An inherent problem with both oil and natural gas production is the deposition of sand particles in pipeline,which could lead to problems such as excessive pressure drops,equipment failure,pipeline erosion,and product...An inherent problem with both oil and natural gas production is the deposition of sand particles in pipeline,which could lead to problems such as excessive pressure drops,equipment failure,pipeline erosion,and production decline.The characterization of sand particles transport and sedimentation in different flow systems such as sandemultiphase mixtures is vital to predict the sand transport velocity and entrainment processes in oil and gas transportation pipelines.However,it seems that no model exists able to accurately characterize the sand transport and deposition in multiphase pipeline.In fact,in the last decade several researchers tried to extend the modeling of liquid-solid flow to gas-liquid-solid flow,but no significant results have been obtained,especially in slug flow condition due to the complexity of the phenomenon.In order to develop and validate a mathematical model properly formulated for the calculation of the sand critical deposition velocity in gas-liquid flow,more and more experimental data are necessary.This paper presents a preliminary experimental study of three phase flows(air-water-sand)inside a horizontal pipe and the application of the sand-liquid models present in literature.Significant observations were made during the experimental study from which several conclusions were drawn.Different sand flow regimes were established by physical observation and data analysis:fully dispersed solid flow,moving dunes and stationary bed.The critical deposition velocities were determined at different sand concentrations.It was concluded that sand transport characteristics and the critical deposition velocity are strongly dependent on the gas-liquid flow regime and on sand concentration.展开更多
This paper presents the results of a sensitivity study carried out to investigate the performances of two commercial codes,OLGA and LedaFlow,used to model the wax deposition process in pipelines under multiphase flow....This paper presents the results of a sensitivity study carried out to investigate the performances of two commercial codes,OLGA and LedaFlow,used to model the wax deposition process in pipelines under multiphase flow.Reliable simulations of the phenomenon are essential to properly design pipelines and to adopt cost-effective strategies for prevention and removal of wax deposits,reducing the risks of blockage.The main limit of the available models is that their predictions depend on a number of parameters which are usually adjusted to fit the experimental data obtained from laboratory deposition tests.Since a reliable upscale criterion has not been developed yet,model predictions have been more suitably validated using real field data,reported in literature.The performances of the commercial codes in modelling wax precipitation and deposition have been compared to each other.展开更多
This paper presents the development and application of an innovative code to extract in an automated way data from the thermo-hydraulic simulator Olga.The results show that the tool can significantly reduce the time n...This paper presents the development and application of an innovative code to extract in an automated way data from the thermo-hydraulic simulator Olga.The results show that the tool can significantly reduce the time needed for the data extraction procedure and increase the reliability of results due to the fact that there is no more the need of the human operator.Moreover,during the data extraction phase,the Olga code is available for running different simulations allowing to optimize the use of this resource.展开更多
文摘An inherent problem with both oil and natural gas production is the deposition of sand particles in pipeline,which could lead to problems such as excessive pressure drops,equipment failure,pipeline erosion,and production decline.The characterization of sand particles transport and sedimentation in different flow systems such as sandemultiphase mixtures is vital to predict the sand transport velocity and entrainment processes in oil and gas transportation pipelines.However,it seems that no model exists able to accurately characterize the sand transport and deposition in multiphase pipeline.In fact,in the last decade several researchers tried to extend the modeling of liquid-solid flow to gas-liquid-solid flow,but no significant results have been obtained,especially in slug flow condition due to the complexity of the phenomenon.In order to develop and validate a mathematical model properly formulated for the calculation of the sand critical deposition velocity in gas-liquid flow,more and more experimental data are necessary.This paper presents a preliminary experimental study of three phase flows(air-water-sand)inside a horizontal pipe and the application of the sand-liquid models present in literature.Significant observations were made during the experimental study from which several conclusions were drawn.Different sand flow regimes were established by physical observation and data analysis:fully dispersed solid flow,moving dunes and stationary bed.The critical deposition velocities were determined at different sand concentrations.It was concluded that sand transport characteristics and the critical deposition velocity are strongly dependent on the gas-liquid flow regime and on sand concentration.
文摘This paper presents the results of a sensitivity study carried out to investigate the performances of two commercial codes,OLGA and LedaFlow,used to model the wax deposition process in pipelines under multiphase flow.Reliable simulations of the phenomenon are essential to properly design pipelines and to adopt cost-effective strategies for prevention and removal of wax deposits,reducing the risks of blockage.The main limit of the available models is that their predictions depend on a number of parameters which are usually adjusted to fit the experimental data obtained from laboratory deposition tests.Since a reliable upscale criterion has not been developed yet,model predictions have been more suitably validated using real field data,reported in literature.The performances of the commercial codes in modelling wax precipitation and deposition have been compared to each other.
文摘This paper presents the development and application of an innovative code to extract in an automated way data from the thermo-hydraulic simulator Olga.The results show that the tool can significantly reduce the time needed for the data extraction procedure and increase the reliability of results due to the fact that there is no more the need of the human operator.Moreover,during the data extraction phase,the Olga code is available for running different simulations allowing to optimize the use of this resource.
