Low-permeability dense reservoirs,including micro-fractured reservoirs,are commonly characterized by high content of clay substances,high original water saturation,high sensitivity to invasive fluids,high capillary pr...Low-permeability dense reservoirs,including micro-fractured reservoirs,are commonly characterized by high content of clay substances,high original water saturation,high sensitivity to invasive fluids,high capillary pressure,complicated structure and anisotropic,high flow-resistance and micro pore throats etc,.Generally they also have lots of natural micro fractures,probably leading to stress sensibility.Main damaging factors in such reservoirs are water-sensibility and water-blocking caused by invasive fluids during drilling and production operations.Once damaged,formation permeability can rarely recovered.Numerous studies have shown that damaging extent of water-blocking ranges from 70% to 90%.Main damaging mechanisms and influencing factors of water-blocking were systematically analyzed.Also some feasible precaution or treating approaches of water-blocking were put forward.In a laboratory setting,a new multi-functional drilling fluid composed mainly of amphion polymer,sulfonation polymer,high effectively preventive water-blocking surfactants,ideal packing temporary bridging agents(TBA) and film-forming agents,etc.,were developed.New low-damage drilling fluids has many advantages,such as good rheological properties,excellent effectiveness of water-blocking prevention,good temporary plugging effect,low filtration and ultra-low permeability(API filtration≤5 mL,HTHP filtration≤10 mL,mud cake frictional coefficient≤0.14,permeability recovery>81%),can efficiently prevent or minimize damage,preserve natural formation and enhance comprehensive development-investment effect in TUHA Jurassic dense sandstone reservoir formation with low-permeability,the only one developing integrated condense gas field.Some references can be provided to similar reservoir formations.展开更多
Streamline-adjustment-assisted heterogeneous combination flooding is a new technology for enhanced oil recovery for post-polymer-flooded reservoirs.In this work,we first carried out a series of 2D visualization experi...Streamline-adjustment-assisted heterogeneous combination flooding is a new technology for enhanced oil recovery for post-polymer-flooded reservoirs.In this work,we first carried out a series of 2D visualization experiments for different chemical flooding scenarios after polymer flooding.Then,we explored the synergistic mechanisms of streamline-adjustment-assisted heterogeneous combination flooding for enhanced oil recovery and the contribution of each component.Test results show that for single heterogeneous combination flooding,the residual oil in the main streamline area after polymer flooding is ready to be driven,but it is difficult to be recovered in the non-main streamline area.Due to the effect of drainage and synergism,the streamline-adjustment-assisted heterogeneous combination flooding diverts the injected chemical agent from the main streamline area to the non-main streamline area,which consequently expands the active area of chemical flooding.Based on the results from the single-factor contribution of the quantitative analysis,the contribution of temporary plugging and profile control of branched preformed particle gels ranks in the first place and followed by the polymer profile control and the effect of streamline adjustment.On the contrary,the surfactant contributes the least to enhance the efficiency of oil displacement.展开更多
The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotat-ing packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer...The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotat-ing packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer solution with acetone as the volatile compound. The influence of the rotating speed of RPB, liquid viscos-ity, liquid flow rate, vacuum degree, and initial acetone content in the liquid on acetone removal efficiency was in-vestigated. The experimental results indicated that the removal efficiency increased with increasing rotating speed and initial acetone content in the viscous liquid and decreased with increasing liquid viscosity and flow rate. It was also observed that acetone removal efficiency increased with an increasing vacuum degree and reached 58% at a vacuum degree of 0.1 MPa. By the comparison with a flash tank devolatilizer, it was found that acetone removal ef-ficiency in RPB increased by about 67%.展开更多
Next generation display and lighting technology calls for thinner,cheaper and more-flexible unit devices.Polymer light emitting transistor(PLET),which integrates logic function of organic field effect transistor(OFET)...Next generation display and lighting technology calls for thinner,cheaper and more-flexible unit devices.Polymer light emitting transistor(PLET),which integrates logic function of organic field effect transistor(OFET),luminescence function of organic light emitting diode(OLED),and potential mechanical properties,is believed to be the raising star in this field.However,great challenges remain in developing the core materials of PLETs,which simultaneously require the integration of high ambipolar mobility and strong solid-state luminescence properties.Herein,high mobility luminescent thienopyrroledione-benzodiathiadiazole-fluorene-based conjugated polymer was chosen as polymer backbone,and polymers TBT-1 and TBT-2(TBT=thienopyrroledione-benzodiathiadiazole-thienopyrrole-dione)with red luminescence were obtained by direct arylation polymerization(DArP).By introducing linear alkyl side chains,the packing orientation is changed from face-on in TBT-1 thin film to edge-on in TBT-2 thin film,which is beneficial for improving the field effect performance.The average hole and electron mobility of TBT-2 are 1.1×10^(-2)and 2.0×10^(-3)cm^(2)·V^(-1)·s^(-1),respectively.This work provides new design strategy for high mobility luminescent conjugated polymers,which can be used in PLETs.展开更多
基金Project(50574061) supported by the National Natural Science Foundation of China
文摘Low-permeability dense reservoirs,including micro-fractured reservoirs,are commonly characterized by high content of clay substances,high original water saturation,high sensitivity to invasive fluids,high capillary pressure,complicated structure and anisotropic,high flow-resistance and micro pore throats etc,.Generally they also have lots of natural micro fractures,probably leading to stress sensibility.Main damaging factors in such reservoirs are water-sensibility and water-blocking caused by invasive fluids during drilling and production operations.Once damaged,formation permeability can rarely recovered.Numerous studies have shown that damaging extent of water-blocking ranges from 70% to 90%.Main damaging mechanisms and influencing factors of water-blocking were systematically analyzed.Also some feasible precaution or treating approaches of water-blocking were put forward.In a laboratory setting,a new multi-functional drilling fluid composed mainly of amphion polymer,sulfonation polymer,high effectively preventive water-blocking surfactants,ideal packing temporary bridging agents(TBA) and film-forming agents,etc.,were developed.New low-damage drilling fluids has many advantages,such as good rheological properties,excellent effectiveness of water-blocking prevention,good temporary plugging effect,low filtration and ultra-low permeability(API filtration≤5 mL,HTHP filtration≤10 mL,mud cake frictional coefficient≤0.14,permeability recovery>81%),can efficiently prevent or minimize damage,preserve natural formation and enhance comprehensive development-investment effect in TUHA Jurassic dense sandstone reservoir formation with low-permeability,the only one developing integrated condense gas field.Some references can be provided to similar reservoir formations.
