水基钻井液用抗高温聚合物增黏剂的研制及作用机理

以2-甲基-2-丙烯酰胺基丙磺酸钠(Na AMPS)、N-乙烯基己内酰胺(VCL)、二乙烯苯(DVB)为共聚单体,采用自由基胶束聚合法制备了新型抗高温聚合物增黏剂SDKP,并通过单因素实验对反应条件进行了优化。采用傅里叶变换红外光谱、紫外光谱、凝胶色谱分别对SDKP的分子结构和平均分子量进行了表征和测定,并评价了增黏剂SDKP在低膨润土钻井液和无固相钻井液中的抗温增黏性能。评价结果表明,SDKP在2.5%低膨润土钻井液中的抗温能力达230℃,在无固相钻井液中的抗温能力达190℃,其在钻井液中具有良好的抗温性能和增黏性能,抗温增黏效果优于国外同类代表产品HE300。最后通过热重分析、环境扫描电镜观测、高温黏度测试等手段,探讨了SDKP的抗温增黏作用机理。     

稠油油溶性降黏剂ASAM/C/O的合成与评价

分析了造成稠油高黏的原因及降黏剂的降黏机理,对降黏剂的分子结构进行设计.先以丙烯酸(A)、苯乙烯(S)、丙烯酰胺(AM)为原料合成了中间产物——三元共聚物ASAM,然后以ASAM、多元醇、长链烷基酸为原料通过两步酯化反应合成了一种稠油油溶性降黏剂ASAM/C/O.通过正交实验确定出中间产物ASAM的最佳合成条件:单体质量比m(丙烯酸)∶m(苯乙烯)∶m(丙烯酰胺)为6∶3∶2,引发剂质量分数1.3%,反应时间为6 h.降黏剂ASAM/C/O的最佳合成条件∶m(ASAM)∶m(C)∶m(O)取6∶2∶1.5,长链烷基酸的碳链长度取18,反应温度在110～120℃之间,反应时间为6 h左右.降黏剂ASAM/C/O具有较好的降黏效果;降黏率与温度有关,随温度降低,降黏率升高;加剂处理后稠油体系的活化能大幅度降低,说明体系内的结构强度减弱.     

聚丙烯酸钠高吸水树脂的新工艺合成研究

以丙烯酸及其钠盐为单体,以过硫酸钾为引发剂,N,N′-亚甲基双丙烯酰胺为交联剂,采用不通氮气及不除去丙烯酸中阻聚剂的新工艺,通过接枝聚合合成了聚丙烯酸钠高吸水树脂。文章研究了丙烯酸的中和度、引发剂用量及交联剂用量对聚丙烯酸钠高吸水树脂吸水率的影响,并通过正交实验对该产品进行了最优化合成工艺条件的研究。实验研究表明,以该新工艺合成的聚丙烯酸钠高吸水树脂的最高吸蒸馏水率为1 060g/g。     

油溶性特稠原油降黏剂——PAEH的研制

首先合成了一定分子量的聚丙烯酸,然后再分别连续投加山梨醇和硬脂酸,通过两步酯化反应合成了一种聚丙烯酸高碳醇酯衍生物油溶性稠油降黏剂———PAEH.研究了合成条件对产物降黏效果的影响,得出了最佳合成条件:丙烯酸、多元醇、硬脂酸的物质量比为1∶0.6∶0.6,合成温度110~115℃,合成时间5~7h.讨论了该降黏剂加量和温度对其降黏效果的影响.结果表明,当其浓度为0.8g/L,温度在42.5~50.0℃时,具有最佳降黏效果.PAEH稠油降黏剂生产工艺简单,产率高,对高稠原油降黏效果明显.     

不同驱动力条件下改性淀粉、羧甲基纤维素钠和黄原胶对水合物形成的影响

研究不同温压条件下加量(质量分数)为0.1%~0.5%的改性淀粉、羧甲基纤维素钠(CMC)和黄原胶(XC)对CH₄水合物形成影响。结果表明3种增黏剂通过对体系中水分子的束缚,不同程度地抑制了水合物的成核及生长;驱动力较弱时,CMC加量达到或超过0.3%后几乎彻底抑制了水合物的形成,XC加量达到0.3%时同样可实现这一抑制效果,但随着XC加量继续增大,受其发泡性及稳泡性较强影响,水合物抑制能力有所弱化,与CMC和XC相比,改性淀粉的水合物抑制性相对较弱;驱动力较强时,3种增黏剂可微弱减缓水合物的形成速率,且XC因其在水溶液中空间结构更复杂,能束缚更多水分子,抑制效果最佳;温度为5~20℃条件下,XC提黏能力较强,且在低温条件下其水溶液的流变性具有较强的可控性,更适用于水合物钻井液体系。     

