Quantitative characterization of vertical zonation of Mesozoic granite weathering reservoirs in the coastal area of eastern Fujian Province,China

Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characterization of granite weathering crust reservoir and provide the basis for oil exploration of granite weathering crust buried hill reservoir,in this paper,the vertical zonation of granite weathering crust reservoir is quantitatively divided by testing and analyzing the uniaxial compressive strength(UCS),magnetic susceptibility(MS),permeability,and chemical index of alteration(CIA)of the Mesozoic granite weathering crust in the coastal area of eastern Fujian.The results show that the granite weathering crust reservoir can be divided into four zones vertically:a soil zone(SZ),weathered and dissolved zone(WDZ),fracture zone(FZ),and bedrock zone(BZ).A cataclastic area is developed in the FZ and BZ,in which structural fractures are well-developed,the fracture surface density is usually greater than 200 m/m^(2),and the contribution to the fractures in the rock mass is up to about 50%,making this the sweet spot of the reservoir.In the SZ,the rocks are loose,and the pores are well-developed.The UCS is less than 10 MPa,and the average rate of change of the UCS(Δ_(σ))is 0.90.The average permeability is 2823.00 mD,and the average rate of change of the permeability(Δ_(κ))is 5.13.The average CIA is 74.9%.The average clay mineral content is 7%.The rocks in the WDZ have been significantly weathered by physical and chemical processes,and the weathering fractures and dissolution pores are well-developed.The average UCS is 18.2 MPa,and the averageΔ_(σ)is 0.70.The average permeability is 143.80 mD,and averageΔ_(κ)is 4.17.The average CIA is 65.3%.The average clay mineral content is 4%.Under the influence of tectonic movement and physical weathering,the rocks in the FZ have developed structural fractures and a few weathered fractures.The average UCS is 57.9 MPa,and the averageΔ_(σ)is 0.18.The average permeability is 5.50 mD,and the averageΔ_(κ)is 2.55.The average CIA is 61.6%.The average clay mineral content is 2%.In the BZ,the rocks are intact and hard.The average UCS is 69.9 MPa,and the average Ds is 0.13.The average permeability is 1.46 mD,and the averageΔ_(κ)is 1.43.The average CIA is 57.8%.The average clay mineral content is less than 1%.The multi-parameter combination of the UCS,Δ_(σ),permeability,Δ_(κ),CIA,and clay mineral content achieved good results in the division of the zones of the weathering crust.The UCS increases gradually from top to bottom,while Ds,permeability,Δ_(κ),CIA,and clay mineral content all decrease gradually.In addition,based on the petrophysical parameters of the rocks,including the density,resistivity,and acoustic velocity,a good division effect was also achieved,which can provide a basis for the vertical zonation of the granite buried-hill weathering crust reservoir.

Quantitative characterization of tight gas sandstone reservoirs using seismic data via an integrated rock-physics-based framework

Seismic characterizing of tight gas sandstone (TGS) reservoirs is essential for identifying promising gas-bearing regions. However, exploring the petrophysical significance of seismic-inverted elastic properties is challenging due to the complex microstructures in TGSs. Meanwhile, interbedded structures of sandstone and mudstone intensify the difficulty in accurately extracting the crucial tight sandstone properties. An integrated rock-physics-based framework is proposed to estimate the reservoir quality of TGSs from seismic data. TGSs with complex pore structures are modeled using the double-porosity model, providing a practical tool to compute rock physics templates for reservoir parameter estimation. The VP/VS ratio is utilized to predict the cumulative thickness of the TGS reservoirs within the target range via the threshold value evaluated from wireline logs for lithology discrimination. This approach also facilitates better capturing the elastic properties of the TGSs for quantitative seismic interpretation. Total porosity is estimated from P-wave impedance using the correlation obtained based on wireline log analysis. After that, the three-dimensional rock-physics templates integrated with the estimated total porosity are constructed to interpret microfracture porosity and gas saturation from velocity ratio and bulk modulus. The integrated framework can optimally estimate the parameters dominating the reservoir quality. The results of the indicator proposed based on the obtained parameters are in good agreement with the gas productions and can be utilized to predict promising TGS reservoirs. Moreover, the results suggest that considering microfracture porosity allows a more accurate prediction of high-quality reservoirs, further validating the applicability of the proposed method in the studied region.

