多组分酸对不同煤阶煤储层化学增透实验研究

查明酸液对不同煤阶煤的酸化效果,能够为提高煤储层导流能力提供一种化学方法。通过对不同煤阶煤样酸化前后煤表面观察、矿物质含量和渗透率测试,得出不同煤阶煤酸化后表面变化特征、矿物质含量变化及渗透率变化规律。结果表明:多组分酸能与煤中的矿物质发生反应,提高煤储层的导流能力。煤中原始裂隙发育程度及矿物质的含量共同影响着增透效果;酸化使煤中的碳酸盐矿物和硫化物减少最多,其次是蒙脱石、绿泥石和伊利石,石英和高岭石减少最少;煤体裂隙越发育,与酸液反应的碳酸盐和硫化物含量越高,酸化增透效果越好。研究结果为多组分酸在煤储层水力压裂中的应用提供了实验支撑。

多组分酸酸化对中马村矿高阶煤增透效果的影响

为了研究酸化对中马村矿煤储层渗透性的影响,用同一体系酸液的不同配方对中马村矿粉状煤样进行了溶蚀试验,并开展了饱水煤样酸化前后的核磁共振试验研究。结果表明:1)针对中马村矿高阶煤优选出的多组分酸最佳配方为质量分数6%HCl+质量分数3%CH_(3)COOH,质量分数2%KCl作为防膨剂,添加适量SDS协同酸化,酸液浸泡煤样最佳时间为24 h;2)经优选出的最佳酸液浸泡的6组煤样的t_(2)谱谱面积皆大于酸化前,酸化时间24 h时的煤样t_(2)谱谱面积约为酸化前谱面积的1.83倍;3)酸化前后煤样中水在各孔径上的比率表明,优选多组分酸溶蚀掉的矿物质主要存在于中马村矿煤样的小孔中。研究成果能为多组分酸对中马村矿低渗煤层酸化增透提供一定的理论基础。

低透气性煤层多组分酸化压裂增透技术研究

为了解决富含碳酸盐类矿物煤层透气性差的问题,提出多组分酸化压裂增透技术。通过实验室测试煤样酸化前后渗透率的变化,确定了适用于三元煤矿的压裂酸液配比:w(HCl)为9%+w(CH 3COOH)为3%+ρ(KCl)为20 g/L。现场工业试验结果表明,三元煤矿采用多组分酸化压裂后,抽采瓦斯混合流量和瓦斯浓度比普通抽采钻孔平均提高了1.34倍和1.70倍。对比传统水力压裂增透技术,多组分酸化压裂通过物理增透和化学增透的联合作用,更有利于煤体孔隙裂隙网络结构的发育,且反应生成的二氧化碳对瓦斯产生了驱替作用,有利于瓦斯抽采;同时扩大钻孔孔径可以有效提高压裂接触面和抽采自由面面积,进一步提高增透抽采效果。

基于煤中不同矿物含量的增透多组分酸配方实验优选

查明对不同煤阶煤增透效果最好的多组分酸配方,能够为多组分酸在煤储层酸化中的应用提供一定的理论依据。采集了不同煤阶煤样(河南义马千秋矿、山西长平矿和山西屯兰矿),进行了多组分酸液对不同煤阶煤溶蚀实验,根据不同多组分酸对不同煤阶煤的溶蚀特征,优选出了不同煤阶煤酸液最优配方。通过酸化前后煤样渗透率测试实验,得出酸化后千秋矿、屯兰矿和长平矿煤样的渗透率分别增加25.76~128.08倍、0.32~1.20倍和0.73~17.22倍,具有良好的酸化增透效果。

19芯碲酸盐玻璃放大光纤的低串扰结构设计及性能仿真

基于空分复用技术的多芯光纤通信核心指标之一是信道串扰,该问题的存在极大地影响着传输距离及信号质量,尤其是在宽带光纤放大系统中。本文重点讨论了弱耦合19芯光纤的串扰问题,同时提出了一种利于多组分碲酸盐玻璃挤压制备的沟槽辅助型19芯光纤,并采用耦合功率理论和有限元法对模型进行了相关性能的数值仿真,系统研究了沟槽尺寸、折射率分布及相关光纤参数对芯间串扰的影响。仿真结果表明,优化设计后的光纤在1550 nm处拥有-156 dB/100 m的低串扰值,可以满足大容量光纤通信用宽带光放大器的应用需求。

