Poor Physical Properties Research Articles

Application of the NOA-Optimized Random Forest Algorithm to Fluid Identification—Low-Porosity and Low-Permeability Reservoirs

As an important unconventional oil and gas resource, tight oil exploration and development is of great significance to ensure energy supply under the background of continuous growth of global energy demand. Low-porosity and low-permeability reservoirs are characterized by tight rock properties, poor physical properties, and complex pore structure, and as a result the fine calculation of logging reservoir parameters faces great challenges. In addition, the crude oil in this area has high viscosity, the formation water salinity is low, and the oil reservoir resistivity shows significant spatial variability in the horizontal direction, which further increases the difficulty of oil and water reservoir identification and affects the accuracy of oil saturation calculation. Targeting the above problems, the Nutcracker Optimization Algorithm (NOA) was used to optimize the hyperparameters of the random forest classification model, and then the optimal hyperparameters were input into the random forest model, and the conventional logging curve and oil test data were combined to identify and classify the reservoir fluids, with the final accuracy reaching 94.92%. Compared with the traditional Hingle map intersection method, the accuracy of this method is improved by 14.92%, which verifies the reliability of the model for fluid identification of low-porosity and low-permeability reservoirs in the research block and provides reference significance for the next oil test and production test layer in this block.

Numerical simulation of CO2 storage with enhanced gas recovery in depleted highly heterogeneous carbonate gas reservoir

Injecting CO2 into depleted gas reservoirs facilitates CO2 storage and enhances natural gas recovery rate (CSEGR), offering significant environmental benefits. Carbonate gas reservoirs are widely distributed globally and are characterized by large reservoir thicknesses, abundant reserves, poor reservoir physical properties, and high heterogeneity. In the depletion state, considerable amounts of natural gas remain in the matrix pores, and numerous natural cavities provide ample space for CO2 storage. Consequently, carbonate gas reservoirs hold great potential for implementing the CSEGR program. To accurately model the flow behavior of CO2 in highly heterogeneous carbonate gas reservoirs and assess the feasibility of implementation the CSEGR program, a three-dimensional numerical model was developed at the reservoir scale using geological data from the fourth section of the Dengying Formation (Deng-4) in the Anyue Gas Field. The study investigates the CH4 production and CO2 storage characteristics of four typical reservoir bodies, tracks the spatial migration of CO2, and explores the effects of CO2 injection rate and interlayer permeability on the CSEGR process. Numerical results show that the cavity-type reservoir is ideal for the CSEGR scheme, with an enhanced gas recovery (EGR) rate exceeding 20%, whereas the fracture-cavity reservoir is unsuitable due to premature CO2 breakthrough caused by natural fractures. The cavity-type reservoir serves as the primary site for CO2 injection and storage, with some CO2 migrating into the pore-type reservoir through interlayer crossflow. For both pore-type and cavity-type reservoirs, the migration distance of the CO2 front is proportional to the square root of the injection time. Lower CO2 injection rates and smaller interlayer permeabilities delay CO2 breakthrough, leading to higher EGR rates. However, reduced injection rates also lower CH4 production rates and extend CO2 injection duration.

Nanoparticle-Enhanced Engine Oils for Automotive Applications: Thermal Conductivity and Heat Capacity Improvements.

The poor thermal and physical properties of conventional engine oils limit vehicle performance and durability. This research aims to investigate the effect of nanoparticles such as fullerene C60, titanium dioxide (TiO2), iron oxide (Fe2O3), and reduced graphene oxide (rGO) nanoparticles on 10W30 Mobil engine oil. In this study, the effect of nanoparticle concentrations at different mass fractions (0.01, 0.05, and 0.1) was examined within the temperature range 30-120 °C. The nanofluids were prepared using a two-step direct mixing method and thermal properties were measured using a LAMBDA thermal conductivity meter, which uses the transient hot wire method according to the ISO standards. Due to the low concentrations of the nanofluids, surfactants were not required at all, and the stability of the nanofluids was visually monitored over a period of four weeks. Accordingly, the largest improvement in thermal conductivity occurred with TiO2/10W30 at a mass fraction of 0.1 wt.% at 80 °C, and the specific heat capacity improved due to Fe2O3/10W30 addition at a mass fraction of 0.1 at 70 °C; these were 5.8% and 14.4%, respectively, for the base oil. Thermal diffusivity remained largely unaffected by the addition of the nanoparticles, and fullerene C60 showed no significant effect on any thermal property. It was concluded that the thermal properties of the engine oil were considerably enhanced by the added nanoparticles at different weight fractions and temperature values.

