Interparticle Porosity Research Articles

Additive Manufacturing of Bonded Nd–Fe–B—Effect of Process Parameters on Magnetic Properties

Isotropic-bonded magnets were fabricated by powder bed fusion additive manufacturing (AM) using a feedstock composed of polymeric binder polyamide 12 (PA-12) and a near stoichiometric Nd2Fe14B atomized nanocrystalline powder. The AM equipment constructed for that purpose uses a computer-controlled laser beam to melt the binder and build the parts layer by layer. Three process parameters were evaluated: layer thickness (LT), hatch spacing (HS), and laser power (LP). For the evaluation of magnetic properties, cylindrical samples with diameter and height of 10 mm were produced and measured in a hysteresisgraph. For a feedstock, based on a 34% volumetric fraction of PA-12, the highest density value achieved was 3.6 g/cm3, resulting in a remanence of 0.3 T. These relatively low values for remanence are due to the isotropic characteristic of the powder, the binder fraction, and the interparticle porosity not being completely eliminated. Results indicate that LT affects densification more significantly than LP and HS. Consequently, remanence follows the same trend. Coercivity has not been affected much by optimized process parameters, since the values of original atomized powder of around 700 kA/m remained practically the same. The overall conclusion shows encouraging results to explore this alternative AM technique to produce net shape permanent magnets.

Diagenetic evolution of a shallow marine Kimmeridgian carbonate ramp (Jabaloyas, NE Spain): implications for hydrocarbon reservoir quality

The upper Kimmeridgian outcrops in Jabaloyas (NE Spain) studied here have significant similarity in terms of carbonate ramp morphology and its facies architecture with Member D of the Upper Jurassic Arab Formation reservoirs in the Middle East. Geological models from analogue outcrops enhance or challenge the understanding of multi-scale sedimentological and diagenetic heterogeneities in the subsurface hydrocarbon reservoir models by providing morphometric parameters. For this purpose, conventional diagenetic studies (petrographic microscopy analysis and cathodoluminescence) have been performed to assess the impact of diagenetic modifications through burial. More than 50 thin sections have been used to define a full paragenetic sequence. Additional mineralogical mapping (Qemscan®) on a selection of thin sections serves as a calibration tool for semiquantitative analytic studies of every mineral phases and the proposed porosity evolution. This work unravels the whole paragenetic diagenetic processes and focused on those that occurred right after deposition to shallow burial (eogenesis). High-sequence stratigraphy allows linking these events to variations of the environmental domains that, in fact, respond most likely to sea-level fluctuations. In particular, it provides key parameters to frame the diagenetic overprint such as cementation processes plugging primary interparticle porosity and selective dissolution linked to master bounding surfaces: calcite meniscus cements in vadose zones and selective dissolution processes linked to firmgrounds. Ultimately, they offer valuable trends that would be potentially relevant to decipher and characterize reservoir parameters for the upscaling workflow of fabrics from microscopic to inter-well scale in carbonate hydrocarbon reservoirs.

Influences of the composition and pore structure of a shale on its selective adsorption of CO2 over CH4

The adsorption capacities of CO2 and CH4 and selectivity of CO2 over CH4 (αCO2/CH4) are important parameters to evaluate the feasibility for applying CO2-ESGR technique (enhance shale gas recovery by CO2 injection) to a shale. Composition and pore structure of shales from different districts of Sichuan basin and their effects on the adsorption capacities of CO2 and CH4 and αCO2/CH4 at different temperatures were studied. Results indicate that shales from Sichuan basin have high TOC (total organic carbon) contents, lots of brittle minerals, large interparticle porosity and wide pore size distributions. The adsorption of CO2 turns from multilayer to monolayer with the increase of temperature, while that of CH4 is mainly in monolayer. The larger adsorption capacity of CO2 than CH4 in shales is not due to the interaction of CO2-shale. High TOC and clay minerals content together improve adsorption capacities of CH4 and CO2. The pore structure parameters have no simple relationship with the adsorption capacity and αCO2/CH4. A shale with a lower TOC content, a smaller amount of micropores and a larger amount of clay minerals has a larger αCO2/CH4, and is more suitable for the its application in CO2-ESGR technique. αCO2/CH4 decreases with the increasing temperature.

