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 suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muf...The suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muffler affects the operation of the compressor owing to gas pressure drop, which causes volumetric and energetic efficiency loss due to the gas specific volume augmentation. Therefore, there is a compromise between sound attenuation and pressure drop increase, which has to be taken into account by compressor designers. In this work, it presents a numerical solution to the flow through a suction muffler in order to analyze the pressure field and point out the main contributions to the overall pressure drop of the flow. A commercial CFD （computational fluid dynamics） code was used to perform the numerical simulations and the results were validated by using experimental data. After analyzing the pressure field, the geometry of the muffler was modified intending to decrease the flow pressure drop. The geometric modification produced a 28% reduction on the overall pressure drop, without influencing the sound attenuation.展开更多
We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes. In the case of free surface incompressible flows, the FS-model is formally obtained, using form...We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes. In the case of free surface incompressible flows, the FS-model is formally obtained, using formal asymptotic analysis, which is an extension to more classical shallow water models. In the same way, when the pipe is full, we propose the P-model, which describes the evolution of a compressible inviscid flow, close to gas dynamics equations in a nozzle. In order to cope with the transition between a free surface state and a pressured （i.e., compressible） state, we propose a mixed model, the PFS-model, taking into account changes of section and slope variation.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
文摘The suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muffler affects the operation of the compressor owing to gas pressure drop, which causes volumetric and energetic efficiency loss due to the gas specific volume augmentation. Therefore, there is a compromise between sound attenuation and pressure drop increase, which has to be taken into account by compressor designers. In this work, it presents a numerical solution to the flow through a suction muffler in order to analyze the pressure field and point out the main contributions to the overall pressure drop of the flow. A commercial CFD （computational fluid dynamics） code was used to perform the numerical simulations and the results were validated by using experimental data. After analyzing the pressure field, the geometry of the muffler was modified intending to decrease the flow pressure drop. The geometric modification produced a 28% reduction on the overall pressure drop, without influencing the sound attenuation.
文摘We present the formal derivation of a new unidirectional model for unsteady mixed flows in nonuniform closed water pipes. In the case of free surface incompressible flows, the FS-model is formally obtained, using formal asymptotic analysis, which is an extension to more classical shallow water models. In the same way, when the pipe is full, we propose the P-model, which describes the evolution of a compressible inviscid flow, close to gas dynamics equations in a nozzle. In order to cope with the transition between a free surface state and a pressured （i.e., compressible） state, we propose a mixed model, the PFS-model, taking into account changes of section and slope variation.