Mechanized and irrigated coffee cultivation promotes physical subsurface constraints in Oxisols

ABSTRACT Soils of the Cerrados (Brazilian Savanna) are deep, well-structured, and well-drained, with flat to gently undulating terrain that favors mechanization for coffee cultivation. However, these soils are susceptible to compaction. This study aimed to assess the effect of mechanization on the physical characteristics of an Oxisol under irrigated coffee cultivation in the Alto Paranaíba-Minas Gerais State. We selected eight areas with different cultivars and years of Arabica coffee plantation, sampling five positions: right soil under the tree crown (RSC), right tractor lines (RTL), interrows (IR), left tractor lines (LTL), and left soil under the tree crown (LSC) at layers of 0.00-0.10, 0.10-0.20, 0.20-0.30, and 0.30-0.40 m. We conducted principal component analysis (PCA) and analysis of variance, comparing means through Tukey’s test (p<0.05). The PCA selected three principal components (PC1, PC2, and PC3) composed of 12 physico-chemical properties from a total of 27 evaluated. Total porosity (TP), mean penetration resistance (PRmean), volumetric moisture (θ) at 100 kPa (θ 100 kPa) and 300 kPa (θ 300 kPa) tensions, particle density (PD), and granulometric fractions (clay, fine sand, and coarse sand) were among the most influential attributes. Total porosity and PRmean demonstrated the existence of compaction in the tractor wheel tracks, particularly in the 0.00-0.20 m layer. The 3.5-year-old plantation did not show significant variations in these properties. The θ 100 kPa and θ 300 kPa were higher in the compacted areas, indicating increased water retention but potentially limiting aeration. Clay content increased with depth, while sand fractions decreased, influencing the soil susceptibility to compaction. The vigor of coffee plants, as identified by satellite images (NDVI), could not be fully associated with the physical constraints of the subsurface, as even areas with low vigor did not consistently correlate with poor physical properties in laboratory analyses. These findings highlight the complex interplay between soil physical properties and coffee plant performance, emphasizing the need for comprehensive management strategies in mechanized coffee cultivation.

Research on the Characteristics and Mechanisms of Supercritical CO2 Displacement of Shale Oil Under Nanoscale Confinement

ABSTRACTShale reservoirs, characterized by compact pores, poor physical properties, and high organic matter content, exhibit significant differences in microscopic flow behavior compared to conventional oil reservoirs. These distinctions complicate the accurate assessment of shale oil reserves and the selection of optimal exploration and development strategies. Understanding the mechanisms and factors influencing microscopic flow in shale oil is crucial for both theoretical and practical aspects of shale oil exploration and development. In this study, molecular dynamics simulations employing the Grand Canonical Monte Carlo method were used to develop a microscale molecular dynamics model for n‐octane (C₈H₁₈) adsorption on various adsorbents. Adsorption energies for organic materials (kerogen), brittle minerals (quartz, albite), carbonate minerals (calcite), and clay minerals (illite, kaolinite, montmorillonite) were calculated to evaluate the adsorption strength of shale oil and CO2 on these adsorbents. Furthermore, a nonequilibrium molecular dynamics (NEMD) approach was utilized to model the CO2 displacement of shale oil in different slit pores, exploring the flow characteristics and displacement mechanisms of supercritical CO2 under nanoscale confinement. This investigation also considered the effects of CO2 density, slit pore surface properties, and driving force magnitudes, providing essential theoretical and technical insights for assessing shale oil reserves and refining exploration and development strategies.

