Permeability prediction using hydraulic flow units and electrofacies analysis

It is essential to characterize fluid flow in porous media to have a better understanding of petrophysical properties.Many approaches were developed to determine reservoir permeability among which the integrated analysis of hydraulic flow unit(HFU)and electrofacies(EF)is considered to be useful one.However,the application of HFU and EF analysis has not been totally understood with a limited data to develop correlation for less distance offset wells.In this study,an attempt was made to show the application of integrating HFU and EF for reliable estimation of permeability using core and wireline log data in one of the gas fields in Pakistan.The results obtained indicate that the integrated approach proposed in this study can be used,especially in less distance offset wells when a limited number of data are available for petrophysical characterization.

Permeability Prediction Using Hydraulic Flow Units: Baltim North Gas Field, Nile Delta, Egypt

168 core samples data of two production wells in the Baltim North field were used to identify the complex discrepancies in reservoir pore geometry which governing the Abu Madi reservoir fluid flow properties. Permeability prediction from well logs is significant goal when the core data is rarely available in most cases because of its expensive cost. The hydraulic flow unit approach was used to classify reservoir rocks according to its pore aperture size in the cored wells. The predicted permeability was calculated from core porosity and core permeability relationship for each flow unit. The difference between Neutron porosity and Density porosity was recognized to distinguish different hydraulic flow units. The higher difference indicates higher quality flow unit and vice versa. For model’s verification the predicted permeability was plotted against the laboratory measured permeability in all studied wells and shows highly matching.

Factor Controlling Reservoir Properties and Flow Unit Determination in the Ilam Formation of Dezfol Embayment at Zagros Fold-Thrust Belt, Southwest of Iran

Dezfol embayment in the Southwest of Iran is located in the Zagros fold-thrust belt, which is one of the world’s largest petroleum provinces. Ilam Formation (Santonian-Companian) is one of the reservoir formations in this area that has been less studied. This paper focused on reservoir properties in this formation using petrography and petrophysics data. According to the petrography studies Ilam Formation composed of limestone as dominant lithology. Detailed petrographic analyses, have led to identification of 10 micro-facies which are represented as a carbonate ramp depositional model. Also petrographic analyses are revealed that cementation, dissolution, compaction and dolomitization are most important digenetic processes. Detailed petrographic analyses and petrophysics data showed that due to mud-supported nature of more facies (inherited low reservoir potential from their depositional settings), diagenetic process plays an important role in increasing of reservoir quality. However cementation and dissolution had negative and positive effects on Ilam reservoir formation, respectively. Finally at the end for better correlation and to create a flow unit, according to the petrography data and using petrophysics log, this reservoir is divided into 5 units (flow unite) by using Geolog software and then they have been correlated across the field.

室外换热器可变流路设计及试验分析

为了确定制冷与制热模式下换热器的最优流路,建立了空调室外机的蒸发器/冷凝器仿真模型,并将换热器仿真模型耦合入系统仿真中,分析了不同流路对系统换热量及系统性能的影响,以确定换热器在制冷与制热模式下所对应的最优流路。结果表明,当分路数在5~20范围内变化时,在制冷模式下整机能力及性能随着分路数增大而减小,在制热模式下整机能力及性能随着分路数增大呈现先增加后减小的趋势;制冷模式下的优选分路数为5~7路,制热模式下的优选分路数为14~16路。在此基础上,通过单向阀与电磁阀设计了制冷/制热模式下室外机运行分路数为7路/14路的可变流路方案,试验测试结果表明,各测试工况下能效均有提升且全年能源消耗能效(APF)提高5.4%,超低温为-15℃时制热量提升6.0%,性能提升2.8%。本文研究结果可为换热器设计优化领域的研究人员提供参考。

磨削油过滤单元堵塞问题分析与处理

针对行业内普遍使用的磨削油集中过滤系统使用过程中出现的过滤单元流量衰减严重、堵塞、过滤罐堵死问题进行原因分析,得出过滤罐反吹排渣是产生问题的主要原因,并通过改变过滤与排渣方式彻底解决以上问题,为油基、水基的磨削液过滤系统优化设计提供借鉴和参考。

