The formation and dissociation of methane gas hydrate at an interface between synthetic seawater （SSW） and methane gas have been experimentally investigated in the present work. The amount of gas consumed during hyd...The formation and dissociation of methane gas hydrate at an interface between synthetic seawater （SSW） and methane gas have been experimentally investigated in the present work. The amount of gas consumed during hydrate formation has been calculated using the real gas equation. Induction time for the formation of hydrate is found to depend on the degree of subcooling. All the experiments were conducted in quiescent system with initial cell pressure of 11.14 MPa. Salinity effects on the onset pressure and temperature of hydrate formation are also observed. The dissociation enthalpies of methane hydrate in synthetic seawater were determined by Clausius-Clapeyron equation based on the measured phase equilibrium data. The dissociation data have been analyzed by existing models and compared with the reported data.展开更多
Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural gases.However,factors like slow formation rate and limited storage capacity obstruct the possible ind...Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural gases.However,factors like slow formation rate and limited storage capacity obstruct the possible industrial application of this technique.Different types of promoters and synergists have been developed that can improve the kinetics and storage capacity of gas hydrates.This review focuses on different kinetic promoters and synergists that can be utilized to enhance the storage capacity of hydrates.The main characteristics,structure and the possible limitations of the use of these promoters are likewise portrayed in detail.The relationship between structure and storage capacity of hydrates have also been discussed in the review.Current status of production of gas from hydrates,their restrictions,and future difficulties have additionally been addressed in the ensuing areas of the review.展开更多
In this work, the effect of sodium dodecyl sulfate(SDS) and combined effect of sodium dodecyl sulfate(SDS) and tetrahydrofuran(THF) on thermodynamic and kinetic properties of CH4+C2H6+C3H8hydrate formation have been s...In this work, the effect of sodium dodecyl sulfate(SDS) and combined effect of sodium dodecyl sulfate(SDS) and tetrahydrofuran(THF) on thermodynamic and kinetic properties of CH4+C2H6+C3H8hydrate formation have been studied. Four different concentrations of sodium dodecyl sulfate(100 ppm, 500 ppm,1000 ppm and 1500 ppm) have been used to see its effect on phase equilibrium condition and formation kinetics. Though sodium dodecyl sulfate(SDS) does not vary the pressure–temperature condition of hydrate formation, it has a prominent favorable effect on induction time, gas consumption, storage capacity and formation rate. The addition of 3%(mol) tetrahydrofuran(THF) to water + SDS system results in large shifts in phase equilibrium boundary to lower pressure and higher temperature. It has been noticed that the addition of tetrahydrofuran further enhances the formation rate. So the mixture of sodium dodecyl sulfate(SDS) and tetrahydrofuran(THF) can be effectively used as promoter for storing natural gas as hydrate.展开更多
A low-viscosity emulsion of crude oil in water can be believed to be the bulk of a flow regime in a pipeline.To differentiate which crude oil would and which would not counter the blockage of flow due to gas hydrate f...A low-viscosity emulsion of crude oil in water can be believed to be the bulk of a flow regime in a pipeline.To differentiate which crude oil would and which would not counter the blockage of flow due to gas hydrate formation in flow channels,varying amount of crude oil in water emulsion without any other extraneous additives has undergone methane gas hydrate formation in an autoclave cell.Crude oil was able to thermodynamically inhibit the gas hydrate formation as observed from its hydrate stability zone.The normalized rate of hydrate formation in the emulsion has been calculated from an illustrative chemical affinity model,which showed a decrease in the methane consumption（decreased normalized rate constant） with an increase in the oil content in the emulsion.Fourier transform infrared spectroscopy（FTIR） of the emulsion and characteristic properties of the crude oil have been used to find the chemical component that could be pivotal in selfinhibitory characteristic of the crude oil collected from Ankleshwar,India,against a situation of clogged flow due to formation of gas hydrate and establish flow assurance.展开更多
基金supported by the University Grant Commission,New Delhi,India,under Special Assistance Program (SAP) to the Department of Petroleum Engineering,Indian School of Mines,Dhanbad,India.
