朱庄水库流域径流量变化特征及影响因素

利用朱庄区域长系列水文资料,对径流量的年内、年际变化特征及变化趋势进行了分析研究,分析了人类活动影响引起下垫面变化导致径流变化的原因,估算了降水和下垫面变化对径流量的影响量。该区域径流量年内、年际变化较大;多年径流量系列呈减少趋势,尤其从20世纪70年代末以来径流量发生了显著变异;下垫面变化是径流量减少的主要原因。     

南水北调中线小南河串流片防洪水位计算

传统的多河流串流计算主要采用水库联调的方法,把串流的各条河流概化为静态水库,库水位水平且不考虑横向流动。为解决串流区水流的横向流动及水面线并不总像库水位一样水平的问题,采用二维非恒定流数学模型计算串流区洪水演进。通过概化地形、考虑入流、糙率、边界条件和水流的横向流动等因素,计算出了整个串流区域的水面线、水深、流速、出流等水力要素,并给出洪水演进模拟图,为确定河流与总干渠交叉建筑物的规模、总干渠左岸沿线水面线和对沿线村庄、农田的防洪影响提供了可靠的依据。     

3D porosity prediction from seismic inversion and neural networks

In this work, we address the problem of transforming seismic reflection data into an intrinsic rock property model. Specifically, we present an application of a methodology that allows interpreters to obtain effective porosity 3D maps from post-stack 3D seismic amplitude data, using measured density and sonic well log data as constraints. In this methodology, a 3D acoustic impedance model is calculated from seismic reflection amplitudes by applying an L₁-norm sparse-spike inversion algorithm in the time domain, followed by a recursive inversion performed in the frequency domain. A 3D low-frequency impedance model is estimated by kriging interpolation of impedance values calculated from well log data. This low-frequency model is added to the inversion result which otherwise provides only a relative numerical scale. To convert acoustic impedance into a single reservoir property, a feed-forward Neural Network (NN) is trained, validated and tested using gamma-ray and acoustic impedance values observed at the well log positions as input and effective porosity values as target. The trained NN is then applied for the whole reservoir volume in order to obtain a 3D effective porosity model. While the particular conclusions drawn from the results obtained in this work cannot be generalized, such results suggest that this workflow can be applied successfully as an aid in reservoir characterization, especially when there is a strong non-linear relationship between effective porosity and acoustic impedance.     

Modeling the permeability of carbonate reservoir using type-2 fuzzy logic systems

In this work, the use of type-2 fuzzy logic systems as a novel approach for predicting permeability from well logs has been investigated and implemented. Type-2 fuzzy logic system is good in handling uncertainties, including uncertainties in measurements and data used to calibrate the parameters. In the formulation used, the value of a membership function corresponding to a particular permeability value is no longer a crisp value; rather, it is associated with a range of values that can be characterized by a function that reflects the level of uncertainty. In this way, the model will be able to adequately account for all forms of uncertainties associated with predicting permeability from well log data, where uncertainties are very high and the need for stable results are highly desirable. Comparative studies have been carried out to compare the performance of the proposed type-2 fuzzy logic system framework with those earlier used methods, using five different industrial reservoir data. Empirical results from simulation show that type-2 fuzzy logic approach outperformed others in general and particularly in the area of stability and ability to handle data in uncertain situations, which are common characteristics of well logs data. Another unique advantage of the newly proposed model is its ability to generate, in addition to the normal target forecast, prediction intervals as its by-products without extra computational cost.     

