碳酸盐岩自转向酸酸液流动模拟实验研究与评价

在自转向酸酸化机理研究的基础上,对实验所用酸液体系从增黏性能、破胶性能和转向性能等方面进行了评价。实验发现,残酸在80℃时黏度可达到1 128.2 mPa·s,具有良好的封堵增黏性能;5%的乙二醇可使残酸黏度降至2 mPa·s,破胶效果好。通过岩心流动实验分别对常规酸和自转向酸在地层中的反应流动进行模拟,绘制了水驱-酸化-水驱全压降曲线。单岩心流动实验表明,自转向酸对于较高渗透率岩心的处理效果优于常规酸液,而对于较低渗岩心改造效果不明显。双岩心流动实验发现,对于不同渗透率差异倍数的两块岩心,自转向酸对于其中的低渗岩心改造效果要好于常规酸,然而随着渗透率极差进一步增大,自转向酸增黏改造效果变差。     

一种泡沫酸配方及其分流酸化性能评价

泡沫酸因其诸多优于常规酸的性能而被广泛应用于油田增产措施中.室内确定了一种泡沫酸体系配方,以12%HCl和3%HF土酸为酸基液,泡沫体系由0.8%复合型起泡剂EL-23与0.3%高聚物稳泡剂D组成.泡沫体系与酸液配伍性好,泡沫半衰期20 min.分流实验表明,泡沫酸显著降低高渗岩心而增加低渗岩心的注入量,泡沫流体在不同渗透率地层的注入量比例得到合理调整.酸化前后渗透率变化率表明,泡沫酸对低渗层的改善程度高于高渗层.泡沫对水层具有选择性封堵能力,防止酸对水层过度酸化,使酸液更充分改善油层的渗流能力.泡沫酸对渗透率和油水层均具有分流选择性酸化的特点.     

绥中36-1油田氮气泡沫逐级调驱实验研究

多层砂岩油藏非均质严重,大段多小层笼统注水时注入水沿高渗透层窜流;利用氮气泡沫驱可有效改善注入剖面。在前人双管实验研究的基础上,创新提出应用三管并联驱替注泡沫逐级调驱的实验方法,重点研究了不同渗透率级差、相同渗透率级差不同渗透率级别和气液比对氮气泡沫调驱效果的影响。研究结果表明经过氮气泡沫调驱后,泡沫有效发挥了调整分流作用,使高渗管、中渗管和低渗管的产液量趋于均匀,体现了"分级堵调、逐级启动"的特性,有效改善了非均质储层的开发效果,对该类油藏的高效开发有一定的借鉴意义。     

不同相对分子质量的APAM的制备及其动力黏度性质研究

以丙烯酰胺(AM)为原料合成了不同相对分子质量的聚丙烯酰胺(PAM).通过碱性水解反应制备了阴离子聚丙烯酰胺(APAM).采用胶体滴定法测定了APAM的水解度,考察了碱的用量、聚合物的相对分子质量对水解度的影响.探讨了温度、pH值、相对分子质量和水解度等因素对APAM动力黏度的影响,并根据实验结果进行了应用实验.研究结果表明:当酰胺基与碱的比例在1∶3时聚合物水解度达到60%,增加碱的用量,其最终水解度保持不变;水解度60%的APAM在温度为25℃、pH=8～10、相对分子质量172×104时的动力黏度达到13 400 mPa·s,将它应用于涂料中,其黏度从57 mPa·s上升至299.5 mPa·s.     

泡沫分流特性研究及应用

泡沫流体在储层酸化中起着重要作用.通过实验研究了泡沫的分流特性,分析了泡沫酸的分流效果.结果表明:泡沫流体在含油岩心中的渗流阻力比在饱和水岩心中的渗流阻力要小得多,泡沫可以大幅提高含油岩心分流量,降低饱和水岩心分流量,具有显著的选择性,含油饱和度是影响泡沫分流效果的最主要因素;泡沫流体在非均质地层中可以有效地控制吸入剖面,降低高渗层的吸入量,提高低渗层的吸入量,使注入流体在不同渗透率地层内均匀推进.现场应用进一步表明,泡沫酸酸化能够有效地增加中低渗透层吸酸量,扩大酸化范围,提高酸化效果.     