Controls on diagenesis and dolomitization of peritidal facies, Early Cretaceous Lower Edwards Group, central Texas, USA

The Early Cretaceous Fort Terrett Formation of Mason County, central Texas, is a succession of subtidal to peritidal mud-dominated facies with minor intervals of bioclastic packstone–grainstone, rudist floatstone, and interbedded chert nodules. The strata conformably overlie the Hensel Formation, which was deposited unconformably on Precambrian basement. The Hensel Formation also contains a significant percentage of dolomite, precipitated within a fine-grained clayey matrix. The Hensel and Fort Terrett Formations were deposited during a transgressive episode, which provided the conditions for the extensive shallow-water Comanche carbonate platform. Siliciclastic and carbonate sediments were deposited along the coastal margin in subtidal, intertidal to supratidal areas. Previous dolomitization models have suggested that high permeability layers are required for dolomitizing brines to flow through a carbonate succession. Although, interparticle porosity in muddy tidal-flat successions can be significant, it has a limited flow capacity. However, interconnected fenestral porosity can allow sufficient fluid flow to move dolomitizing fluids more efficiently through the succession. Thus, it is hypothesized that interconnected fenestral porosity could have had a significant impact on permeability within this muddy succession and provided the pathways and conduits for Mg-rich brines. Four types of dolomite are recognized in the Fort Terrett succession. Three of these dolomite types formed largely by replacement and they occur throughout the succession. Features such as crystal size, crystal face geometry and zonation reflect the progressive development and recrystallization of the dolomite types. Only type 4 dolomite formed as a cement in void spaces during a late diagenetic stage. The direction of the dolomitizing fluid movement is difficult to determine, but it was likely downward in this case, controlled by a density-head driving-mechanism generated by dense hypersaline fluids from an evaporating lagoon.

Novel Amine-impregnated Mesostructured Silica Materials for CO2 Capture

In this work, mesostructured KIL-2 silica materials were synthesized and functionalized by impregnation with two different amino sources, polyethylenimine (PEI) and Tetraethylenepentamine (TEPA), for their application to low temperature CO2 capture. Infrared spectroscopy verified that amino groups were successfully incorporated on the surface of the silica support and within its interparticle porosity. N2 sorption analysis of the synthesized silica materials showed a decrease in surface area and total pore volume as a result of the impregnation with the amine groups. The CO2 capture capacity of prepared sorbents was evaluated by CO2 adsorption/desorption isotherms at 25°C and 90°C. The highest sorption capacity was achieved at 90°C for KIL-2-TEPA material (4.35 mmol/g ads), which is significantly higher than values previously reported in the literature for similar type of disordered mesopore structure materials under similar conditions.

Ground-Penetrating-Radar Characterization and Porosity Evolution of An Upper Pleistocene Oolite-Capped Depositional Cycle, Red Bays, Northwest Andros Island, Great Bahama Bank

Abstract: Linkages among surface sediments, depositional processes, geomorphic forms, stratigraphic architecture, and pore distribution in Bahamian sand bodies and oolite-capped depositional successions have been characterized in recent studies. An understanding of how these parameters, especially porosity, are preserved or modified in the eogenetic environment is essential in bridging the gap between modern and ancient analogs. Two complementary 3D (200 MHz and 400 MHz) ground-penetrating-radar surveys and three shallow cores reveal that the uppermost part of the upper Pleistocene (Marine Isotope Stage 5e) Lucayan Formation at Red Bays, Andros Island, Great Bahama Bank, comprises a single, 6-m-thick upward-shallowing parasequence. Six radar packages (P1–P6) bounded by radar surfaces (S1–S6) have been identified in the two 3D radar volumes. The stratigraphic succession indicates development of a burrowed backshoal lagoon during early flooding of the bank top followed by deposition of flood-tide-driven, low-angle sheet sands and sigmoidal subaqueous dune deposits as the shelf-margin sand shoal moved bankward as a function of continued sea-level rise. Constructional accommodation on the front of the prograding subaqueous dune in the northwest part of the survey area and erosional accommodation created by downcutting of a shallow tidal channel into the upper part of the subaqueous dune depositional unit in the northeast part of the study area were filled with peloid- and ooid-dominated carbonate sands as sea level stabilized. The uppermost radar package is a thin (0.15 to 0.55 m), partially calichified carbonate sand sheet that mantles the entire survey site and that reflects late highstand and fall of sea level. Exposure of the studied interval to meteoric vadose diagenesis over the past 100,000+ years has resulted in partial stabilization of the largely aragonitic precursor sediment through selective partial dissolution of aragonitic grains (mainly ooid cortical layers, peloids, and mollusk shells) accompanied by precipitation of patchily distributed low-magnesium calcite cement. Core data demonstrate a relationship between stratigraphically controlled sedimentological attributes, diagenesis, and pore distribution. Three distinctive zones of porosity were present upon deposition: a lower zone of relatively high interparticle porosity (21.3% to 33.2%) in the medial part of P1, a low-porosity zone (