“Second quantitative characterization”and its application in fractured-vuggy carbonate reservoirs

The Ordovician fracture-vug carbonate reservoirs of Tarim Basin,are featured by developed vugs,caves and fractures.The strong heterogeneity results in huge uncertainty when these reservoirs are quantitatively characterized using merely static seismic data.The effective quantitative characterization of the reservoirs has been an urgent problem to be solved.This study creatively proposes the"second quantitative characterization"technique with the combination of dynamic and static data based on the primary static quantitative characterization and fully considering lots of key influence factors when conducting characterization.In this technique,dynamic analysis methods such as well testing,production rate transient analysis,dynamic reserve evaluation and dynamic connectivity evaluation are used to get understandings on this kind of reservoir.These understandings are used as statistical parameters to constrain the inversion of seismic wave impedance to improve the relationship between wave impedance and porosity and determine the fracture-vug morphology,calculate dynamic reserves,and then a more accurate fracture-vugmodel can be selected and used to calculate the oil-water contact inversely based on the results of"second quantitative characterization".This method can lower the uncertainties in the primary quantitative characterization of fracture-vug reservoirs,enhance the accuracy of characterization results significantly,and has achieved good application results in the fracture-vug carbonate reservoirs of Tarim Basin.

Theoretical Study on Quantitative Characterization of Interlayer Interference in Multi-Layer Commingled Production

X oilfield is a typical layered reservoir with a large vertical span and many oil-bearing formations. There are significant differences in reservoir types and fluid properties among various formations. The interlayer interference is severe in the development process. At present, the interlayer interference research based on dynamic monitoring data cannot meet development adjustment needs. Combined with the field test results, through the indoor physical simulation experiment method, dynamic inversion method, and reservoir engineering method, this paper analyzes the main control factors and interference mechanism of interlayer interference, studies the variation law of interference coefficient, improves and forms the quantitative characteristic Theory of interlayer interference in multi-layer commingled production, and provides theoretical guidance for the total adjustment of the middle strata division in the oilfield.

Quantitative characterization of filamentous fungal promoters on a single-cell resolution to discover cryptic natural products

Characterization of filamentous fungal regulatory elements remains challenging because of time-consuming transformation technologies and limited quantitative methods.Here we established a method for quantitative assessment of filamentous fungal promoters based on flow cytometry detection of the superfolder green fluorescent protein at single-cell resolution.Using this quantitative method,we acquired a library of 93 native promoter elements from Aspergillus nidulans in a high-throughput format.The strengths of identified promoters covered a 37-fold range by flow cytometry.P_(zipA) and P_(sltA)were identified as the strongest promoters,which were 2.9-and 1.5-fold higher than that of the commonly used constitutive promoter P_(gpdA).Thus,we applied P_(zipA)and P_(sltA)to activate the silent nonribosomal peptide synthetase gene Afpes1 from Aspergillus fumigatus in its native host and the heterologous host A.nidulans.The metabolic products of Afpes1 were identified as new cyclic tetrapeptide derivatives,namely,fumiganins A and B.Our method provides an innovative strategy for natural product discovery in fungi.

A deep learning-based method for segmentation and quantitative characterization of microstructures in weathering steel from sequential scanning electron microscope images

Microstructural classification is typically done manually by human experts,which gives rise to uncertainties due to subjectivity and reduces the overall efficiency.A high-throughput characterization is proposed based on deep learning,rapid acquisition technology,and mathematical statistics for the recognition,segmentation,and quantification of microstructure in weathering steel.The segmentation results showed that this method was accurate and efficient,and the segmentation of inclusions and pearlite phase achieved accuracy of 89.95%and 90.86%,respectively.The time required for batch processing by MIPAR software involving thresholding segmentation,morphological processing,and small area deletion was 1.05 s for a single image.By comparison,our system required only 0.102 s,which is ten times faster than the commercial software.The quantification results were extracted from large volumes of sequential image data(150 mm^(2),62,216 images,1024×1024 pixels),which ensure comprehensive statistics.Microstructure information,such as three-dimensional density distribution and the frequency of the minimum spatial distance of inclusions on the sample surface of 150 mm^(2),were quantified by extracting the coordinates and sizes of individual features.A refined characterization method for two-dimensional structures and spatial information that is unattainable when performing manually or with software is provided.That will be useful for understanding properties or behaviors of weathering steel,and reducing the resort to physical testing.

