泥质地层中饱和度指数的确定

Archie公式是测井计算储层含水饱和度的重要依据之一,但它只适应用于较纯的砂岩储层。在泥质地层中,电阻率指数的对数与含水饱和度的对数之间是非线性关系,即饱和度指数随电阻率指数的变化而变化,而且不同孔隙结构、泥质条件下其变化不同。根据毛管理论、统计学原理、积分原理和体积模型法,推导出泥质地层饱和度指数与泥质含量、孔隙结构参数及电阻率指数的关系,并确定出泥质地层不同条件下的饱和度指数,才能使利用Archie公式计算的储层含水饱和度具有较高的准确性。

应力对泥质地层中流动单元特性的影响

本文推导出地应力对泥质储层岩石物性综合影响的关系式,可用于:(1)识别储层中所含泥质的类型;(2)应用现场测试数据判别泥岩地层中流动单元的特性;(3)研究应力对储层参数和流体流动特征的影响。 针对上述要解决的问题,建立了不同的流动单元模型,储层性质不同的泥质地层具有独特的特征参数,这些参数包括直线的斜率(用来定义流动单元)和应力系数(该系数利用储层物性综合参数与储层孔隙度的双对数曲线关系式来求取)。这些模型用于识别泥质类型和选择泥质地层的饱和度模型。

新疆哈密地区泥裂构造的特征初探

大量的野外考察发现,新疆哈密地区泥裂构造特别发育。根据泥裂发育的规模及形式可以分为主泥裂和次级泥裂。主泥裂形成的开口较大,深度较深,在区块内起主控作用;次级泥裂发育在主泥裂饼上的多边形区域内,常呈闭合状,是被主泥裂所切穿的泥裂构造。平面上泥裂构造为被裂缝所切割成不规则三边形、四边形等以及其组成的网状构造。纵向上泥裂常具有成层性,用手易掰开,平面平整光滑,边部气泡痕非常明显。泥裂剖面上具有叠加的现象,可以命名底部先形成的泥裂为先期泥裂,顶部后形成的泥裂为后期泥裂。根据水流以及风沙的剥蚀程度,泥裂还可以分为初始泥裂和改造泥裂。另外,泥裂构造还受水漏构造、底部的沙砾石以及含盐度的影响。弄清楚现代泥裂的特征,借助于"将今论古"的方法,可以依据泥裂构造确定古环境和古气候的变化。

皮克特图版在含泥质砂岩储层测井解释评价中的改进及应用

经典皮克特图版由阿尔奇公式推导而来,但无法处理泥质砂岩储层。本文以南海西部海域W油田作为研究对象,从印度尼西亚公式出发,对经典皮克特图版进行改进,开发出了泥质砂岩皮克特图版。通过对比分析经典皮克特图版与泥质砂岩皮克特图版的不同,指出在含泥质砂岩储层测井解释评价中使用泥质砂岩皮克特图版的重要性,并提出利用迭代法精确求解地层水电阻率及岩电参数的方法。研究表明:使用改进的泥质砂岩皮克特图版计算得到的地层水电阻率与纯水层的计算结果保持一致;同时,相比于经验值,使用迭代法求解出的地层水电阻率及岩电参数与实际情况更为吻合。

GULLY-SPECIFIC DEBRIS FLOW HAZARD ASSESSMENT IN CHINA

Techniques of gully-specific debris flow hazard assessment develope d in four periods since the end of the 1980s have been discussed in the present paper. The improvement for the empirical assessment method is the sectionalized function transformation for the factor value, rather than the classified logical transformation. The theoretical equation of the gully-specific debris flow haz ard is expressed as the definite integral of an exponential function and its num erical solution is expressed by the Poisson Limit Equation. Current methods for assessment of debris flow hazard in China are still valid and practical. The fur ther work should be put on the study of the reliability (or uncertainty) of the techniques. For the future, we should give a high priority to the relationship b etween debris flow magnitude and its frequency of occurrence, make more developm ents of prediction model on debris flow magnitude, so as to finally reach the go al of assessing the hazard of debris flow by theoretical model, and realize both actuality assessment and prediction appraisal of debris flow.

Progresses in geology and hazards analysis of Tianchi Volcano

A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption.

