Depositional Fabric Research Articles

Cerium oxide for L-band Q-switched pulse laser generation

Cerium oxide (CeO2), a rare earth metal oxide belonging to the lanthanide group is a mature engineered nanoparticle that has been developed for various industry applications. The nanoparticle features defects in its lattice structure, which is highly advantageous for bandgap tuning, and is acclaimed for its least cytotoxicity among other metal oxides. In this work, CeO2 is employed as a saturable absorber (CeO2-SA) in the generation of an L-band Q-switched erbium-doped fiber laser. Q-switching was attained at 33.33 mW pump power threshold with a central wavelength of 1600.512 nm. Within 33.33 mW to 153.20 mW pump power range, the Q-switched laser obtained pulse repetition rates between 11.00 to 34.48 kHz, and pulse widths between 39.0 to 12.0 µs, with a high maximum pulse energy of 410 nJ. The Q-switched fiber laser remained stable over a 45-minute observation time at 153.20 mW pump power. The room temperature and direct mechanical deposition fabrication technique of the CeO2-SA in this work demonstrates the extreme simplicity and low cost of the device, which would reduce the overall cost and facilitate a wider technology adoption of pulse laser systems.

Integrating facies, mineralogy, and paleomagnetism to constrain the age and provenance of Paleozoic siliciclastic sedimentary rocks along the northern Gondwana margin: insights from the Araba and Naqus formations in western Gulf of Suez, Egypt

The depositional ages and provenance of the Paleozoic Araba and Naqus Formations along the northern Gondwanan margin in Egypt have remained uncertain due to a lack of index fossils. Resolving this issue is crucial for understanding regional geology during deposition and subsequent tectonic development. We integrate detailed facies analysis, anisotropy of magnetic susceptibility (AMS), paleomagnetism, and mineralogical data to elucidate the genesis and depositional ages of the Araba and Naqus Formations. Petrographic analyses identified seven distinct facies types, providing insights into sedimentary textures, maturity, and sources, with contributions from igneous and metamorphic sources indicated by heavy minerals. X-ray diffraction (XRD) analysis identified accessory minerals such as quartz, goethite, kaolinite, hematite, and anatase. Paleomagnetism isolated two magnetic components (CA and CN) providing the first robust paleo pole positions at Lat. = 70.8° N, Long. = 308.2° E and Lat. = 37.8° N, Long. = 233.1° E, indicating Cambrian and Carboniferous ages for the Araba and Naqus formations, respectively. Thermal demagnetization constrained these dates using established polarity timescales. Mineralogical data indicated that the Araba Formation originated from an igneous source, while the Naqus Formation had a mixed metamorphic-igneous provenance. The integrated AMS and paleomagnetic data reveal evidence of post-depositional deformation. Specifically, the clustering of maximum AMS axes in the NW–SE direction for both formations, suggests the initial presence of a primary depositional fabric. However, prevalent tectonic activity during the Cenozoic appears to have overprinted and modified this fabric through deformation related to rifting of the Gulf of Suez region. Through this novel multi-proxy approach, we have resolved long-standing uncertainties regarding the formations' depositional ages. Our study thereby provides the first chronostratigraphic framework for these strategically important sedimentary units, significantly advancing understanding of regional Paleozoic geology.Graphical abstract

Microporous Ag/AgCl on a Titanium Scaffold for Use in Capillary Reference Electrodes.