Quantitative characterization of pore-fracture system of organic-rich marine-continental shale reservoirs: A case study of the Upper Permian Longtan Formation, Southern Sichuan Basin, China

Although significant progress has been achieved in characterizing marine shale reservoirs, studies that are associated with marine-continental shale reservoirs, particularly quantitative characterizations of shale pore–fracture, remain rare. In this study, 12 black organic-rich marine-continental shale samples were collected from seven wells that were recently drilled in the Upper Permian Longtan Formation in the Southern Sichuan Basin of southern China. X-ray diffraction revealed that clay minerals are the most prevalent component of shale, followed by quartz and calcite. Various pore types were classified and morphologically characterized from images that were obtained with field emission scanning electron microscopy. Shale total porosity, which was measured via mercury injection porosimetry, was between 3.1% and 7.5%. In addition, a pore-fracture interpretation model was built to calculate fractures and matrix porosity, including organic matter porosity, interparticle porosity of brittle minerals, and intraparticle porosity of clay minerals. The model was highly consistent with the measured porosity. Three key parameters were obtained to characterize the development of different types of matrix pores (VTOC>VBri>VClay). Low-pressure N2 and CO2 gas adsorption experiments were conducted to analyze pore volume, special surface area (SSA), and pore-size diameter. The results of the analyses revealed that micropores and macropores (including micro-fractures) are the dominant pores of the Longtan shale reservoir and that micropores provide the dominant shale gas adsorption space. Furthermore, the effects of shale components on pore development, as well as the correlation among different pore structural parameters, were discussed. The results showed that the enrichment of total organic carbon and clay mineral content will benefit the development of the Longtan shale pore–fracture system. Moreover, a good positive linear relationship existed among matrix porosity, pore volume, SSA, average pore diameter, and surface porosity.

Recovery of monosaccharides from lignocellulosic hydrolysates by ion exclusion chromatography

The production of sugars from lignocellulosic biomass is the key to a sustainable, renewable chemical industry. Glucose, xylose and other monosaccharides can be easily produced by hydrolyzing cellulose and hemicellulose, the primary polysaccharides in biomass. However, the hydrolysis of biomass generates byproducts that, together with the mineral acid normally added in the hydrolysis step, have to be removed before the downstream conversion processes. In this work, the recovery of monosaccharides from lignocellulosic hydrolysates by means of Ion Exclusion Chromatography (IEC) has been studied. The analyzed process relies on new pretreatment and hydrolysis steps, involving the neutralization of the hydrolysate with sodium hydroxide. The adsorption behavior of the main components involved in the separation has been experimentally investigated. Pulse tests at the high loading encountered in preparative conditions have been performed for a selected group of model components found in the hydrolysates. For all the electrolytes, the retention volume fraction was always between the interparticle porosity and the total column porosity, confirming that ion exclusion was the dominant retention mechanism. On the other hand, sugars eluted before the total column porosity, indicating partial steric exclusion from the resin pores. This observation was then confirmed by size-exclusion experiments with polyethylene glycol standards, from which the distribution coefficient of the studied sugars has been determined. The comparison between the elution profiles of the same sugars in pure form and as a mixture present in the hydrolysate showed differences in both peak shape and retention times. Therefore, an investigation of the influence of the main electrolytes contained in the hydrolysates on sugars adsorption has been performed through the pulse on a plateau method. The electrolytes were found to enhance the sugars retention by promoting their adsorption onto the resin. However, this effect was not sufficient to explain the observed differences, which were effectively explained in terms of viscous fingering, due to the high viscosity differences between the eluent and the sample. A previously developed model for IEC has been updated to take into account all the observed phenomena and applied to simulate the experimental results. The proposed model was in good agreement with the batch-column elution profiles both for the pure components and for the actual hydrolysate, allowing a quantitative description of the separation.

