四川盆地碳酸盐岩油气勘探实践与认识

四川盆地烃源十分丰富。但油气演化程度高,大多已进入高成熟和过成熟阶段,至今只在侏罗系发现有油藏,三叠系及其更老地层皆为气藏。储层主要为碳酸盐岩,其特点是低孔低渗,平均孔隙度仅1.7%,平均渗透率小于1×10~(-3)μm~2,但其中的“孔洞发育层段”平均孔隙度可达3%～6%。根据四十年的勘探经验,加强预探并争取新发现是四川盆地油气勘探发展的关键。预探中,按构造带规划大中型气田勘探目标,将成藏条件相似、地域上相邻的局部圈闭群作为一个整体勘探对象,实行稀井广探,少井高效。“八五”以来,在高陡构造带勘探技术、储层横向预探技术等方面有长足的进步,勘探成效不断提高,实现了资源序列的良性循环。     

多相地貌单元场地勘察中基岩与卵砾石、孤石的鉴别

在多相地貌单元场地勘察中，基岩与卵砾石的鉴别难度较大。应利用初步感性认识、钻进状态、岩样特征等多手段对基岩与卵砾石进行判别，以提高判别率。     

土体各向异性的再认识

土体原生和次生各向异性有本质不同。从柔度矩阵的角度分析了弹性和弹塑性理论对各向异性的反映 ;复杂应力状态下砂土真三轴试验结果表明 ,次生各向异性对土体应力应变关系有很大影响 ,是土体特性的本质体现 ,在土工数值分析中应当充分考虑其影响。     

通渝隧道围岩变形的神经网络预测

隧道新奥法施工中 ,常以围岩变形量作为评判围岩稳定性和支护结构经济合理性的重要指标。公路隧道围岩变形量是随时间而变化的数据序列 ,因而可以建立一些实时跟踪预测模型和方法。根据通渝隧道围岩拱顶下沉位移变形的特性 ,采用神经网络技术来预测其变形量 ,结果表明该方法简易、有效     

Timing and geochemical characters of the Sanchazi magmatic arc in Mianlüe tectonic zone, South Qinling

The Sanchazi mafic-ultramafic complex in Mianlue tectonic zone, South Qinling can be subdivided into two blocks, i.e. Sanchazi paleo-magmatic arc and Zhuangkegou paleo-oceanic crust fragment (ophiolite). The Sanchazi paleo-magmatic arc is mainly composed of andesite, basaltic and basalt-andesitic gabbro (or diorite), andesitic dyke, plagiogranite and minor ultramafic rocks, which have typical geochemical features of island arc volcanic rocks, such as high field strength element (e.g. Nb, Ti) depletions and lower Cr, Ni contents. The Light rare earth element (LREE) and K enrichments of these rocks and zircon xenocrystals of 900 Ma from plagiogranite suggest that this magmatic arc was developed on the South active continental margin of the South Qinling micro-continent. The U-Pb age of (300 ± 61)Ma for zircons from plagiogranite indicates that the Mianlue paleo-oceanic crust was probably subducted underneath the South Qinling micro-continent in Carboniferous. This is consistent with the formation time (309Ma) of the Huwan eclogite originating from oceanic subduction in Dabie Mountains, suggesting that the Mianlue paleo-ocean probably extended eastward to the Dabie Mountains in Carboniferous. The high-Mg adakitic rocks in Sanchazi paleo-magmatic arc suggest that the subducted oceanic crust was relatively young (＜25Ma) and hot.     

青藏高原祖尔肯乌拉山地区火山岩Ar-Ar年代学初步研究

对祖尔肯乌拉山地区 4个火山岩样品进行了Ar -Ar年龄测定 ,其坪年龄分别为 (40 91± 1 18)Ma、(41 0 7± 0 80 )Ma、(42 0 0± 1 31)Ma、(39 0 0± 2 0 6 )Ma。它们代表了这些火山岩的形成时代 ,表明本区在古近纪始新世中期发生过大规模的火山活动     

Estimation of regional material yield from coastal landslides based on historical digital terrain modelling

High‐resolution historical (1942) and recent (1994) digital terrain models were derived from aerial photographs along the Big Sur coastline in central California to measure the long‐term volume of material that enters the nearshore environment. During the 52‐year measurement time period, an average of 21 000 ± 3100 m³ km^?1 a^?1 of material was eroded from nine study sections distributed along the coast, with a low yield of 1000 ± 240 m³ km^?1 a^?1 and a high of 46 700 ± 7300 m³ km^?1 a^?1. The results compare well with known volumes from several deep‐seated landslides in the area and suggest that the processes by which material is delivered to the coast are episodic in nature. In addition, a number of parameters are investigated to determine what influences the substantial variation in yield along the coast. It is found that the magnitude of regional coastal landslide sediment yield is primarily related to the physical strength of the slope‐forming material. Coastal Highway 1 runs along the lower portion of the slope along this stretch of coastline, and winter storms frequently damage the highway. The California Department of Transportation is responsible for maintaining this scenic highway while minimizing the impacts to the coastal ecosystems that are part of the Monterey Bay National Marine Sanctuary. This study provides environmental managers with critical background data on the volumes of material that historically enter the nearshore from landslides, as well as demonstrating the application of deriving historical digital terrain data to model landscape evolution. Published in 2005 by John Wiley & Sons, Ltd.     

宁东煤田枣泉矿井综合物探效果

为探明宁东煤田枣泉矿井首采区煤层自然范围及充水性，根据采区内地球物理物征，采用高精度磁法，直流电测深法和激发极化法进行综合勘探。在磁法勘探中结合测区曲线特征，建立数据体模型，正演计算烧变岩边界；电法勘探利用烧变岩含水后电阻率降低的特征确定其含水范围及富水性。