Laser land levelling and double row planting improves productivity, water use efficiency and profitability of post monsoon sorghum in black soils

A field experiment was carried out in the winter season of 2017-18 at the engineering farm of navsari agricultural university in navsari, india, to assess how land leveling and configuration techniques affect sorghum (Sorghum bicolor L.) productivity, water usage, and economic returns in heavy-textured black soils (58% clay) with poor physical properties and limited rainfall during the crop period (37 mm). The study employed a factorial randomized block design with three replications, examining three land leveling methods: an unleveled control (0.05% slope), conventional land leveling, and laser-guided land leveling. It also evaluated three land configurations: ridge and furrow, double-row bed planting (90 cm), and triple-row bed planting (150 cm). Results indicated that laser-guided land leveling significantly enhanced growth attributes, yield components, and resource-use efficiency compared to the control. This method achieved the highest grain yield (4000 kg ha-1), fodder yield (16,998 kg ha-1), and water use efficiency (WUE) of 17.0 kg ha-1 mm-1. Among the land configurations, double-row bed planting yielded the highest grain (3367 kg ha-1), fodder (16,717 kg ha-1), and WUE (16.1 kg ha-1 mm-1), outperforming both ridge and furrow and triple-row systems. Laser leveling also led to reduced irrigation time and depth, improving irrigation efficiency. Economic analysis indicated the highest net return (` 70,492 ha-1) and benefit-cost ratio (3.4) with laser leveling, while double-row bed planting yielded the highest net return among configurations (` 69,163 ha-1). The findings suggest that integrating laserguided land leveling with double-row bed planting can significantly improve sorghum productivity, irrigation efficiency, and profitability in the heavy black soils of south gujarat.

Effect of Carrier Agents and Inlet Temperature on Physicochemical Properties of Encapsulated Carrot Coagulum Powder

Background: The carrot (Daucus carota L.) is a popular root vegetable grown throughout the world. In the present study, an attempt was made to use the carrot outgrades, which are purely rejected for aesthetic reasons, not meeting the standards based on size and shape. Further enzymes (Pectinase and Cellulase) are used to extract the carrot coagulum from carrot outgrades. Carrier agents were mixed into carrot coagulum and spray dried at three different inlet air temperatures (160, 170, and 180 °C) to encapsulate enzyme-extracted carrot coagulum. Aim: Carrots are nutritious and mainly rich in carotenoids. Often, very high losses are incurred during post-harvesting operations. A significant proportion of carrots are rejected due to bad aesthetics. Therefore, the objective of the study was to utilise such non-commercial carrot out-grades to recover carotenoids and produce encapsulated powder using spray drying. Methodology: The process of spray drying of enzymatically extracted carrot coagulum was standardised by varying carrier agents (maltodextrin and gum arabica) concentration and at different inlet temperatures. Pectinase (Pectinex Ultra SPL from Aspergillus aculeatus aqueous solution, ≥3,800 units/mL) and cellulose (Celluclast 1.5L from Trichoderma reesei aqueous solution, ≥700 units/g) were obtained from Novozymes, Bangalore. Trans-β-carotene was obtained from Sigma Chemical Company. All other chemicals used were of analytical grade. Results: All physicochemical properties were significantly affected by the carrier agents and temperature. Carotenoid content was highest (9.80%) at an inlet temperature of 170 °C with MD100. Overall moisture content was reduced, while other physical properties were enhanced when the temperature increased. Increasing the gum Arabica content showed a significant increase in moisture content and wettability time, as well as poorer physical properties. Results showed that the physicochemical and microstructural properties of encapsulated carrot coagulum powder (ECCP) were affected by inlet temperatures and carrier agents. Conclusion: Among all the spray-dried powders, the powder dried at 170 °C using maltodextrin at 15% alone had comparatively lower moisture content, good flowability, higher solubility, and less wetting time compared to other combination treatments and inlet temperatures, and thus fulfills the requirement of good quality spray-dried powders. Certainly, carrot out grades have a significant content of total carotenoids, which makes the utilisation of such material worthwhile for processing.

