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Effects of synthesis parameters on the performance of crosslinked Co-polymers with clays for conformance control

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Petroleum Research 2024年第1期9卷 98-108页

作者： A.A.Roslan N.A.A.Aziz N.F.A.Deraman I.Dzulkarnain Petroleum Engineering Department Centre of Research Enhanced Oil Recovery(COREOR)Universiti Teknologi PETRONASSeri IskandarPerakMalaysia Chemical Engineering Department Centre of Research Enhanced Oil Recovery(COREOR)Universiti Teknologi PETRONASSeri IskandarPerakMalaysia

Conformance control or water shut-off is a technique used to improve oil recovery.During conformance control,polymers block high permeability water areas and redistribute water drive toward unswept oil zones.In this study,co-polymers(denoted ATP-PGV/AM-co-AMPS)were synthesized using acrylamide(AM)and 2-acrylamide-2-methylpropane sulfonic acid(AMPS)as the monomers,polyethylene glycol(PEG)-200 and methylenebisacrylamide(MBA)as the crosslinkers,attapulgite(ATP)and bentonite(PGV)as the clay types,and ammonium persulfate(APS)as the initiator,in addition to paraffin oil and surfactants.Samples were synthesized using inverse emulsion polymerization with different concentrations of monomers,crosslinkers,and clays,and they were characterized using Fourier-transform infrared(FTIR)spectroscopy and scanning electron microscopy(SEM)with energy dispersive X-ray spectroscopy(EDX).FTIR spectra of the samples confirmed the existence of sulfonate and hydroxyl groups,which are important for polymer swelling.SEM-EDX images indicated that the morphology and elemental composition were different before and after swelling,confirming the occurrence of swelling.Moreover,samples were placed in sodium chloride solution(20,000 ppm)for 7 days to evaluate swelling at both room temperature and 90°C.Thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC)were used to determine the thermal characteristics of the microparticles.Finally,rheological measurements were used to assess the deformation and rheological behavior of the hydrogels.The results showed that after 1 day,good swelling without loss of mechanical strength was achieved with the composite synthesized using 10%AM,15%AMPS,6%PGV,and 10%ATP.

关键词： Polymer clay Water shut-off Conformance Swelling

Extended wet sieving method for determination of complete particle size distribution of general soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 242-257页

作者： Shengnan Ma Yi Song Jiawei Liu Xingyu Kang Zhongqi Quentin Yue Department of Civil Engineering The University of Hong KongHong KongChina

The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method.

关键词： Particle size distribution(PSD) General soil Silt clay Wet sieving Physical and chemical properties

Study of ZnO nanoparticle-supported clay minerals for electrochemical sensors,photocatalysis,and antioxidant applications

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ChemPhysMater

ChemPhysMater 2024年第1期3卷 83-93页

作者： Mylarappa M N.Raghavendra N.R.Bhumika C.H.Chaithra B.N.Nagalaxmi K.N.Shravana Kumara Department of Chemistry Sri Jagadguru Renukacharya College of ScienceArts&CommerceBengaluru 560009India Department of Chemistry East West Institute of TechnologyBengaluru 560091India Department of Chemistry Maharani Lakshmi Ammanni College for WomenBengaluru 560012India

In view of the current study’s demonstration of the synthesis of clay-doped ZnO composites,we present a low-cost method for producing clay-metal oxide(clay/ZnO).Utilizing the solution combustion technique,a composite of clay/ZnO was produced utilizing citric acid as both a fuel and a complexing agent.The hexagonal unit cell structure of the created clay/ZnO may be seen using XRD patterns.The ZnO-infused clay was visible in FE-SEM micrographs as homogenous,sphere-shaped ZnO.The possible involvement of clay/ZnO photocatalytic activity in the UV-induced photodegradation of malachite green dye was investigated.The 90%degradation rate shows the composite’s outstanding photocatalytic degradation capacity.The resulting substance was electrochemically analyzed using a constructed electrode in 0.1 M KOH electrolyte.It increased its sensor capabilities,which now include chemical and biomolecule sensors,and it excelled in cyclic voltammetry-based redox potential studies.To efficiently evaluate chemically synthesized NPs for electrochemical,sensing,and photocatalytic applications,this study intends to create a solution combustion procedure for the synthesis of clay/ZnO nanocomposite using urea as fuel.

