For many years,the most common acid practice for sandstone acidizing is based on mud acid and dolomite formations using hydrochloric acid.During various stages of sandstone acidizing,different acids react with differe...For many years,the most common acid practice for sandstone acidizing is based on mud acid and dolomite formations using hydrochloric acid.During various stages of sandstone acidizing,different acids react with different minerals,and interactions of minerals with acids are an origin for precipitation reactions,which can be possibly deleterious as they may reduce reservoir permeability.During this research,the effects of chelates on pore size distribution,mineralogy,and grain size distribution have been investigated.Various chelates(GLDA,HEDTA,EDTA)were examined to react with different Berea Sandstone samples at a temperature of 180F and under 1000 psi confining pressure.Experimental techniques and analysis like Tescan Integrated Mineral Analysis(TIMA),were implemented in this research to understand the effect of chelates on Berea Sandstone.These results are related to elemental mass,element deportment,mineral mass,mineral locking,grain size distribution,and particle size distribution of the core samples reacted with different chelating agents.It has been found that all the chelating agents are effective in increasing the porosity and dissolving the cations from the Berea sandstone core sample.HEDTA proved to be more effective in dissolving quartz as compared to other chelates.GLDA proved to be more effective in the dissolution of rutile and zircon minerals.The significance of this research is the application of environment-friendly chelating agents to sandstone formation.Moreover,the detailed mineral analysis revealed that the most number of particles were dissolved by HEDTA.展开更多
In this work,the authors monitored the formation and dissociation process of methane hydrate in four different rock core samples through nuclear magnetic resonance(NMR)relaxation time(T_(2))and 2D imaging measurement....In this work,the authors monitored the formation and dissociation process of methane hydrate in four different rock core samples through nuclear magnetic resonance(NMR)relaxation time(T_(2))and 2D imaging measurement.The result shows that the intensity of T_(2) spectra and magnetic resonance imaging(MRI)signals gradually decreases in the hydrate formation process,and at the same time,the T_(2) spectra move toward the left domain as the growth of hydrate in the pores of the sample accelerates the decay rate.The hydrate grows and dissociates preferentially in the purer sandstone samples with larger pore size and higher porosity.Significantly,for the sample with lower porosity and higher argillaceous content,the intensity of the T_(2) spectra also shows a trend of a great decrease in the hydrate formation process,which means that high-saturation gas hydrate can also be formed in the sample with higher argillaceous content.The changes in MRI of the sample in the process show that the formation and dissociation of methane hydrate can reshape the distribution of water in the pores.展开更多
文摘For many years,the most common acid practice for sandstone acidizing is based on mud acid and dolomite formations using hydrochloric acid.During various stages of sandstone acidizing,different acids react with different minerals,and interactions of minerals with acids are an origin for precipitation reactions,which can be possibly deleterious as they may reduce reservoir permeability.During this research,the effects of chelates on pore size distribution,mineralogy,and grain size distribution have been investigated.Various chelates(GLDA,HEDTA,EDTA)were examined to react with different Berea Sandstone samples at a temperature of 180F and under 1000 psi confining pressure.Experimental techniques and analysis like Tescan Integrated Mineral Analysis(TIMA),were implemented in this research to understand the effect of chelates on Berea Sandstone.These results are related to elemental mass,element deportment,mineral mass,mineral locking,grain size distribution,and particle size distribution of the core samples reacted with different chelating agents.It has been found that all the chelating agents are effective in increasing the porosity and dissolving the cations from the Berea sandstone core sample.HEDTA proved to be more effective in dissolving quartz as compared to other chelates.GLDA proved to be more effective in the dissolution of rutile and zircon minerals.The significance of this research is the application of environment-friendly chelating agents to sandstone formation.Moreover,the detailed mineral analysis revealed that the most number of particles were dissolved by HEDTA.
基金supported by the Guangdong Province Marine Economic Development(Six Major Marine Industries)Special Fund Project([2021]56)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0105)+1 种基金the Guangzhou Science and Technology Project(202201011463)project of the China Geological Survey(DD20211350).
文摘In this work,the authors monitored the formation and dissociation process of methane hydrate in four different rock core samples through nuclear magnetic resonance(NMR)relaxation time(T_(2))and 2D imaging measurement.The result shows that the intensity of T_(2) spectra and magnetic resonance imaging(MRI)signals gradually decreases in the hydrate formation process,and at the same time,the T_(2) spectra move toward the left domain as the growth of hydrate in the pores of the sample accelerates the decay rate.The hydrate grows and dissociates preferentially in the purer sandstone samples with larger pore size and higher porosity.Significantly,for the sample with lower porosity and higher argillaceous content,the intensity of the T_(2) spectra also shows a trend of a great decrease in the hydrate formation process,which means that high-saturation gas hydrate can also be formed in the sample with higher argillaceous content.The changes in MRI of the sample in the process show that the formation and dissociation of methane hydrate can reshape the distribution of water in the pores.
