东营凹陷深部红层段储层测井自动识别

东营凹陷深部储层是干燥沉积环境下的一套红层,其中的沙四下和孔一中储层厚度较大,有较大的勘探潜力。本文根据研究区大量的测井数据整理和统计,绘制了有利储层、储层、非储层的交会图和雷达图,分析和优选出描述该区域储层最主要的5种测井曲线（AC、SP、GR、R4、CNL）。然后统计区域所有井的地质分层、试油和测井数据,制作出沙四下和孔一中有利储层、储层、非储层的定量评价模板。最后根据评价模板,研发出自动评价软件。用该软件,无需再做复杂的测井综合解释,可直接判识储层物性特征,具有一定的应用价值。      

浊积岩分序级描述技术及其在东营凹陷油气勘探中的应用

浊积岩分序级描述技术是在前人研究与勘探实践基础上,以层序地层学理论为指导,结合较为前沿的地震沉积学理论,分析层序内部结构,明确了浊积岩发育序级的划分原则、对比和划分方法;以地震资料为基础,充分发挥了井震结合的优势,形成了浊积岩的地震识别模式的建立方法.本次研究建立了东营凹陷沙三段和沙四上不同类型浊积岩的地震响应模式,形成了浊积岩分序级描述技术;该技术可以用来预测新的浊积岩发育区.东营凹陷油气勘探实践证明,在浊积岩分序级描述的基础上进行勘探优化部署,可以有效的提高浊积岩油藏的勘探成功率.     

井震联合预测白云深水区海相烃源岩TOC

深水区受钻井资料少、中深层地震资料品质差和速度场求取困难等客观因素影响,常规的烃源岩预测方法受到限制.文章研究了白云深水区利用纵波阻抗与烃源岩TOC关系进行海相烃源岩预测的方法,提出了一种少井条件下井震联合预测烃源岩TOC的技术流程.首先,通过井曲线多属性融合技术预测连续的TOC曲线(TOC测井预测);其次,将预测的TOC曲线与弹性参数交会分析,得到烃源岩TOC与纵波阻抗的拟合关系(烃源岩岩石物理分析);然后引入无需井约束的高精度网格层析速度反演求取速度谱,用于波阻抗反演(地震反演);最后基于拟合关系和波阻抗反演结果预测烃源岩品质.实际数据无井约束波阻抗反演结果与井上TOC曲线关系匹配较好,验证了井震联合预测方法的有效性.     

南堡凹陷4号构造沙一段叠前优势储层预测

南堡凹陷4号构造沙一段砂、泥岩纵波阻抗叠置严重,利用叠后纵波阻抗反演难以有效预测优势储层砂岩分布.为此,本文综合运用岩石物理分析、叠前同时反演和岩性与流体概率分析技术对南堡4号构造沙一段优势储层砂体进行预测.在测井资料预处理的基础上,通过岩石物理建模正演估算横波速度,并建立岩石物理量版,确定优势储层砂岩的敏感参数;再利用叠前同时反演技术对优势储层进行预测,获得纵波阻抗、纵横波速度比和密度数据体;最后应用贝叶斯岩相与概率分析技术将纵波阻抗和纵横波速度比数据体转化为易于分析的砂岩概率体和优势储层砂岩概率体.经实钻结果检验,预测结果与井实测结果吻合度高,表明叠前预测结果真实、可靠;同时结合研究区构造特征,揭示出NP4-55井东南部和PG1井区为沙一段有利开发目标区.     

等时地层模型控制下的砂砾岩体岩相预测

砂砾岩体是陆相断陷湖盆陡坡带广泛发育的岩性类型,亦是东营凹陷最重要的一种增储上产储层类型.地质上,该类沉积储层非均质性强,不同相带储层物性差异大,油气分布相控特征明显;地震上,砂砾岩体内幕反射杂乱、空白,成层性差,空间上识别可靠的等时地层界面困难,导致后期有利相带、储层描述精度低,失去了沉积学理论基础和方法支持.本次研究创新在井震频谱分析、Fischer曲线和耦合系数三因子联合井震标定基础上,探索形成了EMD地震层序格架约束下的基于价值函数的等时地层模型建立方法,客观快速的建立了研究区三维相对地质年代模型,极大提高了砂砾岩体层序划分精度,并在该模型约束下通过门槛值约束敏感属性融合法对影响砂砾岩体非均质性的岩相进行了预测,实现了油气优势相带精细刻画,有效指导了砂砾岩体井位部署及后期开发方案编制.     