关键词： clay clay/ZnO Photocatalytic Electrochemical sensors

Investigation of the Fermentation Mode of Rice Husk for the Stabilization of Earth Plaster

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Journal of Minerals and Materials Characterization and Engineering 2024年第1期12卷 17-36页

作者： Nafissatou Savadogo Yasmine Binta Traore Nathael Lankoande Philbert Nshimiyimana Adamah Messan Département de Génie Civil Ecole Supérieure d’Ingénierie de Fada (ESI-F) Université de Fada N’Gourma (UFDG) Fada N’Gourma Burkina Faso Laboratoire Eco-Matériaux et Habitats Durables (LEMHaD) Institut International d’Ingénierie de l’Eau et de l’Environnement (Institut 2iE) Ouagadougou Burkina Faso

Despite its low resistance to humidity, adobe remains the most widely used material for housing construction, particularly in developing countries. The present study aims to assess different modes of use of fermented RH and to evaluate their influence on the behavior of raw earth for application in plaster. The influences of two types of RH are evaluated: granular rice husk (RHg) and powdered RH (RHp). The clay mainly consists of clay (40%), silt (22%), and sand (38.4%), with a small proportion of gravel (0.24%). Its liquidity limit is 40% and the plasticity index is 26.5%. The mixtures were designed using earth and each of the two rice husks at the volumetric content of 10%, 15% and 20% of the total volume mixed with water 36.5%, 38.5% and 40.3% and fermented for three weeks. Each fermented mixture was added to the soil to form the paste, and 40 × 40 × 160 mm3 test speciments were made for characterization. The results generally show an improvement in the physico-mechanical properties and water resistance of the mortars containing fermented RH, with an optimal content between 10% and 15%. The powdered RH improved the performance of the mortar better than granular RH.

关键词： Earth Plaster Rice Husk clay Fermentation Adobe

Experimental Study of the Anti-Corrosion Performance of Montmorillonite K-10 on Rebar in HCl Environment: Application in Mortar for the Rehabilitation of Reinforced Concrete Degraded by Corrosion

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Open Journal of Civil Engineering 2024年第2期14卷 155-167页

作者： Malang Bodian Mariétou Barro Diop-Fall Dame Keinde El-Hadji Dieye Modou Gningue Diop Modou Fall Laboratoire de Chimie Physique Organique et dAnalyse Environnementales (LCPOAE) Dpartement de Chimie Univ Cheikh Anta Diop de Dakar Dakar Senegal Laboratoire de Matriaux de Gnie Civil (LMGC) Ecole Suprieure Polytechnique de Dakar Univ Cheikh Anta Diop Dakar Sngal

This work first investigates the corrosion-inhibiting behavior of montmorillonite K-10 on reinforcing steel. The corrosion-inhibiting power of the clay (Montmorillonite) is determined in a medium HCl (C = 1N) using free corrosion potential monitoring, Tafel potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results of this study showed a satisfactory corrosion-inhibiting efficiency of around 72.665% for the optimum content of 1%. This is due to the presence of a stable oxide layer that protects the metal against corrosion. To validate the concept of montmorillonite as a corrosion inhibitor in repair mortar, we now turn to the influence of montmorillonite on the mechanical properties of mortars in the hardened state. In this part, montmorillonite K-10 is added to the mortar by partial substitution of the cement by 5% and 10% of the cement mass. The aim of this study is to ensure that the addition of this clay to the mortar composition will not have a negative effect on its compressive and flexural strengths. The results of the compression and flexural tests showed that the presence of montmorillonite in the mortar improved flexural and compressive strengths for the different compositions studied.

关键词： clay Reinforced Concrete Corrosion Inhibitor Rehabilitation Electrochemical Methods

Molecular force mechanism of hydrodynamics in clay nanopores

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浙江大学学报(英文版)A辑:应用物理与工程 2023年第9期24卷 817-827页

作者： Shengjie WEI Yuchao LI Peng SHEN Yunmin CHEN MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering College of Civil Engineering and ArchitectureZhejiang UniversityHangzhou 310058China

Nanopores are prevalent within various clay morphologies,and water flow in clay nanopores is significant for various engineering applications.In this study,we performed non-equilibrium molecular dynamics(NEMD)simulations to reveal the molecular force mechanisms of water flow in clay nanopores.The water dynamic viscosity,slip length,and average flow velocity were obtained to verify the NEMD models.Since the water confined in the nanopores maintained a dynamic mechanical equilibrium state,each water lamina can be regarded as a simply supported beam.The applied driving force,the force from clay crystal layers,the force from compensating sodium ions,and the force from other water laminae were further calculated to investigate the force mechanisms.The van der Wals barrier above the surface and hydraulic gradient lead to distribution differences in water oxygen atoms,which contribute to a net van der Waals resistance component of the force from clay crystal layers.Meanwhile,the water molecules tend to rotate to generate the electrostatic resistance component of the force from clay crystal layers and balance the increasing hydraulic gradient.Due to the velocity difference,the water molecules in the slower lamina have a higher tendency to lag and generate a net electrostatic resistance force as well as a net van der Waals driving force on the water molecules in the faster lamina,which together make up the viscous force.