甜菜碱活性剂用作碳酸盐岩酸液转向剂研究

针对高温高盐碳酸盐岩油藏,且油层厚度大、非均质性严重、酸化后易出现含水率上升的问题,开展了甜菜碱两性表面活性剂自转向酸的研究。实验室合成了四种分子结构不同的甜菜碱表面活性剂(CBET-18、CBETXN-18、CBETXN-22S、CBETXN-22J)。评价表明,CBET-18对残酸的稠化能力最强,CBETXN-18对残酸的稠化能力最弱,但CBET-18和CBETXN-22S在15%盐酸中需要较高的溶解温度。甜菜碱表面活性剂在碳酸盐岩表面有吸附作用,会导致润湿性反转;且仅用盐水浸泡即可恢复岩石表面的润湿性,因此它不会对酸化后的生产造成影响。物理模拟实验表明,对于渗透率级差低于5的并联岩心,自转向酸有较好的转向性能,可保证低渗透岩心得到有效酸化。     

聚合物溶液改善吸水剖面能力实验研究

针对聚合物驱过程中窜聚影响聚合物驱效果的现象,开展了聚合物溶液在注入过程中和突破后对吸水剖面改善能力的双管并联岩心驱替实验。对比分析了水驱、恒速聚驱和变速聚驱对吸水剖面的影响程度,绘制了填制不同渗透率岩心所用不同粒径石英砂含量配比图;并通过考虑管线和填砂管端面引起的压力损失对室内计算渗透率进行了改进。结果表明:水驱速度小于2 m L/min时,高低渗分流比远大于渗透率级差,大于4 m L/min分流比与级差吻合;恒速聚驱时在聚合物注入过程中能够有效的改善吸水剖面,但一旦产出端见聚,吸水剖面将会迅速翻转。聚驱速度小于2 m L/min时,高低渗分流比也大于渗透率级差;但比水驱影响小很多。大于4 m L/min时与水驱相同,合理控制注聚速度对聚合物驱提高采收率意义重大。     

相对渗透率调节剂提高采收率优化控制条件研究

相对渗透率调节剂(relative permeability modifier,RPM)可以选择性降低油水相渗透率以提高注入水的波及系数;并改变岩石表面的润湿性,提高采收率。研究了一种阳离子聚合物型的相对渗透率调节剂,测定了RPM对表面润湿性以及油水相渗透率的影响。通过岩心驱油试验考察了不同油藏渗透率、地层润湿性、原油黏度、RPM注入时机、注入水注入速度等条件下RPM驱的驱油效果。实验结果表明,RPM可以将油湿的石英表面润湿性改变为弱水湿,且对水相渗透率降低程度更大;RPM驱适合渗透率大于50×10-3μm2地层;RPM在油湿岩心中具有更高的采收率增值;原油黏度在20 mPa·s时,采收率增值幅度最大;在相似的渗透率条件下,注入速度增大时,水驱采收率与最终采收率均增大;较早注入RPM有更好的最终采收率效果。     

泡沫稳定性能评价及泡沫分流效果试验研究

提供了一种泡沫分流酸化试验研究方法,对起泡剂、稳泡剂的性能进行了试验分析,采用多用途分流酸化试验装置分别进行了泡沫对岩芯的分流效果试验,不同渗透率岩芯的分流效果试验,模拟实际酸化施工过程的分流酸化试验。结果表明,采用泡沫分流技术,对并联岩芯酸化时能有效地实施分流,使低渗透岩芯吸酸量增大,能均匀改善不同渗透性岩芯的最终渗透率,提高酸化效果,同时采用该项技术有效地解决渗透率差异较大的多层油气藏均匀吸酸及均匀解堵问题,无需进行其它分层措施。     

泡沫分流酸化数学模型的建立及应用

泡沫分流酸化能有效解决常规酸化中由于地层渗透率差异而导致的小层进酸不均的问题。基于泡沫圈闭理论和质量守恒原理,建立了泡沫分流酸化的数学模型并进行了求解,同时确定了泡沫分流酸化工艺的设计原则。结果表明：地层表皮系数随着酸化过程逐渐减小,井口和井底压力随泡沫的注入逐渐增大,随酸液的注入逐渐减小;泡沫的注入使高渗层的流量逐渐降低,低渗层的流量逐渐增高,实现后续酸液转向低渗层;在相同的地层条件下,泡沫酸酸化比泡沫段塞分流酸化的分流效果要好,但是作业时间长,井口和井底注入压力较高。现场应用表明泡沫分流酸化能有效封堵高渗层,恢复产能,动用低渗层,适于非均质油藏油气井、重复酸化老井的解堵增产增注。     

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…     

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。     

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

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.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.