阴离子长链疏水缔合聚合物PAAO的合成及溶液性质

以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸钠(AMPS)、丙烯酸正辛酯(OA)合成了阴离子长链疏水缔合聚合物PAAO,考察了PAAO的合成条件。采用傅里叶红外光谱法对分子结构进行表征并对其增黏、抗盐性进行了研究。结果表明:当n(AM)∶n(AMPS)=83∶17,引发剂质量分数为0.09%,反应温度为60℃,疏水单体摩尔分数为1.54%时聚合物PAAO的表观黏度最高。此外强阴离子(-SO2-3)和疏水单体的加入,使PAAO水溶液表现出良好的增黏性、抗盐性。     

稠油油溶性降黏剂的合成与评价

采用丙烯酸十八酯(SA)、苯乙烯(S)、顺丁烯二酸酐(MAH)、丙烯酰胺衍生物(AA)作为聚合反应的单体,通过溶液聚合的方法合成一种油溶性四元聚合物SSAM。在实验中探讨温度、时间和反应物的配比等因素对降黏效果的影响。结果表明:降黏剂加入量为700μg·g~(-1)时,在50℃使春晖稠油的表观黏度下降70%以上,净降黏率到达了40%,有良好的降黏效果。     

阳离子丙烯酰胺型疏水单体与丙烯酰胺共聚物水溶液黏度的研究

将阳离子水溶性表面活性大单体二甲基十六烷基(2-丙烯酰胺基丙基)溴化铵(DHAB)与丙烯酰胺通过自由基混合胶束聚合和溶液聚合法合成了具有不同疏水单体含量、不同缔合强度的疏水聚合物,在80℃条件下用表观黏度法研究了疏水单体含量(0.05 mol%～0.15 mol%)不同的聚合物溶液的缔合强度和温度对聚合物溶液表观黏度及流动活化能的影响.当疏水单体含量为0.15 mol%时,临界缔合浓度约为0.15wt%;实验结果表明外加盐(NaCl、CaCl2)对该类型的聚合物具有明显的盐增黏效应.     

含磺基甜菜碱基团聚丙烯酰胺的合成及其溶液性质

用丙烯酰胺(AM)、N,N-二甲基丙烯酰胺(DMAM)、[3-(甲基乙烯酰胺)丙基]二甲基-(3-磺酸)铵(DMMPPS)和[2-(甲基丙烯酰基氧基)乙基]二甲基-(3-磺酸丙基)氢氧化铵(DMAPS)单体通过氧化还原引发剂引发自由基聚合合成AM-DMMPPS、AM-DMAM-DMMPPS、AM-DMAPS和AM-DMAM-DMAPS 4种两性离子共聚物,并对两性离子聚合物进行表征和性能评价.研究结果表明,实验合成的4种共聚物AM-DMMPPS、AM-DMAMDMMPPS、AM-DMAPS和AM-DMAM-DMAPS都有增黏、抗盐、耐温的效果.在相同的反应条件下,在合成的共聚物中,AM-DMMPPS增黏、抗盐、耐温的效果最佳,其比浓黏度达36.8,dL/g.     

室内胶合板用生物油-淀粉胶黏剂的合成工艺

以生物油、淀粉为主要原料制备绿色环保、价格低廉的生物油-淀粉胶黏剂(BOSA)并用于室内胶合板的制备。以淀粉乳液浓度、丙烯酰胺、过硫酸铵及生物油加入量作为试验因子,以胶黏剂的胶合强度、固含量和黏度作为评价指标,采用正交试验法优选出合成BOSA的最佳合成工艺。结表表明:当淀粉乳液质量分数为40%、丙烯酰胺为20%、过硫酸铵为2.5%、生物油为20%时,胶黏剂的综合性能最好,储存期达到15 d,胶合板胶合强度(1.44 MPa)达到国家标准GB/T 9846—2004中Ⅲ类胶合板(≥0.7 MPa)要求。     

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