Influence of the water layer upon the depth of ground radar investigations in freshwater reservoirs     

M. L. Vladov  A. M. Pyatilova 《Moscow University Geology Bulletin》2009,64(1):59-62

A number of problems associated with detailed investigation of subsurface geological structure below the bottoms of freshwater reservoirs (rivers, ponds, and lakes) arise during the study of the upper portions of geological sections. The present study is aimed at marginal estimation of the penetrating depth of ground radar investigations in freshwater reservoirs (based on bottom reflections), taking into account the complex nature of conductivity and its dependence upon the frequency under ideal conditions with no noise. The same method can be applied for estimating any given dynamic recording range.  相似文献   

Structural controls on fractured coal reservoirs in the southern Appalachian Black Warrior foreland basin   总被引：1，自引：0，他引：1  

Richard H. Groshong Jr.  Jack C. Pashin  Marcella R. McIntyre 《Journal of Structural Geology》2009,31(9):874

Coal is a nearly impermeable rock type for which the production of fluids requires the presence of open fractures. Basin-wide controls on the fractured coal reservoirs of the Black Warrior foreland basin are demonstrated by the variability of maximum production rates from coalbed methane wells. Reservoir behavior depends on distance from the thrust front. Far from the thrust front, normal faults are barriers to fluid migration and compartmentalize the reservoirs. Close to the thrust front, rates are enhanced along some normal faults, and a new trend is developed. The two trends have the geometry of conjugate strike-slip faults with the same σ₁ direction as the Appalachian fold-thrust belt and are inferred to be the result of late pure-shear deformation of the foreland. Face cleat causes significant permeability anisotropy in some shallow coal seams but does not produce a map-scale production trend.  相似文献   

渤海湾盆地深部有利储层发育的主控因素   总被引：7，自引：0，他引：7  

蒋凌志  牛嘉玉  张庆昌  徐国民  孟元林  肖丽华 《地质论评》2009,55(1):73-78

本文主要从沉积、成岩方面及与之相关的因素来分析渤海湾盆地深部有利储层发育的主控因素。研究认为,除了沉积作用外,低地温梯度、高沉积速率、高加热速率、高生烃强度和异常压力等因素影响了成岩作用的进程和强度,对深部储层原生孔隙的保存和次生孔隙的形成产生积极的作用,造成了中部黄骅坳陷深层相对高孔高渗储层发育层段多,物性好,而东部辽河坳陷次之,西部冀中坳陷最差。  相似文献   

大型凹陷向斜区油气倒灌式成藏——以松辽盆地三肇凹陷扶杨油层为例   总被引：5，自引：0，他引：5  

刘宗堡  付晓飞  吕延防  付广  庞磊 《地质论评》2009,55(5):685-692

三肇凹陷扶杨油层为典型大型凹陷向斜区油气倒灌式成藏,利用300条地震剖面、825口井曲线、11口井岩芯和探评井试油资料对扶杨油层断层特征及运动期次、油气下排深度、储层沉积特征等油气成藏主控因素综合研究表明：T2断层受控于基底断层、下部火山口、斜向拉张和伸展量差异四种因素具有平面密集成带、剖面“似花状”组合特征,且油气成藏期活动的油源断层多数为断层密集带边界断层;理论计算超压驱动油气下排深度和实际油底包络面统计扶杨油层含油厚度约为200m;重矿物分析扶杨油层主要受北部拜泉—青冈和西南保康物源影响,两物源在徐家围子地区交汇后向东流出;沉积微相揭示扶杨油层发育向上逐渐退积的河控浅水三角洲沉积体系,顶部为三角洲前缘亚相,中—下部为三角洲分流平原亚相,其中扶Ⅰ7—扶Ⅱ1小层为水退最大期,是油气富集主要层位。明水组末期青山口组源岩达到生油高峰,油气在超压作用下沿开启的断层密集带边界断层幕式下排后沿两侧上升盘河道砂体做短距离侧向运移,即断层密集带两侧地垒或断阶块为油气富集区,而断层密集带内多为地堑式组合,不利于油气聚集,在成藏模式指导下刻画出47个油气富集目标区,为松辽盆地北部扶杨油层下一步的勘探与开发指明了方向。  相似文献   