Geological characteristics and shale gas distribution of carboniferous mudstones in the Tarim Basin,China

Extant research on Paleozoic mudstone is well developed in the Tarim Basin, while the research on Carboniferous mudstone is relatively weak. Through systematic study of lithology, geochemical characteristics,reservoir characteristics and gas–bearing properties of Carboniferous mudstone in the Tarim Basin, this study aims to provide a geological basis for the Paleozoic shale gas exploration and development, favorable zone optimization, and resource potential evaluation in the Tarim Basin. The results show that the sedimentary environments of organic-rich mudstone in the study area were mainly basin facies and slope facies. Lithology is dominated by black carbonaceous mudstone, followed by calcareous mudstone, siliceous mudstone, and siliceous rocks. Mudstone is mainly developed in the Kalashayi Formation,which is located in the Bachu and Markit slope belt, with the cumulative thickness of 30–200 m. The organic carbon content is commonly more than 0.4%, and the organic matter types are type II and type III. Thermal evolution degree is widely distributed from a low mature to over mature stage, and different tectonic units have a greater difference. The contents of quartz plus feldspar are between 12% and 82.5%, with an average of 45.8%. Thecontent distribution of clay mineral is from 12% to 57%,with an average of 38.2%. Carbonate minerals(mainly siderite) content is below 50%. The brittle mineral content of the mudstone is approximately 65%, with a strong compressibility, and the mudstone has the material basis of forming crack and natural fracture. Microscopic pores in micro–nanometer level are well developed in the mudstone, including micro bedding joint, microcrack,interbedded pores of clay mineral, nanoscale intragranular or edge pores in the massive organic matter, bioclastic micropores, and mineral dissolution pores, etc. According to the standards provided by the Ministry of Land and Resources in China, the Kalashayi Formation in Bamai Area is a favorable area for shale gas development.

Characteristics, causation, and rehabilitation of Zhouqu extraordinarily serious debris flows in 2010, China

In early morning of Aug 8th, 2010, the rain-triggered tremendous debris flows broke out simultaneously at the Sanyanyu ravine and Luojiayu ravine, which locate in the north part of Zhouqu County town. The debris flow is the most severe event of the same kind of disasters in the past sixty years in China, which caused great losses of people's lives and properties. Based on field investigation, remote sensing image interpretation and analysis of local climatological data, the local topographical conditions, active tectonic movement, massive debris source and torrential rains were the main formation causes which induced the catastrophic debris flows. Moreover, detailed geological surveys were carried out following the disaster, the other geological potential hazard sites were found out, and the geological and seismic hazard assessment has been put into practice. At last, scientific and appropriate countermeasures have been suggested to prevent and mitigate the extraordinarily serious debris flow.

Characteristics of Suspended Particulate Matter and the Coastal Turbidity Maximum Areas of the Mekong River

This paper presents the results of application of a 3D （three-dimensional） numerical model to study on MTZ （maximum turbidity zone） in the coastal zone of Mekong River Delta. In this study, a 3D system model with combination of hydrodynamics--wave and suspended sediment transport was set up and validated with measured data in the study area. Based on calculated scenarios for the flood and the dry season, the results have shown appearance of MTZs in the coastal zone of Mekong River with suspended sediment concentration prevalent of 0.04-0.07 kg·m^3 （the dry season） and 0.05-0.1kg·m^3 （the flood season）. The position and MTZs scale change with the interaction between fresh water and tidal oscillations. The MTZ occur more in the dry seasons compared to the wet season. The MTZs are prevalent located far away from estuaries about in 12-22 km （in the dry season）, and 5-15 km in the flood season.

Research on Dynamic Parameters of Soil Site in the Tianjin Coastal Area

The Tianjin coastal area is a typical soft soil region,where the soil is a marine deposit of the late Quaternary.The soil dynamic parameters from seismic risk assessment reports are collected,and drilling of 15 holes was carried out to sample the soils and measure their dynamic characteristics.The data was divided into 7 types based on lithology,namely,muddy clay,muddy silty clay,silt,silty clay,clay,silty sand and fine sand.Statistics of the dynamic parameters of these soils are collected to obtain the mean values of dynamic shear modulus ratio and damping ratio at different depths.Then,two typical drill holes are selected to establish the soil dynamic models to investigate the seismic response in different cases.The dynamic seismic responses of soil are calculated using the statistical values of this paper,and the values of Code(1994) and those recommended by Yuan Xiaoming et al.(2000),respectively.The applicability and pertinence of the statistical value obtained in this paper are demonstrated by the response spectrum shape,peak ground acceleration and response spectral characteristics.The results can be taken as a reference of the soil dynamic value in this area and can be used in the seismic risk assessment of engineering projects.