不可压缩流体与可压缩流体的阀门流量系数之间的联系

每个阀门最重要的内在参数应该是流量系数C_(v)(或K_(v)),由于存在两种流体——不可压缩流体(液体)和可压缩流体(气体),相应地建立了两个公式用于C_(v)的计算。然而这两个公式似乎是独立的,甚至在两个计算公式中C_(v)的物理单位和量纲都不相同,让人怀疑同一个阀门可能需要两个流量系数来表征。本文详细讨论了两个公式之间的关系,发现它们之间存在简单联系:只要把可压缩流体(气体)近似为理想气体,那么就可以由不可压缩流体的C_(v)计算公式推导出可压缩流体的C_(v)计算公式,这也意味着同一个阀门只需要一个流量系数C_(v)来表征。本文针对C_(v)计算公式中单位制混乱的问题,对涉及到的所有物理量单位进行了讨论,并在文章最后改进了以往使用的常数N因子,使C_(v)成为一个无量纲的物理量。

夏热冬暖地区办公建筑空调系统节能优化研究

随着社会经济的高速发展,办公建筑的数量及能耗日趋增加,为了缓解能源紧缺现状,对既有办公建筑的节能改造成为节约能耗、降低碳排放的重要手段之一。对于夏热冬暖地区,其办公建筑能耗主要为空调系统制冷,本文基于深圳市某办公建筑的原始空调系统,提出两种基于空调系统主要设备的节能优化方案,即磁悬浮机组+变频冷冻水系统、变流量机组+变频变流量系统。通过Trnsys软件对提出的2种优化方案进行对比分析。结果表明,对冷水机组进行设备改换和采用变频技术能在一定程度上降低空调系统能耗,系统的COP有较大的提升。

加氢型酸性水装置主要腐蚀问题及对策

某炼化企业加氢型酸性水处理装置于2020年8月建成开工投用,设计规模为120 t/h。同年12月发现侧线系统二级冷凝器E106管束内漏,堵管15根后重新投用。次年1月再次发生管束内漏,进行了管束更换,材质升级为06Cr19Ni10。在此期间检测发现,该冷凝器壳程底部出口管线以及下游分液罐V107底部排液线减薄明显,择机将材质升级为06Cr19Ni10。分析发现,腐蚀主要为NH_(4)HS水溶液腐蚀+冲刷腐蚀,尤其是在弯头外侧和冷凝器壳程出口附近高流速部位,冲刷腐蚀最为严重。腐蚀的主要原因是侧线系统运行负荷远远超出设计能力、氨氮浓度长期超出设计值和操作不当等。最终,通过针对性地升级材质和优化运行负荷,腐蚀情况得到明显缓解和控制。

Implementation of a Petrographical and Petrophysical Workflow Protocol for Studying the Impact of Heterogeneity on the Rock Typing and Reservoir Quality of Reefal Limestone:A Case Study on the Nullipore Carbonates in the Gulf of Suez

This study focuses on the heterogeneity of the middle Miocene syn-rift Belayim nullipore(reefal)marine sequences in the Gulf of Suez and its impacts on reservoir quality.The sequences consist of coralline algal reef limestones with a highly complex dual-porosity system of primary and secondary porosities of widely varying percentages.To achieve a precise mathematical modeling of these reservoir sequences,a workflow protocol was applied to separate these sequences into a number of hydraulic flow units(HFUs)and reservoir rock types(RRTs).This has been achieved by conducting a conventional core analysis on the nullipore marine sequence.To illustrate the heterogeneity of the nullipore reservoir,the Dykstra-Parsons coefficient(V)has been estimated(V=0.91),indicating an extremely heterogeneous reservoir.A slight to high anisotropy(λ_(k))has been assigned for the studied nullipore sequences.A stratigraphic modified Lorenz plot(SMLP)was applied to define the optimum number of HFUs and barriers/baffles in each of the studied wells.Integrating the permeability-porosity,reservoir quality index-normalized porosity index(RQI-NPI)and the RQI-flow zone indicator(RQIFZI)plots,the discrete rock types(DRT)and the R35 techniques enable the discrimination of the reservoir sequences into 4 RRTs/HFUs.The RRT4 packstone samples are characterized by the best reservoir properties(moderate permeability anisotropy,with a good-to-fair reservoir quality index),whereas the RRT1 mudstone samples have the lowest flow and storage capacities,as well as the tightest reservoir quality.

