地震工况下兰州南绕城高速公路路堑高边坡格构支护效果评价

以兰州南绕城高速公路已加固典型路堑高边坡为研究对象,利用AutoCAD及ANSYS软件建立所选典型边坡的三维数值模型,在此基础上运用有限差分软件FLAC3D对其在地震工况下的稳定性进行科学评价,目的是为黄土类高边坡工程防护及安全设计提供参考。得出的结论为：当水平向地震加速度为0.1g和0.2g时边坡处于稳定状态,水平向地震加速度为0.3g时边坡处于基本稳定状态,水平向地震加速度为0.4g时边坡处于不稳定状态。研究表明,格构锚杆支护承受了大量拉张应力及剪应变增量等,效果显著,对边坡稳定性发挥了重要作用。因该公路建设区抗震设防烈度为8度,地震加速度设计为0.2g,所以地震工况下的所选格构支护边坡处于稳定（稳定系数为1.15）状态,能够满足规范要求。     

Estimation Algorithms of Methane Sorption Capacity of the Longmaxi Marine Shale in South China

<正>Shale gas is one of the most promising unconventional gas systems.The shale is both the source of,and the reservoir for,natural gas,which is derived from the organic matter within the shale through biogenic and/or thermogenic processes.Natural gas storage in shale differs significantly from conventional gas reservoirs and may be composed of free compressed gas,sorption gas and     

柴北缘中侏罗统湖相泥页岩储层矿物组成与脆性特征

运用X射线衍射技术,对柴北缘中侏罗统46块岩心泥页岩样品和15块露头泥页岩样品进行了定性和定量分析。结果表明研究区泥页岩矿物成分中黏土矿物含量最高,介于33%~79.7%之间,平均54.3%;其次为石英,含量介于14.5%~57.8%之间,平均35.4%;碳酸盐矿物含量较少,总量一般介于0~13%之间,个别样品大于15%,露头样品与岩心样品矿物成分有差别。黏土矿物组合特征反映出研究区进入中成岩阶段,对应有机质演化的成熟阶段,具有适宜页岩油气形成的成熟度条件。扫描电镜显示,研究区泥页岩发育3种孔隙类型。与海相页岩相比,柴北缘中侏罗统泥页岩黏土矿物含量高但敏感性矿物含量低,石英、长石等脆性矿物含量偏低但达到湖相泥页岩开发标准,脆性指数平均为42.6%,整体上具有较好的脆性和可压性,有利于该区湖相页岩的压裂改造。     

基于Adaboost算法和人脸特征三角形的姿态参数估计

提出了一种基于Adaboost算法和人脸特征三角形的姿态参数估计方法。首先利用Adaboost算法训练人脸器官检测器,然后根据人脸器官的几何特征定位人脸特征点,利用获得的人脸特征点构建人脸特征三角形。当人脸发生姿态变化时,利用特征三角形的位置变化进行姿态参数的初步估计。     

http://www.sciencedirect.com/science/article/pii/S167498711200151X

The unconformity surface at the bottom of the Paleogene is one of the most important migration pathways in the Sikeshu Sag of the Junggar Basin,which consists of three layers：upper coarse clastic rock,lower weathering crust and leached zone.The upper coarse clastic rock is characterized by higher density and lower SDT and gamma-ray logging parameters,while the lower weathering crust displays opposite features.The transport coefficient of the unconformity surface is controlled by its position in respect to the basal sandstone; it is higher in the ramp region but lower in the adjacent uplifted and sag areas.The content of saturated hydrocarbons increases with the decrease of the content of nonhydrocarbons and asphaltenes.The content of benzo[c] carbazole decreases as the content of benzo[a]carbazole and [alkyl carbazole]/[alkyl ＋ benzo carbazole] increases.This suggests that the unconformity surface is an efficient medium for the transportation of hydrocarbons.     

川北地区下三叠统飞仙关组优质鲕滩储层成岩演化序列

早三叠世飞仙关期,川北地区为台地与海槽相间的沉积格局,在两者的转换地带,发育了大套台地边缘碳酸盐鲕粒滩。该套储层经历的破坏性成岩作用类型主要有压实、压溶作用和胶结作用,建设性成岩作用主要有泥晶化作用、新生变形及重结晶作用、白云石化作用和溶蚀作用。讨论了各种成岩作用的主要特征及对储层的影响。结合成岩阶段划分,建立了该储层的成岩序列。胶结作用可分为三期,对储层的破坏作用非常强,尤其是第二期胶结作用以后,残存下来的孔隙降至5%左右。白云石化作用主要有混合水白云石化和埋藏白云石化,它不仅将岩石孔隙度提高了5%左右,更重要的是在白云岩中形成了较多的晶间孔,为后期埋藏溶蚀作用创造了施展空间。埋藏溶蚀作用使白云岩中的晶间孔溶蚀扩大,形成晶间溶孔,这是优质白云岩储层形成的必要条件,它可将孔隙度再提高5%～20%左右。     

黄土坡面汇沙对细沟侵蚀的影响与贡献

细沟侵蚀是黄土高原坡面极其重要的侵蚀过程之一,汇沙对细沟侵蚀强弱具有重要影响,阐明汇沙对细沟侵蚀的影响与贡献,可以揭示坡面细沟侵蚀过程机理,并为治理坡面水土流失提供科学依据.采用定流量人工放水的组合小区模拟降雨的方法,对不同降雨强度与不同坡度下黄土坡面汇沙对细沟侵蚀的影响及贡献进行了研究,结果表明:细沟上方汇沙、细沟间汇沙、细沟径流剪切力对细沟侵蚀的影响,在不同降雨强度、不同坡度、不同降雨强度及坡度下皆可用三元对数方程描述;细沟上方汇沙、细沟间汇沙、细沟径流剪切力,以及细沟上方汇沙与细沟间汇沙及细沟径流剪切力三者的交互作用对细沟侵蚀的贡献率,在不同降雨强度下分别为13.18％、4.98％、61.2％及8.26％,在不同坡度下分别为4.73％、1.19％、73.65％及5.4％,在不同降雨强度及坡度下分别为10.84％、0.44％、65.22％及6.97％.     

Evaluation of Upper Triassic T3x5 Source Rocks (Western Sichuan Depression, Sichuan Basin) and their Hydrocarbon Generation and Expulsion Characteristics: Implication for Tight-Sand Gas and Shale Gas Accumulation Potential Assessment

An unconventional, continuous petroleum system consists of an accumulation of hydrocarbons that is found in low-matrix-permeability rocks and contain large amounts of hydrocarbons. Tight-sand gas in the Jurassic and shale gas within the fifth member of Xujiahe Formation (T₃x⁵) are currently regarded as the most prolific emerging unconventional gas plays in China. The conventional and systematical evaluation of T₃x⁵ source rocks was carried out for the first time in the western Sichuan basin (WSD). Hydrocarbon generation and expulsion characteristics (including intensity, efficiency, and amount) of T₃x⁵ source rocks were investigated. Results show that T₃x⁵ source rocks are thick (generally >200 m), have high total organic content (TOC, ranging from 2.5 to 4.5 wt%), and dominated by III-type kerogen. These favorable characteristics result in a great hydrocarbon generating potential under the high thermal evolution history (R _o > 1.2%) of the area. An improved hydrocarbon generation potential methodology was applied to well data from the area to unravel the hydrocarbon generation and expulsion characteristics of T₃x⁵ source rocks in the WSD. Results indicate that the source rocks reached hydrocarbon expulsion threshold at 1.06% R _o and the comprehensive hydrocarbon expulsion efficiency was about 60%. The amount of generation and expulsion from T₃x⁵ source rocks was 3.14 × 10¹⁰ and 1.86 × 10¹⁰ t, respectively, with a residual amount of 1.28 × 10¹⁰ t within the source rocks. Continuous-type tight-sand gas was predicted to develop in the Jurassic in the Chengdu Sag of the WSD because of the good source-reservoir configuration (i.e., the hydrocarbon generation and expulsion center was located in Chengdu Sag), the Jurassic sandstone reservoirs were tight, and the gas expelled from the T₃x⁵ source rocks migrated for very short distances vertically and horizontally. The amount of gas accumulation in the Jurassic reservoirs derived from T₃x⁵ source rocks is up to 9.3 × 10⁸ t. The T₃x⁵ gas shale has good accumulation potential compared with several active US shale-gas plays. Volumetrically, the geological resource of shale gas is up to 1.05 × 10¹⁰ t. Small differences between the amounts calculated by volumetric method compared with that by hydrocarbon generation potential methodology may be due to other gas accumulations present within interbedded sands associated with the gas shales.     

渝东南牛蹄塘组与龙马溪组高演化海相页岩全孔径孔隙结构特征对比研究

中国南方主要富有机质海相页岩寒武系牛蹄塘组和志留系龙马溪组是当前页岩气勘探的重要目标地层,但演化程度普遍偏高,孔隙结构复杂。为加深对这种复杂性的认识,通过场发射扫描电镜、高压压汞实验与低温低压吸附实验(CO_2与N_2),对页岩全孔径孔隙结构特征进行对比研究。研究发现,牛蹄塘组孔体积与龙马溪组页岩的孔体积分别介于0.0202~0.0402 m L/g与0.0255~0.0310 m L/g之间,介孔在两套页岩孔体积中所占比例最大。两套页岩比表面积分别介于13.74~41.26 m~2/g与21.42~27.82 m~2/g之间,微孔与介孔几乎提供了两套页岩全部的比表面。孔隙结构的差异主要表现为牛蹄塘组页岩内溶蚀孔和粒间孔较为发育,有机质孔隙发育不均匀;而龙马溪组页岩内粒内孔、粒间孔和有机质孔隙均较为发育;牛蹄塘组在微孔范围内的孔体积与比表面积占有优势,而介孔与宏孔范围内的孔体积与比表面积均小于龙马溪组。根据实验数据结果与文献的调研,两套页岩孔隙结构差异的主要原因主要是成熟度与埋深的不同影响而形成的。