AgCl-coated silver fabricated with the thermal-electrolytic method can be used to prepare more reproducible reference electrodes than Ag/AgCl prepared with alternative methods such as electrolytic and chemical AgCl deposition or thermal fabrication. However, thermal-electrolytic fabrication requires a scaffold material upon which to build the layers upon. Platinum and rhodium have been used for this purpose as they are mechanically strong and chemically inert, but their cost is prohibitive for wider application. Herein, we report the stability of Ag/AgCl reference electrodes built atop a titanium scaffold using the thermal-electrolytic method and the use of these Ti/Ag/AgCl constructs in capillary-based reference electrodes. Electrochemical characterization shows that the probable presence of small amounts of oxygen at the Ti/Ag interface does not affect the reference electrode performance; in particular, over a wide pH range, the half-cell potential is pH independent. The electrical resistance of the Ti/Ag/AgCl/KCl system is dominated by the charge transfer resistance at the interface of the AgCl to KCl solution but is kept very small by the large AgCl surface area and a high solution concentration of chloride. The resulting high exchange current minimizes the effect of system impurities on the reference half-cell potential. Capillary-based reference electrodes comprising Ti/Ag/AgCl show exceptionally low potential drifts (as low as 0.03 ± 2.01 μV/h) and standard deviations of the potential at or below ±0.5 mV over a 60 h period. These capillary-based reference electrodes are suitable for very small sample volumes while still providing a free-flowing liquid junction that prevents reference electrode contamination.

A data-driven hyperspectral method for sampling of diagenetic carbonate fabrics – A case study using an outcrop analogue of Jurassic Arab-D reservoirs, Saudi Arabia

Diagenetic alteration commonly overprints depositional fabrics in carbonate-dominated sediments and impact reservoir quality. Dolomitization is a prevalent diagenetic process observed in subsurface reservoirs that profoundly alters the depositional precursor's pore network, thereby influencing subsurface storage capacity and fluid flow behavior. Typical workflows to characterize the dolomitized sequences, textures, degree and extent of dolomitization rely on mapping, spatial sampling, and time-consuming geochemical, petrographic and petrophysical analysis. In this study, we propose a hyperspectral data-driven workflow for identifying dolomitized horizons and extracting sample sets optimized to characterize textural and chemical variations. Hyperspectral imaging (HSI) data was acquired with 1.5 mm spatial sampling along a 50 m long core drilled behind an outcrop of the Late Jurassic Jubaila-Arab sequence in Wadi Daqlah, Saudi Arabia. Spectral features in the visible (VNIR), shortwave (SWIR), mid-wave (MWIR), and long-wave (LWIR) infrared regions were then used to classify carbonate mineralogy, allowing for the rapid identification of dolomitized zones, and k-means clustering applied exclusively to the dolomitized areas used to identify intra-dolomite variations and suggest representative sample locations. Petrographic and geochemical analyses were carried out on these samples, revealing that clusters identified with the hyperspectral data represent four distinct diagenetic fabrics. These results demonstrate the value of HSI for objective and data-driven sampling, reducing the number of samples required for petrographic, geochemical and geophysical analysis and hence time and costs required to spatially characterize diagenetic alteration.

Spectrum of Nanopores, Micropores, and Associated Pore Networks and their Origins in Carbonate Strata

Nano- and micropores (defined as pores less than 10 μm in diameter) are common in carbonate reservoirs as either the sole pore type or in combination (dual pore networks) with matrix macropores and fracture pores. These very fine-scale pores form in limestones and dolostones and in associated organic matter (e.g., solid bitumen). Limestone nano- and micropores occur between crystals that are commonly less than 1 to 9 μm in size in limestone, but in dolostone the crystal size can be much larger. Limestone nano- and micropores commonly originate in three ways, although some inherited original nano- and micropores between mud components are preserved. First, in original lime-mud mixtures of aragonite, Mg–calcite, and calcite, the origin is both depositional and diagenetic as aragonite dissolves and reprecipitates because microrhombic calcite, Mg–calcite transforms to microrhombic calcite, and original calcite grains are generally unaffected. Second, in chalks, nano-and micropores are related to the original depositional fabric as interparticle pores between coccoliths and other pelagic allochems. Third, in sediment originally composed of Mg–calcite-rich allochems, nano-and micropores form by transformation of unstable Mg–calcite allochems to microrhombic calcite. In dolostones, nano-and micropores are associated with extensive dolomitization and the nearly complete occlusion of pores (overdolomitization), whereas another diagenetic origin in dolostones is differential dolomitization at the grain scale. Also, in some dolostones, nano- to micropores pores are inherited from precursor microporous limestone. A late process of nano- and micropore formation is subaerial weathering of both limestones and dolostones resulting in pulverulite. This form of micropores is commonly developed at unconformities as enhanced porosity zones. Organic-matter nano- and micropores in solid bitumen, common in thermally mature organic-rich argillaceous limestone, can also be present in coarser-grained carbonates in which solid-bitumen occurs within macropores. Only in organic-rich limestones do organic-matter pores have potential to form an effective pore system. Because nano- and micropores have multiple origins, their lateral and vertical distribution reflects or depends on their origin; therefore, one must not only describe nano- and micropores, but also define their origin. Recognition of nano- and micropores is important because they form tight carbonate reservoirs and have significant effects on permeability, porosity perseveration with burial, hydrocarbon saturation, hydrocarbon recovery, sweep efficiency, storage, and reserve estimations. Not recognizing nano- and micropore networks can lead to errors relative to the aforementioned measurements and as a result, economic evaluations may be invalid.

