鄂尔多斯盆地姬塬地区长6储层渗流特征

对鄂尔多斯盆地姬塬地区长6储层特征、微观渗流特征及影响因素进行综合研究,为开发前期评价提供科学依据。以铸体薄片、扫描电镜等分析化验资料为基础,应用恒速压汞、核磁共振等储层评价新方法对岩石类型、孔隙结构进行分析。研究表明,该区长6储层物性较好,粒间孔发育,储层孔隙结构好,以小孔、微细喉为主,可动流体饱和度高,渗流能力强,有利于高效开发。储层孔隙结构、成岩相及储层润湿性是影响相渗特征的重要因素。     

An assessment of the creep behaviour of Brazilian salt rocks using the multi-mechanism deformation model

Salt rocks are geomaterials that exhibit several peculiarities, which require a particular approach in rock mechanics. In the field, those rocks are usually found in layered/bedded deposits and in domes or similar structures. Creep is one of the main deformation mechanisms associated with salt rocks, and this phenomenon is highly dependent on the stress state, temperature and mineralogy. Salt rock mechanics for engineering applications requires the definition of a powerful constitutive model and this is an ongoing challenge. Among the many available models, one of the most sophisticated physical constitutive models for salt rocks is the multi-mechanism deformation creep model (MD model). The main contribution of this work is to present a first effort in the use of the MD model for Brazilian salt rocks. Material-sensitive parameters have been calibrated for the Brazilian halite through two methodologies. Salt is modelled as an elasto-viscoplastic material. Numerical simulations using the finite element method have been carried out for triaxial creep tests, Pre-salt wellbore closure and mining gallery convergence in order to validate the parameter set and the methodologies. Excellent results have been observed in most of the applications for validation. Even so, validation efforts should continue to consolidate the parameters and identify possible limitations.     

安徽巢湖—肥东地区沉积变质型铁矿带的地质特征及找矿潜力分析

安徽巢湖—肥东一带的铁矿床为中型规模的BIF铁矿床。本文基于已有勘查研究成果,总结归纳矿床地质特征,探讨矿床成因并进行找矿潜力分析。     

The coral communities of the Islas Marias archipelago,Mexico: structure and biogeographic relevance to the Eastern Pacific

Various authors have suggested that the Islas Marias archipelago, Mexico, may play a significant biogeographic role in the dispersal of Indo Pacific coral species into the Eastern Pacific; however, the coral communities of this archipelago have received scarce attention to date. Here, we first addressed coral community structure across the islands and, by employing ordination analysis, minimum spanning tree and particle‐tracking experiments, used this information to evaluate the relevance of the archipelago for coral dispersal. Twenty‐four coral communities were recorded in the archipelago. Coral cover varied significantly among islands: Maria Cleofas had large values (38.5%), intermediate values were observed for Maria Madre (26.5%) and Maria Magdalena (22.84%), and relatively low values were recorded for San Juanito (18.5%). Coral communities mainly consisted of Pocillopora (57.3%) and Porites (25.5%) species, while species of Pavona (16%) and Psammocora (0.6%) made relatively minor contributions. Thirteen stony coral species were identified in the archipelago; of these Psammocora profundacella and Pavona duerdeni represent new records. Ordination analysis, minimum spanning tree and particle‐tracking experiments suggested similar connecting paths in the studied area; in general, the Islas Marias stands as a route for coral dispersal of Indo Pacific species into the Northeastern Pacific. In a regional context, the Islas Marias has three major biogeographic implications to coral dispersal: (i) the archipelago stands as a major stepping stone for the transport of species and individuals among the Revillagigedo archipelago, the Gulf of California and the tropical Mexican Pacific; (ii) the Islas Marias may play a seminal role in maintaining the genetic connectivity between southern and northern coral populations along the Mexican Pacific and (iii) because of its relatively pristine status and low levels of human impact, the archipelago may potentially serve as a source of coral propagules for ecosystem recovery in the Gulf of California and along the Pacific coast of the Mexican mainland following natural and/or human induced perturbations.     

依托无人机倾斜摄影的电力走廊三维重建

电力线路走廊三维重建能够为线路巡检提供重要信息。针对电力走廊倾斜摄影几何需求和地面覆盖要求,该文设计和实现了一套数据采集设备,并实现了面向电力线路走廊三维重建的数据采集和处理。实验结果表明,该文设计的数据采集设备与无人机平台集成,能够较好地获取电力杆塔及其附属设施的航拍影像,实现电力线路走廊与电力设施的三维重建。     

Zur Entstehung der Kantenkiesel

Ohne Zusammenfassung     

Sobre un volcán de Verita recientemente descubierto en el Mioceno de Barqueros. — (Murcia)

While working to construct a geological map. A.Almela, an Engineer of Mines, discovered in Alhama de Murcia a previously unknown volcanic crater. This volcano erupted through the miocene layers and extended above them, thus establishing the date of this eruption as being post-miocene. Since there are no sedimentary rocks in this region of a more recent date it is impossible to fix the date of the eruption any more exactly. The crater is about 1Km. In the surface of the crater one finds slag, scoriaceous lava and compact rocks. The rock is composed of phlogopite, olivine and diopside in phenocrysts in a hyaloid cement with tiny grains of sanidine, olivine and diopside; and a thin layer of phlogopite in a glassy brownish black. A study was made of the chemical constituency of the rocks on the basis of three complete analyses and a comparison was made with the findings already made by Vera-Garrucha and those of Fortuna. All of the data as compiled in the five tables and four diagrams graphically represents the obtained results. The volcanic rocks have a close analogy to those ofOsann’s « Verita » type, which are shown not only by the analytical value of the magmatic parameters but also by the positions of the points shown in diagramsK-mg andLs-Fs-Ks of the three types already analized. In all the samples which have been studied from Barqueros the value of the K₂O is superior to that of Na₂O; it is also greater than that of Vera-Garrucha and less than in that of Fortuna.     

Optimisation of wave energy extraction with the Archimedes Wave Swing

This paper addresses the Archimedes Wave Swing (an offshore wave energy converter, which produces electricity from sea waves). It compares the performances of latching control (a discrete, highly non-linear, intrinsically sub-optimum control strategy), of reactive control, of phase and amplitude control (two optimum control strategies that involve non-causal transfer functions, which have to be implemented with approximations, thus rending the control sub-optimum), and of feedback linearisation control (a non-linear control strategy). From extensive simulations it is concluded that the latter performs clearly better irrespective of the sea state, and leads to a significant increase of absorbed wave power.