Characteristics of water alternating CO_(2)injection in low-permeability beach-bar sand reservoirs

Water flooding can be ineffective in highly heterogeneous low-permeability beach-bar sand reservoirs.The introduction of CO_(2)flooding helps boost the oil production of the reservoirs but only in an early stage.During the late stage of flooding,gas channeling would occur.Water alternating gas(CO_(2))(WAG)process can be used to delay gas channeling and improve the effect of CO_(2)injection,though its adaptability to beach-bar sand reservoirs remains unclear.In order to clarify CO_(2)injection characteristics in these reservoirs,experiments were carried out in high-temperature high-pressure NMR on-line displacement experiment apparatus to simulate different flooding modes on synthetic cores that can reflect the vertical heterogeneity of beach-bar reservoirs.Different CO_(2)injection modes were implemented on these cores and the displacement characteristics and residual oil distribution features during both WAG injection and continuous CO_(2)injection were analyzed quantitatively and qualitatively.The results show that the scheme of WAG injection after continuous CO_(2)injection can obtain better oil displacement efficiency than that of the scheme of continuous CO_(2)injection after WAG injection,but there is no significant difference in respect of oil displacement efficiency of WAG flooding between the mode of bar-injection e beach-production(injection into bar sand e production from beach sand)and the mode of beach-injection e beach-production(injection into and production from beach sand),with the former mode having a higher oil recovery rate.The wider pore-size distribution range of microscopic residual oil after WAG injection shows great potential of enhancing oil recovery from subsequent continuous gas injection.When WAG injection is implemented prior to continuous CO_(2)injection,the displacement effect of the latter is more significant.This research may provide a theoretical basis for CO_(2)EOR in this type of reservoirs.

Tar formation characteristic of integrated process of coal pyrolysis with dry reforming of low carbon alkane over Ni/La_(2)O_(3)-ZrO_(2)

Coal pyrolysis integrated with dry reforming of low-carbon alkane(CP-DRA)is an effective way to improve tar yield.Ni/La_(2)O_(3)-ZrO_(2) with a La/Zr ratio of 4 was a good catalyst for DRA to inhibit carbon deposition and obtain high tar yield in CP-DRA.In this study,the fraction distribution and component of tars from CP-DRA and coal pyrolysis in N_(2) atmosphere(CP-N_(2))were characterized by using several methods to understand the effect of DRA on coal pyrolysis.The isotope trace method was also used to discuss the role of low-carbon alkane in CP-DRA.The results showed that the tar from CP-N_(2)is mainly composed of aliphatic compounds with more C_(al),H_(al) and CH+CH_(2),and the tar from CP-DRA contains more Car,Har,and CH_(3),and has lower weight-average molecular weight and more light tar content than CP-N_(2).A small amount of C_(2)H_(6) addition in CP-DRA will raise the ratio of H_(β) and CH+CH_(2).Electron paramagnetic resonance(EPR)analysis shows that the tar from CP-DRA has a higher radical concentration while the corresponding char has a lower radical concentration.The isotope trace experiment showed that alkanes provide·H,·CH_(3),etc.to stabilize the radicals from coal pyrolysis and result in more alkyl aromatic compounds during CP-DRA.

Development of Superhydrophobic Nano-SiO_(2)and Its Field Application in Low-permeability,High-temperature,and High-salinity Oil Reservoirs

In this study,to meet the stringent requirements on the hydrophobicity of nano-SiO_(2)particles for use in depressurization and enhanced injection operations in high-temperature and high-salinity oil reservoirs,secondary chemical grafting modification of nano-SiO_(2)is performed using a silane coupling agent to prepare superhydrophobic nano-SiO_(2) particles.Using these superhydrophobic nano-SiO_(2)particles as the core agent,and liquid paraffin or diesel as the dispersion medium,a uniform dispersion of nano-SiO_(2)particles is achieved under high-speed stirring,and a chemically enhanced water injection system with colloidal stability that can be maintained for more than 60 d is successfully developed.Using this system,a field test of depressurization and enhanced injection is carried out on six wells in an oilfield,and the daily oil production level is increased by 11 t.The cumulative increased water injection is 58784 m^(3),the effective rate of the measures was 100%,and the average validity period is 661 d.