Structural Architectures of Precambrian Metamorphites in and Around Rongmil –Rongjeng Area, East Garo Hills Districts Meghalaya

The present work elucidates the Precambrian metamorphites in and around Rongmil-Rongjeng area in the light of their polydeformational episodes that witness four pfases of deformation showing multiple interference patterns in the ductlile to brittle fields. Field as well as microstructural study reveals that all the pre existing depositional fabrics have been affected by BD1, the first phase of deformation under progressive metamorphic phase leading to the formation of most dominant, highly penetrative schistose and gneissose fabrics of rocks of amphibolites facies. The second phase of deformation, BD2 forming NW-SE trending up and down facing folds of probable plane non cylindrical nature, was responsible for layer parallel shortening (buckling) of the mechanically active BS0 and BS1 fabrics in the NW-SE longitudinal compressive tectonics. The third phase folds, BF3 refolded the earlier set of folds into non –plane non cylindrical nature and occur as non coaxial, open warp type gently plunging with near vertical axial plane striking NW-SE direction. BD4, the fourth phase deformation is considered as brittle phase and represents the joints, fractures and fault structures.

Bead Characterization for Wire Based Laser Directed Energy Deposition Fabrication Process

A three-dimensional, solid object of almost any shape or design can be created using metal additive manufacturing, often known as metal 3D printing. One of the most popular materials utilized in additive manufacturing is metal. The far more complicated procedure of directed energy deposition (DED) is frequently employed to upgrade or repair existing components. DED fabrication process will be able to construct a 3D metal object with consideration of the weld bead characteristics. Without knowing the weld bead characteristics, the mechanical integrity will not hold as the bead size is not suitable for the product. In the current study, we will study the effect of variation of parameters of the DED machine to be able to print in a continuous deposition and we will also investigate the weld bead characteristics printed by the variation of parameters with the use of DED machine. The variation of parameters of the machine are the laser power with the unit of Watt and the feedrate of the machine with the unit of mm per minute. Nine preliminary samples are printed to check whether the bead can be printed in a continuous line or not. The value of variation of parameters that bring about a continuous deposition will be jotted and continued to be taken to bead characterization for study. Six samples were printed, and the bead width and height are calculated based on the variation of parameters. Based on the result, we found that laser power will increase the bead width, but the bead height needs optimal laser power which is at 473 Watt and optimal feedrate which is on 60 mm per min to reach optimal bead height which is at 2.1162 mm. The effect of the machine feedrate on the other hand is inconsistent, thus more samples need to be gathered.

