塔北西部一间房组碳酸盐岩礁滩体同生期暴露溶蚀作用模式

在详细的钻井资料和岩心的宏观及微观特征研究的基础上,通过对塔北隆起西部奥陶系中统一间房组礁滩体沉积相特征及展布规律的分析,结合礁滩体储层同生期溶蚀作用特征研究,按照古沉积地貌单元结合岩相的方法建立了一间房组礁滩体同生期溶蚀作用模式。研究认为一间房组开阔台地相包括台内滩、滩间海和台内点礁3个亚相,沉积相平面分布稳定;一间房组的同生期暴露溶蚀作用明显,普遍反映出滩体的间歇性暴露的特征:生物钻孔和溶蚀孔洞内充填礁滩体暴露形成的古土壤泥;发育潮间带的化石碎片堆积和软体生物活动遗迹;岩心观察和成像测井可以识别出渗流-潜流带溶蚀作用旋回。按照礁滩相沉积地貌结合岩相的模式,将一间房组开阔台地的浅滩和点礁沉积划分出潮上长期暴露滩、潮间间歇暴露滩、潮下高能滩、瓶筐石障积礁、潮汐水道等地貌单元。     

南缘霍玛吐构造带三维地质建模应用效果

霍玛吐构造带地表、地下地质结构复杂,受二维测网限制,合理地构造建模和准确的速度建场较难,是制约该区圈闭落实和油气发现的主要因素。采用深浅层分层控制法消除层面间的相互干扰、复杂断块分组控制法解决逆断裂上下盘层位关系搭建的难点、层位网格约束法快速准确修改模型局部异常,逐级分解建模,有效解决了复杂构造三维建模难点,最终建成符合实际的三维地质模型。应用井控模型约束三维转深技术实现了多信息约束下的层速度建模与转深。三维空间建模提高了构造解释三维空间合理性,同时为三维空间速度分析与建场提供基础,降低了构造成图误差,提高圈闭落实精度。     

Structural Evolution and Hydrocarbon Potential of the Upper Paleozoic Northern Ordos Basin, North China

The hydrocarbon potential of the Hangjinqi area in the northern Ordos Basin is not well known, compared to the other areas of the basin, despite its substantial petroleum system.Restoration of a depth-converted seismic profile across the Hangjinqi Fault Zone(HFZ) in the eastern Hangjinqi area shows one compression that created anticlinal structures in the Late Triassic, and two extensions in ~Middle Jurassic and Late Early Cretaceous, which were interrupted by inversions in the Late Jurassic–Early Early Cretaceous and Late Cretaceous, respectively.Hydrocarbon generation at the well locations in the Central Ordos Basin(COB) began in the Late Triassic.Basin modeling of Well Zhao-4 suggests that hydrocarbon generation from the Late Carboniferous–Early Permian coal measures of the northern Shanbei Slope peaked in the Early Cretaceous, predating the inversion in the Late Cretaceous.Most source rocks in the Shanbei Slope passed the main gas-migration phase except for the Hangjinqi area source rocks(Well Jin-48).Hydrocarbons generated from the COB are likely to have migrated northward toward the anticlinal structures and traps along the HFZ because the basin-fill strata are dipping south.Faulting that continued during the extensional phase(Late Early Cretaceous) of the Hangjinqi area probably acted as conduits for the migration of hydrocarbons.Thus, the anticlinal structures and associated traps to the north of the HFZ might have trapped hydrocarbons that were charged from the Late Carboniferous–Early Permian coal measures in the COB since the Middle Jurassic.     

Zircon U-Pb Geochronology and Geochemical Characteristics of the Volcanic Host Rocks from the Tongyu VHMS Copper Deposit in the Western North Qinling Orogen and Their Geological Significance

Precise in situ zircon U-Pb dating and Lu–Hf isotopic measurement using an LA-ICP-MS system, whole-rock major and trace element geochemistry and Sr–Nd isotope geochemistry were conducted on the volcanic host rocks of the Tongyu copper deposit on the basis of further understanding of its geological characteristics. Three zircon samples from the volcanic host rocks yielded 206Pb/238 U weighted average ages ranging from 436±4 Ma to 440±5 Ma, which are statistically indistinguishable and coeval with the ca. 440 Ma northward subduction event of the Paleo-Qinling oceanic slab. The volcanic host rocks were products of magmatic differentiation that evolved from basalt to andesite to dacite to rhyolite, forming an integrated tholeiitic island arc volcanic rock suite. The primitive mantle-normalized trace element patterns for most samples show characteristics of island arc volcanic rocks, such as relative enrichment of LILE(e.g. Th, U, Pb and La) and depletion of HFSE(e.g. Nb, Ta, Ti, Zr and Hf). Discrimination diagrams of Ta/Yb vs Th/Yb, Ta vs Th, Yb vs Th/Ta, Ta/Hf vs Th/Hf, Hf/3 vs Th vs Nb/16, La vs La/Nb and Nb vs Nb/Th all suggest that both the volcanic host rocks from the Tongyu copper deposit and the volcanic rocks from the regional Xieyuguan Group were formed in an island arc environment related to subduction of an oceanic slab. Values of ISr(0.703457 to 0.708218) and εNd(t)(-2 to 5.8) indicate that the source materials of volcanic rocks from the Tongyu copper deposit and the Xieyuguan Group originated from the metasomatised mantle wedge with possible crustal material assimilation. Most of the volcanic rock samples show good agreement with the values of typical island arc volcanic rocks in the ISr-εNd(t) diagram. The involvement of crustal-derived material in the magma of the volcanic rocks from the Tongyu copper deposit was also reflected in the zircon εHf(t) values, which range from-3.08 to 10.7, and the existence of inherited ancient xenocrystic zircon cores(2616±39 Ma and 1297±22 Ma). The mineralization of the Tongyu copper deposit shows syn-volcanic characteristics such as layered orebodies interbedded with the volcanic rock strata, thus, the zircon U-Pb age of the volcanic host rocks can approximately represent the mineralization age of the Tongyu copper deposit. Both the Meigou pluton and the volcanic host rocks were formed during the ca. 440 Ma northward subduction of the Paleo-Qinling Ocean when high oxygen fugacity aqueous hydrothermal fluid released by dehydration of the slab and the overlying sediments fluxed into the mantle wedge, triggered partial melting of the mantle wedge, and activated and extracted Cu and other ore-forming elements. The magma and ore-bearing fluid upwelled and erupted, and consequently formed the island arc volcanic rock suite and the Tongyu VHMS-type copper deposit.     