Application of quality by design in granulation process for ginkgo leaf tablet (Ⅰ)： comprehensive characterization of granule properties

In this paper, the granules intermediate prepared from the wet granulation process of ginkgo leaf tablet were taken as the research object, and then the stackability, homogeneity, flowability, compressibility and stability of granules were characterized by using micromeritics evaluation method. The physical fingerprint of granules were constructed by 16 indexes including bulk density, tapped density, span, width, relative homogeneity index, aspect ratio, Hausner ratio, angle of repose, granule flow time, inter-particle porosity, Carr index, specific surface area, pore volume, pore size distribution, loss on drying and hygroscopicity. Furthermore, compressibility parameters (i.e. index of parameter, index of parametric profile and index of good compression) were employed to analyze the compressibility characteristics of the granules. Two principal components (first principal component representing dimension parameter and second principal component representing morphology parameter), could be extracted from the physical fingerprint by the principal component analysis (PCA). The granules' physical fingerprint is of great importance to evaluate the batch-to-batch quality consistency of Ginkgo biloba granules and analyze the potential impacts of granules' quality attributes on product quality, which can provide guidance for the granules' quality control and process development..

Effects of ageing conditions on degradation of acrylonitrile butadiene rubber filled with heat-treated ZnO star-shaped particles in rapeseed biodiesel

The degradation of acrylonitrile butadiene rubber (NBR) after exposure to biodiesel at different oxygen partial pressures in an automated ageing equipment at 80 °C, and in a high-pressure autoclave at 150 °C was studied. The oxidation of biodiesel was promoted by an increase in oxygen concentration, resulting in a larger uptake of fuel in the rubber due to internal cavitation, a greater decrease in the strain-at-break of NBR due to the coalescence of cavity, and a faster increase in the crosslinking density and carbonyl index due to the promotion of the oxidation of NBR. During the high-temperature autoclave ageing, less fuel was absorbed in the rubber, because the formation of hydroperoxides and acids was impeded. The extensibility of NBR aged in the autoclave decreased only slightly due to the cleavage of rubber chains by the biodiesel attack. The degradation of NBR in the absence of carbon black was explained as being due to oxidative crosslinking. The dissolution of ZnO crystals in the acidic components of biodiesel was retarded by removing the inter-particle porosity and surface defects through heat treating star-shaped ZnO particles. The rubber containing heat-treated ZnO particles swelled less in biodiesel than a NBR filled with commercial ZnO nanoparticles, and showed a smaller decrease in the strain-at-break and less oxidative crosslinking.

Rock typing using geological and petrophysical data in the Asmari reservoir, Aghajari Oilfield, SW Iran

The Oligo-Miocene Asmari Formation, which extends over the entire Zagros foreland basin, is one of the most important hydrocarbon reservoirs in the Middle East. The Aghajari Field is one of the largest oilfields in the Zagros basin with the Asmari Formation being the major reservoir rock. We used petrophysical and geological data, by means of the neural network clustering technique, to identify rock types in the Asmari reservoir. Using petrophysical logs, such as gamma ray, sonic, density and neutron, along with calculated reservoir data (water saturation and effective porosity) from 20 wells (5 cored and 15 uncored wells) and their correlation with capillary pressure (Pc) curves, led to recognition of 5 electrofacies (EF1-EF5). These electrofacies were used to extend our interpretations to 60 uncored wells. The link between electrofacies and geological data (obtained from 1100m cores and 2500 thin sections) indicate that both sedimentary and diagenetic processes controlled the reservoir quality of the Asmari Formation. Porosity, permeability, water saturation, and reservoir quality index (RQI) were used to estimate reservoir quality of each electrofacies. EFs 1 and 2 with low porosity and permeability, high water saturation and low RQI are considered as non-reservoir that are related to sedimentary textures (argillaceous nature of wackestone-packstones) and effect of destructive diagenetic processes (cementation, physical and chemical compaction). EFs 3 and 4 show high values of porosity, permeability, RQI, and low percent of water saturations, which characterizes them as good reservoirs rocks. Vuggy, growth framework and interparticle porosities are major in EF-3, while the intercrystaline porosity is the major type in EF-4. Finally, EF-5 is the only electorfacies in the siliciclastic parts of the Asmari Reservoir, which is composed of rounded and well-sorted quartz grains that are slightly cemented. The latter is the best reservoir electrofacies in the Asmari Formation of the Aghajari oilfield due to its’ high values of porosity, permeability, and RQI and low percent of water saturation. Based on vertical distribution of EFs in the Asmari Formation, zones 1, 2, 3 and 4 are the best zones for drilling new productive wells around the oilfield. The results of this research can be useful in the development of the field, taking a decision and proper strategy in the connection of hydrocarbon production and recovery in the future of this field and similar fields.