Depositional model of the Member Deng-2 marginal microbial mound-bank complex of the Dengying Formation in the southwestern Sichuan Basin, SW China: Implications for the Ediacaran microbial mound construction and hydrocarbon exploration

Recent advances in hydrocarbon exploration have been made in the Member Deng-2 marginal microbial mound-bank complex reservoirs of the Dengying Formation in the western Sichuan Basin, SW China, where the depositional process is regarded confusing. The microfacies, construction types, and depositional model of the Member Deng-2 marginal microbial mound-bank complex have been investigated using unmanned aerial vehicle photography, outcrop section investigation, thin section identification, and seismic reflections in the southwestern Sichuan Basin. The microbialite lithologic textures in this region include thrombolite, dendrolite, stromatolite, fenestral stromatolite, spongiostromata stone, oncolite, aggregated grainstone, and botryoidal grapestone. Based on the comprehensive analysis of “depositional fabrics–lithology–microfacies”, an association between a fore mound, mound framework, and back mound subfacies has been proposed based on water depth, current direction, energy level and lithologic assemblages. The microfacies of the mound base, mound core, mound flank, mound cap, and mound flat could be recognized among the mound framework subfacies. Two construction types of marginal microbial mound-bank complex have been determined based on deposition location, mound scale, migration direction, and sedimentary facies association. Type Jinkouhe microbial mound constructions (TJMMCs) develop along the windward margin owing to their proximity to the seaward subfacies fore mound, with a northeastwardly migrated microbial mound on top of the mud mound, exhibiting the characteristics of large-sized mounds and small-sized banks in the surrounding area. Type E’bian microbial mound constructions (TEMMCs) primarily occur on the leeward margin, resulting from the presence of onshore back mound subfacies, with the smaller southwestward migrated microbial mounds existing on a thicker microbial flat. The platform margin microbial mound depositional model can be correlated with certain lateral comparison profile and seismic reflection structures in the 2D seismic section, which can provide references for future worldwide exploration. Microbial mounds with larger buildups and thicker vertical reservoirs are typically targeted on the windward margin, while small-sized microbial mounds and flats with better lateral connections are typically focused on the leeward margin.

Dataset of in-situ coaxial monitoring and print’s cross-section images by Direct Energy Deposition fabrication

Coaxial monitoring of the Direct Energy Deposition (DED) machines enables a real-time material deposition study. Coaxial-images contain substantial melt-pool information and incorporate situational information including the sparks’ intensity, numbers, etc. Recent studies have shown that melt-pool observations correlate directly with machine parameters and artifact properties. Therefore, the melt-pool information not only can assist in measuring the machine’s working condition and determining machine operation parameters’ reliability but also facilitates the deposition characteristics studies like print’s regime and dimensions. This information is gathered during the fabrication and can be expanded to perform various process studies and fault registration. This paper utilizes the Optomec DED machine to fabricate single-track prints with multiple process parameters, while a coaxial camera records the deposition. Each deposited track is then cut perpendicular to the print’s direction to facilitate process parameters correlation study with actual geometrical deposition measured using a microscope. The coaxial images taken during fabrication, along with their process parameters, cross-cut measurements, and a developed image-processing toolbox, are presented alongside this paper to empower future research directions.

(Invited) Water-Based and Defect-Free 2D Material Inks for Printed Electronics

2D materials show great promise for use in flexible electronics because their atomic thickness allows for maximum electrostatic control, optical transparency, sensitivity and mechanical flexibility. In addition, different 2D crystals can be easily combined in one stack, offering unprecedented control on the performance and functionalities of the resulting heterostructure-based device. In addition, solution processing of 2D materials allows simple and low-cost techniques, such as ink-jet printing, to be used for fabrication of heterostructure-based devices of arbitrary complexity.Our group has developed highly concentrated, defect-free, biocompatible, inkjet printable and water-based 2D crystal formulations, by exploiting a supramolecular approach based on non-covalent functionalization of 2D materials with pyrene derivatives [1]. Examples of printed heterostructures, such as arrays of photosensors, programmable logic memories, transistors and memristors will be discussed [2-3]. I will show that inkjet printing can be easily combined with semiconducting 2D materials produced by chemical vapor deposition, allowing simple and quick fabrication of complex circuits on paper, compatible with CMOS technology [4-5] and also offers a simple way to integrate 2D materials into Si-based technology [6].

