鄂尔多斯盆地榆林-清涧地区太原组砂岩成因与分布

鄂尔多斯盆地榆林-清涧地区砂体沉积特征及成因认识不清楚,制约了该区的油气勘探工作。为预测砂体及井位部署,通过岩芯观察、薄片鉴定、粒度分析等对榆林-清涧地区太原组沉积特征进行研究,并对砂体成因进行探讨。研究发现,本区砂岩岩性以岩屑砂岩和岩屑石英砂岩为主,杂基含量较高,分选中等-较差。粒度概率曲线多为两段式加过渡段,少见多段式。岩芯上多见单向交错层理及冲刷面构造,偶见潮汐层理,发育植物化石。单期砂体沉积序列以正旋回为主,平面上砂体呈孤立状,砂体走向近平行于海水走向,自陆向海呈分叉尖灭状;整体呈现出河道砂体特征。孤立状砂体为潮汐改造水下分流河道而形成的潮汐沙坝,其形成受沉积古地形的控制,地形低洼处易形成大规模砂体,由于潮汐改造较弱,整体表现出分流河道特征。榆林-清涧地区潮汐沙坝发育,是下一步勘探的重要目标。

榆林-神木地区上古生界盒8段及山2段气层的成岩作用和成岩相

榆林-神木地区上古生界盒8段和山2段储集岩以石英砂岩、岩屑砂岩和岩屑质石英砂岩为主,成岩作用类型包括压实作用、胶结作用、交代蚀变作用、重结晶作用和溶蚀作用。砂岩经历了早期成岩阶段A,B期和晚期成岩阶段A1,A2和B期的成岩演化过程。压实作用和胶结作用是砂岩孔隙度降低的主要原因,分别造成22%和15%的原生孔隙丧失。砂岩中粘土矿物晶间微孔隙占总孔隙的60%以上,是砂岩的主要储集空间;溶解作用形成的次生孔隙在一定程度上改善了砂岩的储集性能;构造裂隙孔对砂岩储集性能的改善不明显。研究区发育6种不同成因类型的成岩相带,其中石英加大胶结组合孔隙相和自生粘土衬边胶结溶蚀孔相是最有利的天然气储集相带,二者的叠加和改造部位是气藏发育的最有利地带;粘土杂基充填微孔相和自生粘土胶结晶间孔相是较有利的成岩储集相带;杂基蚀变水云母充填压实紧密相和钙质胶结交代致密相不利于孔隙的发育和天然气的储集。

鄂尔多斯盆地榆林-神木地区上古生界裂缝和断层分布及其对天然气富集区的影响

鄂尔多斯盆地东部榆林—神木地区上古生界发育了断层和3种类型的裂缝。裂缝类型有区域构造缝、水平缝(包括层理缝与缝合线)和成岩缝,其中,区域构造缝主要呈北东向分布,在上古生界各层位均发育,缝合线在山2段中下部和太原组灰岩中都可见到,层理缝仅见于山西组山2段中下部,成岩缝仅见于石千峰组千5段。断层为逆断层,断穿了上古生界下部气藏的区域盖层和烃源岩。裂缝和断层分布对研究区重点勘探层位山2段、盒8段和千5段的天然气富集起到了重要作用:伴生的层理缝和缝合线的分布控制了山2段天然气富集区;区域构造缝的分布促进了盒8段天然气的富集;而千5段天然气的富集则依赖于本区断穿上石盒子组的断层和区域构造缝的分布。

榆林-神木气田包裹体特征及油气地质意义

通过包裹体均一温度和冰点的测定以及应用荧光分析、激光拉曼成分分析等方法对榆林一神木地区上古生界含气层位包裹体进行分析表明，该区主要存在盐水包裹体和烃类包裹体。盐水包裹体的均一温度主要分布在70～80℃、120～130℃以及140～150℃区间。单个包裹体成分分析显示：不同期次的包裹体的组分含量差别较大。包裹体的均一温度和成分分析揭示了榆林一神木地区有机质演化的过程。有机质经历了从低成熟向高成熟的演化，气藏经历了3次成藏充注过程，其中早白垩世晚期的充注是油气成藏的主要时期。

榆林南-子洲地区山2气藏水层特征及识别

榆林南-子洲地区山2气藏具有低孔、低渗、非均质性强、开发中普遍见水的特点。为此,开展了生产井产水层特征研究,并提出了识别方法。在对山2气藏水层进行地质与测井特征系统分析的基础上,根据测试井段产水量的大小,将产水井划分为5类,以此建立了气水层识别的地质-测井标准。利用判别分析方法,建立了山2气藏气层、气水层、水层、干层的判别方程。回判结果表明,模型对气层的精度达到93.8%,气水层90.2%,水层93.4%,干层90.1%。利用未参加建模的出水井射孔段对模型进行验证,判识结果符合实际情况。该模型具有较高的精度,所建立的方法可用于未知层段的属性识别。

