Thin Vertical Layer Research Articles

Lithofacies Characteristics and Their Effects on Shale Oil Enrichment: A Case Study from Shahejie Formation of the Qibei Sag, Bohai Bay Basin, China

The lithology and lithofacies assemblage of shale are highly complex and heterogeneous in the continental shale formations due to rapid changes in the sedimentary environment and source material, complicating the evaluation of shale oil enrichment areas, such as the member 3 of the Shahejie Formation in the Qikou sag, Bohaibay Basin, China. We used core observations and descriptions of well F39 × 1 and performed X-ray diffraction, scanning electron microscopy, nitrogen adsorption analysis, and nuclear magnetic resonance analysis to investigate the shale lithofacies characteristics and types in member 3 of the Shahejie Formation, and their effects on shale oil enrichment. The results showed the following. (1) The lithofacies are divided into four types according to the shale’s laminar structure, lithological characteristics, mineral composition, and organic matter content: thin laminar shale, thick laminar shale, massive mudstone, and argillaceous siltstone. These are divided into six subcategories. Each lithofacies has thin vertical layers. (2) The thin and thick laminar shale layers have favorable conditions for shale oil enrichment, such as a high total organic carbon content (TOC) (1.1–1.6%), many micropores (with the diameter of 0.5–2 µm) and fissures, a high residual hydrocarbon content (1.0–2.3 mg/g), and a good source-reservoir relationship, making them suitable for shale oil exploration. (3) The degree of lamina development influences the organic matter and residual hydrocarbon contents, the number of micropores, and the degree of shale oil enrichment. The semi-deep and deep lake facies are favorable areas for shale oil development.

Community homeostasis of coastal microbial mats from the Camargue during winter (cold) and summer (hot) seasons

AbstractMicrobial mats are complex layered biofilms under the effect of continuous daily and seasonal fluctuations in abiotic factors such as nutrients, pH, light, temperature, and salinity. In this study, community variability of microbial mats from the Camargue wetlands (Rhone Delta, southern France) was determined in winter and summer over 2 years, analyzing thin vertical layers at three different depths (0–2, 2–4, and 4–6 mm). Amplicons of the V1–V2 region of the 16S rRNA gene were sequenced to assess changes in the bacterial diversity of the mats. Functionality was inferred according to PICRUSt bioinformatics analysis. The microbial composition of the three layers included more than 30 phyla of bacteria, the major phyla being Proteobacteria, Bacteroidetes, Cyanobacteria, and Spirochaetes. The microbial composition of the layers differed significantly, especially between layer 1 (0–2 mm) and the other two, regardless of the season. Cyanobacteria and Rhodobacteraceae (Alphaproteobacteria) were more abundant in layer 1. Chromatiaceae (Gammaproteobacteria) and Deltaproteobacteria were detected in layers 2 (2–4 mm) and 3 (4–6 mm). Flavobacteriaceae was the predominant family of the phylum Bacteroidetes, being especially abundant in layer 3. Spirochaetes were distributed in all three layers, but above all in layer 2. Pathways related to energy and carbohydrate metabolism indicated that the community was more active in summer than in winter. Carbon fixation in the mats was predominantly through the Wood–Ljungdahl pathway. Heterotrophic diazotrophs appeared to be responsible for a substantial part of nitrogen input, even more than phototrophic microorganisms. Layers 1 and 2 represented a stressed environment, measured by relative abundances of KEGG Orthologs associated with oxidation, starvation, and osmotic and xenobiotic stress, and suffered unbalanced growth in which there is no increase in cell numbers, but it allows the accumulation of polymers, such as polyhydroxybutyrate. The Camargue mats showed a community homeostasis, its populations adapting to fluctuating conditions while maintaining the characteristic structure of vertically stratified functional groups of microorganisms.

