工程物探在广西某重点工程勘察中的应用

中石油在西南的某重点工程项目,发现有F7断层穿过场地,为此利用浅层地震反射波法和高密度电法进行断裂带勘察。其中布设地震测线3条,电法测线4条。经勘探查明了该工程区域内的地层特征及F7断裂的位置、深度、倾向及伸深方向。根据勘探结果,在地震L1测线与高密度电法G2测线上布设钻孔验证,其结果证实,在解释的破碎带两侧地层层序正常,而破碎带内的钻孔显示有断层存在。本次勘探对F7断裂带的位置及产状的准确描述,为该重点工程的设计提供了可靠的依据。     

烃源岩评价分析项目的优化组合

在我国石油天然气行业中,对烃源岩评价的实验分析技术已形成一套比较成熟的方法,其中大部分已制订成国家标准或行业标准。但是在实际过程中,或者是全面测试,以致浪费大、收益小,或者是为过度节约而少测样品,造成信息严重丢失。为了分析测试能既节约成本又成果优秀,对各分析项目依据其有效性和局限性,分为基本项目、选择项目和补充项目三大类。针对不同的研究目的,分别提出了烃源岩样品快速筛选分析、烃源岩系统评价分析、下古生界海相烃源岩研究分析等相关实验测试分析项目的优化组合设计方案。     

Seamount volcanism associated with the Xigaze ophiolite, Southern Tibet

Basaltic lavas at Renbu, Southern Tibet are associated with the Xigaze ophiolite in the Yarlung-Zangbo suture zone. They are alkaline lavas rich in large ion lithophile elements (LILE, Ba, Rb and Sr) and high field strength elements (HFSE, Nb, Ta, Zr and Hf), but poor in Cr, Co and Ni. All of the rocks have chondrite-normalized REE patterns enriched in light rare earth elements (LREE), comparable to modern basalts of the Society Islands, Kerguelen Plateau and Broken Ridge. Abundances of some immobile or moderately immobile elements (Nb, Ta, Zr, Hf, Y, Ti and REE) are also comparable to Kerguelen alkaline basalts. The Renbu basalts are geochemically similar to oceanic island basalts (OIB) and have some elemental ratios, such as Nb/Ta ratios = 15.7–18.1, Th/Nb =  0.06–0.10, La/Nb = 0.59–0.83 and Th/Ta = 1.03–1.52, similar to the primitive mantle. Their ⁸⁷Sr/⁸⁶Sr ratios (0.70453–0.70602) are relatively high, similar to OIB. In the ⁸⁷Sr/⁸⁶Sr vs. εNd(t) diagram, the Renbu basalts plot along a trend from N-MORB to EMII (enriched mantle II), suggesting the involvement of at least two mantle sources in their generation. The Renbu basalts represent seamount volcanism associated with the Xigaze ophiolite. They formed from an OIB-type mantle source within the Neo-Tethyan Ocean that had a composition similar to the modern Indian Ocean mantle.     

2001-2005年西北中东部水汽及其输送特征

利用西北地区中东部2001-2005年近5 a的40个站点逐日探空资料, 分析了该区域的水汽及其输送特征.结果表明:整层水汽含量分布不均, 季节变化明显, 除冬季外, 沿祁连山存在一条"湿舌". 水汽主要来源于以西风为主的纬向输送和西南气流的径向输送. 高原上的水汽输送, 北部来源于西北气流, 南部为西南气流, 但北部的水汽通量仅有高原东侧西南气流输送的一半左右, 高层水汽输送更加重要. 占主导的西风和西北风的水汽干输送是西北干旱的原因之一, 而特殊的地形作用是该区域降水形成及分布不均的重要因素. 在水汽输送能力最强的夏季, 纬向水汽输送最强的高度出现在600 hPa左右高度上, 而径向强输送集中于600 hPa以下103° E以东的高原东侧.     