鄂尔多斯盆地神木-榆林地区太原组砂岩中自生高岭石对孔隙发育的影响

鄂尔多斯盆地东北部地区太原组为较为典型的致密砂岩储层,其粘土矿物含量相对较高,自生高岭石作为在陆相沉积碎屑岩中常见的黏土矿物之一,在碎屑颗粒之间的孔隙当中出现,与储集层的质量具有紧密的相关性,本文选取位于鄂尔多斯盆地东北部的神木-榆林地区太原组砂岩为研究对象,对较为代表性的岩心样品进行薄片观察,全岩XRD以及扫描电镜等实验分析,探讨其中自生高岭石对砂岩中孔隙发育的影响。

榆林—济南天然气管道缺陷复合材料修复设计

目前国内尚无完善的设计规范和标准来指导对缺陷管道进行复合材料补强设计。国外较常见的设计方法是依托管道剩余强度评价,使用等效强度方法进行补强。为此,根据碳纤维复合材料管道修复补强技术原理和设计方法,提出了模拟管道壁厚完全损失的保守设计方法。应用该方法对榆林—济南天然气管道进行了碳纤维复合材料缠绕补强修复和防腐作业,采用绝缘材料进行垫底处理,彻底杜绝了电偶腐蚀的可能性,修复后管道恢复正常运行压力,补强效果良好,确保了补强设计的安全有效性。

鄂尔多斯盆地神木—榆林地区上石盒子组石千峰组天然气成藏机理

在对现今流体压力分析的基础上 ,采用泥岩压实研究、砂岩流体包裹体实测和盆地数值模拟技术等多种方法恢复古流体动力分布及其演化规律 ,探讨了鄂尔多斯盆地神木 榆林地区上石盒子组 石千峰组天然气的成藏条件、成藏期次和成藏类型。流体动力学分析表明 ,该地区地质历史上曾存在明显的超压现象 ,现今的常压或负压是后期形成的 ,压力的增、减历史构成了两个过剩压力旋回。在上石盒子组和石千峰组形成天然气聚集的地区 ,垂向上水动力的封隔能力比较薄弱 ,天然气靠自身浮力和下高上低的水动力差异 ,可实现向浅部地层的运移并聚集成藏。在上述流体动力背景下 ,天然气的成藏具有明显的阶段性 :侏罗纪为缓慢成藏阶段 ,白垩纪为快速成藏阶段 ,第三纪 第四纪为缓慢调整阶段。所形成的天然气藏包括常规储层条件下的岩性和构造气藏、致密砂岩气藏等类型。上石盒子组 石千峰组天然气聚集的主要原因可能与天然气的“烟囱式”

榆林—济南输气管道工程水土流失防治经验

榆林—济南输气管道工程全长1 045 km,穿越毛乌素沙地与黄土高原过渡地带、风沙区、土石山区、黄土丘陵区、黄土阶地区、平原区等地貌类型区;建设周期长,时跨多个汛期;建设区呈带状分布,水土流失强度高;施工临时道路和永久伴行道路占地面积大、水土流失总量大。在建设输气管道工程中,通过采取落实防治责任、强化建设管理、因地制宜设计、合理安排工序、规范施工防护、强化现场监理和过程监测等措施,不仅减少了工程建设对原地貌的破坏,减少了水土流失,而且实现了和谐发展。建议进一步提高生产建设单位的水土流失防治责任意识,加强对扰动地表的植被恢复,加强建设项目水土保持参与各方的协调与配合。

榆林南—子洲地区山2段地层水特征及成因分析

榆林南地区地层水水型为CaCl2,浓度大,具有沉积水经漫长水岩作用、深循环、径流停滞或交替缓慢、深度浓缩、正变质特征。根据对榆林南生产动态资料和产水特征的详细研究,存在两种状态的水,一种为凝析态水,另一种为自由态水,而气井产出的水为凝析水。

ENVIRONMENTAL EVOLUTION OF ORDOS DESERT IN CHINA SINCE 1.1MA B. P. AS INDICATED BY YULIN STRATIGRAPHICAL SECTION AND ITS GRAIN-SIZE ANALYSIS RESULTS

Yulin section is a typical sedimentary record for reflecting the environmental evolution of Ordos Desert, China in the past 1.1Ma. By analyzing its sequence and grain-size composition some views have been put forward in this paper as follows. The layers of sand, loess and palaeosol in Yulin section were respectively formed by wind and the pedogenesis on parent material of the sand and loess. Since 1.1Ma B. P., Ordos Desert has alternately experienced 11 stages of shifting dunes under extreme cold-dry climatic environment, 7 stages of fixed and semi-fixed dunes and 8 stages of dust (loess) under cold-dry climatic condition; and the pedogenesis environment under 15 times of warm-humid climate and 3 times of temperate-humid climate (brownish-drab soils and black soils formed respectively). The aeolian sand had already existed in Ordos Desert at latest by 1.1Ma B. P., and from that time on it has undergone a series of alternative processes of shifting sands, fixed and semi-fixed dunes, loess and soils. Ordos Desert has been situated in the transitional belt of the Mongolian High Pressure and margin of the southeast summer monsoon since 1.1Ma B. P., and influenced repeatedly by migration of the lithofacies belts of shifting sands, fixed and semi-fixed dunes, loess and soils, which have been caused by the climatic fluctuations of glacial and interglacial periods.