复杂储层识别的地震反演方法及其在塔木察格盆地的应用          下载免费PDF全文

陈显森  孙山  张正和  龙江南 《地质科学》2009,44(2):700-706

随着油气藏勘探开发程度的加深,准确识别复杂储层变得愈发重要,地震反演已成为储层预测的核心技术.本文对蒙占国塔木察格盆地南部凹陷1 800 km²地震资料进行波阻抗反演研究,研究工作包括测井曲线的标准化校正、地质框架模型的准确建立及其它反演参数的正确选取.波阻抗反演结果为研究沉积相划分、砂体空问展布的认识提供了可靠依据,在一定程度上解决了该区主要日的层南屯组沉积物源多、相变快和在地震剖面上无法追踪的问题.  相似文献   

基于FPGA的便携式BPC定时接收机设计   总被引：1，自引：1，他引：0  

刘小花  许林生  华宇 《时间频率学报》2012,35(2):88-95

介绍了一种基于FPGA的便携式低频时码接收机系统的设计方案。该接收机的特点是体积小,功耗低,方便户外工作人员携带。描述了该接收机的硬件系统结构,给出了软件算法。硬件结构中,使用了ALTERA公司的EP2C70F672C8芯片,软件部分在QuartusⅡ开发环境下完成。系统测试结果表明,按本方案设计的接收机集成度高,可靠性好,易扩展,易升级,具有一定的实用价值。  相似文献   

基于岩心室应力应变和不确定度分析的致密储层氦孔隙度测量方法          下载免费PDF全文

韩学辉  张浩  毛新军  徐登辉  郭慧英  江佳洋  罗兴平  王振林  刘智桢  李靖  罗振 《地球物理学报》2021,64(1):289-297

致密油气层的物性(孔隙度和渗透率)较差.针对致密储层,目前常用的氦气法孔隙度测量方法存在两个不足:器壁压变性参数G定义不明确;膨胀前压力设置普遍偏小.本次基于氦气法孔隙度测量装置岩心室的应力应变力学分析和不确定度理论分析,开发了一种面向致密储层的氦孔隙度测量方法.本次提出的方法给出了器壁压变性参数G的解析式,并基于G的解析式推导出了新的孔隙度计算公式,将刻度系数减少到1个,简化了刻度过程.其次,基于不确定度理论得到的孔隙度测量不确定度表明:氦气法测量致密储层孔隙度的膨胀前压力大于2 MPa基本可以将孔隙度绝对误差控制在0.5%以内.与高压压汞法孔隙度测量结果对比发现,该方法测量孔隙度的相对偏差在14%以内,远低于常规氦气法测量孔隙度的相对偏差(50%).  相似文献   

Brazilian vs. Paraguayan streams: Differences in water quality in a cross-border subtropical region     

《Limnologica》2021

Monitoring programs are among the first steps to develop robust management strategies, especially in international transboundary waters. Understanding how water quality parameters are impacted by different types of land use promotes a baseline for stakeholders to define the best governance for the management of water resources. Seeking to provide this type of information, we sampled 24 streams – 12 in Brazil and 12 in Paraguay – in February, April, July, September, and November 2019. We determined water quality parameters, grouped into three categories: morphometric, physical and chemical, and nutrients. We explored differences in water quality parameters between countries, and over a one-year sampling. We also tested whether Brazilian and Paraguayan streams are impacted by agriculture, urbanization, and forest cover. Finally, we performed a partial RDA to test the influence of land use on water quality parameters and controlled spatial autocorrelation by including spatial variables (dbMEM) as a condition. Most of the water quality parameters showed significant differences between countries; only turbidity, and pH, presented significant differences between countries and sampling periods, and only water temperature varied significantly along the year. We did not find evidence that different types of land use are causing physical and chemical variance in Brazilian and Paraguayan streams (R² = 0.06, p = 0.68). In conclusion, the results evidenced that the main differences in the water quality parameters occur between countries. Based on the results, transboundary governance can use these data to implement integrated water resources management cooperation.  相似文献   

