PVTX characteristics of oil inclusions from Asmari formation in Kuh-e-Mond heavy oil field in Iran

Incorporating PVT properties and compositional evolution of oil inclusions into reservoir engineering simulator protocols can enhance understanding of oil accumulation, reservoir charge history, and migration events. Microthermometry and volumetric analysis have proven to be useful tools in compositional reconstitution and PT studies of oil inclusions and were used to determine composition, thermodynamic conditions, physical properties, and gas-to-oil ratios of heavy oil samples from Asmari carbonate reservoir in Kuh-e-Mond heavy oil field in Iran. PVT properties were predicted using a PVT black-oil model, and an acceptable agreement was observed between the experiments and the simulations. Homogenization temperatures were determined using microthermometry techniques in dolomite and calcite cements of the Asmari Formation, as well. Based on the homogenization temperature data, the undersaturated hydrocarbon mixture prior to formation of the gas cap migrated with a higher gas-to-oil ratio from a source rock. According to the oil inclusion data, the onset of carbonate cementation occurred at temperatures above 45 °C and that cementation was progressive through burial diagenesis. PVT black-oil simulator results showed that the reservoir pressure and temperature were set at 100 bar and 54 °C during the initial stages of oil migration. Compositional modeling implies that primary and secondary cracking in source rocks were responsible for retention of heavy components and migration of miscible three-phase flow during hydrocarbon evolution. The PT evolution of the petroleum inclusions indicates changes in thermodynamic properties and mobility due to phenomena such as cracking, mixing, or/and transport at various stages of oil migration

Sedimentary environment and palaeogeography of the? Palaeocene–Middle Eocene Kashkan Formation, Zagros fold-thrust belt, SW Iran

The Kashkan Formation (?Palaeocene to Middle Eocene) in the Zagros fold-thrust belt, SW Iran, which is intercala-ted between to marine limestone formations, consists of conglomerates, sandstones and siltstones. The sedimentology and the palaeogeography of the Kashkan Formation had not received any attention thus far, but have now been studied in seven sections, situated in the province of Lorestan. The sediments form twelve lithofacies, three ichnosubfacies and seven architectural elements, which are described, depicted and analysed. The analysis leads to the conclusion that most sediments accumulated in a low-sinuosity, low-gradient braided-river system (characterised by mainly unidirec -tional palaeocurrent directions, and by sheetfloods), that occasionally showed meandering characteristics (represented by overbank deposits and large bars). The deposits of this system closely resemble those of the South Saskatchewan River in Canada, which is considered as the classical example of a sand-bed braided river. The river flowed roughly from North to South, as deduced by palaeocurrent indicators such as imbrication and large- to medium-scale trough cross-stratification (direction measured in the trough axes). This current direction is supported by the southward to south-westward thinning of the formation and by the diminishing average grain size in the same direction. The trace fossils in the Kashban Formation fit all in the Skoyenia ichnofacies, which has here three ichnosubfacies which allow a more detailed palaeoenvironmental reconstruction, indicating that the braided stream passed into the low-energy sho -reface zone of a tidally-influenced sea

Scrutinizing relationships between submarine groundwater discharge and upstream areas using thermal remote sensing: A case study in the northern Persian gulf

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. Nutrient input through submarine groundwater discharge (SGD) often plays a significant role in primary productivity and nutrient cycling in the coastal areas. Understanding relationships between SGD and topo-hydrological and geo-environmental characteristics of upstream zones is essential for sustainable development in these areas. However, these important relationships have not yet been completely explored using data-mining approaches, especially in arid and semi-arid coastal lands. Here, Landsat 8 thermal sensor data were used to identify potential sites of SGD at a regional scale. Relationships between the remotely-sensed sea surface temperature (SST) patterns and geoenvironmental variables of upland watersheds were analyzed using logistic regression model for the first time. The accuracy of the predictions was evaluated using the area under the receiver operating characteristic curve (AUC-ROC) metric. A highly accurate model, with the AUC-ROC of 96.6%, was generated. Moreover, the results indicated that the percentage of karstic lithological formation and topographic wetness index were key variables influencing SGD phenomenon and spatial distribution in the northern coastal areas of the Persian Gulf. The adopted methodology and applied metrics can be transferred to other coastal regions as a rapid assessment procedure for SGD site detection. Moreover, the results can help planners and decision-makers to develop efficient environmental management strategies and the design of comprehensive sustainable development policies

Depositional and Diagenetic Environments of Carbonate-Siliciclastic Rocks of the Glen Dean Formation (Upper Mississippian), Illinois Basin, u.s.a

219 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.About 1200 vertically oriented carbonate, sandstone and shale samples were collected from twenty three stratigraphic sections of the Glen Dean Formation in the Illinois Basin.Detailed petrographic investigation using the microfacies approach has led to the recognition of sixteen distinct carbonate microfacies. Their vertical succession and reciprocal relationships in the different sections and their correlation coefficients led to the recognition of an ideal shallowing upward sequence in turn converted into a horizontal depositional model. The model consists of a shallow open marine subtidal carbonate platform with the following environments from offshore to onshore: lower slope; upper slope; outer bank with three sub-bank environments (foraminiferal, crinoidal, and oncolitic); inter bank; inner bank with three sub-bank environments (bryozoan, oncolitic, and oolitic); lagoon.The petrographic analysis of the siliciclastic rocks led to the recognition of five microfacies: siltstone, quartz arenite, quartz arenite with argillaceous matrix, quartz wacke and shale. A depositional model was developed which consisted of a deltaic complex periodically prograding over the eastern shelf of the Illinois Basin. Consequently, three distinct environments were juxtaposed: delta system, carbonate platform and basin. At times sands and muds cut across the carbonate platform by means of channel systems and were deposited in the basin by gravity flows or major storm surges.The clay mineral assemblage of the shales from the deltaic fringe consists of discrete illite, kaolinite or chlorite, and mixed layer illite/smectite. Kaolinite and chlorite display a north-south zonation due to their physical segregation in the depositional environment with kaolinite in more shoreward and chlorite in more marine environment. The illite/smectite composition ranges from 50 to 85% illite and from 15 to 50% smectite. Its mixed layered structure is short range ordered and/or random. These samples mainly reflect the effects of provenance.The clay mineral assemblage of the shales from the central part of the basin contains long range ordered illite/smectite with the composition of 90 to 95% illite and 5 to 10% smectite. These samples mainly reflect the effects of thermal diagenesis probably due to burial.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD