四川盆地泸州古隆起嘉陵江组储层特征研究

对研究区嘉陵江组沉积背景认识的基础上,通过岩心观察、岩石薄片确定了不同类型的储集岩和储集空间,得出本地区储层岩石类型和储渗空间类型均多样化的特点。从成因角度识别出来了溶蚀孔隙型储层、膏溶孔洞型储层、裂缝型储层等三类储层。研究不同类型储层的孔、渗特征及关系表明,溶蚀孔隙型储层物性要优于膏溶孔洞型储层,而溶蚀孔隙型储层中的颗粒云岩溶蚀孔隙型储层物性最好、颗粒灰岩溶蚀孔隙型物性其次、粉晶云岩溶蚀孔隙型储层物性最差,其原因是不同储层受沉积环境和成岩作用控制和影响。     

Micromechanics of the velocity and normal stress dependence of rock friction

Among the second-order effects on friction the most important are those of variable normal stress and of slip velocity. Velocity weakening, which is usually considered the source of the stick-slip instability in rock friction, has been observed in velocity stepping experiments with Westerly granite. The friction change, , was –0.01 to –0.008 for a tenfold velocity increase. Using normal closure measurements, we observed dilation upon each increase in sliding rate. We also observed, for the first time, time-dependent closure between surfaces during static loading. The dilation that occurred during the velocity stepping experiment was found to be that expected from the static time-dependent closure phenomenon. This change in closure was used to predict friction change with an elastic contact model. The calculated friction change which results from a change in contact area and asperity interlocking, is in good agreement with the observed velocity dependence of steady-state friction. Variable normal stress during sliding has two effects, first in creating new partial slip contacts and locking some existing fully sliding contacts and second in increasing interlocking, for instance when normal load is suddenly increased. As a result, a transient change in friction occurs upon a sudden change in normal load.     

Textural segmentation of digital rock images into bedding units using texture energy and cluster labels

The texture of digital rock images, as recorded, for instance, with borehole imaging devices, is shown to reflect different bedding types. Textural segmentation of borehole images, therefore, subdivides the recorded sequence into bedding units. We show that a textural segmentation algorithm based on the concept of texture energy achieves good results when compared with synthetic as well as real data in which petroleum geologists have performed zonations on cores. Texture energy involves filtering of the original image with a set of texture sensitive masks. The filtering is done as a finite convolution over the size of the masks. On the resulting images the variance is computed over a relatively large sliding window, which, in its practical implementation, covers the full width of the image. The resulting nine one-dimensional curves are then clustered hierarchically into a user-determined number of image texture or lithological bedding classes. Principal component analysis previous to clustering can be used to reduce redundancy in the data. A recurring and relatively ill-defined problem in this field are macro-textures, i.e., the cyclic interbedding of two or more bedding types. We show that sliding Fourier transforms and variable mask scale can successfully address the zonation of macro-textures. In general, the method gives best results with mask sizes equivalent to 2–4 centimeters, reflecting the length scale at which the investigated geological bedding seems to have its highest variation.     

“Tripoli”的含义及译名的讨论

“Tripoli”是一种新型的石英质工业矿物原料,在我国长期被误译为硅藻土,影响地质部门对这一新矿种的认识和寻找。本文追溯了“Tripoli”一名的由来,正确地阐述了“Tripoli”的本质特征,分析了在国内文献中长期被误译的根源,指明了其正确含义,并建议废除各种不正确的中译名,译为“粉石英”。     

Experimental investigation of the elastic modulus of a fractal system—A model of fractured rocks

The elastic properties of a physical model representing a damaged rock matrix were studied using a square lattice deformed under tensile stress. The elastic modulusM of such a system varies in agreement with percolation theory as|x–x _c | ^f , wherex is the damage parameter andx _c the threshold value of the damage parameter,f3.6. Atxx _c the scale dependence ofM can be expressed asML ^–f/v , whereL is the size of the sample andv the correlation exponent in percolation theory.The experimental results are of interest in assessing elastic properties in earthquake focal zones and fault zones in general.     