Migration mechanisms of solid particles in rough fractures and the effects on permeability

The low-permeability sandstone reservoir in the Lufeng block of the South China Sea exhibits poor physical properties, significant heterogeneity, and weak cementation, resulting in an unsatisfactory fracturing effect. The flowback fluids contain a diverse array of solid particles to elucidate the damage mechanisms associated with solid particle migration on hydraulic fractures, a quantitative evaluation of micro-fracture damage within the reservoir was conducted through physical flow experiment combined with fracture roughness assessment technology. This study aimed to identify the key factors affecting particle migration damage and establish a multivariate regression relationship between permeability and fracture roughness, thereby proposing a novel damage evaluation method for offshore low-permeability reservoirs. The results indicate (1) the predominant types of solid particulate damage include formation particles, residues from fracturing fluids, and crushed proppant particles; notably, the degree of damage follows this order: formation particles > fluid residues > proppant particles. (2) Sand production experiments reveal that the sand production rate ranks as follows: formation particles < fracturing fluid residues < proppant particles; similarly, particle size adheres to this sequence: formation particles < fracturing fluid residues < proppant particles. These observations suggest that migration of formation particles is primarily responsible for reservoir damage. (3) The fracture roughness assessment method demonstrates a consistent trend with permeability damage results; furthermore, regression fitting indicates a strong correlation between these two variables, underscoring the high reliability of this methodology. It provides a theoretical foundation for optimizing field operations and mitigating reservoir damage while facilitating efficient development strategies for offshore low-permeability reservoirs.

Mechanochemical Semidry Modification of Fly Ash for Mercury Removal

ABSTRACTFly ash is a potential mercury adsorbent due to its well‐developed pores, but its poor physical and chemical properties limit the efficiency of mercury adsorption so that it needs to improve its adsorption capacity. The mechanochemical semidry modification of fly ash prepared by an all‐round planetary ball mill and the effects of KClO3, S, KCl, and K2SO4 taken as modifiers on mercury removal were investigated by experiment and characterization. The results indicate that the mechanochemical semidry samples demonstrate a larger specific surface area, a more developed pore structure. The mercury removal efficiencies affected by the modifiers rank in descending order as follows: KClO3 > S > KCl > K2SO4. Notably, KClO3 and S are more effective than others, achieving a mercury removal efficiency of 87% and 63%. The mechanism of mercury adsorption of fly ash modified by KClO3 and S is elucidated. The mercury removal is predominantly governed by oxidation, accounting for more than 90%, with weak adsorption. The modified fly ash can be an efficient and economic adsorbent for flue gas mercury removal in coal‐fired flue gas.

Strike‐slip Fault Architecture and its Control on Fractured Carbonate Reservoirs: Insight from Outcrops in the North‐western Tarim Basin, NW China

Abstract Recent exploration has highlighted the critical role of strike‐slip faults in shaping ultra‐deep carbonate reservoirs in the Tarim Basin. This study integrates satellite imagery, UAV photogrammetry, outcrop surveys and microscopic analysis to investigate the architecture of these faults and their impact on reservoir petrophysical properties. The strike‐slip faults exhibit cores consisting of calcite bands, fault breccias and fractures, while the damage zones are predominantly fractured. Thicker fault cores and fault zones are associated with more extensive reservoir development. Individual strike‐slip fault zones are primarily characterized by two sets of fractures intersecting the fault at small angles. When two fault systems interact, the dominant pattern is two sets of fractures intersecting the main fault at small angles and one set at larger angles, facilitating the formation of large‐scale reservoirs. We propose a model for the fault core, which primarily consists of a calcite band and fault breccias. These breccias are composed of original host rock, calcite cement and quartz, which exhibit poor physical properties, while fractures and vugs show favorable reservoir characteristics. This model offers valuable insights into the development of fault‐controlled reservoirs, particularly in the Tarim Basin.