Local geology controlled the feasibility of vitrifying Iron Age buildings

During European prehistory, hilltop enclosures made from polydisperse particle-and-block stone walling were exposed to temperatures sufficient to partially melt the constituent stonework, leading to the preservation of glassy walls called ‘vitrified forts’. During vitrification, the granular wall rocks partially melt, sinter viscously and densify, reducing inter-particle porosity. This process is strongly dependent on the solidus temperature, the particle sizes, the temperature-dependence of the viscosity of the evolving liquid phase, as well as the distribution and longevity of heat. Examination of the sintering behaviour of 45 European examples reveals that it is the raw building material that governs the vitrification efficiency. As Iron Age forts were commonly constructed from local stone, we conclude that local geology directly influenced the degree to which buildings were vitrified in the Iron Age. Additionally, we find that vitrification is accompanied by a bulk material strengthening of the aggregates of small sizes, and a partial weakening of larger blocks. We discuss these findings in the context of the debate surrounding the motive of the wall-builders. We conclude that if wall stability by bulk strengthening was the desired effect, then vitrification represents an Iron Age technology that failed to be effective in regions of refractory local geology.

Origin of authigenic quartz in organic-rich shales of the Wufeng and Longmaxi Formations in the Sichuan Basin, South China: Implications for pore evolution

Primary sedimentary composition of shales and subsequent diagenetic modifications are key factors in controlling the pore development and preservation in shale gas reservoirs. Thin section examination, X-ray diffraction analysis, scanning electron microscopy (SEM) determination with cathodoluminescence and geochemical analyses were combined to investigate Wufeng and Longmaxi shales of the Sichuan Basin. These experimental methods allowed us to focus on the origin of authigenic quartz in organic-rich shales and evaluate its importance in the evolution of shale gas reservoirs. The siliceous shales in Wufeng and Longmaxi Formations contain up to 60% microcrystalline aggregates of quartz, which are more abundant than silt-size detrital quartz to suggest an authigenic origin. Most authigenic quartz originates from biogenic siliceous dissolution and re-precipitate. Therefore, high excess silica concentration indicates a higher surface productivity with more organic matter (OM) deposition. The abundance of OM pores is positively correlated with the excess-Si content (R2 = 0.77). We suggest that the migrated OM filled in authigenic microcrystalline quartz aggregates is the principal matrix for OM pore development. Authigenic microcrystalline quartz aggregates filled in primary pore space and destroyed primary interparticle porosity. However these authigenic quartz can restrain compaction and preserve the internal pore structure as a rigid framework. Pore space is abundant enough in microcrystalline quartz aggregates for oil and bitumen filling during the oil window. Migrated OM filled the associated pore network in authigenic microcrystalline quartz aggregates would more likely to generate a better three-dimensional OM pore network through secondary cracking and provides favorable reservoir spaces for shale gas.

VARIATIONS IN PETROPHYSICAL PROPERTIES OF UPPER PALAEOZOIC MIXED CARBONATE AND NON‐CARBONATE DEPOSITS, SPITSBERGEN, SVALBARD ARCHIPELAGO