Highly Aligned Graphene Aerogels for Multifunctional Composites

Stemming from the unique in-plane honeycomb lattice structure and the sp^(2)hybridized carbon atoms bonded by exceptionally strong carbon–carbon bonds,graphene exhibits remarkable anisotropic electrical,mechanical,and thermal properties.To maximize the utilization of graphene’s in-plane properties,pre-constructed and aligned structures,such as oriented aerogels,films,and fibers,have been designed.The unique combination of aligned structure,high surface area,excellent electrical conductivity,mechanical stability,thermal conductivity,and porous nature of highly aligned graphene aerogels allows for tailored and enhanced performance in specific directions,enabling advancements in diverse fields.This review provides a comprehensive overview of recent advances in highly aligned graphene aerogels and their composites.It highlights the fabrication methods of aligned graphene aerogels and the optimization of alignment which can be estimated both qualitatively and quantitatively.The oriented scaffolds endow graphene aerogels and their composites with anisotropic properties,showing enhanced electrical,mechanical,and thermal properties along the alignment at the sacrifice of the perpendicular direction.This review showcases remarkable properties and applications of aligned graphene aerogels and their composites,such as their suitability for electronics,environmental applications,thermal management,and energy storage.Challenges and potential opportunities are proposed to offer new insights into prospects of this material.

Surface characteristics analysis of fractures induced by supercritical CO_(2)and water through three-dimensional scanning and scanning electron micrography

Morphology of hydraulic fracture surface has significant effects on oil and gas flow,proppant migration and fracture closure,which plays an important role in oil and gas fracturing stimulation.In this paper,we analyzed the fracture surface characteristics induced by supercritical carbon dioxide(SC-CO_(2))and water in open-hole and perforation completion conditions under triaxial stresses.A simple calculation method was proposed to quantitatively analyze the fracture surface area and roughness in macro-level based on three-dimensional(3D)scanning data.In micro-level,scanning electron micrograph(SEM)was used to analyze the features of fracture surface.The results showed that the surface area of the induced fracture increases with perforation angle for both SC-CO_(2)and water fracturing,and the surface area of SC-CO_(2)-induced fracture is 6.49%e58.57%larger than that of water-induced fracture.The fractal dimension and surface roughness of water-induced fractures increase with the increase in perforation angle,while those of SC-CO_(2)-induced fractures decrease with the increasing perforation angle.A considerable number of microcracks and particle peeling pits can be observed on SC-CO_(2)-induced fracture surface while there are more flat particle surfaces in water-induced fracture surface through SEM images,indicating that fractures tend to propagate along the boundary of the particle for SC-CO_(2)fracturing while water-induced fractures prefer to cut through particles.These findings are of great significance for analyzing fracture mechanism and evaluating fracturing stimulation performance.

Research on Characters of Leaf Epidermal Cells' Quantities of Solanaceous Vegetable Crops

Tomatoes,peppers and eggplants' seedings were used as experiment materials to study the leaf development mechanism of solanaceous vegetable crops by using blot observation method.Results showed that an increasing trend was presented at the density of cells and stomata in upper and lower epidermis,but a declined trend was presented at the cells' diameters and the size of stomata with the joint position rising.At the same joint position,no matter in adaxial side or abaxial side,there were some differences among cells diameters,size of stomata,density of cells and stomata.

The Limitations of Polygenic Hypothesis and Theorizing about Dual Multiple Factors and Three Normal Distributions

The original data of Nilsson-Ehle experiment in wheat were analyzed with existent genetic knowledge. It indicated that the core of polygenic hypothesis from this experiment was that a character similarity produced by additive effect of multiple genes was the basis of continuous variation. Its precondition was for effective genes to have equal effect, to show merodominance and binomial distribution and to inherit independently. In fact, quantitative characters were determined by many genes with different property, effect and behavior. So it was difficult to solve all problems of continuous variation by the aid of polygenic hypothesis. The researchers should seek new ways. With Mendelian group as research object and by means of Lyapunov central limit theorem it was proved that both genotypic value G and the environmental effect in a niche E were subordinated to the normal distribution and respectively. According to additivity of the normal distribution the phenotype P = G + E also obeyed the normal distribution P = G + E ~ and quantitative characters showed continuous variation, whether or not the linkage was presented, whether or not every gene effect was equal, whether or not there were dominance and what kind of dominance between alleles. Moreover it was discussed that the quantitative characters in self-fertilized organism and clone were submitted to the normal distribution and presented continuous variation too.

Architecture of deepwater turbidite lobes: A case study of Carboniferous turbidite outcrop in the Clare Basin, Ireland

Through lithofacies analysis and architecture anatomy of the Carboniferous Ross Sandstone turbidites outcropped at western Ireland,the depositional model of deepwater turbidite lobes is established.Seven types of lithofacies are recognized including goniatites-rich shale,laminated shale,laminated siltstone,massive sandstone,fine-medium sandstone with mud-clast,basal gravel,and chaotic mudstone,which can be subdivided into units of three origins,turbidite lobe,turbidite channel,and slide-slump;and four hierarchical levels,lobe complex,lobe,lobe element and single sandstone layer.The lobes show apparent compensational stacking pattern,lobe elements display typical thickening-upward cycles on vertical profile,and the higher the hierarchical level,the better the preservation of the hierarchical boundary is.In general,turbidite lobe deposits appear as tabular,parallel/sub-parallel sandstone and mudstone interbeds,and change from thick,massive sandstone in the proximal end to thinner sandstone and mudstone interbeds from axis to fringe,with the sand-shale ratio and degree of sandstone amalgamation decreasing.

