Naturally fractured rocks contain most of the world's petroleum reserves.This significant amount of oil can be recovered efficiently by gas assisted gravity drainage(GAGD).Although,GAGD is known as one of the most...Naturally fractured rocks contain most of the world's petroleum reserves.This significant amount of oil can be recovered efficiently by gas assisted gravity drainage(GAGD).Although,GAGD is known as one of the most effective recovery methods in reservoir engineering,the lack of available simulation and mathematical models is considerable in these kinds of reservoirs.The main goal of this study is to provide efficient and accurate methods for predicting the GAGD recovery factor using data driven techniques.The proposed models are developed to relate GAGD recovery factor to the various parameters including model height,matrix porosity and permeability,fracture porosity and permeability,dip angle,viscosity and density of wet and non-wet phases,injection rate,and production time.In this investigation,by considering the effective parameters on GAGD recovery factor,three different efficient,smart,and fast models including artificial neural network(ANN),least square support vector machine(LSSVM),and multi-gene genetic programming(MGGP)are developed and compared in both fractured and homogenous porous media.Buckinghamπtheorem is also used to generate dimensionless numbers to reduce the number of input and output parameters.The efficiency of the proposed models is examined through statistical analysis of R-squared,RMSE,MSE,ARE,and AARE.Moreover,the performance of the generated MGGP correlation is compared to the traditional models.Results demonstrate that the ANN model predicts the GAGD recovery factor more accurately than the LSSVM and MGGP models.The maximum R^(2)of 0.9677 and minimum RMSE of 0.0520 values are obtained by the ANN model.Although the MGGP model has the lowest performance among the other used models(the R2 of 0.896 and the RMSE of 0.0846),the proposed MGGP correlation can predict the GAGD recovery factor in fractured and homogenous reservoirs with high accuracy and reliability compared to the traditional models.Results reveal that the employed models can easily predict GAGD recovery factor without requiring complicate governing equations or running complex and time-consuming simulation models.The approach of this research work improves our understanding about the most significant parameters on GAGD recovery and helps to optimize the stages of the process,and make appropriate economic decisions.展开更多
Nowadays, there is a growing emphasis on Inter-basin water transfer projects as costly activities with ambiguous effects on environment, society and economy. Since the concept of climate change was in its embryonic ph...Nowadays, there is a growing emphasis on Inter-basin water transfer projects as costly activities with ambiguous effects on environment, society and economy. Since the concept of climate change was in its embryonic phase before 1990’s, the majority of these projects planned before that period have not considered the effect of long term variation of water resources. In all of these numerous operational and under-construction projects, an intelligent selection of the best water transmission protocol, can help the governments to optimize their expenditures on these projects ,and also can help water resources managers to face climate change effects wisely. In this paper as a case study, Dez to Qomrood inter-basin water transfer project is considered to evaluate the efficiency of three different protocols in long term. The effect of climate change has been forecasted via a wide range of GCMs (Global Circulation Model) in order to calculate the change of flow in the basin's area with different climate scenarios. After these calculation, a water allocation model has been used to evaluate which of these three water transmission protocols (Proportional Allocation (PA), Fix Upstream allocation (FU), and Fix Downstream allocation (FD)) is the most efficient logic switch economically in a framework including both upstream and downstream stakeholders. As the final result, it can be inferred that Fix Downstream allocation (FD) protocol can supply more population especially with urban water for a fix expense and also is the most adapted protocol with future global change, at least in the first round of sustainability assessment.展开更多
文摘Naturally fractured rocks contain most of the world's petroleum reserves.This significant amount of oil can be recovered efficiently by gas assisted gravity drainage(GAGD).Although,GAGD is known as one of the most effective recovery methods in reservoir engineering,the lack of available simulation and mathematical models is considerable in these kinds of reservoirs.The main goal of this study is to provide efficient and accurate methods for predicting the GAGD recovery factor using data driven techniques.The proposed models are developed to relate GAGD recovery factor to the various parameters including model height,matrix porosity and permeability,fracture porosity and permeability,dip angle,viscosity and density of wet and non-wet phases,injection rate,and production time.In this investigation,by considering the effective parameters on GAGD recovery factor,three different efficient,smart,and fast models including artificial neural network(ANN),least square support vector machine(LSSVM),and multi-gene genetic programming(MGGP)are developed and compared in both fractured and homogenous porous media.Buckinghamπtheorem is also used to generate dimensionless numbers to reduce the number of input and output parameters.The efficiency of the proposed models is examined through statistical analysis of R-squared,RMSE,MSE,ARE,and AARE.Moreover,the performance of the generated MGGP correlation is compared to the traditional models.Results demonstrate that the ANN model predicts the GAGD recovery factor more accurately than the LSSVM and MGGP models.The maximum R^(2)of 0.9677 and minimum RMSE of 0.0520 values are obtained by the ANN model.Although the MGGP model has the lowest performance among the other used models(the R2 of 0.896 and the RMSE of 0.0846),the proposed MGGP correlation can predict the GAGD recovery factor in fractured and homogenous reservoirs with high accuracy and reliability compared to the traditional models.Results reveal that the employed models can easily predict GAGD recovery factor without requiring complicate governing equations or running complex and time-consuming simulation models.The approach of this research work improves our understanding about the most significant parameters on GAGD recovery and helps to optimize the stages of the process,and make appropriate economic decisions.
文摘Nowadays, there is a growing emphasis on Inter-basin water transfer projects as costly activities with ambiguous effects on environment, society and economy. Since the concept of climate change was in its embryonic phase before 1990’s, the majority of these projects planned before that period have not considered the effect of long term variation of water resources. In all of these numerous operational and under-construction projects, an intelligent selection of the best water transmission protocol, can help the governments to optimize their expenditures on these projects ,and also can help water resources managers to face climate change effects wisely. In this paper as a case study, Dez to Qomrood inter-basin water transfer project is considered to evaluate the efficiency of three different protocols in long term. The effect of climate change has been forecasted via a wide range of GCMs (Global Circulation Model) in order to calculate the change of flow in the basin's area with different climate scenarios. After these calculation, a water allocation model has been used to evaluate which of these three water transmission protocols (Proportional Allocation (PA), Fix Upstream allocation (FU), and Fix Downstream allocation (FD)) is the most efficient logic switch economically in a framework including both upstream and downstream stakeholders. As the final result, it can be inferred that Fix Downstream allocation (FD) protocol can supply more population especially with urban water for a fix expense and also is the most adapted protocol with future global change, at least in the first round of sustainability assessment.
