A general method has been developed for analyzing pressure buildup data from a well located in a system with both production and injection wells in a closed, bounded two-phase flow reservoir. The proposed method enabl...A general method has been developed for analyzing pressure buildup data from a well located in a system with both production and injection wells in a closed, bounded two-phase flow reservoir. The proposed method enables one to calculate the total mobility or permeability-thickness product, the skin factor, the average drainage-area pressure and the injection-production ratio （at the instant of shut-in） with accuracy from pressure buildup （or falloff） data dominated by a linear trend of reservoir pressure. Out of thousands of well tests, several typical field examples have been presented to illustrate the application of the proposed method for analyzing pressure transient data from a well located in a water-injection multiwell reservoir. And the possible application of this method to heterogeneous systems such as naturally fractured reservoirs is also discussed. Approaches to aid practicing engineers in verifying the buildup interpretation （or recognizing the interference of offset wells） are presented. Extension of the presented method to a gas well located in a multiwell gas reservoir is also suggested展开更多
The high degree of centerline curvature and cross-stream pressure gradient in S-inlet ducts gives rise to boundary layer separation and secondary flows, which result in poor pressure recovery and non-uniform flow in t...The high degree of centerline curvature and cross-stream pressure gradient in S-inlet ducts gives rise to boundary layer separation and secondary flows, which result in poor pressure recovery and non-uniform flow in the outlet interface with the engine. The flowfield in ducts is three-dimensional due to the existence of secondary flow, so ordinary two-dimensional actuations have poor effect on reforming the flow. Synthetic jet actuations extended in different spanwise positions were employed to manipulate the flow, and compared with the two-dimensional actuation, The interaction mechanics between flow separation and secondary flow was studied at first. It was found that the secondary flow enhanced Ol~ weakened flow separation depending on the spanwise position of synthetic jet actuators. Moreover, the J flow separation enhanced the secondary flow, thus causing lower pressure recovery and flow distortion in the duct outlet. The actuators located at different spanwise positions will weaken the secondary flows by improving the flow separation to get energetic and uniform main flow.展开更多
The purpose of this paper is to improve the aerodynamic performances of the last stage turbine and the exhaust hood of a 600MW steam turbine under design and off design conditions. During operation, strong flow intera...The purpose of this paper is to improve the aerodynamic performances of the last stage turbine and the exhaust hood of a 600MW steam turbine under design and off design conditions. During operation, strong flow interactions between the turbine and the exhaust hood impose influences on the flow behavior in the hood and lead to the unsatisfactory aerodynamic performance of the turbine and exhaust hood. So the exhaust hood has the potential to be improved in terms of aerodynamic efficiency. Considering the flow interactions between the turbine and the exhaust hood, the profiles of the diffuser end-wall were optimized. The coupled model turbine and model exhaust hood calculations and experiments were carried out to validate the effects of the optimization. Model experiments show that the design modifications resulted in a substantial increase in the overall pressure recovery coefficient. The flow and aerodynamic performances of the full-scale last stage turbine and full-scale exhaust hood were simulated to explore the flow physics alterations to the modification of diffuser geometry. The wet steam was selected as the flow medium. The actual flow fields trader different operation conditions were analyzed.展开更多
文摘A general method has been developed for analyzing pressure buildup data from a well located in a system with both production and injection wells in a closed, bounded two-phase flow reservoir. The proposed method enables one to calculate the total mobility or permeability-thickness product, the skin factor, the average drainage-area pressure and the injection-production ratio （at the instant of shut-in） with accuracy from pressure buildup （or falloff） data dominated by a linear trend of reservoir pressure. Out of thousands of well tests, several typical field examples have been presented to illustrate the application of the proposed method for analyzing pressure transient data from a well located in a water-injection multiwell reservoir. And the possible application of this method to heterogeneous systems such as naturally fractured reservoirs is also discussed. Approaches to aid practicing engineers in verifying the buildup interpretation （or recognizing the interference of offset wells） are presented. Extension of the presented method to a gas well located in a multiwell gas reservoir is also suggested
基金supported by the National Natural Science Foundation of China (Grant No. 50976007)
文摘The high degree of centerline curvature and cross-stream pressure gradient in S-inlet ducts gives rise to boundary layer separation and secondary flows, which result in poor pressure recovery and non-uniform flow in the outlet interface with the engine. The flowfield in ducts is three-dimensional due to the existence of secondary flow, so ordinary two-dimensional actuations have poor effect on reforming the flow. Synthetic jet actuations extended in different spanwise positions were employed to manipulate the flow, and compared with the two-dimensional actuation, The interaction mechanics between flow separation and secondary flow was studied at first. It was found that the secondary flow enhanced Ol~ weakened flow separation depending on the spanwise position of synthetic jet actuators. Moreover, the J flow separation enhanced the secondary flow, thus causing lower pressure recovery and flow distortion in the duct outlet. The actuators located at different spanwise positions will weaken the secondary flows by improving the flow separation to get energetic and uniform main flow.
基金financially supported by the National Natural Science Foundation of China(Grant No.51336007)
文摘The purpose of this paper is to improve the aerodynamic performances of the last stage turbine and the exhaust hood of a 600MW steam turbine under design and off design conditions. During operation, strong flow interactions between the turbine and the exhaust hood impose influences on the flow behavior in the hood and lead to the unsatisfactory aerodynamic performance of the turbine and exhaust hood. So the exhaust hood has the potential to be improved in terms of aerodynamic efficiency. Considering the flow interactions between the turbine and the exhaust hood, the profiles of the diffuser end-wall were optimized. The coupled model turbine and model exhaust hood calculations and experiments were carried out to validate the effects of the optimization. Model experiments show that the design modifications resulted in a substantial increase in the overall pressure recovery coefficient. The flow and aerodynamic performances of the full-scale last stage turbine and full-scale exhaust hood were simulated to explore the flow physics alterations to the modification of diffuser geometry. The wet steam was selected as the flow medium. The actual flow fields trader different operation conditions were analyzed.
