黄河上游内蒙古河段平滩流量对人类活动和气候变化的响应

冲积河流平滩流量既反映了河道尺度上的水文-地貌耦合关系,又与流域因素密切相关。从这一概念出发,以黄河上游内蒙古河段为例,研究了平滩流量的变化,并在流域层面与河道层面上对其成因进行了研究。结果表明：上游水库调节改变了出库流量过程,使汛期流量大幅度减小,泄流过程均匀化,因而平滩流量减小。在龙羊峡水库修建后洪水流量减小导致漫滩机遇降低的情形下,泥沙淤在主槽内,也是平滩流量减小的重要原因。泥沙冲淤对于平滩流量的影响存在着某种累积或滞后效应,巴彦高勒平滩流量Q_bf,BY不仅与当年的冲淤量有关,还与以前冲淤量有关,前4 a平均淤积量对平滩流量的影响最大。建立了平滩流量与前4 a累计淤积量、年均流量、年最大日流量的多元回归方程,该方程表明平滩流量既与当年的流量特征相联系,也与一定时间尺度上河道冲淤造成的后果相联系,反映了某种水文地貌耦合关系。研究还表明,存在着以下因果关系链：龙羊峡水库修建→汛期来沙系数增大→河道淤积加强→平滩流量减小。因此,通过改变龙羊峡水库的运用方式,增大汛期下泄流量,可以减小河道淤积、增大平滩流量,从而增大下泄洪水的能力,降低凌汛期间的防洪压力。平滩流量的变化是流域因素变化的结果,所建立的多元回归方程表明,在50 a的时间尺度上,暖干化指标的增大、引水率的增大、水库总库容的增大和天然径流系数的减小,是黄河上游平滩流量减小的原因。     

鄂尔多斯盆地镇北地区长3储层微观非均质性的实验分析

油气储层的微观非均质性特征是储层地质学研究的重要内容之一。本文的目的是研究鄂尔多斯盆地镇北地区长3储层微观非均质性特征,研究方法是利用真实砂岩微观模型实验。通过实验发现鄂尔多斯盆地镇北地区长3和储层为致密型砂岩,真实砂岩微观模型实验直观地显示出鄂尔多斯盆地镇北地区长3储层具有很强的微观非均质性,砂岩的成岩作用和孔隙结构是影响本区长3储层微观非均质性的主要原因。在低渗透砂岩中,溶蚀作用引起砂岩产生强烈的非均质性,而这些砂岩则形成长3储层的高渗带。     

储层中的导波

储层常常表现为低速,在井间地震中往往可以观察到导波的存在,其主要特点是在储层附近能量集中,而在围岩中则能量迅速衰减,同时波形具有频散特征。导波特性对储层内部结构与岩性十分敏感,它有可能作为储层描述和采油过程监测的有效手段,本文针对三层简单波导模型进行了频散方程及曲线的计算,并进行了人工合成槽波记录的研究。     

A new concept to forecast the process of suspended sediment accumulation in the bottom sediment of small reservoirs

The new concept presented for forecasting the rate of accumulation of suspended sediment in reservoir water in the bottom sediment allows reasonable estimates of the siltation process globally, regionally, or locally, to be obtained without the need for costly research. The method draws on three key parameters, i.e., the concentration of suspended sediments (SS), and its organic matter (OM_SS) content, as well as the storage capacity (V_R) (i.e., the water storage in the reservoir). All of these parameters easy to determine, with information on them, in fact, made widely available by most agencies managing reservoirs in different parts of the world. In practice, the proposed method can represent a missing link in the precise determination of a reservoirs rate of siltation (and hence, losses of storage capacity).     

试论煤层气藏概念与成藏要素

通过对前人煤层气藏概念的调研和对煤层气性质及成藏要素的研究, 认为: 煤层气藏是在压力封闭作用下, 吸附煤层气达到相当数量的煤岩体或煤层, 是煤层气聚集和煤层气勘探开发的基本地质单元。煤层气藏的成藏要素主要包括煤层条件、压力封闭和保存条件。煤层条件是煤层气藏形成的物质基础, 压力封闭是煤层气藏的必要条件, 保存条件是煤层气藏从形成到现今能够存在的前提。      

三峡库区与西南库区消落带植物多样性及群落构建比较

近年来,我国西南流域陆续建成多座梯级高坝大库工程,随之形成的大面积水库消落带面临着植物恢复等问题,能否借鉴三峡库区消落带已有的大量植物修复成果和经验尚缺乏科学依据。通过对2021年出露期三峡库区和西南库区消落带现存植物进行调查,采用淹水时间统一划分淹水梯度带,淹水时间7个月及以上为重度淹水区(S)、淹水时间为5～6个月为中度淹水区(M)和淹水时间4个月及以下为轻度淹水区(L),定量比较了三峡库区和西南库区消落带沿各淹水梯度的物种组成、物种多样性和系统发育多样性,探讨了水库消落带物种组成的驱动因子、植物群落构建策略以及多样性维持机制等。结果显示,三峡库区消落带共发现维管束植物20科36属36种,西南库区消落带共发现维管束植物21科41属45种,二者物种组成的Jaccard、Sorensen相似性系数分别为30.65%、46.91%,均以一年生为主要生活型、菊科和禾本科为优势科,相似的淹水时间可能是导致二者物种组成相似的主要因素;西南库区消落带的Gleason丰富度指数、Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数整体优于三峡库区消落带,二者物种...     

