超低界面张力的二元驱油体系对水驱残余油启动和运移机理

针对三元复合驱含碱驱油体系引起地层黏土分散和运移、形成碱垢、导致地层渗透率下降,碱还会大幅度降低聚合物溶液的黏弹性,从而降低波及效率等问题,利用新研制的不加碱可形成超低界面张力两性表面活性剂,通过微观模型驱油实验,分析了聚丙烯酰胺/两性表面活性剂二元复合体系对残余油启动、运移的过程,研究了该二元复合体系对水驱后残余油的作用机理.研究表明:具有超低界面张力的聚表二元复合体系利用了聚合物溶液的黏弹特性和表面活性剂体系的超低界面张力特性,使采收率大幅度提高.残余油的启动主要以拉成油滴和油丝两种形式,在运移过程中,较大的油滴又形成更容易被驱替液携带的小油滴,从而使驱油效率提高.     

稠油油藏化学驱采收率的影响因素

采用烷基聚氧丙烯醚硫酸盐和羧基甜菜碱两类两性表面活性剂与碱复配构建具有不同界面张力特点的驱油体系,通过驱油试验评价不同体系对桩西稠油采收率的影响,采用微观驱替试验研究不同体系提高采收率的机制。结果表明:界面张力与采收率没有明显的对应关系;碱通过维持油、水、固三相接触点亲油性和降低油水界面张力,减弱驱替介质沿油与岩石之间的渗入,增强驱替介质从原油中心的突进和分散,提高驱替压力和波及体积;相比于碱和原油反应产生的表面活性剂,外加的表面活性剂亲水性较强,会增强固体表面的亲水性,导致驱油剂沿孔隙壁面突进;表面活性剂-碱体系与原油形成的细分散水包油型乳状液加剧了驱油剂的窜进,不利于提高波及系数;对于稠油油藏,化学驱体系的波及系数是提高采收率的关键因素。     

聚合物/甜菜碱表面活性剂提高水驱后残余油采收率研究

利用不加碱可形成超低界面张力的甜菜碱表面活性剂／聚丙烯酰胺二元复合体系，通过流变性实验，分析了甜菜碱表面活性剂对聚合物／表面活性剂二元复合体系流变性的影响；通过可视化的微观驱油实验和人造岩心驱油实验，分析了聚合物／表面活性剂二元体系的粘弹性和界面张力对采收率的影响，研究了该二元复合体系对水驱后残余油的作用机理。结果表明，实验用的两性表面活性剂体系与油可以达到超低界面张力，表面活性剂体系对无碱二元体系的粘弹性影响非常小。在驱替水驱残余油过程中，形成超低界面张力的甜菜碱表面活性剂／聚丙烯酰胺二元复合体系可以同时发挥活性剂的超低界面张力作用和聚合物溶液的粘弹性作用，使该二元体系的采收率高于单一的表面活性剂体系和聚合物驱油体系，并且该二元体系的粘弹性越大，采收率越高。界面张力由10^-2mN／m降至10^-3mN／m时的最终采收率均高于界面张力为10^-2mN／m时增加聚合物溶液的质量浓度和相对分子质量两种情况下的最终采收率。     

聚合物/甜菜碱表面活性剂提高水驱后残余油采收率研究

利用不加碱可形成超低界面张力的甜菜碱表面活性剂/聚丙烯酰胺二元复合体系,通过流变性实验,分析了甜菜碱表面活性剂对聚合物/表面活性剂二元复合体系流变性的影响;通过可视化的微观驱油实验和人造岩心驱油实验,分析了聚合物/表面活性剂二元体系的粘弹性和界面张力对采收率的影响,研究了该二元复合体系对水驱后残余油的作用机理.结果表明,实验用的两性表面活性剂体系与油可以达到超低界面张力,表面活性剂体系对无碱二元体系的粘弹性影响非常小.在驱替水驱残余油过程中,形成超低界面张力的甜菜碱表面活性剂/聚丙烯酰胺二元复合体系可以同时发挥活性剂的超低界面张力作用和聚合物溶液的粘弹性作用,使该二元体系的采收率高于单一的表面活性剂体系和聚合物驱油体系,并且该二元体系的粘弹性越大,采收率越高.界面张力由10-2 mN/m降至10-3 mN/m时的最终采收率均高于界面张力为10-2 mN/m时增加聚合物溶液的质量浓度和相对分子质量两种情况下的最终采收率.     

