This study aimed to address the challenges of solid waste utilization,cost reduction,and carbon reduction in the treatment of deep-dredged soil at Xuwei Port in Lianyungang city of China.Past research in this area was...This study aimed to address the challenges of solid waste utilization,cost reduction,and carbon reduction in the treatment of deep-dredged soil at Xuwei Port in Lianyungang city of China.Past research in this area was limited.Therefore,a curing agent made from powdered shells was used to solidify the dredged soil in situ.We employed laboratory orthogonal tests to investigate the physical and mechanical properties of the powdered shell-based curing agent.Data was collected by conducting experiments to assess the role of powdered shells in the curing process and to determine the optimal ratios of powdered shells to solidified soil for different purposes.The development of strength in solidified soil was studied in both seawater and pure water conditions.The study revealed that the strength of the solidified soil was influenced by the substitution rate of powdered shells and their interaction with cement.Higher cement content had a positive effect on strength.For high-strength solidified soil,the recommended ratio of wet soil:cement:lime:powdered shells were 100:16:4:4,while for low-strength solidified soil,the recommended ratio was 100:5.4:2.4:0.6.Seawater,under appropriate conditions,improved short-term strength by promoting the formation of expansive ettringite minerals that contributed to cementation and precipitation.These findings suggest that the combination of cement and powdered shells is synergistic,positively affecting the strength of solidified soil.The recommended ratios provide practical guidance for achieving desired strength levels while considering factors such as cost and carbon emissions.The role of seawater in enhancing short-term strength through crystal formation is noteworthy and can be advantageous for certain applications.In conclusion,this research demonstrates the potential of using a powdered shell-based curing agent for solidifying dredged soil in an environmentally friendly and cost-effective manner.The recommended ratios for different strength requirements offer valuable insights for practical applications in the field of soil treatment,contributing to sustainable and efficient solutions for soil management.展开更多
A novel methodology for the formulation design of the multi-component cement additive for the low early strength blend cement was presented by using engineering statistics.Components of cement additive such as trietha...A novel methodology for the formulation design of the multi-component cement additive for the low early strength blend cement was presented by using engineering statistics.Components of cement additive such as triethanolamine,chloride,saccharide and a kind of divalent alcohol were simultaneously tested according to the arrangement of response surface methodology.Mathematical models were established to express the quantitative relationship between the chemical components of cement additive and the compressive strength of treated blend cement.The effectiveness and the possible interactions of these four chemicals contributing to the strength development of blend cement were further explored by the pareto chart and the contour plot.Finally according the performance analysis of four chemicals,the optimized formulations were brought forward and were validated in practical trials by Turkey＇s multiple comparison.展开更多
Integral cement sheaths are crucial for safe and economical hydrocarbon production throughout the well lifecycle.Cement additives tailor short-and long-term cement properties for various well conditions to ensure well...Integral cement sheaths are crucial for safe and economical hydrocarbon production throughout the well lifecycle.Cement additives tailor short-and long-term cement properties for various well conditions to ensure well integrity.Although various additives exist,the current trend in reducing the carbon footprint motivates the developing"greeneradditives that are environmentally friendly and made from renewable and sustainable sources such as cellulose nanocrystals(CNC).CNCs exhibit superior properties and have shown significant impact on cement slurry,including increased degree of hydration,strength,and altered properties.However,most studies on CNCs are intended for construction industry rather than hydrocarbon and geothermal well cementing.Investigating the use of CNCs as high-performance cement additives is therefore of interest due to their potential benefits.This study aims to determine the effect of CNC on vital well cement properties.The effects of CNC were determined using standard American Petroleum Institute(API)test procedures and equipment in an experimental approach.The experimentalfindings indicate that the addition of cellulose nanocrystals(CNC)at a concentration of 2 vol%resulted in a notable increase of 7%in viscosity,a significant decrease of 50%in free water,a remarkable reduction of 78%in cement shrinkage,and no discernible effect on slurry thickening time.Furthermore,the inclusion of a 0.2 vol%of CNC yielded a significant surge of 56%in compressive strength after 21 days and accelerated 500 psi strength development by 9%.However,the investigation revealed that a concentration of 1.5 vol%of CNC represents a threshold concentration or the turning point,beyond which the addition of CNC can negatively impact the studied cement properties.展开更多
