PERMIAN AND TRIASSIC STRATIGRAPHY, ZAGROS BASIN, SOUTH-WEST IRAN

The Permian and Triassic beds deposited in the Zagros Basin form a massive carbonate and evaporite sequence in excess of 2000m. These strata were divided into clearly recognizable and mappable lithostratigraphic units and major lithofacies types using surface exposures, subsurface log information and sample cuttings .
Formation and member designations are given to distinct and widespread lithostratigraphic units and where possible, the boundaries of these units are selected to coincide with sedimentary gaps or boundaries of sedimentary cycles .
A well type-section and a surface reference section are established to illustrate the distribution of these units both vertically and horizontally .
Major unconformities were observed and documented at the base of the Permian and at the top of the Triassic, a smaller break was noted between the Triassic and Permian sediments .
Revision of the Jurassic-Triassic boundary is made, based on this new stratigraphic evidence .  

Vorticity-based coarse grid generation for upscaling two-phase displacements in porous media

Coarse grid generation from finely gridded geological model is a main step in reservoir simulation. Coarse grid generation algorithms aim at optimizing size, number and location of the grid blocks by identifying the important geological and flow features which control flow in porous media. By optimizing coarse grid structure we can improve accuracy of the coarse scale simulation results to reproduce fine grid behavior. A number of techniques have been proposed in the literature. We present a novel coarse grid generation procedure based on vorticity preservation between fine and coarse grids. In the procedure, the coarse grid mesh tries to capture variations in both permeability and fluid velocity using a single physical quantity — “vorticity” which is extracted from single-phase flow simulation. One essential element in the procedure is that the improved coarse grid (ICG) has minimum single-phase vorticity error with respect to the fine grid vorticity. Our numerical investigations on modeling two-phase flow demonstrate that the ICG represents fine grid flow behavior very closely. In addition, our analyses show that the use of single-phase vorticity has only a minor impact on the ICG generation, and its performance is not affected by two-phase flow parameters such as mobility ratio.  

Severe Slugging In a Catenary-shaped Riser: Experimental and Simulation Studies

A series of experiments on two-phase, air-water flow in a flowline-riser geometry have been made. The riser has a catenary-shaped form (10.5 m high), and the flowline has a 2-degree downward inclination toward the riser-base (10.16 cm ID). Experimental data were used to characterize the severe slugging and unstable flows in terms of pressure cycling and fluid production characteristics. A model to study dynamic behavior of severe slugging flow in a pipeline-riser system was also developed under the environment of the OLGA2000 code, and experimental test results were compared with the OLGA model predictions. The motive for this work was to identify areas that pose substantial difficultly to the code for the simulation of severe slugging in a catenary-shaped riser. In addition, numerical experiments, exploring some of the reasons for difference between experimental and simulation results, have been presented in this article.  

Monitoring the aging of beers using a bioelectronic tongue

This paper deals with the implementation and the application of a bioelectronic tongue including three enzymatic biosensors based on tyrosinase and phthalocyanines as electron mediators, to evaluate the changes that occur during the aging of beers. For this purpose, alcoholic and non alcoholic beers, packaged in can and bottle, have been analyzed using cyclic voltammetry. The electrochemical signals showed significant changes during the aging process. The features extracted from the cyclic voltammograms have been used to perform Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA). Data have revealed a clear discrimination among the beer classes in the aging process and the results were confirmed by Probabilistic Neural Networks (PNN) with Radial Basis Functions (RBF) and FeedForward Networks with Backpropagation (BP) learning method. The bioelectronic tongue has demonstrated a good capability to discriminate and classify the beer types satisfactorily in such a way, for all beer treatments, full classification accuracy was found.  

A correlation approach for prediction of crude oil viscosities

The role of reservoir fluid viscosity for reservoir evaluation in performance calculations, planning thermal methods of enhanced oil recovery, evaluation of hydrocarbon reserves and designing production equipment and pipelines makes its accurate determination necessary. Reservoir oil viscosity is usually measured isothermally at reservoir temperature. However, at temperature other than reservoir temperature these data are estimated by empirical correlations. High dependency of oil viscosity on fluid nature and fluid source causes the unique application of these correlations to special cases from which they have been derived.Here, based on Iranian oil reservoirs data; new correlations have been developed for prediction of dead, saturated and under-saturated oil viscosities. These correlations have been derived using so many oil viscosity data. Validity and accuracy of these correlations have been confirmed by comparing the obtained results of these correlations and other ones with experimental data for so many Iranian oil samples. In contrast to other correlations which need so many specific parameters for oil viscosity prediction, this type of correlations need only some field data which always are available. Checking the results of these correlations shows that the obtained results of Iranian oil viscosities in this work are in agreement with experimental data compared with other correlations.  

