Papers by ali shekarifard
HAL (Le Centre pour la Communication Scientifique Directe), 2009
Journal of Petroleum Science and Engineering, Apr 1, 2018
This study examines the effects of ultrasonic waves (US) and microwaves (MW) on the permeability ... more This study examines the effects of ultrasonic waves (US) and microwaves (MW) on the permeability in carbonate cores with different permeabilities of asphaltenes deposited therein. Using US with toluene injection restores permeability in cores with a permeability of less than 20 md, about 18.8% and 29% higher than injection of toluene without US. The US creates
Proceedings, Apr 9, 2018
This paper discusses the effect of microwaves on the flocculation of asphaltene particles. A samp... more This paper discusses the effect of microwaves on the flocculation of asphaltene particles. A sample of Dehlor heavy oil from southwestern Iran was exposed to microwave radiation under anoxic conditions and saturated with helium gas at intervals of 3, 6, and 9 minutes. Then, using a viscometer and normal heptane, the set point of asphaltene flocculation was determined for each sample. The results of the experiments showed that three minutes of exposure to microwave irradiation caused the asphaltene to be flocculated from 34 vol% normal heptanes in the crude sample to 41 vol%. In other words, microwaves inhibited asphaltene aggregation. Based on the results of SARA (Saturation, Aromatics, Resin, Asphaltene) analysis, the largest reduction in asphaltene composition in heavy oil occurred at the 3 min interval. In contrast, at 6 and 9 min, the greatest decrease was observed for resin compounds, which are themselves a natural inhibitor of flocculation. Changes in the structure and reduction of sulfur and nitrogen components of asphaltene also cause microwaves to act as an inhibitor in the flocculation of asphaltene particles. Therefore, reducing the amount of asphaltene compounds and eliminating polar compounds, which is a function of time interval for microwave radiation, delays asphaltene aggregation.
International Geological Congress, Abstracts = Congres Geologique International, Resumes, Jul 10, 2000
Acta Geologica Sinica - English Edition, 2019
The lower Cretaceous rock units of the Koppeh‐Dagh Basin of northeastern Iran were investigated h... more The lower Cretaceous rock units of the Koppeh‐Dagh Basin of northeastern Iran were investigated here in terms of biostratigraphy, depositional setting and geochemical analyses to find out if they, alike other parts of the world, are rich in petroleum. For this purpose, a stratigraphic framework is established using calcareous nannofossil and palynological elements. A nannoplankton zonation based on which subzones of the zones CC7 – CC8 of Sissingh (1977) and their equivalent NC6 – NC8 of Roth (1978) was established indicating a Late Barremian–Albian age. Palynological assemblages led us to establish the local palynozone of Odontochitina operculata. A dominantly marginal basin to a transitional zone between shelf and basin under a dysoxic–anoxic condition with low to moderate sedimentation rates coincided with a gradual sea level rise was introduced as the environment of deposition for the strata via interpretation of the palynological parameters and quantitative palynology. The obta...
Proceedings, 2017
This study examines the effect of microwave irradiation on these precipitates. One 150 ml sample ... more This study examines the effect of microwave irradiation on these precipitates. One 150 ml sample of heavy crude oil from a reservoir in the southwest of Iran, with 12.7765 %wt asphaltene and 7.771 %wt wax content, was subjected to microwave irradiation in developed Fischer assay apparatus for time durations of 5, 10, 15, 20, 25 and 30 minutes. Experimental results show that microwaving for different lengths of time causes changes in wax and asphaltene content. At 15 minutes’ irradiation, the lowest asphaltene content (10.6225 %wt) was observed. The lowest wax content (5.5131 %wt) was found after 10 minutes’ irradiation. These particles, due to their high capacity to absorb microwaves, are severely affected by these waves. The microscopy results of the particle-size analysis (60 %vol. n-heptane) revealed that when irradiation time increased, the range of asphaltene particle sizes decreased. The size range of asphaltene particles in a primary state from 5 µm to 100 µm (54 µm mean particle size) declined after microwave irradiation, and in 30 minutes reached a range of 5 µm to 40 µm (18.5 µm mean particle size). Scanning electron microscopy images of asphaltene particles demonstrate that the microwaves altered the particles’ structure by inducing microcracks.
HAL (Le Centre pour la Communication Scientifique Directe), May 21, 2012
Geochemical characteristics (Rock-Eval pyrolysis and elemental analysis of kerogen), palynofacies... more Geochemical characteristics (Rock-Eval pyrolysis and elemental analysis of kerogen), palynofacies and organic petrography (using light transmitted-reflected-uv microscopy) of the basal black shale from the Shemshak Group (Upper Triassic- Middle Jurassic) in the Tazareh section (Eastern Alborz) have been investigated. The basal black shale is rich in amorphous organic matter with fewer amounts of vitrinite particles that was deposited in lacustrine environment under anoxic to suboxic conditions. According to vitrinite reflectance values (mean VRr=2.1%), organic matter of the basal black shale has experienced high thermal maturity during deep burial. In this study samples residual organic carbon content is 1 wt.% on average. Thermal modeling results using 1D Genex4 software show that the basal black shale of the Shemshak Group became mature during the Middle Jurassic-Lower Cretaceous time and generated hydrocarbon. At the present day, this organic facies in the Tazareh section is thermally over-mature and depleted in hydrogen and is located in the dry gas generation window. Presently, these sediments are considered as shale gas resources.