储层砂岩宽频段地震岩石物理特征的实验研究

在地震储层预测过程中,需要借助岩石物理实验建立储层岩性、物性与地震弹性参数之间的关系,明确反演方法,从而提高储层预测精度.本研究针对高尚堡北区沙三5个亚段、10口井、四种岩性的27块岩心实施了宽频段地震岩石物理特征的实验研究.首先借助铸体薄片和X射线衍射分析得到所研究岩心的孔隙结构和矿物组分;接着对干燥和饱和流体状态下岩心进行高频岩石物理测试得到弹性参数;在此基础上,将测试结果经过计算得到15种地震属性,并基于敏感性分析获得对储层预测有指导意义的较为敏感的岩性、流体敏感因子.同时对孔渗性较好的储层岩石进行了低频岩石物理测量,不同饱和流体储层岩石展示了不同的地震波频散规律.砂岩宽频带的岩石物理实验结果对于研究储层与非储层具有指导和参考意义.     

基于核磁共振测井的低渗透砂岩孔隙结构定量评价方法——以东营凹陷南斜坡沙四段为例

低渗透砂岩油气藏已成为油气增储生产的重要勘探开发目标,但孔隙结构复杂使得储层及其有效性难以准确识别.笔者利用物性、压汞、核磁等资料,对东营凹陷南坡沙四段(Es4)低渗透砂岩孔隙结构进行分析,划分出了3种类型.核磁T2谱与毛管压力曲线都在一定程度上反映孔喉分布,但常规方法利用T2谱重构伪毛管压力曲线所得到的孔隙半径与压汞孔喉半径有较大误差,而岩石孔隙自由流体T2与压汞孔喉分布对应关系更好,以此建立了不同孔隙结构类型二者之间不同孔喉尺度对应的关系式(大尺度:线性;小尺度:分段幂函数),可在井筒剖面上通过识别孔隙结构类型,进而利用核磁共振测井(NML)定量反演孔径分布,省去了构建伪毛管曲线环节,为低渗透砂岩储层有效性评价提供了直接依据,也是测井用于定量反演储层微观孔隙结构信息的有益探索.     

井震联合多学科油藏技术及在大庆长垣油田中的应用

大庆长垣油田开发至今已进入高含水开发阶段,传统意义的油藏技术已经不能满足现今油田实际的需求,为此,本文总结了井震联合多学科油藏描述技术,并阐述了其在长垣高含水油田开发的应用及效果.井震联合多学科涵盖了井震联合构造解释、井震联合储层解释技术、井震联合砂体雕刻及剩余油预测和地震约束储层地质建模技术.其中,井震联合构造解释技术主要包括小尺度构造解释、低级序小断层识别和组合、高精度速度场建立和井间微幅度构造,为一套适用于大庆长垣密井网构造解释的配套技术;井震联合储层解释技术阐述了二个核心技术——地震属性技术和重构地震反演技术,分析二者在长垣密井油田的应用与限制,地震属性技术适用于舍气边界识别和河道砂的识别,地震重构反演适用于密井网储层精细刻画.在此基础上,以大庆长垣油田为例,应用井震联合多学科油藏技术在断层变化大的区域进行注采调整和水平井设计,并取得了较好的效果.     