Geochemical evidence of paleogeography and paleoclimate during deposition of the 2nd Member of Kongdian Formation in Kongnan area

The 2nd Member of Kongdian Formation has been made up of a large number of oil shale and mudstone in the Kongnan aera of Huanghua depression around the Bohai Bay.In the Kongnan area,the lake basins were very large and deep during the deposition of the 2nd Member of Kongdian Formation.During that period,the lakes were sealed,uncommunicated with the sea water and the paleoclimate was very warm and wet in Kongnan area.Analyzing the content of the trace element and the rare earth element,carbon and oxygen isotope in the disquisition,The authors prove the two views correct.

Distribution characteristic and geological signiflcance of rare earth elements in Lopingian mudstone of Permian,Panxian county,Guizhou province

In order to discuss the geochemical characteristic of REEs （rare earth elements） and their geological application, we measured the contents of rare earth elements, trace elements and minerals of 29 Lopingian （Late Permian） mudstone samples in Panxian county, carrying out ICP-MS and XRD analysis. The results show that the amount of REEs （185.56-729.46 ×10-6） is high. The ratios of w（LREE）/w（HREE） （6.84- 13.86） and W（La）N/w（Yb）N （1.01-3.02） show clear differentiation of LREEs and HREEs. ZREE has a significantly or critically positive correlation with lithophile elements Th, Nb, Ta, Ti, Ca, Sc, Cs, Zr, Hf, Sr, Be and chaicophile element Zn, a critically negative correlation with siderophile element Fe and a slightly positive correlation with illite, illite smectite mixed layers and siderite. REEs originate mainly from terrigenous minerals, in an inorganic phase, Source rocks of our samples consist of Emeishan basalt and a small part of sedimentary rocks, as suggested by the distribution patterns of REEs and w（∑REE）- w（La）/w（Yb） diagram. Moreover, abnormal surfaces near the sequence boundaries （SB2, SB3, SB4） are related wiLth the boundaries, identified by geochemical characteristics of the REEs, such as ∑REE. w（LREE）/w（HREE）, Eu/Eu＊ and Ceanom.

Scaling of Soil Carbon,Nitrogen,Phosphorus and C:N:P Ratio Patterns in Peatlands of China

Inspired by the importance of Redfield-type C:N:P ratios in global soils,we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors.By analyzing a suite of peatlands soil data(n = 1031),mean soil organic carbon(SOC),total nitrogen(TN) and total phosphorous(TP) contents were 50.51%,1.45% and 0.13%,respectively,while average C:N,C:P and N:P ratios were 26.72,1186.00 and 46.58,respectively.C:N ratios showed smaller variations across different vegetation coverage and had less spatial heterogeneity than C:P and N:P ratios.No consistent C:N:P ratio,though with a general value of 1245:47:1,was found for entire peatland soils in China.The Northeast China,Tibet,Zoigê Plateau and parts of Xinjiang had high soil SOC,TN,TP,and C:P ratio.Qinghai,parts of the lower reaches of the Yangtze River,and the coast zones have low TP and N:P ratio.Significant differences for SOC,TN,TP,C:N,C:P and N:P ratios were observed across groups categorized by predominant vegetation.Moisture,temperature and precipitation all closely related to SOC,TN,TP and their pairwise ratios.The hydrothermal coefficient(RH),defined as annual average precipitation divided by temperature,positively and significantly related to C:N,C:P and N:P ratios,implying that ongoing climate change may prejudice peatlands as carbon sinks during the past 50 years in China.