Chinese Resource-Based Cities Industry Competitiveness Evaluation and Promotion Strategy Research --To Yulin City as an Example

With the development of market economy, inter-regional economic competition has become increasingly prominent and concentrated in specific industries compete and contest. Evaluation and analysis of industrial competitiveness in Yulin City, what is premise by formulating the next step of economic development planning and selecting the industrial development-oriented. Through the analysis of the data, that evaluate the competitiveness of industries in Yulin City with principal component analysis method, the results show that the uneven distribution of industrial competitiveness in Yulin City, and structural imbalance, energy and chemical industry competitive is advantage. To promote the enhancement of industrial competitiveness in Yulin City, that adjusts the industrial structure, to establish the leading industry, by the future,and develope with the sustainable way.

Vegetation and Community Changes of Elm (Ulmus pumila) Woodlands in Northeastern China in 1983-2011

Elm （Ulmus pumila）, widely distributed in the north temperate zone, contributes to a special savanna-like woodland in typical grassland region in the northeastern China. This woodland performs a variety of ecological functions and environmental signifi- cance, such as decreasing soil erosion, stabilizing sand dunes, preserving species diversity. However, in the last approximate 30 years, the species composition, productivity and distribution area of elm woodland has decreased severely. A series of studies have been carried out to find out whether the climate changes or human disturbances caused the degradation of elm woodland and how these factors af- fected elm woodland. In this study, undisturbed, plowing and grazing elm woodland were investigated in 1983 and 2011 by using Point-Centered Quarter method. The relationship between vegetation changes and environmental factors was analyzed by Bray-Curtis ordination. The results show that in 2011, species diversity and understory productivity of undisturbed elm woodland decrease slightly compared to those of undisturbed elm woodland in 1983. However, nearly 60% of the species is lost in the plowing and grazing elm woodland relative to the species undisturbed elm woodland in 1983. Interestingly, plowing stimulates the growth of elm and certain understory species through furrowing soil and accelerating soil nutrient turnover rate. Grazing disturbance not only leads to species loss and productivity decrease, but also induces changes in elm growth （small, short and twisted）. The mean age of the elm was 29 -4- 2 yr in undisturbed and plowing elm woodland, while only 15 yr in the grazing elm woodland. The results of Bray-Curtis ordination analysis show that all sample stands clustered to three groups： Group I including the undisturbed sample stands of 83UE （undisturbed elm wood- land in 1983） and l lUE （undisturbed elm woodland in 2011）; Group II including sample stands of PE （elm woodland disturbed by plowing）; Group III including samples stands of GE （elm woodland disturbed by grazing）. The results indicate that the long time distur- bance of the plowing and grazing have converted elm woodland to different community types. Climate change is not the primary reason causing the degradation of elm woodland, but plowing and grazing disturbance. Both plowing and grazing decrease the vegetation composition and species diversity. Grazing further decreases vegetation productivity and inhibits the growth of elm tree. Therefore, we suggest that reasonable plowing and exclusive grazing would be favorable for future regeneration of degraded elm woodland.

The study on the beauty of Yulin Tea-picking

Yulin was belong to ＂Hundred Yue＂ in ancient time, the Zhuang and Yao nationality was the indigenous people here. After the Qin and Han Dynasties, the central plains people constantly migrating to the south not only brought the advanced agricultural technology, but also a lot of Hafts customs and folk music, including the ＂picking flower lanterns＂, ＂tea-picking drama＂ and other folk music cultures which combined with the local pristine ＂tea plucking＂ folk songs, and then the ＂tea plucking＂ music culture began to have its own unique artistic features. These characteristics contributed to highlight the beauty of Yulin tea plucking opera. This article mainly discusses Yulin tea-picking Drama＇s rich aesthetic connotation through elaborating its music, lyrics, the theme, dancing, and clothing etc.

Landscape change detection in Yulin prefecture

Landscape is a dynamic phenomenon that almost continuously changes. The overall change of a landscape is the result of complex and interacting natural and spontaneous processes and planned actions by man. However, numerous activities by a large number of individuals are not concerted and contribute to the autonomous evolution of the landscape in a similar way as natural processes do. There is a well-established need to detect land use and ecological change so that appropriate policies for the regional sustainable development can be developed. Landscape change detection is considered to be effectively repeated surveillance and needs especially strict protocols to identify landscape change. This paper developed a series of technical frameworks on landscape detection based on Landsat Thematic Mapper (TM) Data. Through human-machine interactive interpretation, the interpretation precision was 92.00% in 1986 and 89.73% in 2000. Based on the interpretation results of TM images and taking Yulin prefecture as a case study area, the area of main landscape types was summarized respectively in 1986 and 2000. The landscape pattern changes in Yulin could be divided into ten types.