Interfacial built-in electric field and crosslinking pathways enabling WS_(2)/Ti_(3)C_(2)T_(x) heterojunction with robust sodium storage at low temperature

Developing efficient energy storage for sodium-ion batteries(SIBs)by creating high-performance heterojunctions and understanding their interfacial interaction at the atomic/molecular level holds promise but is also challenging.Besides,sluggish reaction kinetics at low temperatures restrict the operation of SIBs in cold climates.Herein,cross-linking nanoarchitectonics of WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,featuring built-in electric field(BIEF),have been developed,employing as a model to reveal the positive effect of heterojunction design and BIEF for modifying the reaction kinetics and electrochemical activity.Particularly,the theoretical analysis manifests the discrepancy in work functions leads to the electronic flow from the electron-rich Ti_(3)C_(2)T_(x) to layered WS_(2),spontaneously forming the BIEF and“ion reservoir”at the heterogeneous interface.Besides,the generation of cross-linking pathways further promotes the transportation of electrons/ions,which guarantees rapid diffusion kinetics and excellent structure coupling.Consequently,superior sodium storage performance is obtained for the WS_(2)/Ti_(3)C_(2)T_(x) heterojunction,with only 0.2%decay per cycle at 5.0 A g^(-1)(25℃)up to 1000 cycles and a high capacity of 293.5 mA h g^(-1)(0.1A g^(-1)after 100 cycles)even at-20℃.Importantly,the spontaneously formed BIEF,accompanied by“ion reservoir”,in heterojunction provides deep understandings of the correlation between structure fabricated and performance obtained.

Solid-state NMR study on sodium intercalation at low voltage window for Na_(3)V_(2)(PO_(4))_(3) as an anode

In-situ XRD,^(31)P NMR and ^(23)Na NMR were used to analyze the interaction behavior of Na_(3)V_(2)(PO_(4))_(3) at low voltage,and then a new intercalation model was proposed.During the transition from Na_(3)V_(2)(PO_(4))_(3) to Na_(4)V_(2)(PO_(4))_(3),Na ions insert into M1,M2 and M3 sites simultaneously.Afterwards,during the transition of Na_(4)V_(2)(PO_(4))_(3)to Na_(5)V_(2)(PO_(4))_(3),Na ions mainly insert into M3 site.

Low-temperature NO_2 sensors based on polythiophene/WO_3 organic-inorganic hybrids

Polythiophene （PTP） was prepared by a chemical oxidative polymerization and nanosized WO3 was prepared by a colloidal chemical method. The organic-inorganic PTP/WO3 hybrids with different mass fractions of PTP were obtained by a simple mechanically mixing the prepared PTP and WO3. The as-prepared PTP/WO3 hybrids have a higher thermal stability than the pure PTP. The gas sensing measurements demonstrate that the PTP/WO3 hybrid sensors exhibit higher response for detecting NO2 at low temperature than the pure PTP and WO3 sensor. The sensing mechanism is suggested to be related to the existence of p-n heterojunctions in the PTP/WO3 hybrids. The response of the PTP/WO3 hybrids is markedly influenced by the PTP mass fraction. The 20% PTP/WO3 hybrid shows high response and good selectivity to NO2 at low temperature （〈90℃）. Therefore, the PTP/WO3 hybrids can be expected to be potentially used as gas sensor material for detecting NO2 at low temperature.

Effects of Low Dose Radiation on Tumor Apoptosis, Cell Cycle and Apoptosis-Related Protein Bcl-2 in Tumor-Bearing Mice

To study the effects of low dose radiation (LDR) on tumor apoptosis, cellcycle progression and changes of apoptosis-related protein Bcl-2 in tumor-bearing mice. Methods:Male mice of Kunming strain were implanted subcutaneously with S180 sarcoma cells in the left inguenas an in situ experimental animal model. Seven days later, the mice were subjected to 75 mGywhole-body γ-irradiation. At 24 and 48 h after the irradiation, all mice were sacrificed. The tumorsizes were measured, and tumor cell apoptosis and cell cycle progression were analyzed by flowcytometry. The expression of apoptosis-related protein Bcl-2 and the apoptotic rate of tumor cellswere observed by immunohistochemistry and electron microscopy. Results: Tumors grew significantlyslower after LDR (P 【 0.05). The tumor cells were arrested in G1 phrase and the expression of Bcl-2protein decreased at 24 h. Apoptotic rate of tumor cells was increased significantly at 48 h afterLDR (P 【 0.01). Conclusion: LDR could cause a G1-phase arrest and increase the apoptosis of tumorcells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. Theorganized immune function and anti-tumor ability are markedly increased after LDR. Our studyprovides practical evidence of clinical application to cancer treatment.

