Almost all sandstone reservoirs contain interlayers. The identification and characterization of these interlayers iscritical for minimizing the uncertainty associated with oilfield development and improving oil and ga...Almost all sandstone reservoirs contain interlayers. The identification and characterization of these interlayers iscritical for minimizing the uncertainty associated with oilfield development and improving oil and gas recovery.Identifying interlayers outside wells using identification methods based on logging data and machine learning isdifficult and seismic-based identification techniques are expensive. Herein, a numerical model based on seepageand well-testing theories is introduced to identify interlayers using transient pressure data. The proposed modelrelies on the open-source MATLAB Reservoir Simulation Toolbox. The effects of the interlayer thickness, position,and width on the pressure response are thoroughly investigated. A procedure for inverting interlayer parametersin the reservoir using the bottom-hole pressure is also proposed. This method uses only transient pressuredata during well testing and can effectively identify the interlayer distribution near the wellbore at an extremelylow cost. The reliability of the model is verified using effective oilfield examples.展开更多
The ultrasonic-assisted extraction of polysaccharides from Hibiscus syriacus L. at 180 W low power was optimized by the single factor tests and orthogonal test. Extraction temperature,ultrasonic treatment time,extract...The ultrasonic-assisted extraction of polysaccharides from Hibiscus syriacus L. at 180 W low power was optimized by the single factor tests and orthogonal test. Extraction temperature,ultrasonic treatment time,extraction times,and material-to-liquid ratio were considered as independent variables. The results suggested that the best extraction condition were determined as the extraction temperature at 80 ℃,the ultrasonic treatment time of 40 min,the material-to-liquid ratio at1∶ 20（ g/ml）,and the extraction times of 3. Under the optimal conditions,the extraction rate of polysaccharides from Hibiscus syriacus was 3. 114%.展开更多
The discharge of large amounts of dye-containing wastewater seriously threats the environment.Adsorbents have been adopted to remove these dyes present in the wastewater.However,the high adsorption capacity,predominan...The discharge of large amounts of dye-containing wastewater seriously threats the environment.Adsorbents have been adopted to remove these dyes present in the wastewater.However,the high adsorption capacity,predominant pH-responsibility,and excellent recyclability are three challenges to the development of efficient adsorbents.The poly(acryloxyethyl trimethylammonium chloride)-graft-dialdehyde cellulose nanocrystals were synthesized in our work.Subsequently,the cationic dialdehyde cellulose nanocrystal cross-linked chitosan nanocomposite foam was fabricated via freeze-drying of the hydrogel.Under the optimal ratio of the cationic dialdehyde cellulose nanocrystal/chitosan(w/w)of 12/100,the resultant foam(Foam-12)possesses excellent absorption properties,such as high porosity,high content of active sites,strong acid resistance,and high amorphous region.Then,Foam-12 was applied as an eco-friendly adsorbent to remove acid red 134(a representative of anionic dyes)from aqueous solutions.The maximum dye adsorption capacity of 1238.1 mg∙g^(‒1) is achieved under the conditions of 20 mg∙L‒1 adsorbents,100 mg∙L^(‒1) dye,pH 3.5,24 h,and 25℃.The dominant adsorption mechanism for the anionic dye adsorption is electrostatic attraction,and Foam-12 can effectively adsorb acid red 134 at pH 2.5–5.5 and be desorbed at pH 8.Its easy recovery and good reusability are verified by the repeated acid adsorption–alkaline desorption experiments.展开更多
文摘Almost all sandstone reservoirs contain interlayers. The identification and characterization of these interlayers iscritical for minimizing the uncertainty associated with oilfield development and improving oil and gas recovery.Identifying interlayers outside wells using identification methods based on logging data and machine learning isdifficult and seismic-based identification techniques are expensive. Herein, a numerical model based on seepageand well-testing theories is introduced to identify interlayers using transient pressure data. The proposed modelrelies on the open-source MATLAB Reservoir Simulation Toolbox. The effects of the interlayer thickness, position,and width on the pressure response are thoroughly investigated. A procedure for inverting interlayer parametersin the reservoir using the bottom-hole pressure is also proposed. This method uses only transient pressuredata during well testing and can effectively identify the interlayer distribution near the wellbore at an extremelylow cost. The reliability of the model is verified using effective oilfield examples.
基金Supported by College Students’Innovative Experiment Project of Hunan Province(2015-49)Outstanding Youth Project of Education Department of Hunan Province(17B139)+1 种基金Innovation Platform Open Fund of Education Department of Hunan Province(15K066)Loudi Science and Technologe Planning Project(Hunan Fanicial and Educational Project 2015-57)
文摘The ultrasonic-assisted extraction of polysaccharides from Hibiscus syriacus L. at 180 W low power was optimized by the single factor tests and orthogonal test. Extraction temperature,ultrasonic treatment time,extraction times,and material-to-liquid ratio were considered as independent variables. The results suggested that the best extraction condition were determined as the extraction temperature at 80 ℃,the ultrasonic treatment time of 40 min,the material-to-liquid ratio at1∶ 20（ g/ml）,and the extraction times of 3. Under the optimal conditions,the extraction rate of polysaccharides from Hibiscus syriacus was 3. 114%.
基金This work was supported by the Natural Science Advance Research Foundation of Shaanxi University of Science and Technology(Grant No.2020XSGG-07)the Key Research and Development Program of Shaanxi Province(Grant No.2022GY-278)the Natural Science Basic Research Program of Shannxi(Program No.2023-JC-YB-104).
文摘The discharge of large amounts of dye-containing wastewater seriously threats the environment.Adsorbents have been adopted to remove these dyes present in the wastewater.However,the high adsorption capacity,predominant pH-responsibility,and excellent recyclability are three challenges to the development of efficient adsorbents.The poly(acryloxyethyl trimethylammonium chloride)-graft-dialdehyde cellulose nanocrystals were synthesized in our work.Subsequently,the cationic dialdehyde cellulose nanocrystal cross-linked chitosan nanocomposite foam was fabricated via freeze-drying of the hydrogel.Under the optimal ratio of the cationic dialdehyde cellulose nanocrystal/chitosan(w/w)of 12/100,the resultant foam(Foam-12)possesses excellent absorption properties,such as high porosity,high content of active sites,strong acid resistance,and high amorphous region.Then,Foam-12 was applied as an eco-friendly adsorbent to remove acid red 134(a representative of anionic dyes)from aqueous solutions.The maximum dye adsorption capacity of 1238.1 mg∙g^(‒1) is achieved under the conditions of 20 mg∙L‒1 adsorbents,100 mg∙L^(‒1) dye,pH 3.5,24 h,and 25℃.The dominant adsorption mechanism for the anionic dye adsorption is electrostatic attraction,and Foam-12 can effectively adsorb acid red 134 at pH 2.5–5.5 and be desorbed at pH 8.Its easy recovery and good reusability are verified by the repeated acid adsorption–alkaline desorption experiments.