From qualitative to quantitative:the state of the art and challenges for plant synthetic biology

Backgrounds:As an increasing number of synthetic switches and circuits have been created for plant systems and of synthetic products produced in plant chassis,plant synthetic biology is taking a strong foothold in agriculture and medicine.The ever-exploding data has also promoted the expansion of toolkits in this field.Genetic parts libraries and quantitative characterization approaches have been developed.However,plant synthetic biology is still in its infancy.The considerations for selecting biological parts to design and construct genetic circuits with predictable functions remain desired.Results:In this article,we review the current biotechnological progresses in field of plant synthetic biology.Assembly standardization and quantitative approaches of genetic parts and genetic circuits are discussed.We also highlight the main challenges in the iterative cycles of design-build-test-learn for introducing novel traits into plants.Conclusion:Plant synthetic biology promises to provide important solutions to many issues in agricultural production,human health care,and environmental sustainability.However,tremendous challenges exist in this field.For example,the quantitative characterization of genetic parts is limited;the orthogonality and the transfer functions of circuits are unpredictable;and also,the mathematical modeling-assisted circuits design still needs to improve predictability and reliability.These challenges are expected to be resolved in the near future as interests in this field are intensifying.

Investigation of Microscopic Pore Structure and Permeability Prediction in Sand-Conglomerate Reservoirs

The microscopic pore structure of sand-conglomerate rocks plays a decisive role in its exploration and development of such reservoirs.Due to complex gravels-cements configurations and resultant high heterogeneity in sand-conglomerate rocks,the conventional fractal dimensions are inadequate to fully characterize the pore space.Based on the Pia Intermingled Fractal Units(IFU)model,this paper presents a new variable-ratio factor IFU model,which takes tortuosity and boundary layer thickness into consideration,to characterize the Triassic Karamay Formation conglomerate reservoirs in the Mahu region of the Junggar Basin,Northwest China.The modified model has a more powerful and flexible ability to simulate pore structures of porous media,and the simulation results are closer to the real conditions of pore space in low-porosity and low-permeability reservoirs than the conventional Pia IFU model.The geometric construction of the model is simplified to allow for an easing of computation.Porosity and spectral distribution of pore diameter,constructed using the modified model,are generally consistent with actual core data.Also,the model-computed permeability correlates well with experimental results,with a relative error of less than 15%.The modified IFU model performs well in quantitatively characterizing the heterogeneity of sand-conglomerate pore structures,and provides a methodology for the study of other similar types of heterogeneous reservoirs.

Initial stages of Nb_(3)Sn phase formation in Nb-bronze matrix composite wires investigated by means of electron microscopy

At present,Nb_(3) Sn superconductors are becoming more popular in high magnetic fields.The growth law of Nb_(3) Sn phase in a planar CuSn/Nb diffusion couple has been studied,whereas the formation mechanism of Nb_(3) Sn phase in a cylindrical CuSn/Nb diffusion couple is still controversial.The purpose of this work is to investigate the growth exponent of Nb_(3) Sn phase at the initial stage of annealing by use of scanning electron microscopy(SEM)through which the thickness of Nb_(3) Sn layer can be obtained.In this study,bronze-processed Nb_(3) Sn multifilamentary wires with different annealing time were investigated.The Nb_(3) Sn phase was formed during isothermal annealing at 670 ℃ by solid-state diffusion,which was accomplished by the movement of Sn atoms from the CuSn/Nb_(3) Sn interface to Nb_(3) Sn/Nb interface.However,the formation mechanism of Nb_(3) Sn phase at the initial stage of annealing is still not well understood.Microstructural evolution of Nb_(3) Sn phase during isothermal annealing was studied by SEM.The mean thickness of the Nb_(3) Sn layer(Δ(xNn3 Sn)) is expressed as a power function of the annealing time(t) by the equation A_(x^(2)Nb_(3) Sn)=k(t/t0)^(n),where t0 is the unit time,k is the reaction rate constant and n is the growth exponent.The growth exponent has the average value of 0.82,which means that the formation of the Nb_(3) Sn phase is both governed by the interface reaction and the grain boundary diffusion.