An Review of International Climate Change Conference and Analysis on Recent Hot Issues

The international climate change negotiation has been carried out over 20 years. The issue of climate change has shifted from a scientific question into a complex political matter which is related to the sustainable development of mankind. Based on the overview of major processes and stages of international climate conferences, this paper analyzed the key measures that major countries have taken to address climate change, as well as the primary tasks of Paris climate conference and recent international actions. The recent international climate policy issues were also analyzed in order to provide suggestions for China’s activel participation in the development of a new round of international climate change system.     

油气藏水力压裂计算模拟技术研究现状与展望

水力压裂技术是油气藏尤其是页岩气开发中的核心技术,利用数值模拟方法进行压裂优化和产能预测又是水力压裂成功的关键。本文首先介绍了水力压裂技术的发展历程。然后从计算模型(二维模型、拟三维模型和全三维模型)和数值模拟方法(基于连续介质和基于非连续介质)两方面对油气藏开发领域的水力压裂计算模拟技术进行较全面的总结。最后,从以下3个方面指出现今研究的不足并提出了进一步的研究建议:(1)全三维模型的完善-全三维模型应当与真实的工程参数和监测数据结合,用于校正模型本身,而校正后的全三维模型又可预测和优化新的现场水力压裂作业; (2)数值模拟方法的选用-已有的水力压裂数值模拟方法种类繁多,需要针对各种方法的适用范围、计算效率和模拟效果等,进行全面的比较和优化; (3)页岩储层中天然裂缝网络的数值模拟-天然裂隙网络加剧了页岩储层力学性质的各向异性,同时水力裂缝沟通天然裂缝活化扩展是有利于储层的增渗增产,对压裂缝网的形态、尺寸和连通率等起着至关重要的作用。因此,数值计算过程中综合考虑页岩储层中天然裂缝与水力裂缝的相互作用,将是未来水力压裂模拟的热点。     

钨在矿物/熔体和溶液/熔体中的分配行为及其对成矿作用的影响

总结了钨(W)在地球不同圈层、不同相以及不同集合体之间的分配行为,并据此来探讨与花岗岩有关的热液型钨矿床的某些成因机制,并将W矿化所需的较高的浓集系数归因于这一系列不均匀分配行为的累积。同时强调了W在溶液/熔体体系,尤其是富F体系中的分配行为是理解其成矿机理的关键。热液中W主要以钨酸(根)和碱性钨酸盐离子存在,后因流经理化条件(温度、盐度、p H值)骤变而沉淀成矿。     

碳酸盐岩洞穴型储层地震综合预测——以塔里木盆地古城低凸起三维区为例

塔里木盆地古城低凸起三维地震工区内的奥陶系碳酸盐岩埋藏深,非均质性强,且无钻井资料。重点对奥陶系鹰山组三段—四段白云岩的串珠状地震反射体进行地质诠释。采用均方根振幅属性预测了储层平面分布规律,应用缝洞雕刻技术预测了裂缝和串珠体发育区,运用相干、曲率属性预测了断裂、裂缝的分布,联合应用频率衰减梯度、低频能量、平均频率和吸收系数等手段进行了油气检测。通过对多种信息的综合分析,评价优选出有利勘探目标。基于上述工作部署的A井,在鹰山组三段灰质白云岩储层中获天然气勘探重大突破,证实了地震综合预测方法的有效性。     

韧性剪切带相关褶皱研究进展

褶皱是韧性剪切带内普遍发育的构造变形,是研究韧性剪切带乃至造山带构造作用的桥梁,但是对于剪切带中存在的这类褶皱国内尚无统一命名,本文根据剪切带内褶皱的最新研究成果,引进了"韧性剪切带相关褶皱"的概念。目前,国内外学者对韧性剪切带相关褶皱(尤其是鞘褶皱)的研究多集中在运动学和动力学上。本文介绍了韧性剪切带相关褶皱的类型及其研究方法,为客观理解韧性剪切带相关褶皱的形成机制提供了新思路和方法,进而为恢复陆内造山作用过程提供了客观的约束条件。