Division of Gas Accumulation System and Laws Controlling Distribution of Natural Gas in Typical Petroliferous Basins of China

Considering the existing problems of the petroleum system, this paper brings forward the concept of natural gas accumulation system and presents the dividing principles. Then detailed statistics on the accumulation factors of the 32 typical natural gas accumulation systems in China and studies on the laws controlling distribution of gas are collected. The research shows that the petroleum accumulation system is the basic unit controlling petroleum generation, migration and accumulation. Generating intensity, generating amount, accumulating efficiency and migration distance plays an important role in the distribution of natural gas. Through analysis on results of resources evaluation, discovered reserves and residual reserves, potential areas in middle-scaled petroliferous basins in China are forecasted in this paper. Ordos, Sichuan, Tarim and Qaidam basins are found out to be the main basins developing and enriching gas accumulation systems.     

Spectroscopic evidence for pressure-induced phase transitions in diopside

 Raman spectra of diopside were collected from atmospheric pressure to 71 GPa. The pressure dependences of 22 modes were determined. Changes occurred in the spectra at three different pressures. First, at approximately 10 GPa, the two Raman modes at 356 and 875 cm⁻¹ disappeared, while the mode at 324 cm⁻¹ split into two modes, diverging at this pressure with significantly different pressure shifts; second, at approximately 15 GPa, a small (1 to 2 cm⁻¹) drop in several of the frequencies was observed accompanied by changes in the pressure dependency of some of the modes; and third, above 55 GPa, the modes characteristic of chains of tetrahedrally coordinated silicon disappeared, while those for octahedrally coordinated silicon appeared. The first change at 10 GPa appears to be a C2/c to C2/c transition involving a change in the Ca coordination. The third change above 55 GPa appears to be a change in the silicon coordination. At 15 GPa, it is suggested that a change in compressional mechanism takes place. Received: 14 November 2000 / Accepted: 9 January 2002     

淤积泥砂对水平地运动作用时刚性坝面动压力的影响

文章基于固体介质，流体介质，液固两相饱和介质的时域显示有限元波动分析方法，研究了可压缩库水条件下淤积泥砂对水平地运动作用时刚性坝面上动压力的影响，研究中分析了作为两相介质处理的淤积泥砂的饱和度、厚度、渗透系数和孔隙率对坝面动压力的影响，还比较了作为流程两相介质，单相固体介质、单相重流体介质处理的不同淤积泥砂层模型间的计算结果差异。     

Spatial and temporal variability of pore‐water pressures in residual soil slopes in a tropical climate

It is critical to understand and quantify the temporal and spatial variability in hillslope hydrological data in order to advance hillslope hydrological studies, evaluate distributed parameter hydrological models, analyse variability in hydrological response of slopes and design efficient field data sampling networks. The spatial and temporal variability of field‐measured pore‐water pressures in three residual soil slopes in Singapore was investigated using geostatistical methods. Parameters of the semivariograms, namely the range, sill and nugget effect, revealed interesting insights into the spatial structure of the temporal situation of pore‐water pressures in the slopes. While informative, mean estimates have been shown to be inadequate for modelling purposes, indicator semivariograms together with mean prediction by kriging provide a better form of model input. Results also indicate that significant temporal and spatial variability in pore‐water pressures exists in the slope profile and thereby induces variability in hydrological response of the slope. Spatial and temporal variability in pore‐water pressure decreases with increasing soil depth. The variability decreases during wet conditions as the slope approaches near saturation and the variability increases with high matric suction development following rainfall periods. Variability in pore‐water pressures is greatest at shallow depths and near the slope crest and is strongly influenced by the combined action of microclimate, vegetation and soil properties. Copyright © 2002 John Wiley & Sons, Ltd.     

华北地区部分井孔稀有气体异常研究

介绍了近年来华北地区宝龙等 3口井稀有气体的显著异常 ,并据其特征与井孔水位动态的关系 ,对稀有气体异常的成因进行了理论分析与实验研究。结果表明 ,水位下降 10 0mm ,岩层孔隙、裂隙中的气体体积膨胀 0 0 0 90 % (气体体积百分比 ,下同 )左右。由于地下水位大幅度下降 ,岩层孔隙压力减小 ,积聚在岩层孔隙、裂隙中的气体体积膨胀溢出 ,导致井孔地下水中稀有气体含量出现异常变化。这些异常是干扰因素所致 ,不是地震异     

The experimental studies on electrical con-ductivities and P-wave velocities of anortho-site at high pressure and high temperature

Introduction The measurements of the compressional wave velocity and electrical conductivity of minerals and rocks are of fundamental importance to look into the earths interior, including composition, geotherm, generation and distribution of fluids and melts. Hydrous minerals formed by metamatu-siom are abundant within the earth. Previous studies have been carried out on the dehydration effect on the electrical conductivity and wave velocity of rocks such as serpentine, amphibole, most of whi…     

Statistic forecast of typhoons going over the Chinese coasts

According to the measured data of typhoons going over the Chinese coasts in 1949-2002, a statistic relative equation showing the relation between the central atmospheric pressure of typhoons in a certain region at a certain period of time and their accumulation of frequency is established, and the concept of recurrence interval of typhoons is put forward, which is of actual significance for typhoon disaster reduction along the coastal area.     

大港油田盐山-庆云地区油气运移富集规律的研究

盐山-庆云地区具多凸多凹、地质条件复杂、多向供油（气）的特点。油气化探异常发育不平衡，具有成带分布、局部富集的特征。西部主要的轻烃（CH4）异常强，东部则是重烃（C2H6、C3H8）异常最发育，由西向东轻烃逐渐下降，重烃不断增加，非烃指标（Hg、△C）异常与重烃异常基本相拟，Ks、Fe^2 异常规律不明显。根据烃类指标的分带性，轻、重烃异常规律和富集特征划分为气显示带，油显示带和油气显示带。中部地区的即油气显示带是油气最有远景的地段。     

冀北发现具鬣刺结构的超基性岩

冀北具鬣刺结构的超基性岩呈透镜状，产于华北克拉通北缘的早元古宙红旗营子群黑云斜长片麻岩之中。富MgO，贫CaO，A12O3和FeO*＝0．86，TiO2介于0．01％-0．02％之间，与SSZ型蛇绿岩中相应岩石的TiO2含量相当。原始地幔标准化的过渡元素配分型式表现为不对称的“W”型，在TiO2和Cu处形成两个明显的负异常“谷”。据此地球化学特征意味着它们可能来自于消减带之下上地幔，为上地幔高度部分熔融的残余物。岩石中鬣刺结构可能是叶蛇纹石高压分解的结果，表明研究区某些变质橄榄岩岩块曾经受过俯冲—消减作用。