深圳宝安区场坪爆破工程设计

设计主要针对在城市复杂环境下进行场坪爆破,通过爆破方案选定及孔网参数的设计,实现控制爆破震动和爆破飞石、磙石的危害,确保爆破施工安全、高效、顺利进行.     

深部地下洞室施工期围岩大变形机制分析

大岗山水电站引水发电系统地下洞室埋深大,花岗岩因风化卸荷强烈,岩脉破碎带发育,应力较高。在施工过程中,岩脉、断层穿越的主变室部位出现较大的变形,严重影响施工安全与进度。采用地质调查和现场监测的方法,结合现场施工情况分析主变室围岩大变形特征和机制,提出2种可能的大变形破坏模式,分析影响围岩大变形的因素,并评价主变室的稳定性。研究结果表明:主变室围岩大变形主要受辉绿岩脉8 1和断层f59,f60控制,同时,地应力高、施工强度大、支护进度滞后加剧围岩的大变形。深部地下洞室施工期的地质调查及现场监测可以及时预测高应力区卸荷围岩的大变形,以确保洞室施工期的稳定安全。研究成果对类似工程具有重要的参考价值。     

新世纪大西洋两岸深水勘探总结和启示浅析

新世纪大西洋两岸深水勘探成为勘探热点和高储量发现区.通过概述该时期勘探历程和成果,总结了大西洋两岸勘探得失成败,并分析了不同类型公司成败的主要原因,认为持续地质研究积累和技术创新是石油巨头保持成功的基础,公司策略、规模、风险识别和抵御风险的能力是保证独立石油公司生存与发展的关键.未来中南大西洋盐下碳酸盐岩、中大西洋两岸...     

易碎岩石大粒径石料开采爆破关键参数研究

随着外海建港项目的增多,在易碎岩石中集中爆破生产大粒径规格石料成为一个难题。通过分析应力波和爆炸气体对裂隙走向和长度的影响,提出了增大最小抵抗线和填塞长度、减小孔间距的单排孔开采方案,以及关键参数的计算公式,并多次得到工程实践的验证。     

小净距隧道开挖工艺对围岩稳定性的影响

为研究小净距隧道的不同开挖工艺对围岩稳定性的影响,对重庆花土岗隧道分别利用全断面法、上下台阶法和单侧壁导坑法进行了开挖有限元数值模拟,分析了小净距隧道不同施工方法对洞周围岩稳定性的影响.结果表明:全断面法对隧道围岩及中夹岩柱的水平位移和应力影响较大;上下台阶法和单侧壁导坑法影响相对较小.施工中应根据实际情况选择合理的开挖方法,及时施作支护并加强监测,保证施工质量.本文的分析方法和计算结果对小净距隧道设计、施工具有一定的参考价值.     

DIAGENETIC-GEOCHEMICAL PATTERNS AND FLUID EVOLUTION HISTORY OF A LOWER JURASSIC PETROLEUM SOURCE ROCK, MIDDLE ATLAS, MOROCCO

Pliensbachian to earliest Toarcian marls and argillaceous limestones exposed at the surface near Aït Moussa (Boulemane Province, Middle Atlas) include the only examples of effective petroleum source rocks so far known in the Moroccan Atlas rift basins. The outcrop interval includes hemipelagic, peri‐Tethyan low latitude source rocks with Type II kerogen (total thickness of 2.5 m with mean TOC of around 3.2%). Early diagenetic, anoxic remineralisation of sedimentary organic matter resulted in hydraulic fractures, calcite cementation, a negative shift of carbon and oxygen stable isotopes relative to marine values (Δδ¹³C = ‐1.1; Δδ¹⁸O = ‐2.0), framboidal pyrite, and relative enrichment of the middle weight rare earth elements (REE). In combination, these attributes of early diagenesis may assist in the identification of other source rock intervals of similar age and setting. Progressive burial produced three generations of Fe‐calcite cemented veins, followed by three generations of replacive dolomite and concluded by ankerite replacing dolomite. Compaction fluids initially caused a slight positive shift of δ¹³C values (Δδ¹³C =+0.4), a flattening of the REE distribution pattern and an increase in REE content, together related to the dewatering of clay. Dolomitizing fluids (dol‐2 and dol‐3) record a positive shift of δ¹³C values (Δδ¹³C =+0.9) suggesting the effects of methanogenesis or an uptake of heavy δ¹³C from underlying rock formations during fluid migration. Dol‐3 is an Fe‐bearing saddle dolomite that carries a positive Eu‐anomaly (Eu/Eu*= 8.1) best explained by ascending hydrothermal fluids which are presumably of Middle Eocene age. A first migration of bitumen is recorded as fluorescent inclusions in dol‐2 (Late Jurassic ‐ Cretaceous), but bituminous fluids remained normally pressured until the establishment of inclined stylolites during Late Eocene tectonic compression. Comparative organic‐geochemical analyses (GC, NMR of inclusions, non‐expelled and expelled bitumen) indicate that thermal maturation advanced significantly after the onset of migration. Differences in terms of Pr/n‐C₁₇, Ph/n‐C₁₈ ratios and aromaticity corroborate the effects of differential expulsion. An exploration strategy should consider both secondary migration via opened tectonic stylolites in association with late‐diagenetic fractures and a persisting tightness that then could have created an unconventional oil reservoir.     

