Accurately predicting the solubility of elemental sulfur in sour gas mixtures is a primary task.As a current and widely-used model on the solubility of elemental sulfur in sour gas mixtures,Chrastil's association ...Accurately predicting the solubility of elemental sulfur in sour gas mixtures is a primary task.As a current and widely-used model on the solubility of elemental sulfur in sour gas mixtures,Chrastil's association model has a big error in the process of predicting experimental data based on different fitting methods.This paper combined with experimental data reported by relevant scholars about elemental sulfur solubility in sour gases and selected density,temperature and pressure as three important influential factors.According to different fitting methods,we can calculate the correlation parameters in Chrastil's model.Then different solubility formulas can be used to predict the solubility of elemental sulfur in sour gas mixtures.Through in-depth research and analysis of Chrastil's solubility model from numerical aspects,it's easy to find the irrationality about Chrastil's solubility model and fitting methods.Especially in fitting methods,further improvement of the fitting method is proposed and used to predict the solubility of elemental sulfur in sour gas mixtures.The calculation results show that some improvements of the predicting precision have been achieved by using the improved fitting method in Chrastil's association model.展开更多
Unconventional reservoirs are normally characterized by dual porous media, which has both multi-scalepore and fracture structures, such as low permeability or tight oil reservoirs. The seepage characteristicsof such r...Unconventional reservoirs are normally characterized by dual porous media, which has both multi-scalepore and fracture structures, such as low permeability or tight oil reservoirs. The seepage characteristicsof such reservoirs is mainly determined by micro-fractures, but conventional laboratory experimentalmethods are difficult to measure it, which is attribute to the dynamic cracking of these micro-fractures.The emerging digital core technology in recent years can solve this problem by developing an accuratepore network model and a rational simulation approach. In this study, a novel pore-fracture dualnetwork model was established based on percolation theory. Fluid flow in the pore of two scales, microfracture and matrix pore, were considered, also with the impact of micro-fracture opening and closingduring flow. Some seepage characteristic parameters, such as fluid saturations, capillary pressure, relative permeabilities, displacement efficiency in different flow stage, can be predicted by proposedcalculating method. Through these work, seepage characteristics of dual porous media can be achieved.展开更多
基金supported by a China National Science and Technology Major Project of Oil and Gas(2016ZX05017-005)a Sichuan Youth Science and Technology Innovative Research Team of Safe and Efficient Development of Sour Gas Reservoir(2014TD0009).
文摘Accurately predicting the solubility of elemental sulfur in sour gas mixtures is a primary task.As a current and widely-used model on the solubility of elemental sulfur in sour gas mixtures,Chrastil's association model has a big error in the process of predicting experimental data based on different fitting methods.This paper combined with experimental data reported by relevant scholars about elemental sulfur solubility in sour gases and selected density,temperature and pressure as three important influential factors.According to different fitting methods,we can calculate the correlation parameters in Chrastil's model.Then different solubility formulas can be used to predict the solubility of elemental sulfur in sour gas mixtures.Through in-depth research and analysis of Chrastil's solubility model from numerical aspects,it's easy to find the irrationality about Chrastil's solubility model and fitting methods.Especially in fitting methods,further improvement of the fitting method is proposed and used to predict the solubility of elemental sulfur in sour gas mixtures.The calculation results show that some improvements of the predicting precision have been achieved by using the improved fitting method in Chrastil's association model.
基金The writers greatly appreciate the financial support of the Major Special Project of PetroChina Co Ltd.(2017E-0406)the National Science and Technology Major Project during the 13th Five-year Plan Period(2016ZX05010-00504).
文摘Unconventional reservoirs are normally characterized by dual porous media, which has both multi-scalepore and fracture structures, such as low permeability or tight oil reservoirs. The seepage characteristicsof such reservoirs is mainly determined by micro-fractures, but conventional laboratory experimentalmethods are difficult to measure it, which is attribute to the dynamic cracking of these micro-fractures.The emerging digital core technology in recent years can solve this problem by developing an accuratepore network model and a rational simulation approach. In this study, a novel pore-fracture dualnetwork model was established based on percolation theory. Fluid flow in the pore of two scales, microfracture and matrix pore, were considered, also with the impact of micro-fracture opening and closingduring flow. Some seepage characteristic parameters, such as fluid saturations, capillary pressure, relative permeabilities, displacement efficiency in different flow stage, can be predicted by proposedcalculating method. Through these work, seepage characteristics of dual porous media can be achieved.