The Late Carboniferous – Early Permian Gipsdalen Group and the Early to Late Permian Templefjorden Group are known hydrocarbon plays in the Arctic region, e.g. on the Finnmark Platform, Loppa High and Sverdrup Basin. Time‐equivalent deposits crop out on the island of Spitsbergen and consist of mixed carbonate and non‐carbonate (primarily siliciclastic, siliceous, organic‐carbon rich and clayey) sediments deposited in continental to deep‐marine settings.In rock samples (n = 73) collected from five outcrop locations on Spitsbergen, thin‐section analysis showed the presence of ten microfacies types ranging from claystones and spiculitic cherts to rudstones and dolostones. Petrophysical and textural properties of the samples were measured to evaluate the link with the acoustic (P‐ and S‐wave) velocities of these generally tight rocks, which have an average porosity of about 2%.Variations in acoustic velocity measurements primarily depend on variations in mineralogical composition (silica versus carbonate) and, to a lesser extent, on variations in porosity and bulk density. Pore networks in the sediments are dominated by microporosity and (micro)cracks, followed by interparticle porosity. Recrystallization effects and pore shape variations show a lesser effect on the P‐wave velocity. Clay content does not exceed 12.7% and also has a secondary impact on the acoustic velocities.Defining which textural and physical parameters control the acoustic properties of these carbonate and non‐carbonate sedimentary rocks will help with the interpretation of the seismic response of equivalent deposits in the subsurface.

Three-dimensional outcrop reservoir analog model: A case study of the Upper Khuff Formation oolitic carbonates, central Saudi Arabia

Oolitic grainstones can contain significant hydrocarbon reserves. Due to variations in sedimentary processes and diagenetic alteration, the porosity and permeability values of these deposits are highly variable. We identified potential reservoir units in the Lower Triassic Khartam Member of the Upper Khuff Formation in central Saudi Arabia using an outcrop analog model by incorporating outcrop porosity and permeability information.Six major surfaces representing fourth-order sequence boundaries were identified in outcrop, and these separate the five zones in the model. In terms of depositional environments, these are defined as Zones 1 and 2 (subtidal and sand sheets deposits in a shoal complex), Zones 3 and 4 (sand sheets and lenses deposits in a back shoal), and Zone 5 (tidal flat). The population of lithofacies with in each zone in the three dimensional (3D) outcrop model was performed separately using a different geostatistical algorithm. The resulting 3D facies model adequately illustrates the continuity of beds and fairly represents the stratigraphic architecture observed in outcrop. The 3D volume of the outcrop model was subdivided into three broad stratigraphic intervals. The lower interval (Zones 1 and 2) was deposited during a rapid sea-level rise at the Permian–Triassic transition and consists dominantly of oolitic units with oomoldic and interparticle porosity. The middle interval (Zones 3 and 4) was deposited during an interval of rapid sea-level fluctuation and is characterized by the appearance of marine fauna after a long-term extinction in the lower Triassic interval. The dominant porosity types within this interval are moldic, interparticle, and intraskeletal. The upper interval (Zone 5) was deposited during a major sea-level regression. This interval contains a significant amount of early diagenetic dolomite and is dominated by interparticle and intercrystalline porosity.The results demonstrate that including porosity values from outcrop measurements in a 3D outcrop facies model can provide more accurate visualizations of reservoir units. This methodology could be used to predict reservoir potential in analogous carbonate reservoirs.

Physical fingerprint for quality control of traditional Chinese medicine extract powders

The physical properties of both raw materials and excipients are closely correlated with the quality of traditional Chinese medicine preparations in oral solid dosage forms. In this paper, based on the concept of the chemical fingerprint for quality control of traditional Chinese medicine products, the method of physical fingerprint for quality evaluation of traditional Chinese medicine extract powders was proposed. This novel physical fingerprint was built by the radar map, and consisted of five primary indexes (i.e. stackablity, homogeneity, flowability, compressibility and stability) and 12 secondary indexes (i.e. bulk density, tap density, particle size<50 μm percentage, relative homogeneity index, hausner ratio, angle of repose, powder flow time, inter-particle porosity, Carr index, cohesion index, loss on drying, hygroscopicity). Panax notoginseng saponins (PNS) extract was taken for an example. This paper introduced the application of physical fingerprint in the evaluation of source-to-source and batch-to-batch quality consistence of PNS extract powders. Moreover, the physical fingerprint of PNS was built by calculating the index of parameters, the index of parametric profile and the index of good compressibility, in order to successfully predict the compressibility of the PNS extract powder and relevant formulations containing PNS extract powder and conventional pharmaceutical excipients. The results demonstrated that the proposed method could not only provide new insights into the development and process control of traditional Chinese medicine solid dosage forms.

