-soluble salts derived from evaporite basins, where seawater dried up and precipitated various salt compounds; the word for the element “potassium” is derived from potash. Potash is produced worldwide at amounts exceeding 30 million metric tons per year, mostly for use in fertilizers. The term “potash” is used by industry to refer to potassium chloride, as well as potassium in sulfate, nitrate, and oxide forms (Neuendorf and others, 2005). For the purposes of this assessment, the term “potash” refers to potassium ores and minerals and potash ore grades. Resource and production values are usually expressed by industry in terms of K2O (potassium oxide) or muriate of potash (KCl, potassium chloride).
The CASB hosts significant discovered potash resources and originated in an inland sea during Late Jurassic time. Seawater flowed into the CASB, mostly from its extreme northwestern margin near the modern Caspian Sea, during several evaporation episodes that deposited at least five different packages of evaporites, with virtually all potash in the second and fourth packages. In this study, the CASB was subdivided into three tracts (permissive areas) for evaluation: the Amu Darya tract in the west, the Gissar tract in the center, and the Afghan-Tajik tract in the east. The Gissar and Amu Darya tracts were quantitatively assessed, whereas the Afghan‑Tajik tract was only qualitatively assessed because of the commonly extreme depth (as deep as 7 km) of the Jurassic salt, extensive deformation, and a lack of known potash deposits.
Two approaches were used to estimate amounts of undiscovered potash in the CASB. Stratabound evaporite deposits in the Amu Darya tract were evaluated using an Adaptive Geometric Estimation (AGE) approach, which estimates in-place potash volumes and tonnages. The Gissar tract was evaluated by using the AGE approach for stratabound deposits and the three-part form of assessment of Singer and Menzie (2005) for discrete halokinetic deposits. In the three-part form of assessment, numbers of undiscovered deposits were estimated and combined with grade and tonnage models to probabilistically forecast the amount of undiscovered potash. The Amu Darya tract is estimated to contain 38 billion metric tons (Bt) of undiscovered potash as K2O by using the AGE approach for stratabound deposits. The hybrid stratabound-halokinetic Gissar tract is estimated to contain between 1 and 16 Bt of undiscovered potash as K2O.
Chapter 1 of this report provides an overview of the history of the CASB and summarizes evaporite potash deposition, halokinesis, and dissolution processes that have affected the current distribution of potash-bearing salt in the CASB. Chapter 2 describes the Gissar tract, an uplifted region that contains a mix of stratabound and halokinetic potash deposits and all of the discovered and exploited potash deposits of the CASB. Chapter 3 describes the Amu Darya tract, where evaporite deposits remain flat-lying and undeformed since their original deposition. Chapter 4 describes the highly deformed and compressed Afghan‑Tajik tract and what is known of the deeply-buried Jurassic salt. Chapter 5 describes the spatial databases included with this report, which contain a collection of CASB potash information. Appendixes A and B summarize descriptive models for stratabound and halokinetic potash-bearing salt deposits, respectively. Appendix C summarizes the AGE method used to evaluate the Gissar and Amu Darya tracts. Appendixes D and E contain grade and thickness data for the Gissar and Amu Darya tracts. Appendix F provides the SYSTAT script used to estimate undiscovered K2O in a CASB tract. Appendix G provides a potash glossary, and appendix H provides biographies of assessment participants.
This manuscript offers a brief review of the geological and cultural history of the western part of Asia (hereafter, WA), which includes Azerbaijan, Afghanistan, Abu Dhabi, the Caspian Sea, Iran, Iraq, Oman, Pakistan, Qatar, Turkmenistan, Turkey, and the United Arab Emirates. There is a particular emphasis on the comprehensive relationship between the earth sciences and the social and cultural aspects of WA, parts of which are also thought of as being part of the Middle East.