Study on quantitative characterization of microscopic pore throat in tight oil reservoir

Tight oil reservoirs exhibit poor physical properties, significant heterogeneity, and intricate pore structures. The investigation of the microscopic pore-throat structure plays a pivotal role in assessing the efficacy of these reservoirs. Using the Chang 8 reservoir in the Yanchi area of the Ordos Basin as a case study, conventional experimental methods were used to analyze and test its pore structure and evaluate the micro pore structure characteristics of the reservoir in this area, but due to the large amount of experimental data obtained by the conventional experimental methods and the difficulty of analyzing them, so we proposed a method of logging and evaluating the quality of the microscopic pore throats. By carrying out the research on the quantitative characterization relationship between the microscopic pore structure parameters and microscopic pore-throat quality of the tight reservoir, the pore-throat quality logging evaluation index PTI was obtained, and the quantitative evaluation standard of microscopic pore-throat quality of the tight sandstone reservoir was established. The findings indicate the following: (1) The predominant pore types within the Chang 8 reservoir in the study region consist mainly of intergranular pores and feldspar dissolved pores, showing an average surface porosity of 3.3%. The reservoir predominantly comprises nano-scale pore throats, contributing to its dense nature. Fluid seepage capacity is primarily governed by relatively larger pores. The main throat radius falls within the range of 101–601 nm, with an average pore throat ratio mainly ranging between 102 and 199. The average movable fluid saturation is measured at 26.51%. (2) After thorough analysis, it has been discerned that four key parameters—porosity (φ), median radius (Rpt50), displacement pressure (Pd), and maximum pore throat radius (Rmax)—exert significant influence on pore throat quality. Consequently, a logging evaluation index, PTI (Pore Throat Index), has been devised to gauge pore throat quality, accompanied by the establishment of a quantitative evaluation standard for the microscopic pore throat quality of tight sandstone reservoirs. (3) The reservoirs within the research area are categorized into four groups: I, II, III, and IV. A higher PTI value indicates superior pore throat quality, leading to an overall enhanced reservoir evaluation. This quantitative evaluation method is of guiding significance for the quantitative characterization of micropore throats in tight oil reservoirs and the efficient development of the oil field in this area, and it is also of some reference significance for the quantitative characterization of micropore throats in similar tight sandstone reservoirs.

Development Unit Division of Low Permeability Reservoir in Y Block, Ordos Basin

The Y block reservoir in Ordos Basin is a typical low porosity and permeability tight sandstone reservoir with poor physical property and strong heterogeneity. On the plane, the small layer sand body Changes quickly, the continuity is poor, the pressure distribution is uneven, and the principal side effect is uneven. In the section, the liquid production in the stratification is not clear, the washing degree of the small layer is different, and the water contradiction in the multi-direction of the single layer is prominent. At present, the overall reservoir decline is fast, some Wells have low productivity and high water cut, and most of the Wells have more open layers. In this paper, based on geological factors and development dynamic factors, combined with fracture identification, the first development unit of Y block reservoir is divided, and on the basis of the first development unit division, the second development unit is further divided according to the situation of small layer division and correlation. The division of the secondary development units can correspond the development contradiction to the small layer, and has guiding significance for the evaluation of the subsequent reservoir development effect and the fine adjustment of development policy.

Effect of Lime, Mineral Fertilizer and Manure on Soil Characteristics and Yield of Four Maize Hybrids