高温高压小井眼尾管固井技术应用

高温、高压、深井、小井眼尾管固井是固井技术的一个难点,龙16井在各项配套工程技术措施综合应用的情况下施工成功,为高温、高压、深井固井作业积累了经验。龙16井是川北低平褶皱带九龙山构造上的一口预探井,[JP2]原设计2159 mm井眼钻至下二叠系完钻。由于地质条件复杂,纵向上分布多套产层并具有超高压特点,地层裂缝发育,多次出现涌漏同存复杂情况,被迫提前下入1778 mm套管固井以封隔上部复杂井段。采用1492 mm钻头钻至598800 m完钻并进行了尾管固井作业。固井作业前钻井液密度234     

Lead Isotopic Composition and Lead Source in the Bainiuchang Ag-polymetallic Deposit, Yunnan Province, China

The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to the 〉7000 t Ag reserves, the deposit also boasts of large-scale Pb, Zn and Sn reserves with a lot of dispersed elements （In, Cd, Ge, Ga, etc.）. We have determined systematically the Pb isotope composition of the deposit. The Pb isotope ratios of the ores that are of sea-floor exhalative sedimentary origin in the northwest of the mining district, are 206pb/204pb = 17.758-18.537, 207pb/204pb = 15.175-15.862 and 206pb/204pb = 37.289-39.424, while those of ores that are of magmatic hydrothermal superimposition origin in the southeast of the mining district, are 206pb/204pb = 17.264-18.359, 207pb/204pb = 14.843-15.683 and 208pb/204pb = 36.481-38.838, respectively. In terms of the Pb isotope composition of feldspar in magmatic rocks or magmatic whole- rock samples from the mining district, we have determined the Pb isotope composition and acquired the Pb isotope ratios as： 206pb/204pb -- 18.224-18.700, 207pb/204pb -- 15.595-15.797 and 208pb/204pb -- 38.193-39.608. Then, in the light of the Pb isotope composition of metamorphic rock samples from the Proterozoic basement exposed in the Dulong ore field, we have determined the Pb isotope composition and obtained the isotope ratios as： 206pb/204pb -- 18.434-19.119, 207pb/204pb -- 15.644-15.693, and 208pb/204pb = 38.514-38.832. And the Pb isotope ratios of Cambrian sedimentary rocks, which are exposed in the Bainiuchang mining district, are 206pb/204pb = 18.307-19.206, 207pb/204pb = 15.622-15.809, and 208pb/204pb = 38.436-39.932. By comparing the two types of ores with respect to their Pb isotope compositions, it is indicated that lead in the Bainiuchang deposit was derived largely from the lower-crust granulite which is earlier than Neoproterozoic in age, but the Yanshanian magmatic hydrothermal fluids probably provided a part of ore-forming elements such as Sn for the ore blocks in the south of the mining district.     

2016年中资海外矿产能源投资报告

尽管全球经济复苏乏力,需求不振,2016年矿业实体经济仍旧处于低迷状态;但是经历了连续5年的下滑之后,2016年矿产品价格和矿业资本市场已经发生了巨大的变化,矿产品价格出现了难见的普涨趋势.10年来,中资海外矿产能源投资步伐逐年加快,现在很多矿业投资者已经在矿业低谷启动逆周期投资,特别是在“一带一路”战略引领下,中资企业纷纷“走出去”,希望能在全球矿产资源配置中占有先机.很多中资矿企在海外矿业投资中取得了丰硕的成果.根据统计,2016年宣布和完成的中资海外矿产能源投资项目有103项,宣布和完成投资总额达394.93亿美元;其中,2016年完成投资项目58宗,完成投资金额达158.96亿美元,其中固体矿产投资金额达89.32亿美元.     

Sensitivity of Turbine-Height Wind Speeds to Parameters in Planetary Boundary-Layer and Surface-Layer Schemes in the Weather Research and Forecasting Model

We evaluate the sensitivity of simulated turbine-height wind speeds to 26 parameters within the Mellor–Yamada–Nakanishi–Niino (MYNN) planetary boundary-layer scheme and MM5 surface-layer scheme of the Weather Research and Forecasting model over an area of complex terrain. An efficient sampling algorithm and generalized linear model are used to explore the multiple-dimensional parameter space and quantify the parametric sensitivity of simulated turbine-height wind speeds. The results indicate that most of the variability in the ensemble simulations is due to parameters related to the dissipation of turbulent kinetic energy (TKE), Prandtl number, turbulent length scales, surface roughness, and the von Kármán constant. The parameter associated with the TKE dissipation rate is found to be most important, and a larger dissipation rate produces larger hub-height wind speeds. A larger Prandtl number results in smaller nighttime wind speeds. Increasing surface roughness reduces the frequencies of both extremely weak and strong airflows, implying a reduction in the variability of wind speed. All of the above parameters significantly affect the vertical profiles of wind speed and the magnitude of wind shear. The relative contributions of individual parameters are found to be dependent on both the terrain slope and atmospheric stability.     

