非均质条件下聚表二元驱可视化物理模拟研究

为了能够更好地认识平面非均质油藏的油水流动动态及二元体系(聚合物/表面活性剂)在非均质油藏中的应用,采用可视化物理模拟方法直观研究了平面非均质油藏的注水驱油机理。向水驱之后的模拟油层注入二元体系,通过观察模型中二元驱体系流动情况来分析注入二元体系后不同段塞在模拟油层的情况。实验证明二元体系可以有效地提高油层采收率和波及系数。     

龙虎泡低渗透油田聚表二元复合驱实验研究

针对龙虎泡低渗透油田水驱开发效果差、采收率低等特点,开展了聚合物和表面活性剂二元复合驱在低渗透油藏适应性的室内评价实验.注入性实验表明,相对分子量为2 200万的FP-3聚合物注入渗透率46.45×10-3μm2的岩心未发生堵塞,具有良好的注入选择性及封堵选择性.驱油实验表明,聚合物和表面活性剂可分别提高低渗透岩心驱油效率10%和20%,且表面活性剂容易注入,可降低注入压力.在聚合物和表面活性剂不同段塞组合实验中,两者分段塞注入的方式优于单独注入表面活性剂或将两者混合后注入的方式,其中先注聚合物后注入表面活性剂的段塞组合方式最好,可提高采收率17.74%.因此,对于非均质性较弱的低渗透油田,可采用聚表二元复合驱技术,先注入聚合物降低储层的非均质性,后注入表面活性剂启动低渗区的剩余油.     

非均质油藏中水气交替驱油机理研究

分别利用均质和非均质岩心模型,进行了连续气驱和水气交替驱油实验,研究了不同非均质性模型中,注气方式对气驱油效果影响的差异。结果表明,均质模型中水驱后连续注气与水气交替提高驱油效率幅度分别为15.8%和14.9%,注气方式对气驱油效率影响较小;而非均质模型中直接水气交替驱原油采收率为78%,连续注气、间歇注采和周期注气原油采收率分别为41.9%、32.2%和42.3%,水气交替注入原油采收率最高,气体注入方式对气驱原油采收率影响较大。均质模型中,气驱后水气交替驱时,水段塞为主要驱油段塞;而非均质模型中,气驱后水气交替驱时,气体段塞是主要驱油段塞。     

低渗和特低渗油层CO2-N2复合驱研究

针对低渗-特低渗油层CO₂-N₂复合驱提高采收率,以大庆外围YS油田的特低渗透油层为背景,进行了数值模拟和物理模拟两方面的研究。利用CMG数值模拟软件GEM模块,建立了一维长细管、均质、非均质理想模型及五点法井网单元模型,分别对CO₂-N₂复合驱的驱油方式、影响因素、五点法井网单元模型下的段塞组成进行了模拟计算及分析。与此同时,在室内分别选用30 cm长的低渗透、特低渗透天然岩心,各进行了5种不同驱替方案的实验研究,确定了CO₂-N₂复合中CO₂合理段塞尺寸及驱油效果,并验证了数值模拟计算的可靠性。研究结果表明,低渗-特低渗透油层CO₂-N₂复合驱不宜采用CO₂与N₂混合驱方式,而应采用一次注入合理的CO₂段塞(约0.3PV)＋N₂的段塞组合驱方式,这样不仅可以减少CO₂用量,而且可以充分发挥CO₂与N₂各自的优势,获得优于全部注CO₂驱的驱油效果;且油层渗透率越低、渗透率级差越小或长厚比越大,越有利于提高CO₂-N₂复合驱采收率;厚度小于井距1%的油层也有利于CO₂-N₂复合驱提高采收率。     

非均质储层纳微米聚合物颗粒体系驱油实验研究

为了深入揭示低渗透储层非均质性对聚合物颗粒分散体系驱油效果的影响,采用平板填砂模型和岩芯串、并
联组合实验技术,对纳微米聚合物颗粒分散体系进行了非均质驱油实验研究,并分析了纵向、横向非均质性和渗透率
级差对驱油效果的影响。平板填砂模型模拟实验结果表明,聚合物颗粒分散体系对改善储层纵向非均质性效果更明
显,在纵向非均质模型中提高的采收率比横向非均质模型高9.83%。岩芯组合模拟实验结果表明,随着渗透率级差增
加,聚合物颗粒分散体系提高串、并联岩芯组合模型的采收率均逐渐增大,在相近渗透率级差变化情况下,聚合物分散
体系提高串联岩芯组合模型的采收率增幅为6.65%,而提高并联岩芯组合模型的采收率增幅为9.48%;渗透率级差越
大,高、低渗岩芯的分流量相差越大,聚合物颗粒分散体系调驱后,高渗岩芯的分流量降低,低渗岩芯的分流量增大。     

