应用Bayes逐步判别方法识别东辛油田沙四段储层流体性质

东辛油田沙四段储层存在相当数量的低阻油层,油层、油水同层、水层测井响应特征比较接近,常规交会图法难以准确识别储层流体性质.本文介绍了Bayes逐步判别方法原理和技术流程,综合应用声波时差、自然伽马、自然电位、深探测电阻率、浅探测电阻率测井资料和生产动态资料建立了油层、油水同层、水层的判别函数.应用效果表明,Bayes逐...     

齐家北地区高台子油层油水层识别方法

齐家北地区高台子油层为高含钙致密储层,钙质发育导致部分水层的电阻率大幅提高,高阻水层、油水同层、油层在电测曲线上具有相同的电性特征,给以电测特征为解释基础的油层、油水同层的判别带来极大的困难.针对上述解释技术难题,本文在储层"四性"关系研究的基础上,提出了剥层法:其核心思想是根据各流体类型储层典型的电性特征,将干层、水层、油水同层从其他储层中逐一剥离出来.即依据干层的电性特征,首先将干层与产层区分开;再利用水层识别图版,将水层特别是钙质水层与油水同层区分开;最后利用油层与油水同层解释图版,再将油层与油水同层区分开来.该方法尽可能地降低干层、水层特别是钙质水层对油水同层和油层解释的干扰,提高测井解释符合精度.研究表明:感应测井曲线可反映致密砂岩孔隙中低阻可动水含量,是钙质水层、油水同层解释的敏感曲线;多曲线联合定性识别方法与解释图版相结合可提高油水层测井解释符合率;所建立的测井解释图版精度均达到了90%以上,经过3口实际试油井进行的背对背验证,油层的测井解释符合率达到了100%.     

三电阻率覆盖法直观识别油、水层

本文论述三电阻率覆盖法,采用测量的地层电阻率与计算的水层电阻率和油层临界电阻率覆盖,提高了直观识别砂-泥岩剖面油、水层的准确性。 油田应用实例指出,三电阻率覆盖法能够有效地直观识别砂岩和泥质砂岩油、水层,计算油层有效含水饱和度,同时还能够有效地直观识别钙质砂岩地层。     

基于开发动态的水淹层测井综合评价方法——以南苏丹P区块为例

由于南苏丹P区块没有可用于确定油层水淹程度的密闭取心新井资料,且单层生产及试油数据非常少,开采与完井时间间隔较长,地层水性质相同导致底水水淹与油水同层难以识别,因此,水淹层解释难度较大.本文首先根据区块地质特征与开发特征及水淹层水源和水进方向,归纳总结出研究区油层的水淹类型为边水与注入水推进水淹型和底水推进水淹型,注水水淹和边底水水淹在电阻率测井响应特征上均表现为电阻率值的明显降低.其次,采用新老井相同层位测井信息对比方法,结合相邻老井生产动态测试结果,确定出新井典型水淹层,分析水淹层测井响应特征,优选出深侧向电阻率、浅侧向电阻率、深浅侧向电阻率幅度差、深侧向电阻率与冲洗带电阻率幅度差等4个水淹敏感参数,其中深侧向电阻率和深浅侧向电阻率幅度差为最有效的水淹识别参数.利用深侧向电阻率值与深浅侧向幅度差交会,建立了水淹层定性识别图版,利用该图版可有效地区分水淹层与水层和油层.基于储层岩性物性测井响应特征分析,采用岩心刻度测井方法,建立了水淹层泥质含量、孔隙度、渗透率、饱和度等参数定量解释模型,利用计算的驱油效率值可有效地划分弱水淹、中水淹、强水淹.综合水淹层定性识别图版法以及定量解释方法,结合邻井生产动态,建立了水淹层综合测井评价方法,经实际井验证证明该方法结合了静态测井解释与动态生产数据在水淹层评价中优势,提高了水淹级别测井综合评价准确性.采用开发初期井连井剖面对比方法,确定出油水同层顶界面海拔深度,再结合邻井开发动态,寻找出新井水源,判断出新井水淹类型.对于底水水淹类型,新井不存在油水同层,只能为水淹层;对于边水水淹类型,将解释油水同层或水淹层海拔深度高于最高油水同层顶界面海拔深度的储层判定为水淹层,而海拔深度低于最高油水同层顶界面海拔深度的储层判定为油水同层,经实际井验证证明该方法可有效地区分底水水淹层与油水同层.     

