排序方式： 共有13条查询结果，搜索用时 31 毫秒
1.
A maximum difference conjoint (MDC) model was part of a questionnaire toassess floodplain residents' preferences for the outcomes of water level managementinside an enclosed embankment system on the left bank of the Dhaleswari River, calledthe Compartmentalization Pilot Project (CPP)-Tangail. The outcomes were described as(a) varied flood depths in the rice field, (b) incidence of flooding on the courtyard andinside homes, (c) changes in floodplain and culture fisheries, and (d) varied conditionsof drainage congestion. Following a standard survey, the respondents from inside andoutside a completed section of the compartment (Cluster 1b) were shown profiles of these flood management outcomes and were asked to indicate for each profile the one most preferred and the one least preferred item. The results of the study indicated that the respondents had a clear preference for preventing flooding of their homes and courtyards and for an ideal water depth of 2 ft in the aman rice fields. At the same time, they also showed a strong concern about malfunctioning of sluices and to a lesser extent about the changes in the fish habitat. The successful application of the MDC as an approach to model tradeoffs among rural residents of Bangladesh shows that a relatively complex quantitative survey method, incorporating choice cards as pictograms, can be applied successfully even in a developing country. 相似文献
2.
Paleokarst system development in the San Andres Formation, Permian Basin, revealed by seismic characterization 总被引：1，自引：0，他引：1
Paleokarst systems are one of the major factors resulting in carbonate reservoir heterogeneity and compartmentalization. Nevertheless, few effective workflows have been proposed to map the 3D distribution of such systems. We describe a detailed seismic characterization approach integrating core, well log and rock physics analysis, to reveal a complex subsurface paleokarst system in the San Andres Formation, Permian basin, West Texas. In the area of high volume production, the collapsed paleokarst system is characterized by irregularly developed crackle and fracture breccias, mosaic breccias and cave fillings in the Upper San Andres Formation, which are delineated using seismic acoustic impedance. Along the transition from platform to basin, the paleokarst system is marked by a linear collapse including sags and small vertical faults that are recognizable in seismic imaging. Production data indicates that tight paleokarst zones cause reservoir compartmentalization and influence fluid communication between wells. The complex paleokarst system development is explained using a carbonate platform hydrological model, an outcrop analogue similar to modern marine hydrological environments within carbonate islands. Our method of model development for complex subsurface paleokarst systems may be applicable to other paleoenvironments. 相似文献
3.
4.
Fluid depletion within a compacting reservoir can lead to significant stress and strain changes and potentially severe geomechanical issues, both inside and outside the reservoir. We extend previous research of time‐lapse seismic interpretation by incorporating synthetic near‐offset and full‐offset common‐midpoint reflection data using anisotropic ray tracing to investigate uncertainties in time‐lapse seismic observations. The time‐lapse seismic simulations use dynamic elasticity models built from hydro‐geomechanical simulation output and a stress‐dependent rock physics model. The reservoir model is a conceptual two‐fault graben reservoir, where we allow the fault fluid‐flow transmissibility to vary from high to low to simulate non‐compartmentalized and compartmentalized reservoirs, respectively. The results indicate time‐lapse seismic amplitude changes and travel‐time shifts can be used to qualitatively identify reservoir compartmentalization. Due to the high repeatability and good quality of the time‐lapse synthetic dataset, the estimated travel‐time shifts and amplitude changes for near‐offset data match the true model subsurface changes with minimal errors. A 1D velocity–strain relation was used to estimate the vertical velocity change for the reservoir bottom interface by applying zero‐offset time shifts from both the near‐offset and full‐offset measurements. For near‐offset data, the estimated P‐wave velocity changes were within 10% of the true value. However, for full‐offset data, time‐lapse attributes are quantitatively reliable using standard time‐lapse seismic methods when an updated velocity model is used rather than the baseline model. 相似文献
5.
藻类对重金属的耐性与解毒机理 总被引：22，自引：1，他引：22
重金属是一类具有潜在危害的重要污染物,越来越多的重金属被排入水体,对水生生态环境构成严重威胁.藻类在长期响应重金属胁迫过程中,建立起一系列的适应机制.藻类通过控制重金属的吸收、富集、转运与解毒,使不同细胞组分中的重金属维持在正常浓度范围内.这些保护机制主要包括藻细胞的某些胞外组分与重金属结合,从而减少重金属进入胞内;在重金属诱导下藻细胞可合成金属结合蛋白或多肽;重金属诱导藻细胞合成一些代谢物使其免受伤害或修复由重金属胁迫造成的损伤;藻细胞通过液泡区室化作用使重金属远离代谢;藻细胞对重金属具有排斥与排出作用. 相似文献
6.