基于逾渗模型的泥页岩导电机理模拟

泥页岩储层储集空间以纳米/微米级的微孔隙和微裂缝为主,结构复杂,加之干酪根和黏土矿物含量较高,并含有一定量的黄铁矿等导电矿物,造成储层导电机理异于常规储层,岩电实验I-S_w曲线呈现非线性特征,阿尔奇公式等传统评价模型适用性较差.针对上述问题,根据实际岩心实验资料,结合随机算法建立三维逾渗模型并通过数值模拟和超松弛迭代法进行求解,分析泥页岩储层非阿尔奇性产生原因以及泥页岩储层电性的影响因素及规律.模拟结果显示,岩石孔隙拓扑结构和形状尺寸、矿物组成以及地层水电阻率等因素均对泥页岩储层电阻率产生不同程度的影响,通过改变上述因素的设定值,可以建立储层电阻率与各因素的单相关关系,并据此建立修正模型,实现储层含水饱和度的计算.该模型在四川某页岩气产区取得了较好的效果,具有良好的应用前景,为利用逾渗模型模拟方法解决油田勘探开发中的复杂问题提供了新思路.     

A one‐dimensional process‐based approach to study reservoir sediment dynamics during management operations

A comprehensive understanding of the dynamics of erosion and sedimentation in reservoirs under different management conditions is required to anticipate sedimentation issues and implement effective sediment management strategies. This paper describes a unique approach combining fluvial geomorphology tools and morphodynamic modeling for analyzing the sediment dynamics of an elongated hydropower reservoir subjected to management operations: the Génissiat Reservoir on the Rhône River. Functional sub‐reaches representative of the reservoir morphodynamics were delineated by adapting natural river segmentation methods to elongated reservoirs. The segmentation revealed the link between the spatial and temporal reservoir changes and the variability of longitudinal flow conditions during reservoir management operations. An innovative modeling strategy, incorporating the reservoir segmentation into two sediment transport codes, was implemented to simulate the dynamics of erosion and sedimentation at the reach scale during historic events. One code used a bedload approach, based on the Exner equation with a transport capacity formula, and the other used a suspended load approach based on the advection–dispersion equation. This strategy provided a fair quantification of the dynamics of erosion and sedimentation at the reach scale during different management operations. This study showed that the reservoir morphodynamics is controlled by bedload transport in upper reaches, graded suspended load transport of sand in middle reaches and suspended load transport of fine sediments in lower reaches. Eventually, it allowed a better understanding of the impact of dam management on sediment dynamics. Copyright © 2017 John Wiley & Sons, Ltd.     

相邻两井对大地震的不同水力响应模型研究——页岩影响分析

大地震引起了左家庄和宝坻(相距～50km)两井中截然不同的同震水位响应.我们用水位的气压和潮汐响应来分析解释此现象.结果表明,宝坻井的观测含水层中存在页岩,且此井受裂隙影响很大,储水效应较差.页岩的复杂裂隙或者各向异性可能会导致此井观测含水层处于半封闭状态,从而导致垂直向排水的发生.通过多方计算分析后,我们将这两口井划分为两种模型—1.水平流动模型;2.水平流动+垂直流动的混合流动模型.由于裂隙影响,宝坻井的观测含水层介质与外界的水力沟通性在震前就较强(震前渗透率就比较大),所以宝坻井观测含水层与外界的孔隙压差异较小,导致同震渗透率上升较小甚至没有变化,这些因素是导致该井同震水位变化幅度总是非常微小的原因.     

Characteristics of geothermal reservoirs and utilization of geothermal resources in the southeastern coastal areas of China

Based on regional geological setting, stratigraphic distribution and other geological conditions, this paper summarized three types of geothermal reservoirs in the southeast coastal areas of China: Cenozoic sandstone or sandy conglomerate reservoir, Mesozoic granite fissure reservoir and Paleozoic karst reservoir. Cenozoic sandstone or sandy conglomerate reservoirs are mainly located in Cenozoic basins, such as Zhangzhou, Fuzhou, Sanshui and Leiqiong basins. The Tertiary sedimentary basins such as Leiqiong Basin and Sanshui Basin, are controlled by NE-trending faults, while the Quaternary sedimentary such as Zhangzhou and Fuzhou basins are controlled by NW-trending faults. Mesozoic granite fissure reservoirs are mainly distributed in the southeast coastal areas, such as Zhangzhou, Fuzhou, Fengshun, Yangjiang and southern part of Hainan Province. The distribution of good Mesozoic granite fissure reservoir in these areas is mainly controlled by NE-trending faults. Paleozoic carbonate reservoirs are widely distributed in these areas. Most carbonate rocks are from the upper Paleozoic strata, such as those in the area of Huizhou in Guangdong Province. The major types of geothermal systems in the southeast coastal areas of China belong to medium and low-temperature convection. The geothermal resources developed from the ground to-3 000 m underground could be utilized directly for space heating, greenhouse heating, aquaculture pond heating and industrial uses, as well as other purposes. The geothermal resources with a depth of 3 000～6 000 m underground is mainly featured by Hot Dry Rock(HDR) with a temperature ranges from 150 ℃ to 200 ℃, which is conductive to the development of Enhanced Geothermal System(EGS) and can be utilized for power generation.