来宾冶炼厂矾渣挥发窑低浓度SO_2烟气处理

研究采用锌沸腾炉烟尘吸收来宾冶炼厂矾渣挥发窑低浓度SO2 烟气。结果表明 ,SO2 吸收率随着锌焙尘浆液pH值的降低下降较快 ,随着浆液总Zn量的增加先升后跌 ,总Zn量为 90 g/L时 ,吸收率最高。控制浆液pH值在 5 0左右 ,单塔 (一块塔板 )吸收率可达 65 %～ 75 %。采用 3级吸收 ,SO2 总吸收率 >98% ,排放尾气中SO2 <80 0mg/L ,符合国家排放标准。吸收浆液ZnSO3加硫酸分解 ,放出的SO2 气体送制酸系统 ,溶液送锌系统处理。

肾移植患者外周血中的CD4~＋ CD25~＋ CD127^(low/-)调节性T细胞

背景:越来越多的实验在分析免疫耐受标志,以期能够更好地辅助患者进行移植后免疫抑制治疗。目的:分析肾移植后患者外周血中CD4+CD25+CD127low/-调节性T细胞在肾移植免疫耐受中的作用。方法:采集62例肾移植后患者(急性排斥反应组22例,移植稳定组40例)及20例健康对照者的外周抗凝血,经免疫染色,应用流式细胞仪分析CD4+CD25+CD127low/-调节性T细胞所占CD4+T细胞百分含量,同时采用ELISA方法检测患者血清中白细胞介素2和白细胞介素10的质量浓度。结果与结论:移植稳定组中CD4+CD25+CD127low/-调节性T细胞所占CD4+T细胞百分含量显著高于健康对照组和急性反应排斥组(P<0.01);CD4+CD25+CD127low/-调节性T细胞百分含量与白细胞介素2呈显著负相关(P<0.05),与白细胞介素10呈显著正相关(P<0.01)。提示CD4+CD25+CD127low/-调节性T细胞在肾移植后免疫耐受的机制中发挥了一定作用。

光导纤维化学发光传感器传感原理研究(Ⅰ)——低浓度 SO_2 传感器

本文研制了一种测定低浓度ＳＯ２的光导纤维化学发光传感器。研究了ＳＯ２敏化鲁米诺—Ｈ２Ｏ２体系化学发光反应的原理，研究了鲁米诺—ＣｌＯ－电生化学发光体系测定低浓度ＳＯ２的原理。该测定体系结构简单，不需任何光源，测定低浓度ＳＯ２，线性良好，重现性好，响应快。

不同矿浆温度下Ca^(2+)、Mg^(2+)对黄铁矿可浮性的影响

这是一篇矿物加工工程领域的论文。通过单矿物浮选实验、浮选溶液化学、Zeta电位、XPS,研究了不同矿浆温度下Ca^(2+)、Mg^(2+)对黄铁矿浮选效果的影响机理,结果表明:低温能够明显抑制黄铁矿的浮选,且温度降低能够明显弱化Ca^(2+)、Mg^(2+)对黄铁矿浮选的抑制作用。当矿浆温度从20℃降至5℃时,矿浆中带电粒子运动速度减慢,Zeta电位增大,生成氢氧化钙镁沉淀的临界pH值增大,纯水矿浆中黄铁矿表面的FeO/OH的比例减小,Ca^(2+)、Mg^(2+)矿浆中黄铁矿表面FeO/OH含量的降低幅度减小,减少了黄铁矿表面的氧化程度和活性吸附位点,减少了Ca^(2+)、Ca(OH)+,Mg^(2+)和Mg(OH)+等离子在黄铁矿表面的吸附;但低温并不改变Ca^(2+)、Mg^(2+)在黄铁矿表面的存在形式和吸附状态,pH值为9时,钙镁均以Ca^(2+)、Ca(OH)+、Mg^(2+)、Mg(OH)+的形式存在并吸附在黄铁矿表面。

