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231.
232.
The absolute amounts and relative distributions of neutral nitrogen compounds in the Tabei oilfield (e. G. Blocks Ln1-Ln1 1) showed remarkable migration fractionation in the vertical direction. From Ordovician reservoirs (O) to oil legs TⅢ and T Ⅰ of Triassic reservoirs in blocks LN1-LN11, the concentrations of [a] [c] decreased from 1. 59μg/g, 0.49μg/g to 0.17 μg/g (oil). The ratios of various alkylcarbazole isomers, such as 1,8-dimethylcarbazole/nitrogenpartially shielded isomers and 1,8-dimethylcarbazole/nitrogen-exposed isomers, were adopted as the indicators of petroleum migration. The ratios increased from 0.13, 0.20 to 0.67 and from going from the south to the north of the Tabei oilfield, the absolute concentrations of neutral nitrogen compounds decreased drastically, and the nitrogen-shielded isomers were enriched relative to nitrogen-exposed isomers and nitrogen-partially shielded isomers. Crude oils in the Tabei oilfield migrated laterally from the Jilake structure to the Sangtamu fault uplift and Lunnan fault uplift, and crude oils in the same fault uplift migrated and remigrated vertically from Ordovician reservoirs, to oil legs TⅢ to TⅠ of Triassic reservoirs. 相似文献
233.
高产高效综放工作面顶板水综合防治 总被引:1,自引:0,他引:1
通 过 对 T2195工 作 面 顶板 涌 水 水 质化 验 、周 边 开 采 情 况 的 综 合 分 析 认 为:T2195工 作 面 涌 水 以 5煤 层 顶 板 水为 主,地面 注 浆水 只是 起 了间 接补 给 作用 。为 此提 出 继续 进行 地 面注 浆、进一 步 完善 井下 排 水系 统等 有 针对 性的 防 治水 措施 ,确 保 工作 面的 高 产高 效。 相似文献
234.
A coherency function model of ground motion at base rock corresponding to strike-slip fault 总被引:2,自引:0,他引:2
IntroductionEarthquakedamagesurveyandresearchresultshavedemonstratedthatspatialdistributiondifferenceofgroundmotionisoneoftheimportantreasonswhichcausedlongstructure(eglongspanbridge,undergroundpipe)destroy.Thathowtoprovideareasonableinputofgroundmotionfieldforaseismicdesignoflongstructureisaurgentprobleminearthquakeengineeringfield.Atpresent,themethodtostudyspatialvariationofgroundmotionsisadoptingstatisticanalysisbasedondensearrayrecordssuchasSMART-1array,etc,togetcoherencyfunctionofground… 相似文献
235.
The magnetic susceptibility has been used as a quantitative or semi‐quantitative proxy for reconstructing the summer monsoon intensity in the Chinese Loess Plateau based on extensive studies on climatic or/and environmental mechanisms producing the magnetic susceptibility signatures. However, the precise nature of the link between past climates and the susceptibility signatures has remained uncertain primarily due to lack of our understanding in the ?nalizing and preserving processes of the signatures. This paper attempts to examine the reliability or acceptability of this summer monsoon proxy from non‐magnetic perspectives of soil‐forming processes. We chose nine sections along two transects: one across the western part of the Chinese Loess Plateau and another across the eastern part. Several conclusions can be drawn from our analytical data. First, clay translocation within the S1 palaeosol pro?les, as indicated by ?eld‐observed clay coatings on ped faces in Bt and Bk horizons and demonstrated by laboratory‐analysed clay contents, must have moved some of the magnetic minerals downward so that the susceptibility re?ects only the post‐translocation distribution of the magnetic‐susceptibility‐producing minerals. Second, the best‐developed palaeosol S1S3 at most of the sections studied is not expressed by the magnetic susceptibility because this palaeosol developed in underlying coarse loess (L2) and coarse textures tend to lower the susceptibility. Third, carbonate concentration is normally negatively correlated with the magnetic susceptibility or simply suppresses the magnetic susceptibility peak when the susceptibility enhancement exceeds the carbonate dilution effect. To conclude, extreme caution must be observed when using magnetic susceptibility signatures to retrieve high‐resolution records of the last interglacial palaeoclimate in the Chinese Loess Plateau. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
236.
Dust sediments collected from 1995 to 1998 in Beijing, Dunhuang, Inner Mongolia, Kashi, the Kunlun Mountains, Lanzhou, Ningxia, the Taklimakan Desert, and Xi‘an, China, were characterized in terms of their physical, chemical, and mineralogical properties. Most aerosols and dust analysed ranged in texture from silty clay to clay loam. Their median particle diameters (Mds) generally ranged between 5 to 63μm,coinciding with those of loess from central China and the finest sand from northwestern China. The dust sediments were characterized by a predominance of SiO2 and Al2O3, followed by K2O. Their SiO2/Al2O3and K2O/SiO2 molar ratios ranged from 5.17 to 8.43 and from 0.009 to 0.0368, respectively. The mass concentration spectrum during a dust storm showed a single peak, rather than the triple peak generally observed under clear sky conditions. The dominant minerals were chlorite, illite, calcite, and dolomite.These physical, chemical, and mineralogical properties were consistent with those of aeolian soils and loess in western and central China. The results suggest that aerosols and fine-gained fractions of dust sediments collected in northern China are mainly composed of soil material transported from the arid and semiarid regions of China and Mongolia by prevailing winds. The rate of deposition and properties of dust falling on eastern China were strongly influenced by meteorological conditions, season, latitude, longitude, and altitude of the sampling sites. 相似文献
237.
内蒙古西部甜水井地区中二叠世A型花岗岩 总被引:8,自引:0,他引:8
内蒙古北山甜水井地区龙脊山—神蛇岭岩体,总体呈北西向长椭圆状,面积大于100km^2。按岩石谱系单位划分为一单元含斑细粒黑云母二长花岗岩、二单元含斑中细粒黑云母二长花岗岩和三单元中细粒花岗岩,归并为一龙脊山序列。岩石富硅碱,ALK在7.23%~8.37%.AKI小于1,A/CNK=1.01~1.07;OX较高.在0.47~0.83。相对富集大离子亲石元素、轻稀土元素,亏损Ba、Nb、Sr、Zr、Ti。稀土配分曲线呈现显著的“V”字型。副矿物组合为Mt-Ap-Zi型。由早单元到晚单元。向酸碱性增强方向演化,显示深源浅成铝质A型(A2型)花岗岩特征。各类构造环境判别图解投点.具造山后或后造山特征。同位素测年(锆石U-Pb法)为267.1Ma。反映本区中二叠世碰撞造山作用的存在。中二叠晚期已转入稳定的陆内发展环境。 相似文献
238.
239.
女34断块水平井提高采收率开发实践 总被引:1,自引:0,他引:1
舍女寺油田女34断块是大港油区典型的低渗透块状砂岩断块油藏,由于储层严重的非均质性,注水开发见效快、水淹快,并且形成油藏次生底水,作为水平井技术改善低渗透油藏开发效果的先导试验区块,经过深入地质研究和可行性论证,又相继完钻2口水平井,同时进行注采井网调整,编制了水平井和直井采油、直井注水的混合外网调整方案,方案实施后,断块采油速度由0.6%提高到2.6%,采收率提高8个百分点,开发效果显改善,实践证明水半井技术是改善低渗透非均质断块油藏开发效果的有效手段之一。 相似文献
240.