复杂岩性油藏酸压技术在青海油田的试验应用

青海油田众多勘探开发区域的储层均属于复杂岩性油藏 ,采用单纯的砂岩酸化或碳酸盐岩储层酸压技术均有很多缺陷。为此 ,使用针对复杂岩性油藏开发的“稠化酸深度酸压 +多组分酸闭合裂缝酸化”组合技术 ,在狮 2 4斜井、跃灰 4井等进行了先导性试验 ,取得了显著的改造效果。

青海尕斯E3^2复杂岩性油藏深度酸压技术先导性试验研究

青海油田尕斯E3 2 油藏储层岩性复杂 ,碳酸盐岩平均 36 .75 %,碎屑岩 39%,粘土矿物 2 4.2 5 %。油藏基质低孔低渗 ,天然裂缝为主要油气通道。油层中深 330 0m ,平均温度 115℃。针对这种复杂岩性储层 ,建立了既不同于纯碳酸盐岩储层的深度酸压 ,又不同于砂岩储层基质酸化的组合技术 ,即“稠化酸深度酸压 +多组分酸闭合酸化”的增产技术方法 ,优选了适合储层改造的液体体系。并在跃灰 4井进行了先导性试验 ,酸压后返排率 95 %以上 ,初产 40m3 /d ,稳定产量 2 0 .2m3 /d ,取得了较好的增产效果。

环江油田长8层注水井酸化增注工艺

通过对环江油田长8注水井欠注原因的分析,提出了深部酸化降压增注的技术思路,开展了酸液体系和酸化工艺研究,现场实施取得了良好的效果,为该区注水井降压增注提供了有效的手段。

低渗碳酸盐岩储层深度酸化酸液体系优选与评价

叙利亚碳酸盐岩稠油油藏储层渗透率低,冷采产量低,达不到经济开采界限,热采注汽困难,效率低。针对这些问题,开展了深度酸化研究,研制了一种多组分缓速转向酸酸液体系,并测试了其酸岩反应速度,同时采用双源CT扫描仪、扫描电镜、透射电镜、压汞分析以及酸溶薄片法分析了酸化前后岩心的变化。结果显示新研制出的多组分缓速转向酸的酸岩反应速度比常规盐酸小了一个数量级,具有较好的缓速效果,酸化后的岩心孔隙度、渗透率、孔喉半径均有大幅的提高,酸蚀溶孔明显,喉道能够贯穿整个岩心。

In Vitro Anti-influenza Virus Activities of Sulfated Polysaccharide Fractions from Gracilaria lemaneiformis

In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiforrnis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides （PGL）, Gracilaria lemaneiformis polysaccharide fraction-1 （GL-1）, Gracilaria lemaneiformis polysaccharide fraction-2 （GL-2） and Gracilaria lemaneiformis polysaccharide fraction-3 （GL-3） were studied by the Methyl thiazolyl tetrazolium （MTT） method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect （CPE） on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit （PFU）, MTT and CPE methods. The results showed： i） Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii） Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides （PGL and GL-2） both of which exhibited higher antiviral activity; iii） A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions

Recent advances in fixation of CO_(2) into organic carbamates through multicomponent reaction strategies

Carbon dioxide(CO_(2)) is the main greenhouse gas and also an ideal C1 feedstock in organic synthesis because it is abundant,nontoxic,nonflammable,and renewable.The synthesis of organic carbamates using CO_(2) as a phosgene alternative has attracted extensive attention because of the importance of carbamates in organic synthesis and in the pharmaceutical and agrochemical industries.In recent decades,many multicomponent reaction strategies have been designed for constructing different types of organic carbamate molecules.Most of these methods rely on the in situ generation of carbamate anions from CO_(2) and amines,followed by reactions with other coupling partners.Synthetic strategies for acyclic carbamates include nucleophile‐electrophile coupling,nucleo‐phile‐nucleophile oxidative coupling,difunctionalization of unsaturated hydrocarbons,and C–H bond functionalization.Strategies for the synthesizing cyclic carbamates include carboxylative cyclization of in situ‐generated unsaturated amines and difunctionalization of unsaturated amines with CO_(2) and other electrophilic reagents.This review summarizes the recent advances in the synthesis of organic carbamates from CO_(2) using different multicomponent reaction strategies.Future perspectives and challenges in the incorporation of CO_(2) into carbamates are also presented.

