Towards quantitative evaluation of gas injection using time‐lapse seismic data     

Reza Falahat  Asghar Shams  Colin MacBeth 《Geophysical Prospecting》2011,59(2):310-322

Of particular concern in the monitoring of gas injection for the purposes of storage, disposal or improved oil recovery is the exact spatial distribution of the gas volumes in the subsurface. In principle this requirement is addressed by the use of 4D seismic data, although it is recognized that the seismic response still largely provides a qualitative estimate of moved subsurface fluids. Exact quantitative evaluation of fluid distributions and associated saturations remains a challenge to be solved. Here, an attempt has been made to produce mapped quantitative estimates of the gas volume injected into a clastic reservoir. Despite good results using three accurately repeated seismic surveys, time‐delay and amplitude attributes reveal fine‐scale differences though large‐scale agreement in the estimated fluid movement. These differences indicate disparities in the nature of the two attributes themselves, which can be explained by several possible causes. Of most impact are the effects of processing and migration, wave interference effects and noise from non‐repeatability of the seismic surveys. This subject highlights the need for a more careful consideration in 4D acquisition, amplitude processing and use of true amplitude preserving attributes in quantitative interpretation.  相似文献   

Comparing landscape evolution models with quantitative field data at the millennial time scale in the Belgian loess belt     

A. J. A. M. Temme  I. Peeters  E. Buis  A. Veldkamp  G. Govers 《地球表面变化过程与地形》2011,36(10):1300-1312

  相似文献   

Changes of P, Ca, Al and Fe contents in fringe marshes along a pedogenic chronosequence in the Pearl River estuary, South China   总被引：2，自引：0，他引：2  

Rong Xiao  Honggang ZhangHaifeng Gao  Xinhui LiuAndreas Wilkes 《Continental Shelf Research》2011,31(6):739-747

Soil and plant samples were collected in four fringe marsh zones (i.e., A, B, C and D zones) along a pedogenic chronosequence in the Pearl River estuary in the Spring of 2009. Samples were subjected to a total digestion technique and analyzed for P, Ca, Al and Fe in order to study the changes of nutrient contents, storages in soils and their bioavailabilities to wetland plants (e.g. Cyperus malaccensis) in four zones. Results showed that soil Ca increased with depth along soil profiles, while P, Al and Fe generally kept constant in soil profiles in four zones. Al and Fe contents in the top 10 cm soils showed significant decreases from D to A zone, while a significant increase in Ca contents (P<0.05). Significant increases along pedogenic chronosequence for P, Al and Fe at 30-40 cm soil horizons were also observed. Ca was mainly accumulated in plant aboveground parts; Al and Fe were accumulated in the belowground parts; while P was homogenously distributed among the tissues of C. malaccensis. C. malaccensis in D zone had lower Bio-concentration factors (BCFs) of P in the shoots and Al and Fe in the roots, and higher values of Ca in the shoots than those in older zones (P<0.05). Compared to Al and Fe, both Ca and P had relatively higher translocation capacities for C. malaccensis, while only lower TFs for P and higher values for Al and Fe in D zone were observed than those in A and B zones (P<0.05). Except for Al with no significant changes, the total BCFs for P and Fe showed an increasing trend with soil ages, while a decreasing trend for Ca. The total bio-storage factors (TBSFs) of P and Ca declined with the pedogenic time, whereas an increase for Fe. The results of this study can contribute to the wetland conservation and management in the Pearl River estuarine region.  相似文献   

A wetting and drying algorithm with a combined pressure/free-surface formulation for non-hydrostatic models     

S.W. Funke  C.C. Pain  S.C. Kramer  M.D. Piggott 《Advances in water resources》2011,34(11):1483-1495