文摘The formation and dissociation of methane gas hydrate at an interface between synthetic seawater （SSW） and methane gas have been experimentally investigated in the present work. The amount of gas consumed during hydrate formation has been calculated using the real gas equation. Induction time for the formation of hydrate is found to depend on the degree of subcooling. All the experiments were conducted in quiescent system with initial cell pressure of 11.14 MPa. Salinity effects on the onset pressure and temperature of hydrate formation are also observed. The dissociation enthalpies of methane hydrate in synthetic seawater were determined by Clausius-Clapeyron equation based on the measured phase equilibrium data. The dissociation data have been analyzed by existing models and compared with the reported data.
基金We gratefully acknowledge the financial assistance provided by Science and Engineering Research Board(SERB)under the Department of Science and Technology(DST)New Delhi,India,and Ministry of Earth Sciences(MoES)Government of India,New Delhi to the Department of Petroleum Engineering,Indian Institute of Techology(ISM),Dhanbad,India.
文摘Gas hydrates have recently emerged as a better alternative for the production,storage,and transportation of natural gases.However,factors like slow formation rate and limited storage capacity obstruct the possible industrial application of this technique.Different types of promoters and synergists have been developed that can improve the kinetics and storage capacity of gas hydrates.This review focuses on different kinetic promoters and synergists that can be utilized to enhance the storage capacity of hydrates.The main characteristics,structure and the possible limitations of the use of these promoters are likewise portrayed in detail.The relationship between structure and storage capacity of hydrates have also been discussed in the review.Current status of production of gas from hydrates,their restrictions,and future difficulties have additionally been addressed in the ensuing areas of the review.
基金the financial assistance provided by University Grants Commission, New Delhi, India, under Special Assistance Program (SAP) to the Department of Petroleum Engineering, Indian School of Mines, Dhanbad, India
文摘In this work, the effect of sodium dodecyl sulfate(SDS) and combined effect of sodium dodecyl sulfate(SDS) and tetrahydrofuran(THF) on thermodynamic and kinetic properties of CH4+C2H6+C3H8hydrate formation have been studied. Four different concentrations of sodium dodecyl sulfate(100 ppm, 500 ppm,1000 ppm and 1500 ppm) have been used to see its effect on phase equilibrium condition and formation kinetics. Though sodium dodecyl sulfate(SDS) does not vary the pressure–temperature condition of hydrate formation, it has a prominent favorable effect on induction time, gas consumption, storage capacity and formation rate. The addition of 3%(mol) tetrahydrofuran(THF) to water + SDS system results in large shifts in phase equilibrium boundary to lower pressure and higher temperature. It has been noticed that the addition of tetrahydrofuran further enhances the formation rate. So the mixture of sodium dodecyl sulfate(SDS) and tetrahydrofuran(THF) can be effectively used as promoter for storing natural gas as hydrate.
基金the financial assistance provided by University Grants Commission, New Delhi, India, under Special Assistance Program (SAP) to the Department of Petroleum Engineering, Indian School of Mines, Dhanbad, India
文摘A low-viscosity emulsion of crude oil in water can be believed to be the bulk of a flow regime in a pipeline.To differentiate which crude oil would and which would not counter the blockage of flow due to gas hydrate formation in flow channels,varying amount of crude oil in water emulsion without any other extraneous additives has undergone methane gas hydrate formation in an autoclave cell.Crude oil was able to thermodynamically inhibit the gas hydrate formation as observed from its hydrate stability zone.The normalized rate of hydrate formation in the emulsion has been calculated from an illustrative chemical affinity model,which showed a decrease in the methane consumption（decreased normalized rate constant） with an increase in the oil content in the emulsion.Fourier transform infrared spectroscopy（FTIR） of the emulsion and characteristic properties of the crude oil have been used to find the chemical component that could be pivotal in selfinhibitory characteristic of the crude oil collected from Ankleshwar,India,against a situation of clogged flow due to formation of gas hydrate and establish flow assurance.