Characterization of Upper Cretaceous Matulla and Wata clastic reservoirs from October field, Central Gulf of Suez, Egypt

The objective of this study was to integrate petrographic thin sections, SEM, XRD, routine core analysis, gas chromatography, and wireline logs to present a comprehensive petrographic and petrophysical assessment of the shallow marine clastic reservoirs of the Coniacian-Santonian Matulla Formation and upper Turonian Wata Formation from the October field, Central Gulf of Suez Basin. The fine to very fine-grained glauconite-bearing subarkose quartz arenites of the Matulla and Wata reservoirs exhibit good intergranular primary porosity with good pore connectivity. Moderate to slight compaction and grain to grain pressure solution resulted in a slightly inhomogeneous packing of framework grains. Feldspar dissolution contributed to the secondary porosity which improved the reservoir quality, while quartz overgrowth and minor calcite cementation are inferred as porosity destroying diagenetic agents. Pore-filling kaolinite and clay phases also had a negative effect on reservoir storage capacity. Routine core analysis indicated > 20% porosity and up to 412 mD permeability in the meso-megaporous sandstones of both the reservoirs. Permeability anisotropy analysis of Matulla samples indicates the dominance of primary depositional fabric and isotropic pores with minor scattered/connected horizontal pores and vertical pore connectivity. Wireline log-based quantitative petrophysical assessments exhibit low shale volume and higher hydrocarbon saturation (up to 80%) on both the reservoirs, which is also supported by the gas chromatography data confirming the presence of oil in the Matulla, and Wata pay zones based on interpreted gas balance, wetness, and character ratios. The study concludes excellent reservoir properties in the Upper Cretaceous clastic intervals of the October field.

Anatomy of fractures: Quantifying fracture geometry utilizing X-ray computed tomography in a chalk-marl reservoir; the Lower Cretaceous Valdemar Field (Danish Central Graben)

Naturally fractured reservoirs tend to show heterogeneous permeability with open fractures enhancing the inherent diagenetic and depositional matrix fabric. Natural open fractures may function as pathways for fluid flow in tight (low matrix permeability) carbonate reservoirs and have a significant impact on the directions, magnitudes and heterogeneities of fluid flow and reservoir rock strength. Open fractures may however also facilitate the invasion of formation water while fractures that are partially or completely cemented can act as barriers to fluid flow. As a result, natural fractures significantly impact reservoir flow rates, anisotropy, storage, connectivity, recovery, and production. X-ray Computed Tomography (CT) offers a non-destructive technique to evaluate petrophysical parameters, such as porosity and permeability, and to assess the geometry, connectivity, and density of natural fractures, which are important constituents of chalk reservoirs. The purpose of this study is to investigate different types of naturally occurring fractures within the Lower Cretaceous succession of the Valdemar Field in the Danish North Sea. Six samples of core displaying at least one natural fracture on the surface are imagined; two samples of open fractures with plumose structure and hackle marks, three samples of shear fractures and finally one sample with deformation bands. The samples are imaged by CT and internal fractures are manually mapped. Image analysis provides detailed information on the fracture geometry in addition it indicates the presence of numerous microfractures hitherto not recorded in the Lower Cretaceous of the Danish North Sea. Core data show that fracture intensity can be significantly greater than calculated by conventional core interpretation techniques based on core surface observations. Further, apertures of both major and minor fractures are measured in CT images of all samples to determine if specific fracture types display characteristic that can distinguish them from other fracture types. As open fracture intensity increases, so too does permeability, likely enhancing reservoir connectivity on the field scale.

Engineering Analysis of Non-Braided Polycaprolactone Bioresorbable Flow Diverters for Aneurysms.

