The influence of an acoustic logging tool on borehole guided wave propagation should be considered in the processing and inversion of the guided waves for formation acoustic property estimation. This study introduces ...The influence of an acoustic logging tool on borehole guided wave propagation should be considered in the processing and inversion of the guided waves for formation acoustic property estimation. This study introduces an equivalent-tool theory that models the tool response using an elastic rod with an effective modulus and applies the theory to multipole acoustic logging for both wireline and logging while drilling （LWD） conditions. The theory can be derived by matching the tool’s acoustic impedance/conductance to that of the multipole acoustic wavefield around the tool, assuming that tool radius is small compared to wavelength. We have validated the effectiveness and accuracy of the theory using numerical modeling and its practicality using field data. In field data applications, one can calibrate the tool parameters by fitting the theoretical dispersion curve to field data without having to consider the actual tool’s structure and composition. We use a dispersion correction example to demonstrate an application of the simple theory to field data processing and the validity of the processing result.展开更多
CPS （cyber-physics system） engineering brings new revolutionary opportunities for multi-disciplinary and complex processes, like oil extraction from oil sands. Based on an established unified feature modeling scheme...CPS （cyber-physics system） engineering brings new revolutionary opportunities for multi-disciplinary and complex processes, like oil extraction from oil sands. Based on an established unified feature modeling scheme, a software modeling framework to simulate the process of SAGD （steam-assisted gravity drainage） is proposed. The main purpose of this work was to apply CPS in the complex production engineering informatics modeling as it applied to SAGD. Existing physics models and simulation algorithms for main SAGD phenomena were reviewed, and an integrated ontology model via a feature-based approach has been developed. Conservation laws were used as the governing principles, while the transport phenomena were modelled via the primary phenomenon features. The representation of typical data flows targeting to the functional simulation scenarios by applying the concept of phenomenon features was also done. The definition of this feature type represents a new expansion of the emerging unified feature scheme for engineering software modeling. Slotted liners were taken as the well-completion option and their design and specifications were included in the case study model. The unique representation of the planned software design is developed and expressed with graphical diagrams of the UML （unified modelling language） convention.展开更多
A single-column model is constructed based on parameterizations inherited from the Finite-volume/Spectral Atmospheric Model F/SAMIL and tested in simulations of tropical convective systems. Two representative convecti...A single-column model is constructed based on parameterizations inherited from the Finite-volume/Spectral Atmospheric Model F/SAMIL and tested in simulations of tropical convective systems. Two representative convection schemes are compared in terms of their performances on precipitation types, individual physical tendencies, and temperature and moisture fields. The main difference between the two selected schemes is in their representation of entraining/detraining process. The Tiedtke scheme assumes bulk entrainment, while the Zhang–Mc Farlane scheme parameterizes entrainment/detrainment rates under the spectrum concept. Large-scale forcing and verification data are taken from the GATE phase III field campaign, during which abundant convective events were observed. Given the same triggering function and closure assumption, results show that entrainment/detrainment representation remains the dominant factor on the simulation of cumulus mass flux and of temperature and moisture fields. By analyzing sources and sinks of heat and moisture, this study reveals how parameterization components compensate for each other and make model results insensitive to parameterization changes in certain fields, thus suggesting the need to treat parameterizations as systems rather than individual components.展开更多
基金supported by the Fundamental Research Funds for the Central Universities and the National Hi-tech Research and Development Program of China (863 Program) (Grant No. 2007AA06Z232 )
文摘The influence of an acoustic logging tool on borehole guided wave propagation should be considered in the processing and inversion of the guided waves for formation acoustic property estimation. This study introduces an equivalent-tool theory that models the tool response using an elastic rod with an effective modulus and applies the theory to multipole acoustic logging for both wireline and logging while drilling （LWD） conditions. The theory can be derived by matching the tool’s acoustic impedance/conductance to that of the multipole acoustic wavefield around the tool, assuming that tool radius is small compared to wavelength. We have validated the effectiveness and accuracy of the theory using numerical modeling and its practicality using field data. In field data applications, one can calibrate the tool parameters by fitting the theoretical dispersion curve to field data without having to consider the actual tool’s structure and composition. We use a dispersion correction example to demonstrate an application of the simple theory to field data processing and the validity of the processing result.
文摘CPS （cyber-physics system） engineering brings new revolutionary opportunities for multi-disciplinary and complex processes, like oil extraction from oil sands. Based on an established unified feature modeling scheme, a software modeling framework to simulate the process of SAGD （steam-assisted gravity drainage） is proposed. The main purpose of this work was to apply CPS in the complex production engineering informatics modeling as it applied to SAGD. Existing physics models and simulation algorithms for main SAGD phenomena were reviewed, and an integrated ontology model via a feature-based approach has been developed. Conservation laws were used as the governing principles, while the transport phenomena were modelled via the primary phenomenon features. The representation of typical data flows targeting to the functional simulation scenarios by applying the concept of phenomenon features was also done. The definition of this feature type represents a new expansion of the emerging unified feature scheme for engineering software modeling. Slotted liners were taken as the well-completion option and their design and specifications were included in the case study model. The unique representation of the planned software design is developed and expressed with graphical diagrams of the UML （unified modelling language） convention.
基金jointly supported by the National Natural Science Foundation of China(41305102)the National Basic Research Program of China(2014CB441202,2013CB955803)
文摘A single-column model is constructed based on parameterizations inherited from the Finite-volume/Spectral Atmospheric Model F/SAMIL and tested in simulations of tropical convective systems. Two representative convection schemes are compared in terms of their performances on precipitation types, individual physical tendencies, and temperature and moisture fields. The main difference between the two selected schemes is in their representation of entraining/detraining process. The Tiedtke scheme assumes bulk entrainment, while the Zhang–Mc Farlane scheme parameterizes entrainment/detrainment rates under the spectrum concept. Large-scale forcing and verification data are taken from the GATE phase III field campaign, during which abundant convective events were observed. Given the same triggering function and closure assumption, results show that entrainment/detrainment representation remains the dominant factor on the simulation of cumulus mass flux and of temperature and moisture fields. By analyzing sources and sinks of heat and moisture, this study reveals how parameterization components compensate for each other and make model results insensitive to parameterization changes in certain fields, thus suggesting the need to treat parameterizations as systems rather than individual components.