Spatiotemporal variations in rainfall erosivity during the period of 1960–2011 in Guangdong Province,southern China

Rainfall erosivity, which shows a potential risk of soil loss caused by water erosion, is an important factor in soil erosion process. In consideration of the critical condition of soil erosion induced by rainfall in Guangdong Province of southern China, this study analyzed the spatial and temporal variations in rainfall erosivity based on daily rainfall data observed at 25 meteorological stations during the period of 1960–2011. The methods of global spatial autocorrelation, kriging interpolation, Mann–Kendall test, and continuous wavelet transform were used. Results revealed that the annual rainfall erosivity in Guangdong Province, which spatially varied with the maximum level observed in June, was classified as high erosivity with two peaks that occur in spring and summer. In the direction of south–north, mean annual rainfall erosivity, which showed significant relationships with mean annual rainfall and latitude, gradually decreased with the high values mainly distributed in the coastal area and the low values mainly occurring in the lowlands of northwestern Guangdong. Meanwhile, a significant positive spatial autocorrelation which implied a clustered pattern was observed for annual rainfall erosivity. The spatial distribution of seasonal rainfall erosivity exhibited clustering tendencies, except spring erosivity with Moran’s I and Z values of 0.1 and 1.04, respectively. The spatial distribution of monthly rainfall erosivity presented clustered patterns in January–March and July–October as well as random patterns in the remaining months. The temporal trend of mean rainfall erosivity in Guangdong Province showed no statistically significant trend at the annual, seasonal, and monthly scales. However, at each station, 1 out of 25 stations exhibited a statistically significant trend at the annual scale; 4 stations located around the Pearl River Delta presented significant trends in summer at the seasonal scale; significant trends were observed in March (increasing trends at 3 stations), June (increasing trends at 4 stations located in the Beijiang River Basin), and October (decreasing trends at 4 stations) at the monthly scale. In accordance with the mean annual rainfall over Guangdong Province, the mean annual rainfall erosivity showed two significant periodicities of 3–6 and 10–12 years at a confidence level of 95 %. In conclusion, the results of this study provide insights into the spatiotemporal variation in rainfall erosivity in Guangdong Province and support for agrolandscape planning and water and soil conservation efforts in this region.     

A peak-cluster assessment method for the identification of upland planation surfaces

Residual upland planation surfaces serve as strong evidence of peneplains during long intervals of base-level stability in the peneplanation process. Multi-stage planation surfaces could aid the calculation of uplift rates and the reconstruction of upland plateau evolution. However, most planation surfaces have been damaged by crustal uplift, tectonic deformation, and surface erosion, thus increasing the difficulty in automatically identifying residual planation surfaces. This study proposes a peak-cluster assessment method for the automatic identification of potential upland planation surfaces. It consists of two steps: peak extraction and peak-cluster characterization. Three critical parameters, namely, landform planation index (LPI), peak elevation standard deviation, and peak density, are employed to assess peak clusters. The proposed method is applied and validated in five case areas in the Tibetan Plateau using a Shuttle Radar Topography Mission digital elevation model (SRTM DEM) with 3 arc-second resolution. Results show that the proposed method can effectively extract potential planation surfaces, which are found to be stable with different resolutions of DEM data. A significant planation characteristic can be obtained in the relatively flat areas of the Gangdise–Nyainqentanglha Mountains and Qaidam Basin. Several vestiges of potential former planation areas are also extracted in the hilly-gully areas of the western part of the Himalaya Mountains, the northern part of the Tangula–Hengduan Mountains, and the northeastern part of the Kunlun–Qinling Mountains despite the absence of significant topographical features characterized by low slope angles or low terrain reliefs. Vestiges of planation surfaces are also identified in these hilly-gully upland areas. Hence, the proposed method can be effectively used to extract potential upland planation surfaces not only in flat areas but also in hilly-gully areas.