PETROPHYSICAL CHARACTERISTICS OF SOURCE AND RESERVOIR ROCKS IN THE HISTRIA BASIN, WESTERN BLACK SEA

The petroleum system in the Histria Basin, Western Black Sea, includes Oligocene source rocks and Upper Cretaceous — Eocene reservoir rocks. Here we report on the petrophysical characteristics of these source and reservoir rocks using mercury intrusion porosimetry data from 14 core samples collected from five wells drilled on the East Lebada, West Lebada and Pescarus structures. Samples were in general dominated by carbonate lithologies with minor shales. Petrophysical parameters analyzed were: median pore-throat radius, average pore-throat radius, apparent porosity, pore-throat size distribution, pore-throat type, pore-throat sorting, maximum threshold entry radius, pore-throat radius at 35% mercury saturation (R35), and air permeability. Reservoir rock quality was estimated using a permeability / porosity / pore-throat type plot.
The Oligocene samples showed little petrophysical variation. Samples were relatively homogenous and had the same pore-throat type (nano), were well sorted, had unimodal pore-throat distribution (suggesting the existence of a single fluid phase), had similar values for median and average pore-throat radius, and similar values for R35 and maximum threshold entry radius. Upper Cretaceous – Eocene samples were more heterogeneous in terms of petrophysical properties, and reservoir quality was in general higher than in the Oligocene interval. Average porosity and calculated air-permeability values were 18.4% and 0.37 mD, respectively for Upper Cretaceous samples; and 11.8% and 27.11 mD, respectively for Eocene samples. A case study of Oligocene and Cretaceous – Eocene samples from well West Lebada 817 is presented.
This paper represents the first petrophysical study of source and reservoir rocks in the Histria Basin, Western Black Sea. The results will help to establish the links between petrophysical characteristics, age and depositional environment for source and reservoir rocks in other basins bordering the Black Sea.     

济阳坳陷车西地区烃源岩研究

从烃源岩分布、烃源岩的有机质类型、丰度以及成熟度等几个方面,对济阳坳陷车西地区烃源岩的地球化学特征进行了综合研究,并对主要烃源岩系的条件差异进行了分析判断。研究表明区内对油气成藏有贡献的烃源岩主要为沙三中下亚段;油气成藏作用从生烃洼陷中心向四周扩展;车西洼陷南斜坡勘探前景广阔。     

高铜价下低品位铜资源的综合利用技术开发

本文提出了第三代白银炼铜法的工艺发展方向,并阐述了利用第三代白银炼铜法,结合选矿和生物浸出技术,处理白银集团公司露天废石的工艺技术优势。     

A discrete model for prediction of radon flux from fractured rocks

Prediction of radon flux from the fractured zone of a propagating cave mine is basically associated with uncertainty and complexity. For instance, there is restricted access to these zones for field measurements, and it is quite difficult to replicate the complex nature of both natural and induced fractures in these zones in laboratory studies. Hence, a technique for predicting radon flux from a fractured rock using a discrete fracture network (DFN) model is developed to address these difficulties. This model quantifies the contribution of fractures to the total radon flux, and estimates the fracture density from a measured radon flux considering the effects of advection, diffusion, as well as radon generation and decay. Radon generation and decay are classified as reaction processes. Therefore, the equation solved is termed as the advection-diffusion-reaction equation (ADRE). Peclet number (Pe), a conventional dimensionless parameter that indicates the ratio of mass transport by advection to diffusion, is used to classify the transport regimes. The results show that the proposed model effectively predicts radon flux from a fractured rock. An increase in fracture density for a rock sample with uniformly distributed radon generation rate can elevate radon flux significantly compared with another rock sample with an equivalent increase in radon generation rate. In addition to Pe, two other independent dimensionless parameters (derived for radon transport through fractures) significantly affect radon dimensionless flux. Findings provide insight into radon transport through fractured rocks and can be used to improve radon control measures for proactive mitigation.