西安南郊丰水年秋季土壤水分研究

 通过对西安南郊丰水年秋季土壤含水量的测定，研究了地下0~6 m之间土壤含水量的变化与土壤干层的恢复问题。研究结果表明，丰水年西安南郊人工林下2~3 m的土壤含水量在20％左右，远远高于正常年份的土壤含水量，而且大于表层和深层的土壤含水量。分析得出，土壤干层发育较弱的地区在降水丰富的年份可以得到一定程度的恢复；西安地区基本适合进行人工造林；通过人工措施，增强降水入渗和土壤含水量，对树木成活和长期的生长应当具有明显的作用。     

Na depletion in modern adakites via melt / rock reaction within the sub-arc mantle

Interaction between slab-derived melt and mantle peridotite and the role of slab melt as a metasomatizing agent in the sub-arc mantle is being increasingly recognized. Adakite, the slab melt erupted on the surface, usually exhibits anomalously high MgO, CaO, Cr and Ni contents that indicate interaction with mantle peridotitite. Here we note that Cenozoic adakites have Na₂O contents below 5.8 wt.% with ∼95% samples lower than 5.0 wt.%, and are generally depleted in this component relative to experimental basalt partial melts (mostly beyond 5.0 wt.% and up to 9.0 wt.% Na₂O) produced under 1.5-3.0 GPa conditions that are most relevant to adakite production. We interpret the adakite Na depletion to be also a consequence of the melt / rock reaction that takes place within the hot mantle wedge. During ascent and reaction with mantle peridotite, primary adakite melts gain mantle components MgO, CaO, Cr and Ni but lose Na₂O, SiO₂ and perhaps K₂O to the mantle, leading to Na-rich mantle metasomatism. Selective assimilation of predominately mantle clinopyroxene, some spinel and minor olivine at high T/P has been considered to be an important process in producing high-Mg adakites from primary low-Mg slab melts [Killian, R., Stern, C. R., 2002. Constraints on the interaction between slab melts and the mantle wedge from adakitic glass in peridotite xenoliths. Eur. J. Mineral. 14, 25-36]. In such a process, Na depletion in the assimilated melt is the result of dilution due to the increase in melt mass. Phase relationships in the reaction system siliceous melt + peridotite and quantitative calculation suggest that assimilation of mantle clinopyroxene, olivine and spinel and fractional crystallization of sodic amphibole and orthopyroxene, under conditions of moderate T/P and increasing melt mass, is also an important process that modifies the composition of adakites and causes the Na depletion.     

冲击凿岩钎杆的瞬态动力学分析

以ANSYS为平台，按照真实工作状态对凿岩钎杆进行了瞬态动力学分析，并对不同活塞形状下分析结果数据进行了比较，为冲击凿岩系统设计提供了理论依据。     

PDC钻头切削齿破岩载荷规律的分析

对PDC钻头冠部形状及不同的布齿密度和切削齿在不同的磨损状态下对PDC钻头切削齿受力的影响进行了分析；用相邻的3个切削齿之间的关系(不同的切削齿与切削齿之间的径向距离和切削齿之间的高度差)来分析PDC钻头冠部形状和切削齿布齿密度对切削齿受力的影响，以及将切削齿的磨损状态简化成与切削齿在钻头上装配方向垂直的平面来分析切削齿磨损状态对切削齿受力的影响。     

双坡面临空岩质边坡滑动破坏模式下的稳定性分析

多数岩质边坡稳定性分析已基本解决了常走向单坡面临空的边坡平面滑动问题。然而,在路堑边坡工程和自然边坡中有很多边坡坡面并不是平面,它包含多个坡面。多坡面边坡包含两个或多个不同走向的坡面。多坡面边坡几何特征不同于单坡面边坡,所以滑动条件也不一样。在赤平投影图上,多坡面的滑动包络线是组成边坡的每个坡面单独投影包络线的组合。为了探讨方便,只讨论了双坡面临空岩质边坡的滑动破坏模式,并将其分为双坡面临空下的平面破坏和楔形体破坏。在赤平投影图上,双坡面滑动区域定义为双坡面边坡滑动包络图中两侧坡面的真倾线之间的面积。如果有一两个节理面真倾向线落在滑动区内,滑动破坏才可能发生。