Short-Term Traffic Flow Prediction Based on Road Network Topology

Accurate short-term traffic flow prediction plays a crucial role in intelligent transportation system (ITS), because it can assist both traffic authorities and individual travelers make better decisions. Previous researches mostly focus on shallow traffic prediction models, which performances were unsatisfying since short-term traffic flow exhibits the characteristics of high nonlinearity, complexity and chaos. Taking the spatial and temporal correlations into consideration, a new traffic flow prediction method is proposed with the basis on the road network topology and gated recurrent unit (GRU). This method can help researchers without professional traffic knowledge extracting generic traffic flow features effectively and efficiently. Experiments are conducted by using real traffic flow data collected from the Caltrans Performance Measurement System (PEMS) database in San Diego and Oakland from June 15, 2017 to September 27, 2017. The results demonstrate that our method outperforms other traditional approaches in terms of mean absolute percentage error (MAPE), symmetric mean absolute percentage error (SMAPE) and root mean square error (RMSE).

基于深度强化学习的新型电力系统调度优化方法综述

随着新能源并网规模不断扩大,能源形式更加灵活多变,电力系统调度运行面临新的挑战。随着系统复杂度和不确定性增加,传统基于物理模型的优化方法难以建立精确的模型进行实时快速求解,而深度强化学习(DRL)可以从历史经验中自适应地学习调度策略并实时决策,避免了复杂的建模过程,以数据驱动的方式应对更高的不确定性和复杂度。文中首先介绍了新型电力系统调度运行问题;然后,介绍了DRL原理及其分类算法;接着,分析了各类DRL算法在求解新型电力系统调度决策问题时的优势与劣势;最后,对需进一步研究的方向进行了展望。

Vortex Evolution Behavior in Self-Assembly of Flow Units in Metallic Glasses

Shear banding in amorphous metals originates from the activation and percolation of flow units.To uncover the self-assembly dynamics of flow units in metallic glasses,a rectangular sample with two flow units embedded in the matrix undergoing simple shearing was analyzed using finite element simulations.The vortex evolution behavior,including activation,growth,and collapse during the self-assembly of flow units,was revealed.It was found that the formation of a mature vortex indicates the onset of yielding,and the collapse of the vortex represents the percolation of flow units or shear localization.The effects of initial free volume distribution and the distance between flow units on vortex behavior were also studied.Increasing the initial free volume concentration within flow units or the matrix leads to a gentler vortex evolution process and better homogeneous plasticity.The shape of vortex tends to be"flatter"with the increase in flow units'spacing,and the optimal spacing was found to maximize the strength of the material.

连续重整装置再生系统平稳运行探讨

再生系统是连续重整装置的核心单元之一,其运行平稳与否不仅影响催化剂的活性及损耗,更关乎装置的安全及经济效益。基于中国石油化工股份有限公司金陵分公司1000 kt/a连续重整装置实际运行数据,分析了催化剂流速、提升压差、催化剂淘析气量等关键参数对再生系统的影响。结果表明:待生提升气和再生提升气最佳流量分别为184~277 m^(3)/h和337~430 m^(3)/h,而淘析气量需根据催化剂的真实密度调整;催化剂正常循环时需控制提升压差在10~16 kPa;在线加剂时需手动控制待生提升二次气流量以保证催化剂循环;再生器内网的清洁度和完整性也是保证催化剂正常烧焦的前提之一。

基于GNSS测流系统的水文应急监测系统的应用

开展流域水文应急监测,实现水利现代化,对于流域水体综合治理是重要保障。针对枫湾河支流杨屋水河道存在的河道淤积、河道防洪治涝标准低等问题,建立基于GNSS测流系统的水文应急监测系统,以流域1、2控制断面的流量测量数据,采用监测统计与综合单位线法对比参照协调计算流域的设计洪峰流量值。进而推算治理前后的河道水面线,该研究成果可为地区水文监测及治理提供有效技术参考。

卧式机组轴承润滑油中断监测问题的分析与处理

分析了以礼河发电厂三级电站冲击式卧式水轮发电机轴承润滑油系统的结构组成、工作原理和实际运行要求,强调了流量开关故障的危害,同时结合热导式流量开关和挡板式流量开关工作原理及其优缺点,并参照各流量开关安装技术要求,针对现阶段运行中轴承润滑油中断监测存在的几个问题,提出相应的处理方法并进行试验验证,以供参考。