BURIAL HISTORY RECONSTRUCTION AND THERMAL MODELLING AT KUH-E MOND, SW IRAN

At the Kuh-e Mond anticline (Fars Province, SW Iran) and in nearby offshore structures, large volumes of natural gas are reservoired in the Permian — Early Triassic Dehram Group while heavy oil has been discovered in the Cretaceous Sarvak and Eocene Jahrum Formations. In this paper, we use data from six exploration wells and from nearby surface exposures to reconstruct the burial history at Kuh-e Mond. Regional observations show that the thick sedimentary fill in this part of the Zagros Basin was subjected to intense tectonism during the Zagros Orogeny, with a paroxysmal phase during the late Miocene and Pliocene. Thermal modelling and geochemical data from Kuh-e Mond and adjacent fields allows possible hydrocarbon generation and migration mechanisms to be identified. Maturities predicted using Lopatin's TTI model are in accordance with maturities obtained from vitrinite reflectance measurements.
We show that formations which have source potential in the nearby Dezful Embayment (including the Pabdeh, Gurpi, Gadvan and Kazhdumi Formations) have not reached the oil window in the Mond wells. Moreover, their organic carbon content is very low as they were deposited in oxic, shallow-water settings. Underlying units (including the Ordovician and Cambrian) could have reached the gas window but contain little organic matter. Silurian shales (Sarchahan Formation), which generate gas at Kuh-e Gahkum and Kuh-e Faraghan (north of Bandar Abbas) and in Saudi Arabia and elsewhere in the Middle East, are absent from the Mond structure.
The absence of source rocks suggests that the gas and heavy oil accumulations at Kuh-e Mond and at nearby fields have most probably undergone long-distance lateral migration from distant source kitchens.  

Isolation, identification and monitoring of contaminant bacteria in Iranian Kefir type drink by 16S rDNA sequencing

Iranian Kefir type drink (IKTD) is a highly consumed, traditional Iranian, fermented milk product. To improve monitoring procedures for food safety 32 industrial Kefir type drinks from 4 brands and 8 different production dates as well as 32 samples from pasteurized milk of the same Kefir manufacturers and air of the production sites were analyzed for contaminations. 16S rDNA extraction from Kefir samples as well as 16S rDNA obtained from samples incubated on Columbia agar were analyzed using PCR/DGGE, cloning, sequencing and phylogenetic classification. Already DGGE analysis indicated contaminations including Bacillus strains. Subsequently analysis of cultured clones indicated contaminations with Bacillus sp. including Bacillus cereus, Bacillus thuringiensis and Paenibacillus sp. in 9 (28%) from all analyzed samples. Also 38% of pasteurized milk samples were contaminated with B. cereus. The average count of B. cereus was 74 ± 19 cfu/ml. B. cereus and B. thuringiensis were found as contaminant bacteria in the air of the all manufacturing sites. These results suggest that milk is one of the most important sources of contamination with Bacillus sp., especially B. cereus for Kefir products in Iran. But bacterial contamination in Kefir samples might also originate from the air of the production sites. 16S rDNA analysis accelerates monitoring strategies.  

Incidence of aflatoxin M1 in human breast milk in Tehran, Iran

This study examined the exposure of infants to aflatoxin M1 (AFM1) and of lactating mothers to aflatoxin B1 (AFB1), using AFM1 in breast milk as a biomarker for exposure to AFB1. An enzyme-linked immunosorbent assay (ELISA) was modified for the analysis of AFM1 in breast milk samples from 160 women in Tehran, Iran. AFM1 was detected in 157 samples by average concentration of 8.2 ± 5.1 ng/kg (range 0.3–26.7 ng/kg).The concentration of AFM1 in one sample was higher than the maximum tolerance limit accepted by European Union and USA (25 ng/kg), but in 55 samples was higher than the maximum concentration recommended by Australia and Switzerland (10 ng/kg).Logistic regression Analysis failed to show significant correlation between AFM1 and gestational age, education, postnatal age, gender, nationality, clinical condition, the number of family member, the number of children, type and amount of dairy consumption, vegetable, fruits, oil and meat. But it was significant relation to the cereal consumption, also to the height at birth.