NMM Simulation of Electromagnetic Waves in Cylindrical Geometries With an Extremely Thin Vertical Layer

NMM Simulation of Electromagnetic Waves in Cylindrical Geometries With an Extremely Thin Vertical Layer

Technological innovations in construction of underground caverns in basaltic rocks at Baihetan Hydropower Station on Jinsha River

The two underground powerhouses on the left and right banks of Baihetan Hydropower Station (BHT-HS) are symmetrically arranged inside basaltic rocks in the alpine gorge reach of the lower Jinsha River. Each of them is equipped with 8 sets of 1,000 MW hydraulic turbine generators, with the largest unit capacity, total installed capacity, span of main powerhouse (i.e. 34 m), diameter of dome-shaped tail-regulating chamber (max diameter of 48 m) and scale of underground caverns around the world. Due to complex layout, interaction between caverns and high hollowing rate, the construction process of the underground cavern group is faced many challenges. For example, the cavern excavation is located in the high ground stress area dominated by horizontal tectonic stress; the underlying basalt fractures are well developed, and the rock is hard and brittle, with low crack initiation strength; columnar jointed basalts develop locally; a number of large and weak gently-sloped shear zones develop diagonally cutting the main powerhouse. Following the construction ideology of “understanding, utilization, protection, monitoring, and feedback analysis on the surrounding rock masses during the construction period”, and with the engineering construction procedure of “the excavation, analysis, prediction and inspection of each rock layer”, this paper proposes a set of innovation construction technologies including “advanced pre-control, thin vertical layer, small planar partition, short excavation progress, fine blasting, strong and quick support, short interval monitoring, quick feedback, precise dynamic optimization” to control the internal cracking of the hard and brittle basaltic rocks, discontinuous deformation of staggered zones and spatio-temporal deformation of underground caverns in high geostress. It has promoted the safe and orderly construction of BHT-HS, the technical progress of the construction of hydropower station projects in China, and may also be applicable to the design and construction of similar projects worldwide.

Stationary convective regimes in a thin vertical layer under the local heating from below

Numerical and experimental results obtained for the steady-state flow in a thin vertical liquid layer heated locally from below are discussed. Based on these results, two laminar regimes at Rayleigh numbers from Ra = 102–107 have been distinguished. The first regime is characterized by a symmetric two-roll convective pattern. As soon as the Rayleigh number exceeds some critical value, the mirror symmetry is broken, and convective plumes tilt. A deflection of convective plumes from the vertical affects heat transfer conditions, and therefore this behaviour can be viewed as a second laminar regime. The location of the boundary between these two laminar regimes is considered in relation to the heat conduction at lateral boundaries, the aspect ratio of sides, the heater size, and the thickness of a working liquid layer.

동토 플랜트 유체기계 구조물 설치를 위한 PET 골재적용 말뚝의 주면작용 수평력 평가

Pile foundations constructed on extremely cold regions cause serviceability problems of superstructures from repeated actions of ground freezing and thawing. Oil sand module plants are mainly constructed on seasonal frozen ground. Due to the freezing and thawing actions of grounds, vertical movements of piles have been observed. To solve these erratic pile movement problems, thin vertical layer of PET aggregates is installed around the pile shaft to prevent potential unfavorable pile movements. There is no known method to calculate “thin PET aggregate layer” -surrounded pile shaft resistance (capacity) against vertical loads; therefore, this experimental research is conducted. Specifically, in this study, horizontal (normal) pressures on pile shaft were assessed varying PET aggregate layer thickness based on the experiment.

Lifting regimes of thermal plumes in vertical layer

Theoretical investigation of the dynamics of free thermal plumes in a thin vertical layer has been performed for the case of a cavity heated from below by means of a dotted thermoelement. Three-dimensional numerical modeling has been carried out with the help of package OpenFOAM. This integrable platform is meant for calculations in the area of continuous media mechanics. Four basic plume growth types (viscous-diffusive, inviscid-diffusive, viscous-nondiffusive and inviscid-nondiffusive regimes) are found. Animated images for various lifting regimes are obtained to observe the time-dependent behavior of thermal plumes. The stages of plume formation in a relatively thin layer, its steady lifting and deceleration by the top boundary have been analyzed for different profiles of the plume front. The interaction of two synchronous plumes is studied numerically, and the formation of a common thermal front is demonstrated.