Hydrothermal dolomitization: simulation by reaction transport modelling

Abstract Reaction transport modelling (RTM) has been successfully used to simulate dolomitization and to predict the lateral extension of dolomitized bodies as potential hydrocarbon reservoirs in the subsurface as well as to give insights into the dolomitization process itself. Geological configurations that have been tested include reflux dolomitization, thermal convection and dolomitization in compactional burial settings. In this study the hydrothermal dolomitization model has been tested with a RTM approach where a limestone reservoir in an intermediate burial setting is fluxed in the presence of deep feeding faults. Hydrothermal fluids migrate upwards from the deep basin areas through extensional fault conduits reaching more permeable levels in the reservoir. The fluids enter the primary interparticle porosity and dolomitize the limestone creating moldic and vuggy porosity. The simulations demonstrate the importance of faulting in this dolomitization process. An effective control on dolomitization is thus exerted by the permeability distribution. Moreover, the type and reactivity of the fluids entering the limestone reservoir exert important controls on the extent of the dolomite bodies.

Fibrous silica mesoporous ZSM-5 for carbon monoxide methanation

Abstracts A core-shell fibrous silica mesoporous ZSM-5 (FmZSM-5) has been developed by employing microemulsion system coupled with zeolite crystal-seed crystallization method and unprecedented applied in CO methanation. The FmZSM-5 showed greatly enhanced catalytic activity with the rate of CO conversion (0.0708 μmol-CO/m 2 s) and the rate of CH 4 formation (0.0488 μmol-CH 4 /m 2 s) at 723 K, which is two-fold higher than that of the conventional recrystallized mZSM-5 (RmZSM-5). Besides, it showed high stability with no sign of deactivation up to 50 h. The presence of oxygen vacancies led to the increase in interparticle porosity, basicity, and CO and H 2 adsorption sites which are believed to be the keys for remarkably improved in CO methanation. Additionally, the influence of diffusion limitation was indicated to be negligible. Such a unique core-shell fibrous silica mesoporous ZSM-5 and their excellent catalytic properties suggest the significant application possibilities in base-catalyzed reaction especially in the production of methane.

A pore scale study on fluid flow through two dimensional dual scale porous media with small number of intraparticle pores

Abstract In the present study, the fluid flow in a periodic, non-isotropic dual scale porous media consisting of permeable square rods in inline arrangement is analyzed to determine permeability, numerically. The continuity and Navier-Stokes equations are solved to obtain the velocity and pressure distributions in the unit structures of the dual scale porous media for flows within Darcy region. Based on the obtained results, the intrinsic inter and intraparticle permeabilities and the bulk permeability tensor of the dual scale porous media are obtained for different values of inter and intraparticle porosities. The study is performed for interparticle porosities between 0.4 and 0.75 and for intraparticle porosities from 0.2 to 0.8. A correlation based on Kozeny-Carman relationship in terms of inter and intraparticle porosities and permeabilities is proposed to determine the bulk permeability tensor of the dual scale porous media.

Analysis of Sedimentary Environment and Sequence Stratigraphy of Middle-Late Permian Sediments in Coastal Fars, Iran (Zireh Gas Field, Well ZH-A)

The current paper is focused on the facies, sedimentary environment and depositional cycles study of the Middle-Late Permian sediments in the South Fars Zireh Gas Field, the subsurface section of well ZH-A. Four hundred thin-sections obtained from cores and cuttings were examined under standard petrographic microscope. For this study research, Corel Draw X6, Corel Photo-Paint, DN2 Microscopy Image Processing System, Scope Photo, Autodesk Map, Geocalc and Auto Cad 2014 were utilized. Based on microfacies analysis and significant founa and flora, fourteen major facies in four facies associations comprising tidal flat (A), lagoon (B), shoal (C) and open marine (D) identified in the well ZH-A. This formation was deposited in inner part of a homoclinal ramp. Based on depositional cycles, seven main 3rd order sequences were revealed in the Well ZH-A. The ooid grainstone facies with interparticle and oomoldic porosity has high reservoir potential. The diagenetic processes like dolomitization and dissolution have significant effect in the reservoir quality. Based on research results, a major framework can be weaved and used to correlate reservoir layering.