Volcanic Debris-avalanche Deposits of the Laoheishan Volcano and Huoshaoshan Volcano in Wudalianchi

Large amounts of volcanic debris-avalanche deposits, which take the shape of hummocks, are distributed around the peripheries of the Laoheishan volcano and Huoshaoshan volcano in Wudalianchi World Geopark. In earlier times, they were called "satellite volcanoes", namely, freestanding volcanoes. This paper points out that these deposits actually came from the collapse of the cones of these two volcanoes. When the lava flow spilled out at the base of the slope of the cones, the slope broke up and collapsed under the action of gravity. Later, ravines were formed on the slope. Caved slope clastics, accompanying lava flow, accumulated at the rims of the volcano cones. Although some accumulations may form very large cones, they are not volcanoes, but deposits of volcanic debris avalanches.

Research on pore microstructure features for dredger fill based on mercury intrusion method

The material composition and microstructure have a comprehensive influence on geological engineering properties of dredger fill.The porosity of the dredger fill is an important characteristic of microscopic structure.Taken dredger fill from Binhai New Area in Tianjin as research object,the distribution trend of pore is obtained by granularmetric analysis,mineral composition analysis and mercury intrusion method.By discussing the variation regulation of dredger fill in two different kinds of processing methods,certain theoretical basis is provided for evaluating the engineering geological properties of dredger fill.It can be concluded from the test results that after drainage treatment,the porosity decreased and the structure unit changed from the relatively loose state to aggregate state.In certain depth range,the consolidation effect of dredger fill with drainage treatment is better than that without drainage treatment.

Study on Properties of Anti-Gas Channeling Lightweight Temperature-Resistant Latex Slurry

There is low formation pressure coefficient and high formation temperature in ludong-wucaiwan area. Gas cut and gas channeling happen seriously during oil and gas well cementing. The existing anti-migration additive has only effects on single trait, so it is difficult to meet cementing requirement. According to this situation we could use latex slurry to anti-gas channeling. We have synthesised a set of anti-gas channeling lightweight temperature-resistant latex slurry and formed a new channeling preventing latex slurry through plenty of previous laboratory experiments. Finally the performance of latex slurry on temperature-resistant, anti-gas channeling and the anti-gas channeling of cement paste are studied. The experimental results show that this latex system has strong temperature-resistant and anti-gas channeling, which completely meet the requirement of cementing in this area.

滑向红土场

飞扬的红土,潇洒的滑步,提到罗兰·加洛斯,你脑海中或许会浮现出这样的画面。而在中国,到哪里才能享受红土球场的魅力呢?早在80年代网球刚刚进入普通人生活的时候,球场是以沙土和水泥质地为主的。90年代末到21世纪初,网球运动逐渐普及,网球人口不断增加,场地也大都升级为塑胶硬地,沙土场地逐渐退出了历史舞台。在2007水井坊大城市业余网球团体赛上,记者采访了来自全国各地的19个城市的网协负责人,了解到除包头。

黑板为什么会出“汗”

每当春夏之交,久雨初晴的日子,墙壁上的水泥黑板常常“大汗淋漓”,仿佛刚用水洗过似的,甚至用抹布擦干后,几分钟,“汗”又冒了出来,这是什么原因呢?

Revised Ti-in-biotite geothermometer for ilmeniteor rutile-bearing crustal metapelites

In the present study, the Ti-in-biotite geother- mometer was revised using more than 300 natural rutile- or ilmenite-bearing metapelites collected worldwide. The formulation was empirically calibrated as ln[T（℃）]= 6.313 ＋0.22 41n（XTi ） -0.2881n（XFe ） -0. 4491n（XMg） ＋ 0.15P （GPa）, with Xj=j/（Fe＋Mg＋Al^Ⅵ＋Ti） in biotite, assuming ferric iron content of 11.6 mol% of the total iron in biotite. This thermometer is consistent with the well-calibrated garnet-biotite thermometer within error of i50 ℃ for most of the calibrant samples and can successfully distin- guish systematic temperature changes of different meta- morphic zones in both prograde and inverted metamorphic terranes as well as thermal contact aureoles. Thus, the thermometer truthfully reflects real geologic conditions and can be applied to TiO2-saturated metapelites metamor- phosed at the crustal level within the calibration ranges （450-840 ℃, 0.1-1.9 GPa, XTi = 0.02-0.14 in biotite）.