Pseudogley soils in Serbia are characterized by poor chemical and physical properties that limit maize yields. Nevertheless, they are still used on large areas due to their favorable topographic position and lack of better-quality soils. It is common practice to regularly apply mineral fertilizers to these soils, but this does not increase maize yields to an economically sufficient level, although the doses are increased. At the same time, the inappropriate application of mineral fertilizers deteriorates soil chemical properties. Lime is only moderately used in Serbia despite its known benefits, whereas manure is not satisfactorily used. Therefore, a two-factorial experiment was set up as a randomized block design with three replications and conducted near Kraljevo, Serbia, to investigate the effect of mineral fertilizers, manure and lime on maize growth. The experiment included three fertilization regimes: F—application of common fertilizer doses, LF—application of the same fertilizer doses with 3 t·ha−1 of lime, and LMF—application of the same fertilizer doses with lime and 30 t·ha−1 of manure. The response of four maize hybrids to different fertilization practices was investigated. The soil was acid, poor in humus, and contained an increased content of mobile aluminum. There was a significant increase in the 3-year average yield of all hybrids in LMF- and LF-treatments compared with F-treatment, 30.7 and 25.6%, respectively. The increase in yield was accompanied by an improvement in soil chemical properties after three years, i.e., increased soil reaction in LF- and LMF-treatments, increased content of available phosphorus, an increase in base saturation by 61 and 75%, and aluminum immobilization by 2.55 and 4.19 fold, respectively, compared to initial conditions. The hybrid NS 640 demonstrated the highest yield when only mineral fertilizers were used, which indicated its tolerance to the unfavorable physical and chemical soil properties and suggested that it can be recommended for growing on pseudogleys without applying amelioration practices. The hybrids NS 6030 and ZP 606 achieved statistically significantly higher yields than the other hybrids when lime and manure were applied, which indicates that adequate fertilization coupled with soil improvement practices should be used in order to achieve satisfactory yields. The obtained results showed that liming can be considered as a longer-term sustainability practice in maize production in Serbia on pseudogley soils, and that there is an array of maize hybrids which can be grown depending on management strategies applied.

Thermal Safety Research of Lithium-Ion Batteries Based on Flame-Retardant Phase Change Materials

Pure phase change materials (PCMs) have drawbacks such as low thermal conductivity and poor physical properties like flammability, which limit their further application in battery thermal management systems. This paper introduces an innovative flame-retardant composite phase change material (CPCM) made from paraffin, expanded graphite, chitosan (CS), ammonium polyphosphate (APP), and aluminum hypophosphite (AHP). The physicochemical properties and flame-retardant performance of CPCMs with five different flame-retardant ratios of 9%, 12%, 15%, 18%, and 21% are studied, and their application effects in battery thermal safety are revealed. The results show that the combination of flame retardants CS, APP, and AHP exhibits effective synergistic effects, and the prepared CPCM exhibits good flame-retardant properties and thermal management effects. The CPCM exhibits outstanding thermal management performance when the flame-retardant content is 12%. At a maximum discharge rate of 3C, compared to natural air-cooling conditions, the maximum battery temperature and temperature difference are controlled within the safe range of 41 °C and below 5 °C, respectively. The CPCM can play an important role in the thermal safety of lithium-ion batteries.

Analisis Karakteristik Aspal Berdasarkan Batuan Reservoir Kabupaten Buton Provinsi Sulawesi Tenggara

Factors influencing the content of asphalt is the process of formation, moisture content and the type of reservoir rocks, then to do the research on the characteristics of asphalt based on reservoirnya rocks. The purpose of this research is to know the physical nature of Asphalt Buton Rock based on reservoirnya. The method used is the sokhlet method. The data used is data of rocks reservoir site I and II, the physical properties of the data of the asphalt. Of research results obtained at the location I have rocks limestone reservoir with poor porosity features have higher levels of bitumen (23-47%), the asphalt is more dense and hard, CaCO3 content was higher (86,66%) whereas in a location that has a reservoir rock II sandstones with physical characteristics of good porosity have lower levels of bitumen (20-40%), the asphalt is relatively more malleable, a higher SiO2 content (17,06). From the results it can be concluded that the physical nature of asphalt location I have poor porosity and physical properties II location has good porosity, on the location of research levels obtained 20-47%.