This paper reports a nonbraided, bioresorbable polycaprolactone (PCL) flow diverter (FD) for the endovascular treatment of aneurysms. Bioresorbable FDs can reduce the risk associated with the permanent metallic FDs as they are resorbed by the body after curing of aneurysms. PCL FDs were designed and fabricated using an in-house hybrid electromelt spinning-fused deposition fabrication unit. Flow diverter's properties, surface qualities, and mechanical characteristics of PCL FDs of 50%, 60%, and 70% porosities were studied using scanning electron microscope (SEM), atomic force microscopy (AFM), and high precision universal testing machine (UTM). The deployability through a clinically relevant catheter was demonstrated in a PDMS aneurysm model. The angiographic visibility of the developed PCL FDs was evaluated using BaSO4 and Bi2O3 coatings of various concentration. The average strut thicknesses were 74.12 ± 6.63 μm, 63.07 ± 1.26 μm, and 56.82 ± 2.09 μm for PCL FDs with 50%, 60%, and 70% porosities, respectively. They average pore areas for the 50%, 60% and 70% porosities FDs were 0.055 ± 0.0056 mm2, 0. 0605 ± 0.0065 mm2, and 0.0712 ± 0.012 mm2, respectively. The surface quality was great with an RMS roughness value of 14.45 nm. The tensile, radial strength, and flexibility were found to be satisfactory and comparable to the nonbraided coronary stents. The developed PCL FDs were highly flexible and demonstrated to be deployable through conventional delivery system as low as 4 Fr catheters in a PDMS aneurysm model. The visibility under X-ray increases with the increasing concentration of coating materials BaSO4 and Bi2O3. The visibility intensity was slightly higher with Bi2O3 coating of PCL FDs. The overall results of the engineering analysis of the developed nonbraided PCL FDs are promising.

Broadband and wide angle nonreciprocal thermal emission from Weyl semimetal structures

Nonreciprocal thermal emission is a cutting-edge technology that enables fundamental control over thermal radiation and has exciting applications in thermal energy harvesting. However, thus far one of the foremost challenges is making nonreciprocal emission operate over a broad wavelength range and for multiple angles. In this work, we solve this outstanding problem by proposing three different types of structures that always utilize only one Weyl semimetal (WSM) thin film combined with one or two additional dielectric or metallic layers and terminated by a metallic substrate. First, a tradeoff relationship between the magnitude and bandwidth of the thermal nonreciprocity contrast is established based on the thickness of the WSM film. Then, the bandwidth broadening effect is demonstrated via the insertion of a dielectric spacer layer that can also be fine-tuned by varying its thickness. Finally, further control on the resulting strong nonreciprocal thermal radiation is demonstrated by the addition of a thin metallic layer in the proposed few layer designs. The presented composite structures work for a broad frequency range and for multiple emission angles, resulting in highly advantageous properties for various nonreciprocal thermal radiation applications. Moreover, the proposed designs do not require any patterning and can be experimentally realized by simple deposition fabrication methods. They are expected to aid in the creation of broadband nonreciprocal thermal emitters that can find applications in new energy harvesting devices.

Diagenesis and reservoir quality of Neoproterozoic dolomitized microbialites following multi-stage diagenetic fluid activity: a case study of the Sinian Dengying Formation, China

Neoproterozoic marine microbialites have been targets for exploration and hydrocarbon reservoir development. The original depositional fabric and diagenesis control the pore systems of microbialites, leading to the complicated origin of microbialite reservoirs. This study aimed to reveal the origin of microbialite reservoirs following multi-stage diagenetic fluid activity in the fourth Member of the Dengying Formation in the central Sichuan Basin in southwestern China. The fourth Member of the Sinian Dengying Formation developed dolomitized microbialites, mainly including stromatolites, laminates, and thrombolites. Based on the background of tectonic movement, petrology and geochemistry examinations were executed to analyze the origin of the microbialite reservoir. Based on the cathodoluminescence and the homogenization temperature of the brine inclusions, it is credible that there were four stages of diagenetic fluid activities in the burial diagenesis. In the first stage, the microbialite reservoir was charged by oil in the Silurian period, with evidence from residual asphalt around the pores. In the second stage, dolomite precipitated to incompletely fill the pore spaces. In the third stage, the silica-rich diagenetic fluid with high temperature resulted in the precipitation of authigenic quartz. In the last stage, the oil charged again during the Triassic period, followed by siliceous filling, with residual asphalt filling the pore spaces. There were two stages of subaerial emergence, which occurred in two episodes of the Sinian-Early Cambrian Tongwan movement. The evidence for the two tectonic events includes two phases of dolomites with meteoric water origin, two cycles of V, Sr, and Na element profiles, two instances of negative excursion δ18O isotope, and two cavity layers. By comparison, the karstification of reservoirs in the Tongwan III episode could generate a higher quality of reservoir than that in the Tongwan II episode. As a result, the quality of the microbialite reservoir from the fourth Member of the Dengying Formation was mainly improved by the subaerial exposure in the Tongwan III episode and then was partly destroyed by the siliceous filling. The identification of multi-staged diagenetic fluid charging can illustrate the evolution of the reservoir quality of Neoproterozoic microbialites.