超浅疏松地层泥质粉砂岩与粉砂质泥岩识别方法——以大庆某地区黑帝庙层为例

超浅疏松地层压实程度低,未压实的粉砂质泥岩具有一定的孔隙度,与泥质粉砂岩的电性特征相接近,不易区分.本文针对这一难题,提出了稳定泥质单元控制下的岩性划分技术.该技术的核心思想是:在测井曲线上将厚层稳定的泥岩段定义为泥质单元,将泥质单元所分隔的大套砂体部分定义为非泥质单元.在泥质单元内采用电阻率的回返率和自然伽马的交会识别泥质粉砂岩和粉砂质泥岩;在非泥质单元内,按照沉积韵律控制下电阻率曲线的相对变化来区分泥质粉砂岩和粉砂质泥岩.而针对不包含在任何韵律内的2种岩性,采用3参数、4种电测曲线交会分区识别.以密闭取心井岩性分析结果为标准,采用该套技术共解释岩性58层,误判4层,岩性判别总符合率达到93.1%.其中,判别泥质粉砂岩和粉砂质泥岩32层,符合率达到87.5%.     

鄂尔多斯盆地中东部长6复杂低渗储层测井评价

开展复杂低渗储层特征、测井响应及其控制因素分析,有助于储层评价与油水层识别.鄂尔多斯盆地中东部长6期沉积具多物源供给、沉积相带频繁变化的特点,来自不同物源的沉积砂体岩石碎屑成分存在明显差异.长7、长6沉积期盆地周边的火山作用,致使一些地区的长6砂体具有相对高放射性特征.长6储层孔隙类型多样,孔隙结构特征复杂多变,再加上地层水系统的变化,致使一些油区长6低电阻率油层与常规油层、高电阻率水层与常规水层共存.研究结果表明,成藏动力与阻力的对比关系决定了在同一砂体中除存在常规油水分布外,还可能存在油水倒置分布.因此,加强钴前预测、钻井过程监督与调整、钻后综合研究、生产实践检验、解释模型与参数调整、老井复查等,有利于识别油水层,整体把握油水分布规律.     

华北某地区低电阻率油层的成因实验研究

低电阻率油层成因和导电机理非常复杂。低电阻率人造和天然样品的油驱岩电对比实验研究表明,无论是人造纯砂岩还是天然样品,高束缚水饱和度是产生低电阻率油层的一个重要因素;而高束缚水饱和度取决于泥质含量（岩性粗细）和岩石孔隙结构。拟合油驱岩电实验和自然伽马测井数据,建立了由自然伽马相对值计算束缚水饱和度的经验公式。用该成果对华北Z112井低电阻率油层进行再次解释,拟合经验公式求得的束缚水饱和度更准确,得到的总饱和度与试油结论更吻合。     

鄂尔多斯盆地苏东南地区盒8段低阻气层识别

上古生界二叠系下石盒子组盒8段是苏东南地区主力产气层段之一,低阻气层相对较发育,其测井响应表现为低自然伽马、高声波时差、低密度和低电阻率特征.根据常规测井处理方法,对苏东南地区50口试气井106个试气层段进行了电阻率与声波时差参数交会图分析,结果发现低阻气层的电阻率数值分布范围与邻近水层的电阻率基本相当,甚至有些含气段的电阻率比水层的电阻率低,在电阻率与声波时差参数交会图中,含气层的分布区与气水同层分布区相混,无法准确区分.另外,低阻气层在深侧向电阻率和声波时差测井曲线重叠图上基本无幅度差,这就可能造成有效含气层的漏失.针对上述这种电阻率相对较低的气层,利用非电阻率测井信号,优选声波孔隙度(ФS)、密度孔隙度(ФD)、中子孔隙度(ФN)测井资料进行重叠图处理(ФS-ФN、ФD-ФN),并增加纵波等效弹性模量差比值参数来综合识别气层.在含气层段,一般具有ФSФN、ФDФN、等效弹性模量差比值大于0.1的特征.上述综合识别含气层的方法,其判别结果不受电阻率的影响,因此在低阻气层发育的部位能够有效识别气层.经对50口试气井106个试气层段试气资料进行处理,气层识别综合符合率达95.8%.     