一种基于“四区”的低渗透油藏CO_(2)埋存量计算方法及应用

CO_(2)驱油和埋存能有效减少温室气体排放量达到碳中和目标,已有的CO_(2)埋存量计算方法主要针对CO_(2)的静态埋存量进行粗略计算,未考虑实际生产过程中CO_(2)埋存量的变化。针对上述问题,运用CO_(2)溶解、CO_(2)波及体积和驱油机理,将CO_(2)驱油与埋存过程分为气相区、两相或近混相区、扩散区和油相区,并基于“四区法”计算CO_(2)埋存量,得到了不同烃类的注入孔隙体积倍数、注入压力、注气速度下的CO_(2)动态埋存量的变化规律。将研究成果应用于W油田低渗储层,结果表明:注入烃类孔隙体积倍数、压力、注气速度与总埋存量呈正相关性,当压力由12 MPa升至30 MPa,CO_(2)埋存总量增加15.53×10^(4)t;当注气速度由5 t/d增加至30 t/d,峰值CO_(2)埋存总量由3.51×10^(4)t提高至12.62×10^(4)t。研究成果可为同类油藏开展CO_(2)驱油与埋存项目提供新的思路。

低渗砂岩油田CO_(2)驱化学机理及提高采收率研究

针对低渗砂岩油藏进行了CO_(2)驱开发技术研究,分析了CO_(2)驱油化学机理及主要影响因素。基于目标油藏流体特征进行了PVT拟合,确定其CO_(2)驱最小混相压力,明确了不同压力及注入时机对CO_(2)驱采收率、气油比、含水率及驱动压差等的影响规律,探究了CO_(2)泡沫驱在提高采收率方面的效用。结果表明:24.5 MPa为目标区域CO_(2)驱的最小混相压力,采收率会随着压力的升高而增加,28 MPa时CO_(2)驱提高采收率可达30.57%。气体突破时间、总采收率与CO_(2)注入时机密切相关,CO_(2)注入越早,越有利于采收率的提高,出口含水率为60%时注入可提高采收率39.13%。CO_(2)泡沫驱可以在一定程度上起到提高采收率的效用。

中深层稠油水平井前置CO_(2)蓄能压裂技术

利用准噶尔盆地西北缘乌夏地区中深层稠油油藏参数,对水平井前置CO_(2)蓄能压裂技术的开发机理、关键操作参数及开发效果进行了详细研究。研究结果表明:①伴随压裂—焖井—生产等开发阶段的延伸,前置CO_(2)蓄能压裂后的油井逐步显现出增能改造、扩散降黏、膨胀补能、释压成泡沫油流等特性,井底流压提高了2~4MPa,CO_(2)扩散至油藏的1/3,原油黏度降至500mPa·s以下,泡沫油流明显;②研究区最优压裂段间距为60m、裂缝半长为90m、裂缝导流能力为10t/m,CO_(2)最佳注入强度为1.5m3/m,注入速度为1.8m3/min,油井焖井时间为30d,油藏采收率提高了2%~3%;③通过与常规压裂生产效果进行对比,前置CO_(2)蓄能压裂技术可使产油量提高5.2t/d,预测CO_(2)换油率达2.45,开发效果显著提升。