关键词： Molecular dynamics Hydrodynamics clay Nanopore Molecular force Boundary effect Viscous force

Determination of groundwater buoyancy reduction coefficient in clay:Model tests,numerical simulations and machine learning methods

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Underground Space 2023年第6期13卷 228-240页

作者： Weixin Sun Hanlong liu Wengang Zhang Songlin liu Liang Han School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing 400045China

Groundwater plays an essential role in stabilizing underground structures.However,hydrostatic uplift forces from groundwater can create safety hazards.This paper obtained the groundwater buoyancy reduction coefficients of 36 types of clays through model tests and conducted a finite element simulation to obtain the buoyancy reduction coefficients of additional clays with varying soil properties.Machine learning methods,including extreme gradient boosting(XGBoost)and random forest(RF)algorithms,were used to analyze and identify the soil parameters that have a significant impact on the reduction of groundwater buoyancy.It was found that the permeability coefficient and saturation are the primary factors that influence the reduction of groundwater buoyancy.Additionally,the prediction models developed by XGBoost and RF were compared,and their accuracy was evaluated.These research findings can serve as a reference for designing underground structures that can withstand the potential risk of buoyancy in clay.

关键词： clay Buoyancy reduction coefficient Numerical simulation Model test Machine learning

Reliability analysis of excavated slopes in undrained clay

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Frontiers of Structural and Civil Engineering 2023年第11期17卷 1760-1775页

作者： Shuang SHU Bin GE Yongxin WU Fei ZHANG Key Laboratory of the Ministry of Education for Geomechanics and Embankment Engineering College of Civil and Transportation EngineeringHohai UniversityNanjing 210098China

A novel approach based on the upper bound theory is proposed to assess the stability of excavated slopes with spatially variable clay in undrained conditions.The proposed random limit analysis is a combination of the deterministic slope stability limit analysis together with random field theory and Monte Carlo simulation.A series of analyses is conducted to verify the potential application of the proposed method and to investigate the effects of the soil undrained shear strength gradient and the spatial correlation length on slope stability.Three groups of potential sliding surfaces are identified and the occurrence probability of each sort of failure mechanism is quantified for various slope ratios.The proposed method is found to be feasible for evaluating slope reliability.The obtained results are helpful in understanding the slope failure mechanism from a quantitative point of view.The paper could provide guidance for slope targeted local reinforcement.

关键词： slope stability spatial variability limit analysis random field clay

Acoustic logging response law in shales based on petrophysical model

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Petroleum Science 2022年第5期19卷 2120-2130页

作者： Song Hu Wei-Nan Liu Ying-Ming Liu Kun Liu Petroleum Exploration and Production Research Institute SINOPECBeijing100083China Shenzhen Branch of CNOOC(China)Co. Ltd.ShenzhenGuangdong518067China Research Institute of Petroleum Exploration and Development CNPCBeijing100083China

Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic logging response law is of great importance.Different petrophysical models are adopted for the equivalence of organic matter,clay,matrix minerals,and fractures,in Wufeng-Longmaxi shale formation in the Jiaoshiba area.Finally,the self-consistent approximation model is used to combine different components,and a shale petrophysical model with a complex pore structure is constructed.The model verification results show it has good predictability for shale.Based on the model,the effect of different mineral compositions and different types of pores are studied.The results show that:1)The effect of clay and organic matter is very complex,and the variation laws of layered clay(organic matter)and dispersed clay(organic matter)on the acoustic wave are consistent.2)Layered clay or organic matter leads to the formation anisotropy increase,which makes the acoustic time difference greater than that of containing dispersed clay(organic matter).3)The fracture is the main control factor of anisotropy,and the anisotropy of gas-bearing fracture is higher than that of water/oil fracture.

关键词： Shale reservoir Acoustic logging Response law Complex pore structure clay Fracture Organic matter