Characteristics of Nitrogen-Fixing Bacteria Isolated from the Rhizosphere at Kaolin Lake, Belitung, Indonesia

Characteristics of Nitrogen-Fixing Bacteria Isolated from the Rhizosphere at Kaolin Lake, Belitung, Indonesia

Calculating the water production rate in a low-saturation reservoir based on the modified curved capillary theory

Low-saturation reservoirs have complex geological backgrounds, diverse genetic mechanisms, poor physical properties, variable pore structures, and low permeabilities. It also has a wide range of oil–water coexistences and low oil saturations, which make it difficult to accurately calculate their water production rate. To address these issues, this study investigates low-saturation reservoirs in the Nanpu Sag, focusing on petrophysical characteristics and relative permeability variations in samples with different pore structures. A range of petrophysical experiments, including coupled oil-water phase percolation, petroelectrical testing, nuclear magnetic resonance (NMR), and X-ray diffraction (XRD), were conducted to analyze fluid interactions and pore structure impacts. From these experiments, a new pore structure factor was proposed to enhance the existing curved capillary theory. The results showed that this modification improved calculation accuracy for water production rate. The enhanced model was applied to actual logging data and validated against test production results, demonstrating its effectiveness. This study offers both theoretical and practical advancements. It improves the understanding of fluid dynamics in low-saturation reservoirs and provides a reliable tool for fluid identification during exploration. This model can guide more accurate reservoir assessments and support optimized production strategies, improving efficiency in managing these challenging reservoir environments.

Study on the shutdown and restart process of a crude oil pipeline

Abstract The crude oil pipelines are relatively complex, with a wide variety of transported oil types with significantly varying physical properties. A numerical simulation method was proposed to explore whether crude oil with extremely poor physical properties (high viscosity and condensation temperature) can be transported safely, considering the pipeline’s complicated characteristics during shutdown and restart. A mathematical and physical model of a crude oil pipeline was presented, and the explicit forward differentiation method and characteristic line were used to solve the equations. A computer program was written using Python to simulate the shutdown and restart process of the pipeline. The transportation of extremely poor-quality crude oil under extreme conditions was simulated for both autumn and winter scenarios, with a 10-hour shutdown followed by a restart. For the autumn condition, the pipeline could restart safely. However, in winter, the pipeline experienced unsafe phenomena such as rapid flow reduction and pressure increase after restarting. Analyzing the oil temperature along the pipeline revealed the cause of these issues, providing technical support for the safe operation of crude oil pipelines.

Diagnosis, Classification and Management of Black Sodic Soils :An Overview

Black sodic soils pose a significant challenge in agricultural production, particularly in arid and semi-arid regions where high sodium content degrades soil structure and fertility. These soils suffer from nutrient deficiencies, poor physical properties, and increased susceptibility to erosion, leading to reduced crop productivity and economic losses. Sodicity is exacerbated by poor irrigation practices and the rising demand for water. This review explores the characteristics, diagnosis, and classification of black sodic soils, alongside strategies for their sustainable management, focusing on amelioration techniques such as the use of soil amendments and organic materials.

Origin of Crude Oils in the Lower Yanchang Formation of Yan'an Area in Ordos Basin, China.

The clastic rocks of the Yanchang Formation in the Ordos Basin display poor physical properties but are rich in petroleum resources, exhibiting significant exploration potential. However, due to the existence of multiple sets of oil-bearing formations, hydrocarbon-generating formations, and a large longitudinal span, elucidating the correspondence between crude oil and source rocks is vital for further exploration. This study concentrates on the Lower Yanchang Formation of Triassic in the Yan'an area of the Ordos Basin, aiming to perform refined oil-source correlation. The findings indicate that the relative contents of diasteranes [DiaC27βα (20S + 20R), DiaC28βα (20S + 20R), and DiaC29βα (20S + 20R)] are instrumental in categorizing hydrocarbon sources. By examination of the biomarker characteristics of crude oils in the Lower Yanchang Formation, it is detected that there are variations in hydrocarbon source contributions across the Wuqi, Shunning, and Xihekou areas and among different formations. In conclusion, the oils within the lower assembly in the study area primarily originate from a composite source, which includes Chang-7 black mudstone in the center of the lake basin, Chang-9 black mudstone in the Wuqi region, and Chang-9 dark mudstone in other areas. The Chang-7 dark mudstone in other areas plays a minor role in the lower assembly crude oil genesis, while the Chang-10 dark mudstone has a negligible influence on the lower assembly oil source of the Yanchang Formation.