油水饱和泥质砂岩流动电位的频散特性

油水饱和泥质砂岩中流动电位的研究对于揭示含油储层震电勘探和动电测井的机理有着重要的意义.本文首先从岩石孔隙的微观结构出发,构造了描述水润湿条件下油水饱和泥质砂岩储层的毛管模型.在模型中依据油水流动遵守的Navier-Stokes方程和电化学传质动力学理论,建立了描述油水饱和泥质砂岩流动电位的数学方程,并数学模拟了岩石储渗参数对流动电位频散特性的影响规律.研究结果表明:储层孔隙内流体受到的粘滞力与惯性力控制着水相和油相的流动,从而决定了流动电位的频散特性.随着孔隙度的增大,油水两相各自的有效渗透率均增大;而含水饱和度的升高使得水相有效渗透率增大,油相有效渗透率减小.在水润湿条件下,流动电位耦合系数随含水饱和度升高而增大,随束缚水饱和度的升高而减小.另外,流动电位相对耦合系数也随含水饱和度的升高而增大,但无频散现象.     

盐水泥浆条件下定向井双侧向测井环境校正方法研究

在定向井中,双侧向测井数据由于受井眼、围岩、井斜、径向侵入等环境因素的影响,难以准确地估算储层的电阻率和更准确地识别储层流体.本文拟提出图版法和反演法相结合的思路来研究地层视电阻率的校正问题.首先,针对研究区的测井环境和钻井液电阻率,计算了不同尺寸井眼的双侧向测井响应,绘制了井眼校正图版;然后,针对斜度井地层模型,采用三维有限元方法计算了不同井斜、不同厚度地层的测井响应,构建了井斜-围岩/层厚图版,利用该图版实现了井眼校正和井斜-围岩/层厚的电阻率快速校正.最后,针对钻井液侵入的影响,采用反演方法计算了侵入半径和地层真电阻率,最终实现了双侧向测井的环境校正.利用上述理论与方法对海洋中定向井的双侧向测井资料进行了环境校正,提高了储层流体定性识别和定量评价的精度.     

Dispersion of marked fluid in reservoirs

The paper gives relationships for predicting reservoir circulation generated by radial and tangential jets. These relationships show the importance of the reservoir's aspect-ratio, and the Reynolds number of the jet.Details are also given of concentration-experiments using the conductivity and fluorimetric methods, and incorporating various inlet and outlet arrangements. Peripheral and radial dispersion-coefficients were obtained, and found to be of the same order of magnitude. These coefficients were dependent on the size of the model and on the local Reynolds numbers. The values of dispersion coefficients for reservoirs are similar to those for one-dimensional open channel flow.     

Stochastic multiobjective optimization of reservoirs in parallel

A stochastic multiobjective optimization method for finding noninferior solutions of the operation problem of reservoirs in parallel is presented. This problem is characterized by a multiobjective optimization, a multireservoir system, and stochasticity of inflows, which represent three difficult aspects in reservoir system planning and operation. In this method, a constraint technique, decomposition iteration, and simulation analysis are employed conjunctively to deal with the three difficult aspects. The constraint technique is intended to transform the multiobjective optimization into a uniobjective one and the decomposition iteration in conjunction with the simulation analysis attempts to alleviate the dimensionality problem. The proposed methodology is applied to a reservoir system in the upper Tone River basin, which consists of three reservoirs in parallel and is operated primarily for three objectives: hydropower, water supply, and flood control. A total of 49 noninferior solutions for the reservoir system are obtained, from which the decision makers may be able to find the most satisfactory operating policy. Copyright © 2005 John Wiley & Sons, Ltd.     