Natural convection in a vertical porous cavity filled with a non‐newtonian binary fluid

AbstractNumerical and analytical study of natural convection in a vertical porous cavity filled with a non‐Newtonian binary fluid is presented. The density variation is taken into account by the Boussinesq approximation. A power‐law model is used to characterize the non‐Newtonian fluid behavior. Neumann boundary conditions for temperature are applied to the vertical walls of the enclosure, while the two horizontal ones are assumed impermeable and insulated. Both double‐diffusive convection (a = 0) and Soret‐induced convection (a = 1) are considered. Scale analysis is presented for the two extreme cases of heat‐driven and solute‐driven natural convection. For convection in a thin vertical layer (A ≫ 1), a semianalytical solution for the stream function, temperature, and solute fields, Nusselt and Sherwood numbers are obtained using a parallel flow approximation in the core region of the cavity and an integral form of the energy and constituent equations. Numerical results of the full governing equations show the effects of the governing parameters, namely the thermal Rayleigh number, RT, the Lewis number, Le, the buoyancy ratio, φ, the power‐law index, n, and the integer number a. A good agreement between the analytical predictions and the numerical simulations is obtained. © 2012 American Institute of Chemical Engineers AIChE J, 58: 1704–1716, 2012

Interpretation of complex geological structures with the use of forward and inverse modeling of magnetotelluric field

General assumptions of 1D and 2D modeling and inversion were presented in this paper. Methodology of magnetotelluric data interpretation was described including analysis of dimensionality of geoelectrical medium and its influence on choosing the proper interpretation model. Relations between initial model and final results of inversion were shown based on magnetotelluric (AMT and CSAMT) data from Grabownica oil and gas field. The second example was from the Lodyna oil field. A possibility of interpretation of thin vertical layers, which can approximate the Lodyna field by 1D and 2D MT inverse procedures was analyzed. Dependences between final geological models and MT curve type (TE mode or TE mode) taken to interpretation were shown. Finally, methodology of interpretation was proposed.

Back Cover: Laser & Photon. Rev. 3(3)/2009

Laser & Photonics ReviewsVolume 3, Issue 3 Back Cover Back Cover: Laser & Photon. Rev. 3(3)/2009 First published: 14 April 2009 https://doi.org/10.1002/lpor.200990005AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract Azimuthal emission pattern of a photonics crystal LED. The scattering of the few guided modes of the LED's thin vertical layer stack by the photonic crystal results in a Star-of-David-shaped pattern for a single frequency. The scanning electron microscope picture in the background shows the hexagonal lattice. (Picture: C. Wiesmann et al., pp. 262–286, in this issue) Volume3, Issue3April 2009 RelatedInformation

Physical models of rifting and transform faulting, due to ridge push in a wedge-shaped oceanic lithosphere

By scaled physical modelling, we have investigated the mechanical response to gravitational forces in an oceanic lithosphere, overlying a less dense asthenosphere. In the models, an upper wedge-shaped layer of sand represented an oceanic lithosphere (0–35 Ma old, with a half-spreading velocity of 3 cm/yr), and a lower layer of polydimethylsiloxane (PDMS), mixed with dense wolframite powder, represented the asthenosphere. In the models, as in nature, isostatic compensation resulted in uplift of ridges and subsidence on their flanks. The resulting relief was responsible for ridge push. We tested two main configurations: straight ridges and offset ridges. In all the models, ridge push was sufficient to cause plate motion, underlying advection, and symmetrical rifting at the ridge axis. There was no need to impose plate motions through external pistons and motors. In models of straight ridges, the style of normal faults in the axial rift zone depended on the local thickness of the brittle sand layer. For thick layers, normal faults rafted out from the active zone of rifting, creating a fossil topography of tilted blocks, between faults dipping toward the ridge. In a model of an offset ridge, with thin lithosphere at the ridge crest and no embedded weakness, ridge push was responsible for a short transform fault, linking en-échelon rifts. In a similar model, but with thick lithosphere, an oblique rift formed at about 20° to the offset trace. We conclude that ridge push was not adequate to create an ideal transform fault. In a model of an offset ridge, with an embedded thin vertical layer of pure PDMS at 90° to the ridge, transform motion concentrated along this weak layer, and the resulting structural style was very similar to that in nature. On the basis of these results, we infer that, in nature, (1) ridge push can indeed drive plate motion, and (2) ridge push can drive strike-slip motion on transform faults, provided that these are weaker than the adjacent oceanic lithosphere and that they form early in the history of spreading.

