A three-dimensional,two-phase,five-component mathematical model has been developed to describe flow characteristics of clay particles and flocs in the profile control process,in which the clay particle suspension is i...A three-dimensional,two-phase,five-component mathematical model has been developed to describe flow characteristics of clay particles and flocs in the profile control process,in which the clay particle suspension is injected into the formation to react with residual polymer.This model considers the reaction of clay particles with residual polymer,apparent viscosity of the mixture,retention of clay particles and flocs,as well as the decline in porosity and permeability caused by the retention of clay particles and flocs.A finite difference method is used to discretize the equation for each component in the model.The Runge-Kutta method is used to solve the polymer flow equation,and operator splitting algorithms are used to split the flow equation for clay particles into a hyperbolic equation for convection and a parabolic equation for diffusion,which effectively ensures excellent precision,high speed and good stability.The numerical simulation had been applied successfully in the 4-P1920 unit of the Lamadian Oilfield to forecast the blocking capacity of clay particle suspension and to optimize the injection parameters.展开更多
Chemical flocculants are widely used in treating mature fine tailings(MFT)produced during bitumen extraction processes,among which polymers with high molecular weight(HMW)have demonstrated efficacy in dewatering and c...Chemical flocculants are widely used in treating mature fine tailings(MFT)produced during bitumen extraction processes,among which polymers with high molecular weight(HMW)have demonstrated efficacy in dewatering and clay flocculation.The long polymer chains carry sufficient functional groups to simultaneously interact with multiple clay surfaces,thereby modulating clay surface properties and facilitating the aggregation of clay particles.Significant efforts have been devoted to enhancing the flocculation and dewatering performance of polymer reagents.Despite some successes,the design of new and effective polymer flocculants with desired performance is hindered by the limited fundamental understanding of clay-polymer interaction mechanisms.In this work,interaction mechanisms between polymer flocculants and clay particles are reviewed.Solid flocculation by polymers can be driven by multiple mechanisms,either independently or in combination,due to the diverse properties and solution chemistry involved.Factors that affect the interactions are analyzed,with a particular focus on the effects of clay surface features,pH,ions,and asphaltene.Addressing ongoing debates regarding the synergy of multiple types of polymer segments,the influence of multi-valent ions,and the effects of amphiphilic asphaltene can significantly expedite the design of more effective flocculants and flocculation processes.展开更多
A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavati...A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading.展开更多
基金support from the National High Technology Research and Development Program of China (863 Program) ( 2007AA06200)"Taishan Scholars" Construction Project (No. ts20070704)
文摘A three-dimensional,two-phase,five-component mathematical model has been developed to describe flow characteristics of clay particles and flocs in the profile control process,in which the clay particle suspension is injected into the formation to react with residual polymer.This model considers the reaction of clay particles with residual polymer,apparent viscosity of the mixture,retention of clay particles and flocs,as well as the decline in porosity and permeability caused by the retention of clay particles and flocs.A finite difference method is used to discretize the equation for each component in the model.The Runge-Kutta method is used to solve the polymer flow equation,and operator splitting algorithms are used to split the flow equation for clay particles into a hyperbolic equation for convection and a parabolic equation for diffusion,which effectively ensures excellent precision,high speed and good stability.The numerical simulation had been applied successfully in the 4-P1920 unit of the Lamadian Oilfield to forecast the blocking capacity of clay particle suspension and to optimize the injection parameters.
基金the financial supports from National Natural Science Foundation of China(Grant number:52304071)MOE Key Laboratory of Petroleum Engineering(China University of Petroleum,Grant number:2462024PTJS002)。
文摘Chemical flocculants are widely used in treating mature fine tailings(MFT)produced during bitumen extraction processes,among which polymers with high molecular weight(HMW)have demonstrated efficacy in dewatering and clay flocculation.The long polymer chains carry sufficient functional groups to simultaneously interact with multiple clay surfaces,thereby modulating clay surface properties and facilitating the aggregation of clay particles.Significant efforts have been devoted to enhancing the flocculation and dewatering performance of polymer reagents.Despite some successes,the design of new and effective polymer flocculants with desired performance is hindered by the limited fundamental understanding of clay-polymer interaction mechanisms.In this work,interaction mechanisms between polymer flocculants and clay particles are reviewed.Solid flocculation by polymers can be driven by multiple mechanisms,either independently or in combination,due to the diverse properties and solution chemistry involved.Factors that affect the interactions are analyzed,with a particular focus on the effects of clay surface features,pH,ions,and asphaltene.Addressing ongoing debates regarding the synergy of multiple types of polymer segments,the influence of multi-valent ions,and the effects of amphiphilic asphaltene can significantly expedite the design of more effective flocculants and flocculation processes.
基金supported by Fundamental Research Funds for the Central Universities (No.FRF-TP-14-033A1)TIMODAZ project as part of the sixth EURATOM framework programme for nuclear research and training activities (2002–2006)The Department of Diagnostic and Interventional Radiology of the CHUV and the collaboration with Laboratoire 3S-R,Grenoble are gratefully acknowledged
文摘A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading.