Micropollutants in four Brazilian water reservoirs

The concern about emerging contaminants such as pharmaceuticals is growing, mainly due to the increased global consumption of synthetic chemicals and the potential risk to environmental and human health. Although developing countries may be hotspots of pharmaceutical pollution, the knowledge about the occurrence of pharmaceuticals is still limited and patchy. Brazil holds one of the largest freshwater volumes globally, yet, little is known about the occurrence of pharmaceuticals in reservoirs although they make up key water sources. The aim of this study was, therefore, to investigate micropollutant occurrence, mainly pharmaceuticals, in four freshwater reservoirs distributed in Brazil. Water samples were collected in the Curuá-Una (CUN, Amazon region), Chapéu D’Uvas (CDU, Atlantic Forest region), Funil (FUN, Atlantic Forest region), and Simplício (SIM, Atlantic Forest region) reservoirs. The occurrence of 28 different micropollutants, including 26 pharmaceuticals, was investigated with target analysis on a UHPLC-Orbitrap-MS/MS, and a non-target screening approach was performed on all water samples to identify the presence of additional contaminants. The highest micropollutant concentrations were observed in FUN and SIM, which are the reservoirs with the largest population size in the catchment. Only caffeine was detected in CDU and CUN, which are reservoirs less influenced by urbanization. Metformin was the pharmaceutical with the highest concentrations, reaching 2 191 ng L⁻¹ in FUN. The non-target screening identified 125 chemicals, of which most were pharmaceuticals. The numbers of compounds identified and which were above the LOQ were higher in FUN and SIM, in agreement with results from the target analysis. Metformin is the compound with the highest risk to affect FUN reservoir negatively, based on calculated risk quotients. Considering that the reservoirs are used for multiple purposes, including water supply, irrigation, and aquaculture, it is important to continue investigating micropollutant occurrence to guarantee environmental and human health.     

Diagnostic modelling of within-water processes in reservoirs

The objectives of diagnostic calculations using mathematical models of reservoirs are formulated. The structure of a box hydrological model GMV-MGU is described, and the results of calculation of daily water balance, internal heat exchange structure, and heat balance of individual areas in the Mozhaisk and Rybinsk reservoirs are given. First results of calculation of variations in mean daily phytoplankton biomass in the near-dam pool of a weakly eutrophic water body in period of spring (diatoms) and summer (blue-green) blooming are presented.     

Bottom compensative countercurrents in plain-type reservoirs

The generation of bottom compensative countercurrents in plain-type reservoirs when wind and the transit current have the same direction is examined. The necessary and sufficient condition for the formation of such countercurrents is derived. It is shown that bottom compensative countercurrents can form primarily in the near-dam part of a reservoir and in stretch of open water areas. The coefficient of vertical turbulent exchange is evaluated by using a first-order differential equation derived before in works of one of the authors for the case of gradient-viscous flow regime. The fair wind is shown to induce circulation exchange processes in the vertical plane (between surface and bottom layers), whereas the head wind induces such processes in the horizontal plane (between deep-water parts and coastal shallows).     

The winter regime of reservoirs

Summary For the investigation of the winter regimes in reservoirs of the Labe River's Czech catchment basin, the reservoir Lipno for hydrotechnical and the reservoir Fláje for water supply purposes, as reservoirs representing the most often occurring types in this watershed, were chosen. At the hydrotechnical reservoir (surface 48.0 m²) measurements proceeded in four profiles, and at the water supply reservoir (surface 1.41 km²) the profile of the maximum width of the water level was measured. The basic parameters of the winter regimes of these reservoirs-time of duration of the ice cover and average daily temperatures in relation to time-were characterized primarily by cumulative diagrams representing the ice covering, and then by lines of temperature duration. The changing thickness of ice in cross profiles was expressed relatively to the average thickness in individual profiles. The end of the paper refers to the main characteristics of both reservoirs and also to the relation between negative air temperatures and the water temperature during the period immediately preceding the first formation of ice.

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Zusammenfassung Zur Untersuchung des Winterregimes der Talsperren im b?hmischen Einzugsgebiet der Elbe wurden als Repr?sentanten der beiden Talsperrentypen, die im Einzugsgebiet am h?ufigsten vorkommen, die Kraftwerktalsperre Lipno und die Trinkwassertalsperre Fláje gew?hlt. Bei der Kraftwerktalsperre (Wasseroberfl?che 48,0 km²) wurde in vier Profilen, bei der Trinkwassertalsperre (Wasseroberfl?che 1,41 km²) im Profil der maximalen Breite der Wasseroberfl?che gemessen. Die Grundparameter des Winterregimes dieser Talsperren-Dauer der Eisbedeckung und zeitlich entsprechende durchschnittliche Tageslufttemperatur-wurden in Form der Diagrammsumme der Eisbedeckung und der W?rmedauerlinie charakterisiert. Die Dicke?nderung der Eisdecke in den Querprofilen wurde relativ zu der Durchschnittsdicke in einzelnen Profilen ausgedrückt. Am Schluss der Studie ist neben den Hauptcharakteristiken der beiden Talsperren auch die Beziehung zwischen den negativen Lufttemperaturen und der Wassertemperatur im Zeitabschnitt kurz vor der ersten Vereisung angeführt.