Study on Depositional Fabric and Environmental Characteristics of Dendrolites in the Cambrian Zhangxia Formation: An Example from the Houziyu Section of Ezhuang Town, Zibo, Shandong Province, Eastern China

The dendrolites composed of light gray massive micrite limestone occur at the top of the Cambrian Zhangxia Formation in Houziyu Section, Zibo, Shandong Province. Because it is very difficult to study the genesis of microbial rocks through “the function of diagenesis filter,” this paper analyzes its genetic mechanism by characterizing the sedimentary fabric and formation environment of dendrolites and it is of great significance to study microbial carbonate deposited in geological history in oil exploration. The Cambrian Zhangxia Formation in the Houziyu section is a marine deposit. The macroscopic shrub-like fabric of centimeter scale can be seen on the surface of the tree-shaped stone, with small biological burrows and remnants of calcareous mud components after filling. The microstructure observation shows that the main fabric of the dendrolites is a dark micrite matrix, bright calcite cement, clastic particles, and a calcified cyanobacteria biological community. Detailed supplementary information on the diversity of calcified microorganisms in dendrolites has been made through the study of various types of calcified cyanobacteria and calcified residual substances in the microbial membrane of calcified cyanobacteria in the dendrolites of the study area. It is clear that dendrolites are the product of the calcification of biofilms or microbial mats dominated by cyanobacteria. With the deepening of this kind of research, it is bound to raise the research of microbial carbonate to a new level in China and provide great help to find oil and gas resources in marine strata of microbial origin in China.

Integrated Diagenetic-Depositional Facies (IDDF) characterization and 3D geomodeling in carbonate reservoirs

Carbonate reservoirs are very prone to diagenetic modification of pre-existing fabrics. The process around the modification of pre-existing depositional fabrics is often interrelated with diagenetic phases that impact reservoir quality and distribution. Characterization and 3D modeling of these features have always been a challenge in the upstream industry. This paper outlines a novel workflow for characterizing and modeling the Integrated Diagenetic-Depositional Facies (IDDF) in carbonate reservoirs, from 1D IDDF classification and Neural Network (NN) estimation, to 2D IDDF trend and seismic-based probability region modeling, culminating with the 3D geo-cellular modeling processes. The workflow integrates several geoscience data sets including; linking of petrographic thin sections analyses with other scales of data from core descriptions, well-logs signatures, Routine Core Analyses (RCA), Production Logging Tool (PLT) inflow analyses, diagenetic proxies and depositional concepts. The IDDF workflow ties these features with 3D seismic attribute region extraction to benefit 3D geo-cellular property modeling. This workflow greatly improves reservoir quality prediction, 3D reservoir modeling and volume estimation.

Reservoir Description, Diagenesis and Reservoir Quality of the Deep Marine Sediments in the Propagation Stage of Rift Basin