基金financial support from the National Natural Science Foundation of China (Grant No. 51574269)the National Science Foundation for Distinguished Young Scholars of China (Grant No. 51625403)+3 种基金the Important National Science and Technology Specific Projects of China (Grant No. 2016ZX05025-003)the Fundamental Research Funds for the Central Universities (Grant No. 15CX08004A, 18CX02169A)China Postdoctoral Science Foundation (Grant No. 2017M622319)the Natural Science Foundation of Shandong Province (Grant No. ZR2018BEE004)
文摘Streamline-adjustment-assisted heterogeneous combination flooding is a new technology for enhanced oil recovery for post-polymer-flooded reservoirs.In this work,we first carried out a series of 2D visualization experiments for different chemical flooding scenarios after polymer flooding.Then,we explored the synergistic mechanisms of streamline-adjustment-assisted heterogeneous combination flooding for enhanced oil recovery and the contribution of each component.Test results show that for single heterogeneous combination flooding,the residual oil in the main streamline area after polymer flooding is ready to be driven,but it is difficult to be recovered in the non-main streamline area.Due to the effect of drainage and synergism,the streamline-adjustment-assisted heterogeneous combination flooding diverts the injected chemical agent from the main streamline area to the non-main streamline area,which consequently expands the active area of chemical flooding.Based on the results from the single-factor contribution of the quantitative analysis,the contribution of temporary plugging and profile control of branched preformed particle gels ranks in the first place and followed by the polymer profile control and the effect of streamline adjustment.On the contrary,the surfactant contributes the least to enhance the efficiency of oil displacement.
基金Supported by the National Natural Science Foundation of China (20821004)the National High Technology Research and Development Program of China (2006AA030202)the Program for New Century Excellent Talents in University of China(NCET-07-0053)
文摘The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotat-ing packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer solution with acetone as the volatile compound. The influence of the rotating speed of RPB, liquid viscos-ity, liquid flow rate, vacuum degree, and initial acetone content in the liquid on acetone removal efficiency was in-vestigated. The experimental results indicated that the removal efficiency increased with increasing rotating speed and initial acetone content in the viscous liquid and decreased with increasing liquid viscosity and flow rate. It was also observed that acetone removal efficiency increased with an increasing vacuum degree and reached 58% at a vacuum degree of 0.1 MPa. By the comparison with a flash tank devolatilizer, it was found that acetone removal ef-ficiency in RPB increased by about 67%.
基金This work was supported by the Project of the Ministry of Science and Technology of China(Nos.2022YFB3603800,2018YFA0703200)the National Natural Science Foundation of China(Nos.52233010,51725304,61890943,52103245,22021002)the CAS Project for Young Scientists in Basic Research,China(No.YSBR-053).
文摘Next generation display and lighting technology calls for thinner,cheaper and more-flexible unit devices.Polymer light emitting transistor(PLET),which integrates logic function of organic field effect transistor(OFET),luminescence function of organic light emitting diode(OLED),and potential mechanical properties,is believed to be the raising star in this field.However,great challenges remain in developing the core materials of PLETs,which simultaneously require the integration of high ambipolar mobility and strong solid-state luminescence properties.Herein,high mobility luminescent thienopyrroledione-benzodiathiadiazole-fluorene-based conjugated polymer was chosen as polymer backbone,and polymers TBT-1 and TBT-2(TBT=thienopyrroledione-benzodiathiadiazole-thienopyrrole-dione)with red luminescence were obtained by direct arylation polymerization(DArP).By introducing linear alkyl side chains,the packing orientation is changed from face-on in TBT-1 thin film to edge-on in TBT-2 thin film,which is beneficial for improving the field effect performance.The average hole and electron mobility of TBT-2 are 1.1×10^(-2)and 2.0×10^(-3)cm^(2)·V^(-1)·s^(-1),respectively.This work provides new design strategy for high mobility luminescent conjugated polymers,which can be used in PLETs.