The following ammonoid and nautiloid taxa are described for the first time from the Upper Triassi... more The following ammonoid and nautiloid taxa are described for the first time from the Upper Triassic succession (Ekrasar Formation, Shemshak Group) of northern Alborz, Iran: Arcestes sp., Arcestes ( Pararcestes ?) sp., Thisbites cf. agricolae Mojsisovics, Stikinoceras cf. kerri Mc Learn, Giesbachites sp., Griesbachites cf. pseudomedleyanus Diener, Griesbachites cf. himalayanus Wang & He, and Proclydonautilus ? sp. Palaeobiogeographically, the studied ammonoids are Tethyan in character, and stratigraphically attributed to the lower Lower Norian ( Guembelites jandianus Zone, possibly also Malayites paulckei Zone). The biostratigraphic data of this study demonstrate the diachronous base of the Shemshak Group: it is older in the northern Alborz (lower Lower Norian), but younger in Central Iran and probably also in the southern Alborz (Middle Norian).
ammonoids of the Shemshak Group in Alborz, Iran and their palaeobiogeographical and biostratigrap... more ammonoids of the Shemshak Group in Alborz, Iran and their palaeobiogeographical and biostratigraphical importance.
As the reserves of petroleum are being depleted, oil shales become more and more important as an ... more As the reserves of petroleum are being depleted, oil shales become more and more important as an alternative source of liquid fuels. . Hydraulic fracturing is one of the main stimulating techniques to enhance recovery from oil shale reservoirs. A simplified numerical model has been developed to account for mechanical propagation of hydraulic fracturing in these reservoirs. Aperture and fracture conductivity play key roles in the determination of fracturing geometry/pattern. In addition, since aperture plays a decisive role in determination of proppant type/size and conductivity of the fractures, this important parameter is quantified considering its own influencing variables. We present a complex hydraulic fracture pattern propagation model based on the Finite Element Method (FEM) and distinct element method as a design tool that can be used to optimize treatment parameters under complex propagation conditions. Finally, some strategies are proposed for optimization of hydraulic frac...
In the present work, the effect of in situ electromagnetic retorting technologies on the oil shal... more In the present work, the effect of in situ electromagnetic retorting technologies on the oil shales was reviewed. In this literature review on oil shales dielectric properties, we found that the relative dielectric constant (e′) and imaginary permittivity (e″) decrease with increased frequency and remain constant at higher frequencies. Formation fluids and mineral-bound water also affect measured dielectric properties. This review presents and synthesizes prior work on the influence of applied frequency on the dielectric properties of oil shales that can aid in the future development of frequency specific in situ retorting technologies and oil shale grade assay tools. The results obtained revealed that this process can be efficiently used for the purpose. The oil shale seems related to the retorting of the shale and the products of the degradation of the kerogen. In addition, the obtained oil has interesting characteristics. It is more maltenic, less polar than the oils obtained by ...
In the Ardakan barite ore deposits, two groups of copper ore minerals have been identified in the... more In the Ardakan barite ore deposits, two groups of copper ore minerals have been identified in the barite veins. The hypogene ore minerals consist of chalcopyrite and chalcocite, which are associated with pyrite. The Supergene ore minerals are mainly composed of secondary Cu-sulfides (such as covellite, yarrowite and anilite), Cu-carbonates (malachite and azurite) and Cu-oxides (cuprite). Chalcopyrite is the most important hypogene Cumineral which has been altered to Cu-supergene minerals. Chalcopyrite tarnishing were developed along the joints, fractures and grain boundaries as films and veinlets. The tarnish color on the chalcopyrite varies from deep blue, pale blue, pink, yellow and dark gray. The tarnish phases in the chalcopyrite were studied using SEM EDXA. Sequences of the chalcopyrite alterations by the continued oxidation are as following: chalcopyrite (CuFeS2), covellite (CuS), yarrowite (Cu9S8), spionkopite (Cu39S28), geerite (Cu 1.6S) and anilite (Cu 1.75S). Alteration an...
journal of sciences islamic republic of iran, 2017
Proper determination of bed boundaries in layered reservoirs is vital for accurate petrophysical... more Proper determination of bed boundaries in layered reservoirs is vital for accurate petrophysical interpretation of conventional logs. In the wellbore, logs continuously measure physical properties of reservoir while the properties change stepwise. This continuous representation of logs may lead to ignorance of some high potential reservoir zones. The main reasons for continuous nature of logs in laminated reservoirs are the influence of shoulder beds on the reading of logging tools and low vertical resolution of these devices.In this paper we optimized a Laplacian filter to detect bed boundaries in conventional well logs. These blocking-based boundaries are validated with FMI derived bed boundaries. Then the calculated petrophysical properties including porosity and volume of minerals and fluids are distributed into the detected beds. Comparison of petrophysical interpretation of logs based on blocking and FMI derived bedding showed that the petrophysical properties re...
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Papers by ali shekarifard