基金Funded by the Science and Technology Project of Jiangsu Provincial Transportation Department(No.2022Y13)。
文摘This study aimed to address the challenges of solid waste utilization,cost reduction,and carbon reduction in the treatment of deep-dredged soil at Xuwei Port in Lianyungang city of China.Past research in this area was limited.Therefore,a curing agent made from powdered shells was used to solidify the dredged soil in situ.We employed laboratory orthogonal tests to investigate the physical and mechanical properties of the powdered shell-based curing agent.Data was collected by conducting experiments to assess the role of powdered shells in the curing process and to determine the optimal ratios of powdered shells to solidified soil for different purposes.The development of strength in solidified soil was studied in both seawater and pure water conditions.The study revealed that the strength of the solidified soil was influenced by the substitution rate of powdered shells and their interaction with cement.Higher cement content had a positive effect on strength.For high-strength solidified soil,the recommended ratio of wet soil:cement:lime:powdered shells were 100:16:4:4,while for low-strength solidified soil,the recommended ratio was 100:5.4:2.4:0.6.Seawater,under appropriate conditions,improved short-term strength by promoting the formation of expansive ettringite minerals that contributed to cementation and precipitation.These findings suggest that the combination of cement and powdered shells is synergistic,positively affecting the strength of solidified soil.The recommended ratios provide practical guidance for achieving desired strength levels while considering factors such as cost and carbon emissions.The role of seawater in enhancing short-term strength through crystal formation is noteworthy and can be advantageous for certain applications.In conclusion,this research demonstrates the potential of using a powdered shell-based curing agent for solidifying dredged soil in an environmentally friendly and cost-effective manner.The recommended ratios for different strength requirements offer valuable insights for practical applications in the field of soil treatment,contributing to sustainable and efficient solutions for soil management.
基金Funded by National Basic Research Program of China (No.2009CB623100)
文摘A novel methodology for the formulation design of the multi-component cement additive for the low early strength blend cement was presented by using engineering statistics.Components of cement additive such as triethanolamine,chloride,saccharide and a kind of divalent alcohol were simultaneously tested according to the arrangement of response surface methodology.Mathematical models were established to express the quantitative relationship between the chemical components of cement additive and the compressive strength of treated blend cement.The effectiveness and the possible interactions of these four chemicals contributing to the strength development of blend cement were further explored by the pareto chart and the contour plot.Finally according the performance analysis of four chemicals,the optimized formulations were brought forward and were validated in practical trials by Turkey＇s multiple comparison.
文摘Integral cement sheaths are crucial for safe and economical hydrocarbon production throughout the well lifecycle.Cement additives tailor short-and long-term cement properties for various well conditions to ensure well integrity.Although various additives exist,the current trend in reducing the carbon footprint motivates the developing"greeneradditives that are environmentally friendly and made from renewable and sustainable sources such as cellulose nanocrystals(CNC).CNCs exhibit superior properties and have shown significant impact on cement slurry,including increased degree of hydration,strength,and altered properties.However,most studies on CNCs are intended for construction industry rather than hydrocarbon and geothermal well cementing.Investigating the use of CNCs as high-performance cement additives is therefore of interest due to their potential benefits.This study aims to determine the effect of CNC on vital well cement properties.The effects of CNC were determined using standard American Petroleum Institute(API)test procedures and equipment in an experimental approach.The experimentalfindings indicate that the addition of cellulose nanocrystals(CNC)at a concentration of 2 vol%resulted in a notable increase of 7%in viscosity,a significant decrease of 50%in free water,a remarkable reduction of 78%in cement shrinkage,and no discernible effect on slurry thickening time.Furthermore,the inclusion of a 0.2 vol%of CNC yielded a significant surge of 56%in compressive strength after 21 days and accelerated 500 psi strength development by 9%.However,the investigation revealed that a concentration of 1.5 vol%of CNC represents a threshold concentration or the turning point,beyond which the addition of CNC can negatively impact the studied cement properties.
