Various types of radars with different horizontal and vertical detection ranges are deployed in China, particularly over complex terrain where radar blind zones are common. In this study, a new variational method is d...Various types of radars with different horizontal and vertical detection ranges are deployed in China, particularly over complex terrain where radar blind zones are common. In this study, a new variational method is developed to correct threedimensional radar reflectivity data based on hourly ground precipitation observations. The aim of this method is to improve the quality of observations of various types of radar and effectively assimilate operational Doppler radar observations. A mudslide-inducing local rainstorm is simulated by the WRF model with assimilation of radar reflectivity and radial velocity data using LAPS（Local Analysis and Prediction System）. Experiments with different radar data assimilated by LAPS are performed. It is found that when radar reflectivity data are corrected using this variational method and assimilated by LAPS,the atmospheric conditions and cloud physics processes are reasonably described. The temporal evolution of radar reflectivity corrected by the variational method corresponds well to observed rainfall. It can better describe the cloud water distribution over the rainfall area and improve the cloud water analysis results over the central rainfall region. The LAPS cloud analysis system can update cloud microphysical variables and represent the hydrometeors associated with strong convective activities over the rainfall area well. Model performance is improved and the simulation of the dynamical processes and moisture transport is more consistent with observation.展开更多
We carried out time-lapse analysis in a producing Niger Delta X-field, by first investigating the response and sensitivity of rock properties/attributes to lithology and pore fill in 3-D cross plot domain and by Gassm...We carried out time-lapse analysis in a producing Niger Delta X-field, by first investigating the response and sensitivity of rock properties/attributes to lithology and pore fill in 3-D cross plot domain and by Gassmann’s fluid substitution modeling. Furthermore, 4-D seismic data were inverted into acoustic impedance volumes through model based inversion scheme. This served as input into a multi-attribute neural network algorithm for the extraction of rock attribute volumes based on the results of the petrophysical log analysis. Subsequently, horizon slices of rock properties/ attributes were extracted from the inverted seismic data and analyzed. In this way, we mapped hydrocarbon depleted wells in the field, and identified probable by-passed hydrocarbon zones. Thus, the integration of well and time lapse seismic (4-D) data in reservoir studies has remarkably improved information on the reservoir economic potential, and enhanced hydrocarbon recovery factor.展开更多
时移地震数据处理质量控制技术是时移地震资料处理的重要组成部分,为了研究该技术在海洋时移地震数据的受限因素及应用效果,首先介绍时移地震重复性的两个主要参数NRMS(Normalization Root Mean Square)和PRED(Predictability),随后详...时移地震数据处理质量控制技术是时移地震资料处理的重要组成部分,为了研究该技术在海洋时移地震数据的受限因素及应用效果,首先介绍时移地震重复性的两个主要参数NRMS(Normalization Root Mean Square)和PRED(Predictability),随后详细分析影响时移地震的重复性因素,进而给出在处理上的时移质量控制要点,最后通过南海某工区的时移地震数据进行了检验和分析。结果表明,通过参考本文给出的控制要点,可达到在精细的质量控制过程中提高时移地震数据的重复性。展开更多
基金supported by a National Department of Public Benefit Research Foundation of China(Grant No.GYHY201406001)NSFC(National Science Foundation of China)project(Grant Nos.41105072,41130960,41375057and 41375041)Hubei Meteorological Bureau project(Grant No.2016S02)
文摘Various types of radars with different horizontal and vertical detection ranges are deployed in China, particularly over complex terrain where radar blind zones are common. In this study, a new variational method is developed to correct threedimensional radar reflectivity data based on hourly ground precipitation observations. The aim of this method is to improve the quality of observations of various types of radar and effectively assimilate operational Doppler radar observations. A mudslide-inducing local rainstorm is simulated by the WRF model with assimilation of radar reflectivity and radial velocity data using LAPS（Local Analysis and Prediction System）. Experiments with different radar data assimilated by LAPS are performed. It is found that when radar reflectivity data are corrected using this variational method and assimilated by LAPS,the atmospheric conditions and cloud physics processes are reasonably described. The temporal evolution of radar reflectivity corrected by the variational method corresponds well to observed rainfall. It can better describe the cloud water distribution over the rainfall area and improve the cloud water analysis results over the central rainfall region. The LAPS cloud analysis system can update cloud microphysical variables and represent the hydrometeors associated with strong convective activities over the rainfall area well. Model performance is improved and the simulation of the dynamical processes and moisture transport is more consistent with observation.
文摘We carried out time-lapse analysis in a producing Niger Delta X-field, by first investigating the response and sensitivity of rock properties/attributes to lithology and pore fill in 3-D cross plot domain and by Gassmann’s fluid substitution modeling. Furthermore, 4-D seismic data were inverted into acoustic impedance volumes through model based inversion scheme. This served as input into a multi-attribute neural network algorithm for the extraction of rock attribute volumes based on the results of the petrophysical log analysis. Subsequently, horizon slices of rock properties/ attributes were extracted from the inverted seismic data and analyzed. In this way, we mapped hydrocarbon depleted wells in the field, and identified probable by-passed hydrocarbon zones. Thus, the integration of well and time lapse seismic (4-D) data in reservoir studies has remarkably improved information on the reservoir economic potential, and enhanced hydrocarbon recovery factor.
文摘时移地震数据处理质量控制技术是时移地震资料处理的重要组成部分,为了研究该技术在海洋时移地震数据的受限因素及应用效果,首先介绍时移地震重复性的两个主要参数NRMS(Normalization Root Mean Square)和PRED(Predictability),随后详细分析影响时移地震的重复性因素,进而给出在处理上的时移质量控制要点,最后通过南海某工区的时移地震数据进行了检验和分析。结果表明,通过参考本文给出的控制要点,可达到在精细的质量控制过程中提高时移地震数据的重复性。