蒸汽-空气复合驱提高稠油采收率研究

为进一步提高稠油热采的采出程度,开展了蒸汽空气复合驱的研究。主要从室内实验及数值模拟研究了蒸汽空气复合驱的最优空气与蒸汽的质量比。通过对不同空气与蒸汽质量比的室内实验研究,可以看出随着空气与蒸汽的质量比升高,采出程度先上升后下降。当空气与蒸汽的质量比为2：32时,蒸汽空气复合驱的采出程度最高,为68.67%;此时填砂管出口端的温度与蒸汽驱相差不大。当空气与蒸汽的质量比大于3：32时,蒸汽空气复合驱的采出程度低于蒸汽驱,此时填砂管出口端的温度远低于蒸汽驱的温度。通过CMG数值模拟对辽河油田X区块的蒸汽空气复合驱的研究,得到了与室内实验相同的趋势。由于室内实验与现场的差异性,其优化的数值有所差异。通过辽河油田X区块的现场试验,蒸汽空气复合驱空气与蒸汽的质量比为1：16.1。该现场试验区块中原油日产量上升,原油含水率下降,有力地验证了室内实验及数值模拟结果的正确性。     

非均质特低渗透油藏CO_2驱气窜规律研究

特低渗透油藏在二氧化碳驱油过程中极易发生气窜现象,严重影响注气开发效果。为了有效地封堵气窜优势通道,提高二氧化碳气驱的波及体积和驱油效率,建立不同渗透率级别的非均质岩芯模型、高渗透带气窜模型、裂缝模型等室内实验模型,测得二氧化碳在不同阶段的见气时间、气窜时间及采出程度;在此基础上选用含地层水、淀粉、不饱和单体、交联剂、成胶控制剂等组分的高强度高性能封窜剂(乙二胺)在不同渗透类型岩芯模型进行二氧化碳封窜控制实验。实验结果表明,二氧化碳气体的波及体积受气窜影响严重,岩芯非均质性越强,气窜现象越严重,气驱效果越差;在渗透率级差较小的情况下,采出程度随渗透率级差的增加而降低,当级差大于100时,采出程度急剧下降,气窜严重,低渗透储层难以波及到,造成总采出程度低。通过高强度高性能乙二胺封窜剂,能够稳定封堵基质中的相对高渗层的窜流,有效扩大二氧化碳驱的波及体积有效扩大CO_2驱的波及体积,室内提高采收率30%以上。     

喇嘛甸油田三类油层三元复合驱注入方案优选研究

首先进行三元复合驱室内岩心实验,对三类油层三元复合驱段塞组合驱油效果进行评价,然后用Petrel软件建立试验区相控地质模型,应用CMG软件中的STARS模块,对喇嘛甸油田三类油层三元复合驱不同段塞组合注入方案进行数值模拟研究。三类油层室内岩心驱油实验研究表明,天然岩心中水驱最终采收率为45.32%,进行三元段塞组合驱油最终采收率较水驱提高了12.48%,三类油层比一、二类油层更为均质,更适合以提高驱油效率为主要机理的三元复合驱;数值模拟结果表明,4种三元复合驱段塞组合方案中,方案5的最终采收率为52.67%,最终采收率比不加密井网水驱开发提高了13.94%,比加密井网水驱开发提高了9.79%,综合含水率下降了9%左右,确定方案5为最佳的注入段塞组合方案。     

高温化学复合驱油方式优化评价研究

针对双河油田VI油组高温非均质油藏,使用油层砂充填长管模型,研究几种化学复合驱油体系中表面活性剂、聚合物、低度交联聚合物、有机碱以及交联剂之间的色谱分离特征。实验结果表明,95℃下三元复合体系流经填砂管时,聚合物最先突破,碱随后突破,表面活性剂的突破滞后最大;有机碱的加入能起到降低表面活性剂吸附的作用,而交联剂对于表面活性剂吸附影响不明显。根据色谱分离程度,采用层间非均质人工压制物理模型,对比评价了二元、三元复合驱油体系及几种组合驱油方式的驱油效果,优选出主段塞为有机碱三元复合体系、前后保护段塞为交联聚合物的驱油体系,水驱后可提高采出程度24.2%。该研究成果可以对高温非均质油藏三次采油的高效开发提供参考依据。     

热力泡沫复合驱提高稠油采收率研究

蒸汽驱开采稠油油藏时存在蒸汽超覆和蒸汽窜流,降低了蒸汽的波及效率。国内外采用注蒸汽的同时添加非凝析气体和耐高温起泡剂,进行热力泡沫复合驱,取得了令人满意的效果。利用物理模拟驱替实验和数值模拟技术,研究了热力泡沫复合驱提高稠油采收率的机理及开发效果。实验研究表明：蒸汽驱转热力泡沫复合驱后,驱油效率在蒸汽驱的基础上提高38.5%,达到81.0%。辽河高升油田的数值模拟研究表明：热力泡沫复合驱的采收率高于单一蒸汽驱,泡沫能够封堵蒸汽窜流通道,抑止蒸汽超覆,改善油藏的温度分布,是一种行之有效的三次采油方式。     

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.