The high pressure static adsorption curves of shale samples from Silurian Changning-Weiyuan Longmaxi Formation were tested by using high pressure isothermal adsorption equipment.The physical modeling of depletion prod...The high pressure static adsorption curves of shale samples from Silurian Changning-Weiyuan Longmaxi Formation were tested by using high pressure isothermal adsorption equipment.The physical modeling of depletion production was tested on single cores and multi-core series by using self-developed shale gas fluid-solid coupling experiment system.The adsorption and desorption laws were summarized and a high pressure isothermal adsorption model was established.The calculation formula of gas content was corrected,and the producing law of adsorption gas was determined.The study results show that the isothermal adsorption law of the shale reservoir under high pressure was different from the conventional low pressure.The high pressure isothermal adsorption curve had the maximum value in excess adsorption with pressure change,and the corresponding pressure was the critical desorption pressure.The high pressure isothermal curve can be used to evaluate the amount of adsorbed gas and the producing degree of adsorption gas.The high pressure isothermal adsorption model can fit and characterize the high pressure isothermal adsorption law of shale.The modified gas content calculation method can evaluate the gas content and the proportion of adsorbed gas more objectively,and is the theoretical basis of reserve assessment and production decline analysis.The producing degree of adsorption gas is closely related to the pressure,only when the reservoir pressure is lower than the critical desorption pressure,the adsorption gas can be produced effectively.In the process of gas well production,the pressure drop in the near-well area is large,the production of adsorption gas is high;away from the wellbore,the adsorption gas is low in production,or no production.展开更多
In this work,an equilibrium-dispersion model was successfully established to describe the breakthrough performance of Ca(II) imprinted chitosan(Ca(II)-CS) microspheres packed column for metal adsorption,and the assump...In this work,an equilibrium-dispersion model was successfully established to describe the breakthrough performance of Ca(II) imprinted chitosan(Ca(II)-CS) microspheres packed column for metal adsorption,and the assumptions of Langmuir isotherms and axial dispersion controlled mass transfer process were confirmed.The axial dispersion coefficient in Ca(II)-CS microspheres packed column was found to be almost proportional to the linear velocity and fit for prediction through single breakthrough test.Sensitivity analysis for breakthrough curve indicated the axial dispersion coefficient as well as Langmuir coefficient was sensitive variable for deep removal requirement.The retrieval of the adsorption isotherms of Ca(II)-CS microspheres from breakthrough curve was fulfilled by modelling calibration.A strategy based on the correlation between adsorption isotherms and breakthrough performance was further proposed to simplify the column adsorption design using absorbents with small/uniform size and fast adsorption kinetics like Ca(II)-CS microspheres to cut down the gap between lab and industry.展开更多
Adsorption isotherm is the most fundamental information related to chromatography. To calculate the parameters of Langmuir ad-sorption isotherm of thymidine, frontal analysis (FA) and elution-curve method (ECM) were a...Adsorption isotherm is the most fundamental information related to chromatography. To calculate the parameters of Langmuir ad-sorption isotherm of thymidine, frontal analysis (FA) and elution-curve method (ECM) were adopted in reversed-phase high performance liguid chromatography (RP-HPLC). In FA, the concentration of stationary phase was measured from the elution curves and the isotherm was deter-mined by regression analysis, while the parameters by ECM were obtained by parameter optimization. The adsorption isotherms of thymidine from the two methods were very similar. The superiority of ECM over FA was that the consumption of sample was less and only one or two in-jections of sample were required.展开更多
基金Supported by China National Science and Technology Major Project(2017ZX05037-001)the "13th Five-Year Plan" National Demonstration Project(2016ZX05062-002-001)
文摘The high pressure static adsorption curves of shale samples from Silurian Changning-Weiyuan Longmaxi Formation were tested by using high pressure isothermal adsorption equipment.The physical modeling of depletion production was tested on single cores and multi-core series by using self-developed shale gas fluid-solid coupling experiment system.The adsorption and desorption laws were summarized and a high pressure isothermal adsorption model was established.The calculation formula of gas content was corrected,and the producing law of adsorption gas was determined.The study results show that the isothermal adsorption law of the shale reservoir under high pressure was different from the conventional low pressure.The high pressure isothermal adsorption curve had the maximum value in excess adsorption with pressure change,and the corresponding pressure was the critical desorption pressure.The high pressure isothermal curve can be used to evaluate the amount of adsorbed gas and the producing degree of adsorption gas.The high pressure isothermal adsorption model can fit and characterize the high pressure isothermal adsorption law of shale.The modified gas content calculation method can evaluate the gas content and the proportion of adsorbed gas more objectively,and is the theoretical basis of reserve assessment and production decline analysis.The producing degree of adsorption gas is closely related to the pressure,only when the reservoir pressure is lower than the critical desorption pressure,the adsorption gas can be produced effectively.In the process of gas well production,the pressure drop in the near-well area is large,the production of adsorption gas is high;away from the wellbore,the adsorption gas is low in production,or no production.
基金the National Natural Science Foundation of China(2117613621422603)the National Science and Technology Support Program of China(2011BAC06B01)
文摘In this work,an equilibrium-dispersion model was successfully established to describe the breakthrough performance of Ca(II) imprinted chitosan(Ca(II)-CS) microspheres packed column for metal adsorption,and the assumptions of Langmuir isotherms and axial dispersion controlled mass transfer process were confirmed.The axial dispersion coefficient in Ca(II)-CS microspheres packed column was found to be almost proportional to the linear velocity and fit for prediction through single breakthrough test.Sensitivity analysis for breakthrough curve indicated the axial dispersion coefficient as well as Langmuir coefficient was sensitive variable for deep removal requirement.The retrieval of the adsorption isotherms of Ca(II)-CS microspheres from breakthrough curve was fulfilled by modelling calibration.A strategy based on the correlation between adsorption isotherms and breakthrough performance was further proposed to simplify the column adsorption design using absorbents with small/uniform size and fast adsorption kinetics like Ca(II)-CS microspheres to cut down the gap between lab and industry.
文摘Adsorption isotherm is the most fundamental information related to chromatography. To calculate the parameters of Langmuir ad-sorption isotherm of thymidine, frontal analysis (FA) and elution-curve method (ECM) were adopted in reversed-phase high performance liguid chromatography (RP-HPLC). In FA, the concentration of stationary phase was measured from the elution curves and the isotherm was deter-mined by regression analysis, while the parameters by ECM were obtained by parameter optimization. The adsorption isotherms of thymidine from the two methods were very similar. The superiority of ECM over FA was that the consumption of sample was less and only one or two in-jections of sample were required.