Convergent development of experimental landforms with differing rainfall and substrate properties     

Shunji Ouchi 《地球表面变化过程与地形》2021,46(5):1083-1095

Four runs of experimental landform development, with the same uplift rate, different rainfall intensity, and the same material of different permeability adjusted by the degree of compaction, showed complicated effects of rainfall and mound-forming material. In the run with more rainfall on less permeable material, low separated ridges developed in the uplifted area, because abundant overland flow promoted valley erosion and slope processes from early stages. In the run with less rainfall on less permeable material, valley incision proceeded mostly in major valleys where surface water converges. Canyons developed during early stages and later a high massive mountain emerged. The effect of rainfall difference, however, appeared completely opposite on more permeable material accompanied by lower shear strength. In the run with more rainfall on more permeable material, a massive mountain similar to that with less rainfall on less permeable material appeared, and low separated ridges appeared in the run with less rainfall on more permeable material as in the run with more rainfall on less permeable material. In the former case, similar amount of water available for Hortonian overland flow in early stages estimated from rainfall rate and permeability can explain the development of similar landforms. In the latter case, while abundant surface water with more rainfall on less permeable material made fluvial erosion active from early stages, the deficiency in surface water with less rainfall on more permeable material apparently attenuated fluvial erosion but possibly accentuated slope processes and slope failures by seepage water flow through more permeable material of low shear strength. The active erosion from early stages apparently resulted in the development of enduring similar low landforms later in the dynamic equilibrium stage. These experimental results indicate that similar landforms can emerge from different environmental and lithologic controls, and that process does not necessarily follow from form.  相似文献   

Role of reservoir regulation and groundwater feedback in a simulated ground-soil-vegetation continuum: A long-term regional scale analysis     

Jianhui Wei  Ningpeng Dong  Benjamin Fersch  Joël Arnault  Sven Wagner  Patrick Laux  Zhenyu Zhang  Qianya Yang  Chuanguo Yang  Shasha Shang  Lu Gao  Zhongbo Yu  Harald Kunstmann 《水文研究》2021,35(8):e14341

The regional terrestrial water cycle is strongly altered by human activities. Among them, reservoir regulation is a way to spatially and temporally allocate water resources in a basin for multi-purposes. However, it is still not sufficiently understood how reservoir regulation modifies the regional terrestrial- and subsequently, the atmospheric water cycle. To address this question, the representation of reservoir regulation into the terrestrial component of fully coupled regional Earth system models is required. In this study, an existing process-based reservoir network module is implemented into NOAH-HMS, that is, the terrestrial component of an atmospheric–hydrologic modelling system, namely, the WRF-HMS. It allows to quantitatively differentiate role of reservoir regulation and of groundwater feedback in a simulated ground-soil-vegetation continuum. Our study focuses on the Poyang Lake basin, where the largest freshwater lake of China and reservoirs of different sizes are located. As compared to streamflow observations, the newly extended NOAH-HMS slightly improves the streamflow and streamflow duration curves simulation for the Poyang Lake basin for the period 1979–1986. The inclusion of reservoir regulation leads to major changes in the simulated groundwater recharges and evaporation from reservoirs at local scale, but has minor effects on the simulated soil moisture and surface runoff at basin scale. The performed groundwater feedback sensitivity analysis shows that the strength of the groundwater feedback is not altered by the consideration of reservoir regulation. Furthermore, both reservoir regulation and groundwater feedback modify the partitioning of the simulated evapotranspiration, thus affecting the atmospheric water cycle in the Poyang Lake region. This finding motivates future research with our extended fully coupled atmospheric–hydrologic modelling system by the community.  相似文献