7.
勘探异常压力天然气藏的新思路--探明非常规天然气资源的关键要素 总被引：4，自引：0，他引：4
异常压力天然气藏(Anomalously Pressured Gas,APG)主要指“盆地中心”天然气系统(BCGS)中，天然气含量丰富，但开发程度相对较低的天然气资源。例如，美国怀俄明州Wind River盆地的面积约为8500mi^2，其USGS异常压力天然气资源量估计是900Tcf，但目前产气量累积不足1Tcf。丰富的天然气资源与开发程度的不平衡在所有“盆地中心”异常压力天然气藏中是很典型的。因此，对于蕴藏在BCGS中极其丰富的天然气资源，尚待更为有效的开发。过去，开发APG资源困难且昂贵，但最近怀俄明州Greater Green River和Wind River盆地的开发成功，以及早些时候阿尔伯达、Denver—Julesburg和San Juan盆地的成功开发均表明，更为有效的开发是做得到的。最重要的是，当异常压力天然气藏的开发取得成功的时候，财政上的回报是显著的。为了更充分地开发盆地中心APG资源，大幅度提高天然气资源转换为能源储量的比率和数量，则需要新的和更富有创新性的开发策略、技术和判断方法。经过多年的努力，天然气新技术开发公司(IDT)的研究团队已经研发出一系列高效勘探和开发异常压力天然气藏的新的有效方法。应用IDT技术可以在钻井之前为开发者提供下列必要的信息：(1)天然气饱和的岩石／流体系统的空间分布，包括压力封存箱边界；(2)区域压力界面或正常和异常压力(或超压，或欠压)的流体之间界线的位置和性质；(3)流体中天然气和水含量的确定；(4)微裂缝群的识别和空间分布；(5)断层的方位和时序；(6)储层属性特征。借助由IDT技术所提供的油气系统的信息，可以使开发者设计并应用最优化钻井方案，从而避免当前与含气异常压力地层开发有关的许多灾难性的陷阱。 相似文献
8.
正Seagull Lake is an unusual saline lake,having a marine spring connected to a large continental ecosystem.With climate change the balance between the two is likely to change.This lake originated about 6000 years ago as a 相似文献
9.
Using photomosaics and measured sections, this outcrop study characterizes facies- to sandbody-scale heterogeneity in the fluvial and coastal-plain deposits of the Blackhawk Formation of the Wasatch Plateau, Utah, USA, as an outcrop analog for the fluvial tight-gas reservoirs of the adjacent greater western Rocky Mountain basins as well as for conventional fluvial reservoirs elsewhere. Analysis on eight contiguous, vertical cliff-faces comprising both depositional-dip- and -strike-oriented segments provides field-validation and calibration of the entire range of fluvial heterogeneity, where: 1) large-scale heterogeneity (10's of m vertically and 100's of m laterally) is associated with stacking of channelized fluvial sandbodies encased within coastal-plain fines, 2) intermediate-scale heterogeneity (1's of m vertically and 10's of m laterally) is related to type and distribution of architectural elements like bar-accretion and crevasse-splay units within individual sandbodies, and 3) small-scale heterogeneity (10's of cm vertically and 1's of m laterally) is attributed to facies spatial variability within individual architectural elements.At a reservoir-scale (∼6 km strike-transect), impact of these heterogeneities has resulted in potential stratigraphic compartmentalization in varied patterns and scales within and among three zones, which have similar lateral extents. Distinct vertical or lateral compartmentalization, contrasting net-to-gross pattern, width-constraint by either large- or intermediate-scale heterogeneity, disparity in communication between principal reservoir compartments by intermediate-scale heterogeneity, and reservoir-quality segregation to barrier styles rendered by small-scale heterogeneity are documented in an array of trends. These intriguing trends are challenging to correlate across the reservoir-scale dataset, contributing to multiple, analogous exploration and production uncertainties. For improved tight-gas exploration and production strategy of the western Rocky Mountain basins, study results were also used in developing potential predictive tools: 1) thickness threshold of individual channelized sandbody favoring multiple well intersection, 2) aspect ratio in performing probabilistic sandbody-width estimation, and 3) prediction of sandbody amalgamation using underlying coal thickness. 相似文献
10.
山东省人体舒适度的REOF分析 总被引：10，自引：0，他引：10
本文使用1971~2000年山东省90个气象测站的整编气候资料,采用旋转经验正交分解(REOF)的方法,对山东四季及全年的人体舒适度进行分析,得到人体舒适度分区,并进一步探讨了各区域人体舒适度指数的变化趋势,为开展区域性人体舒适度预报和气候研究打下基础。 相似文献