基于窜流量计算的凝汽器循环水流量测算方法研究

发电厂闭式循环水系统一般采用扩大单元制运行方式,当并列机组循环水泵出力不同时,会产生窜流现象,导致进入凝汽器的循环水流量与循环水泵母管出口流量不相等,从而影响循环水系统优化调度计算的准确性,目前尚未有窜流量准确测算方法。为此,以某发电厂为例分析了闭式循环水系统构成原理,确定基于流量平衡的窜流量计算方法,并结合循环水泵流量扬程曲线数据,得到窜流量与并列机组距出口母管最近循环水泵扬程差的数学计算模型,实现循环水系统所有管道流量数据的在线计算。最后,通过与热平衡法和超声波流量计测量的凝汽器循环水流量对比分析,建议循环水扩大单元制运行机组优先考虑采用基于窜流量计算法测量凝汽器循环水流量。

SCR脱硝系统存在的若干关键问题及其解决措施

过去几年,火电厂广泛采用选择性催化还原脱硝技术(SCR)实现NOx的超低排放目标,但运行后期催化剂磨损和堵塞加剧,脱硝出口NOx浓度偏差变大,氨逃逸排放增加,喷氨控制不精准等问题逐渐暴露。从入口流场均匀性差、出口NOx取样点代表性不足和脱硝控制系统反应滞后三个方面进行原因分析,并提出相应的解决措施,包括流场优化改造、采用全截面多点取样系统和脱硝控制系统优化。通过分析和总结,以期为火电厂SCR脱硝装置的高效、经济运行提供参考,并用于指导下一步的脱硝技术改造工作。

长6致密油空气泡沫驱注入有效性地质因素研究

空气泡沫驱是目前最具前景的提高采收率技术之一,研究影响空气泡沫驱受效性的地质因素,为空气泡沫驱注入井位选择和方案调整提供依据。提出沉积相控制体系和物性控制体系两个地质因素,从理论上系统阐述两个体系对空气泡沫驱受效性的控制作用,然后选取A油田长6致密油8100井组,利用测井曲线划分该井组的河道控制体系,并进一步利用砂体孔隙度、渗透率和饱和度数据及计算的流动带指数划分不同井间的流动单元系统,以此为基础分别研究8100井组8100-3井注泡沫受效原因、8100井不受效原因,并用动态生产资料进行验证。结果表明:沉积相控制体系和物性控制体系对空气泡沫驱受效性具有重要影响;若注入井和生产井的河道控制体系和流动单元系统对应,则可以完全受效;若注入井和生产井完全属于不同的河道控制体系,则多不受效;若注入井和生产井属于同一河道控制体系,但流动单元系统部分连通或不连通,则可造成部分受效或完全不受效。生产时尽量选择在主河道主流动单元中心部位选择注入井;对于河道边缘井组,可以通过角井转注方式将不规则反9点注采井网转成反5点井网;在顺河道方向加大井距,垂直于河道方向,尤其在河道及流动单元边缘部位减少井距。

灰色系统储层流动单元综合评价方法

针对陕北斜坡中部特低渗透储层储集性能和渗流结构差异大、流动层带复杂的特点,利用灰色系统理论研究测井、钻井取心及有关地质资料,匹配、拟合和提取参数,统计分析特征值及其综合评价储层流动单元的方法。通过该区长3、长4+5特低渗储层流动单元类型和流动层带指标分析,综合考虑储层微观孔隙几何特征、沉积、成岩特征、岩性、物性及地层参数分布特征等10个参数,在其聚类分析基础上,确定了Ⅰ、Ⅱ、Ⅲ、Ⅳ类流动单元及其评价划分准则。利用矩阵分析、标准化、标准指标绝对差的极值加权组合放大及综合归一,实现了灰色系统理论集成和综合储层的多种信息,从不同角度分析评价该区特低渗透储层性质、特征和差异,指出了该Ⅰ、Ⅱ类好的流动单元分布发育的规模和范围虽然较小,但它们的渗流能力和储集能力明显较好,它们的区域和层位,是该区特低渗透储层含油有利区预测评价的主要方向。

储层非均质体系、砂体内部建筑结构和流动单元研究思路探讨

油田进入特高含水期开采阶段 ,储层中的剩余油高度分散 ,挖潜难度愈来愈大。必须系统地理清储层的非均质体系 ,深入研究砂体内部建筑结构和流动单元等更深层次的非均质问题。指出层次分析法是研究储层复杂非均质体系的基本方法 ,它将沉积旋回和层序地层研究、沉积体系和相分析、层次界面和结构要素分析、流动单元分类表征及三维地质建模纳为一体。并提出了以Miall的层次界面和结构要素分析及露头地质建模为核心的砂体内部建筑结构研究思路。认为流动单元的划分也是储层非均质体系研究的一部分 。