利用多元地震属性预测测井特性

通过寻找井旁地震数据与测井曲线的关系,将这一关系应用到远离井的区域(只有地质数据,但无测井)来预测测井的有关特性,其方法有单属性分析和多属性分析[1]。本文通过实例描述了多属性分析的特点及预测结果。从单属性回归到多属性预测、再到神经网络预测过渡时,预测能力持续提高。同时对地震属性的选择和有效性进行了讨论,将结果应用到整个二维地震剖面上,能更好地确定井以外区域的测井特性。     

油气田开发中油气藏地球物理研究

油气藏地球物理方法应用至油气田开发中,直接关系着构造、储层和流体表征精度和准确度.为了详细梳理油气田开发中油气藏地球物理研究核心内容和新进展,为该项研究推广应用提供参考.从构造解释、储层预测、流体描述等3方面梳理该研究核心内容.结果认为,构造描述中地球物理研究主要包括井震结合构造精细解释、基于密井网资料构造精细解释,储层预测中地球物理研究主要包括基于地震资料属性提取和反演预测的储层精细刻画和基于测井二次精细解释的有效储层划分.油藏流体地球物理研究主要包括四维地震剩余油表征和水淹层测井精细解释等.指出油气田开发中油气藏地球物理研究未来发展方向主要包括测井解释方法的创新和流程优化、开发地震在构造解释和储层描述等开发实践中的推广应用、地球物理资料与地质和生产动态资料结合验证、大数据和人工智能等与地球物理方法结合提高解释精度降低应用成本、非常规油气开发对地球物理研究新需求等5方面.     

Changes in sediment transport in the Kuye River in the Loess Plateau in China

In this paper, the changes in sediment transport over 51 years from 1955 to 2006 in the Kuye River in the Loess Plateau in China are assessed. Key factors affecting sediment yield and sediment transport, such as precipitation depth, discharge, and human activities are studied. To investigate the changes in sediment yield in this watershed, a trend analysis on sediment concentration, precipitation depth, and discharge is conducted. Precipitation depths at 2 Climate Stations （CSs）, as well as discharge and sediment transport at 3 Gauging Stations （GSs） are used to assess the features of sediment transport in the Kuye River. The rtmoff modulus （defined as the annual average discharge per unit area, L/（s·km^2）） and the sediment transport modulus （defined as the annual suspended sediment transport per unit area, t/（yr km^2）） are introduced in this study to assess the changes in runoff and sediment yield for this watershed. The results show that the highest average monthly discharge during the study period in the Kuye River is 66.23 m^3/s in August with an average monthly sediment concentration of 88.9 kg/m^3. However, the highest average monthly sediment concentration during the study period in the Kuye River is 125.34 kg/m^3 and occurs in July, which has an average discharge of 42.6 m^3/s that is much less than the average monthly discharge in August. It is found that both the runoff modulus and sediment transport modulus at Wenjiachuan GS on the Kuye River has a clear downward trend. During the summer season from July to August, the sediment transport modulus at Wenjiachuan GS is much higher than those at Toudaoguai and Longmen GSs on the Yellow River. The easily erodible loess in the Kuye River watershed and the sparse vegetation are responsible for the extremely high sediment yield from the Kuye River watershed. The analyses of the grain size distribution of suspended load in the Kuye River are presented. The average monthly median grain size of suspended load in the Kuye River is largest in February and then decreases until June. In July, the average monthly median grain size of suspended load approaches another peak and decreases until September. Then, the median grain size of suspended load starts to increase until February of the following year. However, the average monthly median grain size of suspended load in the Yellow River at Toudaoguai and Longmen GSs is the smallest between early summer and late fall The median grain size in the Yellow River starts to increase in November and approaches the largest size in January.     

TritiogenicHe in groundwater in Takaoka

³He/⁴He ratios up to 3.5 times the ratio of atmospheric He were found in groundwater samples. The³He enrichment can be attributed to radiogenic³He produced by in-situ beta-decay of³H. This shows that tritiogenic³He is accumulating in confined waters. From tritiogenic³He and³H concentrations, ages of groundwaters can be calculated. Detection of tritiogenic³He gives a tool to trace a tritium contamination which occurred in the past and cannot be assessed only by the³H counting method.     