The exploration and exploitation of the downthrown side of the productive upthrown Pre-rifting reservoirs at the Gulf of Suez marked bring a renaissance to the rift basin Exploration. This work documents the reservoir performance, trap geometry, and structural style of the downthrown deep marine stratigraphic entrapment. In addition, it outlines the requirements necessary beyond the production mitigations and limits. To gain better understanding of Asl Formation (deep marine) reservoir characteristics early in the exploration program, Asl Formation was cored in the north October J-5 well. A continuous 366- foot (112m) core was recovered including the main reservoir interval, which is producing over 12,000 barrel of oil per day. The J-5 Asl Formation has been interpreted as a synthetic, mixed clastic-carbonate turbidity deposit. Three major lithofacies described are recognizable on electric log. These are sandstone, shale and carbonates. The sandstones dominate the lower portion of the core and are the main oil producing section. Sandstone porosity and permeability range from 17 to 27% and 30 millidarcies to 3 darcies, respectively. Compared to the sandstone, the carbonate turbidites have poorer reservoir quality. They dominate the upper portion of the core and are composed of coarse fossil debris, silica framework grains and rock fragments. Horizontal and vertical permeabilities with rock types. Both the sandstone and carbonate sections of the J-5 core have experienced a complex diagenetic history. Deposition of the cored interval was initiated by a convulsive geological event such as flashflood or earthquake. These events would likely generate sufficient energy for mobilization of onshore and/or near shore sediments into multiple gravity flows having regional extent. The reservoir quality is controlled by a combination of primary depositional fabric and subsequent diagenetic modification. This research work can guide future exploration of reservoir-prone deep marine deposits in the Red Sea Rift and provide a reference for the subsurface deep-water reservoir quality analysis in the propagation stage in the Rift Basins.

Additive manufacturing of corrosion-resistant maraging steel M789 by directed energy deposition

Conventional maraging steels feature a combination of high strength and toughness, but they often suffer from low corrosion resistance. Hence, maraging steel M789 was developed to alleviate this issue while maintaining its strength. Most studies of maraging steels processed by additive manufacturing (AM) focus on utilizing laser powder bed fusion (LPBF). However, the research in laser-directed energy deposition (L-DED) fabrication of corrosion-resistant maraging steels is limited. The different cooling rates experienced by materials during L-DED and LPBF processing give rise to differing microstructures and mechanical properties. In this study, the L-DED process was adopted to manufacture nearly-fully dense M789 parts, which were subsequently subjected to direct aging and solutionizing + aging heat treatments. Electron backscatter diffraction (EBSD) analysis reveals a martensitic structure in both as-fabricated and heat-treated samples with the presence of austenite in the as-fabricated and directly aged samples. Scanning transmission electron microscopy (STEM) and transmission Kikuchi diffraction (TKD) reveal the presence of Ti- and Al-rich precipitates within the martensites after the solution and aging treatment, suggesting that Orowan looping around precipitates, grain boundary strengthening, and solid solution strengthening are responsible for the high yield strength of L-DED M789. Besides, the as-fabricated alloy shows higher pitting potential than solutioned and aged sample. This work serves as a guidance for the fabrication of corrosion-resistant maraging steels by L-DED and accelerate the implementation of maraging steels for marine and offshore applications.

Development of material extrusion 3D printable ABS/PC polymer blends: influence of styrene–isoprene–styrene copolymer on printability and mechanical properties

ABSTRACT In this work, a series of 3D printable ABS/PC blends were successfully prepared via filament extrusion and fused deposition fabrication. Influence of styrene–isoprene–styrene (SIS) copolymer on printability and mechanical properties were examined. It was revealed that SIS not only enhances the compatibility of the two blend phases, but also enhances the 3D printability of the resulting materials. The effect of print temperature, bed temperature, print speed, layer thickness, number of shell and infill density on mechanical properties of the printed parts were investigated using the Taguchi experimental design method, and the samples were printed using optimized process parameters according to the Taguchi method. It was revealed that the optimization of extrusion multiplier was an efficient method to overcome voids in the printed parts. Interestingly, incorporation of SIS considerably improved the adhesion and distribution of the blend phases. In addition, with an increase in SIS content, tensile strength, yield strength, elastic modulus, and hardness were found to decrease, whereas Izod impact strength and percentage elongation values of the 3D-printable blend increased. Finally, an efficient post-processing technique was successfully employed to improve the aesthetics of additive manufactured specimens. This work provides a facile strategy to prepare new 3D-printable polymer blends with improved adhesion between phases and minimized voids in the printed parts.