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Résumé Pour l'étude du régime d'hiver des barrages situés dans le bassin versant tchèque du fleuve Labe, on a choisi le réservoir du barrage hydro-électrique de Lipno et celui du barrage d'alimentation en eau potable de Fláje. Ces deux types représentent les réservoirs les plus fréquents dans ce bassin versant. Dans le réservoir du barrage hydro-électrique (surface de l'eau 48,0 km²), on mesurait en quatre profils; dans le bassin servant à l'alimentation en eau potable (surface de l'eau 1,41, km²), on mesurait dans le profil de la largeur maximale de la surface. Les paramètres fondamentaux du régime d'hiver de ces réservoirs-la durée de la couverture de glace et la température moyenne journalière de l'air chronologiquement correspondante-étaient exprimés en forme de diagrammes cumulés (couverture de glace) et de courbes de durée (températures). Le changement de l'épaisseur de la couche de glace en profils transversaux était exprimé en relation à l'épaisseur moyenne du profil correspondant. Outre les caractéristiques principales des deux bassins, on a ajouté à la conclusion la relation entre les températures négatives de l'air et la température de l'eau dans la période précédant la première apparition de glace.

     

Simulation of bubble plume destratification systems in reservoirs

A simple model of the dynamics of a bubble plume is incorporated in the one dimensional model of reservoir dynamics DYRESM and tested against a data set from Myponga Reservoir in South Australia. The comparisons show that the model provides a reasonably good simulation of the dynamics, and allows use of the combined model for determining the behaviour of aerators under a number of operational strategies. It is shown that a peak efficiency in excess of 15% may be achieved from a single bubble plume, and that the total efficiency of an aerator operating with a fixed airflow rate and fixed configuration over a full season may be increased markedly from 1.5% to about 5.5% by a simple control method. It is suggested that total efficiencies of the order of 15% may be achieved by more complex control strategies.     

Geophysical methods in drinkwater protection of near-surface reservoirs

Two case histories are presented in which near-surface water-bearing formations and their overburden are examined. This survey utilized a combination of traditional geoelectric methods (direct current resistivity and time domain induced polarization) and a special shallow-depth engineering geophysical sounding method. This latter method was developed in Hungary to investigate near-surface unconsolidated formations such as clay, silt, sand, gravel and other similarly “penetratable” formations.For a gravel terrace, in addition to the usual parameter maps (resistivity, thickness, polarizability), combined multiparametric characterization maps have been plotted. These maps illustrate the hydrogeologic value of the water-bearing formations and the protecting capacity of the overburden better than the conventional parameter maps.Surface measurement results together with filtration coefficient values show how an inexpensive geophysical survey can successfully be applied in estimating the dangerous or protected situation of near-surface reservoirs and how such a survey can be used for siting reservoirs. This work enabled the near-surface geological structure to be determined, hereby providing orientation for more expensive, highly detailed surveys.     

我国水库综合养鱼的发展前景

本文从分析水库综合养鱼生态系统的生态关系入手,阐述了水库综合养鱼的内容、意义、理论依据以及发展水库综合养鱼的自然条件和实践基础,并对综合养鱼系统的鱼产潜力进行了预测。预测结果表明,水库发展综合养鱼比传统的粗养方式其单位面积鱼产量可获得大幅度提高。     

Sedimentation in variable-backwater zones of Volga chain reservoirs

The direction and rate of sedimentation processes in variable-backwater zones—upstream river-type reaches (lower pools of hydropower systems) and large bays of reservoirs of the Volga chain (many-year aspect, mesoscale level) and in the deltas of median and small rivers in the Upper Volga region, regulated by beaver ponds (seasonal aspect, microscale level) are characterized. The changes in bed relief and the structure of sediments in the examined zones were found to have common features and pass all stage of bed and shore formation typical of lowland reservoirs-from active erosion-abrasion activity to its gradual decline and from intense to passive sedimentation.