江苏油田三元复合驱研究

针对江苏普通稠油油藏水驱采收率低的问题,通过配方优化和岩心物模驱替实验,构建了适合区块原油的三元复合驱配方。首先通过动态界面张力评价,筛选出了具有较高界面活性的表面活性剂/碱体系;同时采用不同HLB值的表面活性剂复配,优化体系的亲水亲油平衡,获得了具有超低界面张力的二元体系。最后通过岩心驱替物理模拟实验,评价了碱/表二元复合驱、聚合物驱、三元复合驱的驱油能力。结果表明,对于普通稠油油藏,单纯碱/表二元体系由于无法提高波及系数导致其提高采收率能力较差,而三元驱体系可以兼顾波及系数与洗油效率,所以获得了较高的采收率,因此对于水驱稠油提高采收率的首要指标是提高驱油剂的波及效率。     

驱油体系和油层的相互作用浅析

三元复合驱是20世纪80年代中期提出的三次采油新方法。它是由碱/表面活性剂/聚合物复配而成的三元复合驱油体系,既有较高的粘度,又能与原油形成超低界面张力,从而提高原油采收率。     

磺酸盐型Gemini表面活性剂的合成及在三次采油中的应用研究

为了提高驱油用表面活性剂降低油水界面张力的能力,以提高原油的采收率.合成了磺酸盐型Gemini表面活性剂,并将其与石油磺酸盐复合,采用tx-500界面张力仪测定了复合体系降低油水界面张力的能力.研究表明:当质量分数为1%时,磺酸盐型Gemini表面活性剂-石油磺酸盐复合体系能降低油水界面张力至4×10-4～6×10-4 mN·m-1.磺酸盐型Gemini表面活性剂的加入使得磺酸盐型Gemini表面活性剂与石油磺酸盐之间产生协同效应,提高了原油的采收率.     

三元复合驱体系/大庆原油间界面张力研究

研究了彬表面活性剂／聚合物三元复合驱体系与大庆原油间形成低界面张力的特性。结果表明：在降低界面张力方面，碱与表面活性剂之间存在显著的协同效应。而聚合物与碱、聚合物与表面活性剂之间不存在明显的协同效应。本文还初步探讨了超低界面张力的形成机理，并研究了碱浓度、表面活性剂浓度对复合体系／大庆原油间界面张力的影响。     

耐温抗盐强乳化聚-表二元复合驱油体系研究及应用

针对高温高盐油藏采用常规聚合物和表面活性剂驱油效果较差的问题,将耐温抗盐型聚合物SPAM-1和阴-非离子复合型表面活性剂YANC-E进行复配,研制了一种适合高温高盐油藏的耐温抗盐强乳化聚-表二元复合驱油体系,并通过室内实验评价了驱油体系的综合性能。结果表明：该二元复合驱油体系的耐温性能较强,在115℃下老化后,体系的黏度保留率仍能达到90%以上,界面张力仍能达到10^-3mN/m数量级;体系具有良好的抗盐性能,当矿化度大于100 000 mg/L时,体系仍能保持较高的黏度和较低的界面张力;体系具有良好的长时间老化稳定性能,在储层温度和矿化度条件下老化60 d后的黏度保留率在85%以上,界面张力始终维持在10^-3mN/m范围内;驱油体系与原油形成的乳状液稳定性较强,放置120 min后乳状液的分水率小于20%,具有较强的乳化性能;驱油体系在地层条件下吸附6次后仍能保持较高的黏度和较低的界面张力,具有良好的抗吸附性能。另外,岩心水驱结束后注入0.5 PV二元复合驱油体系,能使采收率继续提高25%以上,驱油效果较好。A区块内5口采油井在实施耐温抗盐强...     

BHJ型甜菜碱表活剂物理驱油实验研究

针对三元复合驱中碱的注入所带来的采出液处理困难以及对地层造成损害等问题,运用新型甜菜碱表面活性剂BHJ,论述了不加碱又能达到低界面张力聚合物／表面活性剂二元驱油体系性能。综合所有均质和非均质岩心的实验结果并通过分析,我们认为采用甜菜碱BHJ活性剂的无碱二元驱油体系驱油效果好于采用Ss的弱碱（Na2CO3）三元体系和采用Sy的强碱（NaOH）三元体系。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to