A wetting and drying method for free-surface problems for the three-dimensional, non-hydrostatic Navier–Stokes equations is proposed. The key idea is to use a horizontally fixed mesh and to apply different boundary conditions on the free-surface in wet and dry zones. In wet areas a combined pressure/free-surface kinematic boundary condition is applied, while in dry areas a positive water level and a no-normal flow boundary condition are enforced. In addition, vertical mesh movement is performed to accurately represent the free-surface motion. Non-physical flow in the remaining thin layer in dry areas is naturally prevented if a Manning–Strickler bottom drag is used. The treatment of the wetting and drying processes applied through the boundary condition yields great flexibility to the discretisation used. Specifically, a fully unstructured mesh with any finite element choice and implicit time discretisation method can be applied. The resulting method is mass conservative, stable and accurate. It is implemented within Fluidity-ICOM [1] and verified against several idealized test cases and a laboratory experiment of the Okushiri tsunami.  相似文献   

Study on the S-wave Splitting Characteristics in the Longtan Reservoir Area,Guangxi,China     

Shi Haixi  Zhao Cuiping 《中国地震研究》2011,25(2):213-226

In this paper,the shear wave splitting features of the Longtan reservoir area are studied by adopting the traditional cross-correlation coefficient method and polarization analysis,using the data recorded by the seismic network founded by a project under the National Science and Technology Pillar Program from April 2009 to April 2010.We found that most of polarization directions at seismic stations are consistent with the direction of the overall regional stress field,but local structures and faults may con...  相似文献   

结构抗震设计时程分析法的分析研究   总被引：1，自引：0，他引：1  

李建亮  赵晶  李福海  何玉林  亢川川 《四川地震》2011,(4):25-28

文章回顾了我国抗震设计规范的演变过程,将时程分析法与底部剪力法和振型分解反应谱法进行了对比,指出了时程分析法在抗震设计计算中的地位与作用,时程分析法是能够考虑地震动三要素、地震环境、结构的非线性和能量损耗及损伤的真正动力分析方法,是比底部剪力法和振型分解反应谱法更精确、更可靠、更合理的方法,不应仅仅作为补充计算的方法,...  相似文献   

Google地图应用之广东省地区JOPENS地震速报系统   总被引：1，自引：0，他引：1  

刘军  陈贵美 《华南地震》2011,31(3):41-49

利用Google公司提供的电子地图服务,以B/S结构(即浏览器和服务器结构)作为系统设计架构,监听JOPENS实时系统发送的地震触发消息,访问JOPENS数据库,根据广东省地区的监测要求,制定检索、筛选策略,获取地震详细信息,显示在浏览器网页上.采用Google地图的JOPENS地震速报系统可以使地震信息发布的显示内容...  相似文献   

JOPENS流服务与TDE-324系列地震数据采集器实时数据流接口程序的设计与实现   总被引：1，自引：0，他引：1  

吴永权  黄文辉 《华南地震》2011,31(3):50-59

JOPENS系统是为地震台网中心开发的数据处理软件系统,为使地震台站记录到的实时数据流能接入JOPENS系统处理,必须为数采开发对应的接口程序,用来接收地震台站数采的实时数据流.介绍了JOPENS的流服务与珠海泰德公司生产的TDE-324系列数采实时数据流接口的设计思想与实现过程,并对接口程序进行了故障处理能力试验检测...  相似文献   

S波分裂在皖北地震中的研究应用     

曾宪军  童国林 《地震地磁观测与研究》2011,32(6):56-61

利用S波分裂方法的基本理论及计算方法,重点研究了皖北地区具有代表性的利辛张村附近周边地区25 km内,自1999年蒙城地震台数字化测震仪器正式记录以来至2010年9月,ML2.0及以上地方震的单台地震波形,利用有关S波分裂方法进行处理,得到该地区不同时段的S波的偏振方向及延迟时间,为皖北地区地震活动性研究及应力活动状态...  相似文献   

识别天然地震和人工爆破的判据选择   总被引：4，自引：4，他引：0  

王婷婷  边银菊 《地震地磁观测与研究》2011,32(6):62-67

从快速识别事件性质的要求出发,分析了天然地震和人工爆破的发震时间,P波初动方向,P波、S波振幅比值,P波、S波最大振幅与尾波持续时间比值等判据,得到P波初动方向和P最大振幅与S最大振幅比值是识别爆破和地震的两个有效判据,为研制“识别天然地震和人工爆破的分类决策支持系统”提供了应用依据.  相似文献