Oscillation of the convective flow around an air bubble in a vertically stratified surfactant solution

The appearance of oscillatory modes of the concentration convection around an air bubble in an aqueous solution with a vertical gradient of surfactant concentration was revealed experimentally. The solution filled a thin vertical layer containing an air bubble in the form of a short horizontal cylinder with a free lateral surface. Due to a small layer thickness, two-dimensional flows and concentration distributions were generated in the liquid. Their evolution was investigated using an interferometric technique. It was found that the flow oscillation was caused by a specific interaction between the diffusion and two solutal (capillary and gravitational) mechanisms of convective mass transfer, which had quite different characteristic times. The time variation of the oscillation period was analyzed in relation to the surfactant concentration gradient, the average solution concentration, and the concentration Marangoni number. It was shown that the ratio of the dimensionless oscillation frequency to the Marangoni number is time independent and is the same for different liquids and various orientations of the concentration gradient.

Vibrational Convection in an Inclined Fluid Layer Heated from Below

The stability of mechanical equilibrium of an inclined fluid layer with respect to three-dimensional perturbations under the action of high-frequency vibration is studied. It is shown that under heating from below the spiral perturbations are always the most dangerous for vibration transverse to the layer. For vertical vibration the stability limit is determined by three-dimensional perturbations whose shape depends in a complicated way on the angle of inclination of the layer and the vibrational Rayleigh number. In the limiting case of a thin vertical layer supercritical vibrational-convective motions are calculated numerically and analytically and scenarios of transition from quasi-equilibrium to irregular motions are studied.

Air-Sea Momentum Transfer by Means of Short-Crested Wavelets

Abstract Recent laboratory studies of Okuda and others revealed shear stress “spikes” over wavelet crests as the principal instruments of air-sea momentum transfer. Examination of other laboratory evidence shows that sharp local intensifications of skin friction is a characteristic of reattaching flow in three-dimensional separation only. Flow reattachment over a downwind wavelet crest ensures the coincidence of high shear stress and downwind orbital velocity, resulting in energy input to the fluctuating motion, i.e., a coupling of the wavelets to the wind. Such coupling is shown to occur over short-crested wavelets at a specific waveheight-to-wavelength ratio. Under the shear stress spikes a thin vertical layer develops on the water surface, which rides over the essentially irrotational motion of the wavelets. Thickening of the vortical layer over the windward face of a wavelet causes a positive pressure perturbation in quadrature with downward vertical velocity, which tends to transfer energy to the wav...

Effect of convective velocity on longitudinal diffusivities in a fluidized cascade separator

AbstractExperimental results are presented on the separation of trace quantities of charcoal particles from salt crystals in a counter‐current fluidized cascade, for a range of paddle velocities extending over two decades. Interpretation of these data suggests that longitudinal diffusivity D is a function of horizontal convective velocity vH. The dependence of D on vH is attributed to mechanisms similar to those occurring when a pulse of soluble dye is suddenly injected into a solvent flowing in a pipe or a capillary, a situation first analyzed by Taylor(1,2).Experimental measurements were also made on the dispersion of a thin vertical layer of tracer material, following fluidized channel flow, using the same materials and conditions as were used in the fluidized cascade experiments. These data confirmed the general form of the dependence of D on vH found with the cascade, but yielded much lower values. The reasons for the discrepancy are not known, and further work is required to clear up this discrepancy.

Wave regimes of ascending flow of a thin layer of a viscous liquid in contact with a gas

The flow of a liquid in thin layers is one of the hydrodynamic problems of chemistry and heat engineering. The large surface area of films and their small thickness make it possible to accelerate thermal, diffusive, and chemical processes at the gas-liquid boundary. Theoretical studies of liquid flow in a vertical descending thin layer are presented in [1–4]. In this paper we study ascending wave flows of a liquid in a thin vertical layer in contact with a gas, i.e., flows in the direction opposite the action of the force due to gravity, with account for the action of the gas on the liquid surface. Such motions are encountered when oil is extracted from strata that are saturated with gas. At some distance from the stratum the oil and gas separate: the gas travels at high velocity inside the pipe, occupying a considerable portion of the pipe, and the liquid is displaced toward the pipe walls, forming a thin film. In certain cases a wave-like interface develops between the oil and gas that travels with a velocity greater than that of the liquid but less than the average gas velocity. Similar phenomena are observed in high velocity mass exchangers. We examine the effect of the gas for both laminar and turbulent flow. Studies that neglect the effect of the gas flow on the liquid show that for waves on the film surface whose lengths are considerably longer than the average thickness of the layer, the liquid motion in the film is described by boundary layer equations in which account is taken of the mass force, i.e., the force due to gravity. With some approximation, we can assume that in accounting for the effect of the gas on the liquid the liquid flow is described by these same equations.