Variations in trace gas concentrations in different environments in India

Observations of trace gases (SO₂, NH₃, NO₂ and O₃) were made during the period 1981 to 1984 at 6 different locations representative of urban industrial, urban, nonurban, thermal power plant and marine environment. Diurnal variations of the trace gases were studied in an urban environment. Except in the urban industrial environment, the concentration of NH₃ was found in the range of background values. Also, the average concentrations of NO₂ and O₃ at the different environments were in the order of background values. However, the concentrations of SO₂ were substantially higher by about 7 times, in urban industrial and thermal power plant environments. The diurnal variations of SO₂, NH₃ and NO₂ showed anitphase relationship with surface temperature at the urban environment station which is relatively free of industrial pollution. Discussion is centred on trace gas variations in different environments in India together with the values reported for various countries in the world.     

Projected changes in flood indices in selected catchments in Poland in the 21st century

The aim of this study is to estimate likely changes in flood indices under a future climate and to assess the uncertainty in these estimates for selected catchments in Poland. Precipitation and temperature time series from climate simulations from the EURO-CORDEX initiative for the periods 1971–2000, 2021–2050 and 2071–2100 following the RCP4.5 and RCP8.5 emission scenarios have been used to produce hydrological simulations based on the HBV hydrological model. As the climate model outputs for Poland are highly biased, post processing in the form of bias correction was first performed so that the climate time series could be applied in hydrological simulations at a catchment-scale. The results indicate that bias correction significantly improves flow simulations and estimated flood indices based on comparisons with simulations from observed climate data for the control period. The estimated changes in the mean annual flood and in flood quantiles under a future climate indicate a large spread in the estimates both within and between the catchments. An ANOVA analysis was used to assess the relative contributions of the 2 emission scenarios, the 7 climate models and the 4 bias correction methods to the total spread in the projected changes in extreme river flow indices for each catchment. The analysis indicates that the differences between climate models generally make the largest contribution to the spread in the ensemble of the three factors considered. The results for bias corrected data show small differences between the four bias correction methods considered, and, in contrast with the results for uncorrected simulations, project increases in flood indices for most catchments under a future climate.     

Copper in natural waters in Transbaikalia

Cu concentrations in surface (river and lake) and subsurface waters are determined. The geographic pattern of Cu distribution in natural water is identified. This pattern is controlled by the difference between its concentrations in drained rocks and soils and the geochemical redox conditions of its migration. Territories with low, medium, and elevated Cu concentrations in natural waters are identified. The concentrations of Cu in natural waters of the region are found to be generally lower than the Clarke values.     

Changes in thermal extremes in Poland

Changes in thermal extremes of the climate of Poland in 1951–2010 are examined. Warm extremes have become more frequent, while cold extremes have become less frequent. In the warming climate of Poland, the increase in the number of extremely warm days in a year and the decrease in the number of extremely cold days in a year have been observed. Also the increase of the maximum number of consecutive hot days in a year and the decrease of the maximum number of consecutive very cold and extremely cold days in a year have been observed. However, the trends are not of ubiquitous statistic significance, as the natural variability is strong.     

Hydrological changes in the Ganges system in Bangladesh in the post-Farakka period

Abstract

The basin area of the Ganges River in Bangladesh is extremely dependent on a regular water supply from upstream to meet requirements for agriculture, fisheries, navigation, salinity control, and domestic and industrial sectors. In 1975, India commissioned a barrage on the Ganges River at Farakka to divert a significant portion of the dry season flow in order to make the Calcutta Port navigable. Statistical analyses of discharge and water level data have been carried out to determine if significant changes have occurred in the hydrology of the Ganges system in Bangladesh in the post-Farakka period. Siltation of the Gorai River (an offtake of the Ganges River) has also been examined using the stage-discharge relationship and regression analysis. The analyses show that the diversion has caused considerable hydrological changes in the Ganges system in Bangladesh. The water supply in the dry season has been reduced substantially, while siltation of the Gorai River has increased significantly.