Chromatographic separation of Be（Ⅱ） from Mg（Ⅱ）, Ca（Ⅱ）, Sr（Ⅱ） and Ba（Ⅱ） using poly[dibenzo-18-crown-6] and L-arginine

A simple and selective method for the separation of Be（Ⅱ） was developed using poly[dibenzo-18-crown-6] as a stationary phase in column chromatography. The study was carried out in L-arginine medium. 1.0-8.0 M HCl and CH3COOH, 0.5-8.0 M HBr, HClO4 and H2SO4, 0.2-1.0 M EDTA and 0.02-0.12 M ammonium oxalate were found to be an efficient eluents for Be（Ⅱ）. The capacity of polymer was 0.554-0.01 mmol/g of crown polymer. The tolerance limit of various cations and anions were reported. Be（Ⅱ） was quantitatively separated from Mg（Ⅱ）, Ca（Ⅱ）, Sr（Ⅱ） and Ba（Ⅱ）. The selective separation of Be（Ⅱ） was possible from multicomponent mixtures. The method was extended to determine Be（Ⅱ） from geological samples. Method was simple, rapid and selective having good reproducibility （approximately4-2%）.

An efficient synthesis of polysubstituted tetrahydropyrimidines using acidic Al_2O_3 as solid media

A series of polysubstituted tetrahydropyrimidines were synthesized in moderate to good yields via a one-pot, four-component reaction of an alkyne, formaldehyde, and amines in solid media acidic Al2O3. The advantages of this protocol include mild reaction conditions, broad substrate scope, and environmentally friendly reaction media.

Multi-component hydrogen-bonding salts formed between imidazole and aromatic acids:Synthons cooperation and crystal structures

Imidazole base was crystallized with different aromatic carboxylic acids 2,4-dihydroxybenzoic acid, 5-chlorosalicylic acid, and 1,8-naphthalic acid, affording three new binary molecular organic salts of [(C 3 H 5 N 2 + )·(C 7 H 5 O 4 )] (1), [(C 3 H 5 N 2 + )·(C 7 H 4 O 3 Cl )] C 7 H 5 O 3 Cl (2), and [(C 3 H 5 N 2 + ) (C 12 H 7 O 4 )] (3). Proton transfer occurs from the COOH of carboxylic acid to nitrogen of imidazole in all complexes (1-3), leading to the hydrogen bond N-H…O in all structures. To our knowledge, the recognition pattern between the carboxylic acid group and imidazole (acid-imidazole synthon) is less well-studied so far. The cooperation among COOH, COO and imidazolium cation functional groups for the observed hydrogen bond synthons is examined in the three structures. Generally, the strong N-H…O and O-H…O hydrogen bonds define supramolecular architecture and connectivity within chains, while weaker C-H…O hydrogen bonds play the dominant role in controlling the interactions between layers in these novel organic salts. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss.

Prediction of vapor-liquid-liquid-hydrate phase equilibrium for multicomponent systems containing tetrahydrofuran

Numbers of hydrate-based new techniques require the algorithm to be able to perform multiphase flash calculation where one phase is a gas hydrate phase.Tetrahydrofuran(THF)is frequently used as a thermodynamic promoter in the development of hydrate-based technique,which can reduce the hydrate formation pressure,especially when methane or hydrogen exists.However,it is a hard work to describe accurately the phase behavior of THF-water system due to their polarities.It has been proved that the water-in-oil(W/O)emulsion can raise the hydrate formation rate and improve the single stage separation efficiency,and furthermore prevent the hydrate from agglomeration to plug the facilities.The goal of this work is to present an extension of our previous work to the prediction of the vapor-liquid-liquid-hydrate equilibrium of such complex systems.These include ternary and quaternary mixtures with W/O emulsion containing THF.The proposed algorithm of four phase equilibrium calculation is very simple due to avoiding the complexity of simultaneous solution of the sophisticated equation group.The calculation results were found to be in satisfactory agreement with the experimental data.