松辽盆地茂8井三维地震区薄互层储层预测方法及效果

本文针对松辽盆地陆相薄互层的沉积特点,结合茂８井三维地震区块的实际情况,采用“滑动相关法”确定地震地质层位,准确标定了各反射同相轴的地质含义。依据砂岩或砂层组在三维剖面上的特征,充分发挥人机联作解释系统的优势,利用振幅、频率对主要含油层系砂岩的横向变化进行了深入研究,经钻井验证取得了较好的效果。     

小浪底水库支流倒灌与淤积形态模型试验

利用小浪底水库实体模型开展水库拦沙后期运用方式长系列年试验,对争议较大的库区支流倒灌及其淤积形态问题进行重点分析。结果表明:库区最大支流畛水河口门狭窄且库容较大,拦门沙问题最为突出,其纵坡面形态与设计有一定的差别;支流年淤积量与当年大于2600 m3/s流量时段的总水量有较好的相关性;通过优化水库运用方式可较长时期保持动态三角洲淤积形态,有利于支流库容的有效利用;水库干流河床处于动平衡状态时,支流河床仍然会逐渐淤积抬升而使得干支流淤积面高差趋于减少。     

汾河水库上游河流水环境风险评价

研究以满足太原市集中饮用水源地水质要求为前提,采用河流一维水质模型,模拟和定量评价了汾河水库上游突发性水环境污染事故风险。具体包括：识别污染事故风险危害,表征水环境危害大小,估算事故危害区范围以及危害期长短;最终定量评价了汾河上游水环境风险,为制定汾河上游水环境风险防范与控制对策提供了技术依据。     

尾矿砂对引滦黎河及于桥水库的影响研究

随着铁矿石的加工生产,大量的尾矿砂堆积在黎河两岸,在降雨或径流作用下,大量的尾矿砂进入河道,对引滦水质及河道产生影响。分别从尾矿砂对引滦水质、于桥水库以及尾矿砂起尘对河道的影响3个方面进行了研究探讨,研究成果对引滦黎河治理尾矿砂具有重要的指导意义。     

Reservoir Operation Optimization: A Nonstructural Solution for Control of Seepage from Lar Reservoir in Iran

Abstract

In this paper, the results of utilizing a deterministic dynamic programming model for operation of Lar Reservoir in Iran are discussed. This reservoir has experienced extensive seepage from the start of its operation. The optimization model consists of a three-step cycle, which began with the optimization of reservoir operation for a given set of streamflows. The optimal policies are then analyzed in a regression procedure to obtain a set of operating rules. After the first run, operating rules from the previous run were placed as a new constraint on the water releases with some pre-assigned tolerance and the cycle continues. The model also consisted of mathematical functions for modeling the seepage from Lar Reservoir as a function of storage head in the reservoir. The loss function in the model was also modified in order to incorporate parameters that reduce the seepage. Results of different scenarios showed the significant effect of optimal policies on reduction of seepage and increasing the reliability of water supply to Tehran Metropolitan Area. A pumping station was also proposed to utilize the inactive part of the reservoir, in access of over 100 MCM, in order to reduce the seepage. The effectiveness of different pumping capacities to reduce the seepage was also investigated.     

西安黑河金盆水库季节性热分层的水质响应特征

以西安市金盆水库为对象,通过对水温、水化学及水生生物因子的连续监测,初步探明其动态水体分层过程与季节性水质迁移分布的内在相关性.研究表明:水库于每年3—12月间形成并保持热分层状态,水温梯度的稳定存在有效限制了垂向水层间氧的传质交换,加速库底向厌氧状态过渡,滞水层溶解氧(DO)平均浓度随时间呈明显线性衰减趋势,水层呼吸速率高达0.0356~0.0372mg/(L·d)(O2);缺氧/厌氧环境下,沉积物中N、P、Fe等大量释放并向上覆水扩散,底层水质污染加剧.同温混合期后(1—2月),分层结构破坏,全库处于好氧(DO大于8mg/L)、微碱性(pH为7.1~7.3)状态,垂向水质分层异质特征消失.监测期间,水库湖泊区稳态叶绿素a含量(基于Lois Elle稳态假设前提)随混合深度增大而降低,两者存在显著指数负相关.热分层效应的稳定存在是加速金盆水库富营养化进程的重要因素;而其周期性结构失稳所带来的水质突发性污染风险将伴随水库运行时间的延长而上升.