苍柴调中方辅助改善肝郁脾虚型肥胖2型糖尿病的疗效及对胰岛素抵抗、FFA、LDL-C水平的影响

目的:探讨苍柴调中方辅助改善肝郁脾虚型肥胖2型糖尿病(T2DM)的疗效,并分析其对胰岛素抵抗、游离脂肪酸(FFA)、低密度脂蛋白胆固醇(LDL-C)水平的影响。方法:选取2020年4月至2023年4月该院收治的肝郁脾虚型肥胖T2DM患者100例,根据随机数字表法分为两组,各50例。对照组患者使用二甲双胍治疗,观察组患者在对照组基础上联合苍柴调中方辅助治疗。观察两组患者的治疗效果,比较两组患者治疗前后中医症状积分、糖代谢指标[空腹血糖(FBG)、空腹胰岛素(FINS)、胰岛素抵抗指数(HOMA-IR)]、血清FFA、LDL-C、肿瘤坏死因子α(TNF-α)水平的差异,并对不良反应发生率进行统计。结果:观察组患者的治疗总有效率高于对照组,不良反应发生率低于对照组,差异均有统计学意义(P<0.05)。治疗后,观察组患者倦怠乏力、精神抑郁、脘腹闷胀及大便黏滞等中医症状积分均低于对照组,差异均有统计学意义(P<0.05)。与治疗前比较,两组患者治疗后的FBG、HOMA-IR、FINS水平均明显降低,其中观察组患者治疗后的FINS、FBG及HOMA-IR水平低于对照组,差异均有统计学意义(P<0.05)。观察组患者治疗后的血清LDL-C、FFA、TNF-α水平均低于对照组,差异均有统计学意义(P<0.05)。结论:苍柴调中方辅助治疗可明显提高肝郁脾虚型肥胖T2DM患者的治疗效果,改善胰岛素抵抗,下调血清FFA、LDL-C水平。

复合添加MgO和La_(2)O_(3)对纳米微晶氧化铝陶瓷微观结构的影响

纳米微晶氧化铝磨料具有良好的通用性和高精度磨削能力,且性价比较高,在机械制造、轴承、模具、汽车等领域有广泛的应用潜力。本研究以勃姆石(γ-AlOOH)为原料,MgO、La_(2)O_(3)为添加剂,采用溶胶-凝胶工艺合成纳米微晶氧化铝。通过差示扫描量热仪、X射线衍射仪、扫描电子显微镜和从头算分子动力学方法模拟计算研究了添加剂对微晶氧化铝相转化、物相组成、微观结构及力学性能的影响。结果表明:复合添加MgO和La2O3可以使氧化铝中间相θ-Al_(2)O_(3)向α-Al_(2)O_(3)转化的温度从1257℃降低到1105℃,将致密化温度从1600℃降低到1350℃,将微晶氧化铝的晶粒尺寸从1.04 mm减小到120 nm,实现了低温致密烧结。

胜利油田CO_(2)高压混相驱油与封存理论技术及矿场实践

针对胜利油田开展CO_(2)驱油与封存面临的原油轻烃含量低混相难、储层非均质性强波及效率低、易气窜全过程调控难等问题,通过室内实验、技术攻关和矿场实践,形成CO_(2)高压混相驱油与封存理论及关键技术。研究发现,提高地层压力至1.2倍最小混相压力之上,可以提高原油中的中重质组分混相能力,增大小孔隙中的原油动用程度,均衡驱替前缘,扩大波及体积。通过超前压驱补能实现快速高压混相,采用梯级气水交替、注采耦合、多级化学调堵等技术全过程动态调控渗流阻力,实现采收率与封存率的协同最优。研究成果应用于高89-樊142 CCUS(二氧化碳捕集、利用与封存)示范区,区块日产油由254.6 t提高至358.2 t,预计实施15年可提高采出程度11.6个百分点,为CCUS规模化应用提供理论和技术支撑。

利用化学助剂强化CO_(2)埋存实验设计

结合储层CO_(2)埋存技术,自主搭建了地层温度压力条件下CO_(2)埋存实验装置,开展了多介质辅助CO_(2)埋存实验研究。研究结果表明,乙醇-KOH体系能够有效进行CO_(2)矿化埋存,其中96%乙醇+3 g KOH 500 mL溶液捕集CO_(2)能力最强,是最佳的CO_(2)矿化埋存溶液配比。经CO_(2)矿化埋存后,低渗透岩心孔隙度平均降低7.07%,孔隙度变化率与孔隙度呈正相关关系,渗透率平均降低16.01%。因此,96%乙醇+3 g KOH能够加速CO_(2)在储层中的CO_(2)沉淀过程,缩短CO_(2)在储层中的矿化埋存时间。该研究可重复性、准确性和可扩展性较强,能够激发学生自主设计实验的积极性及创新意识,培养学生的独立思考能力,有利于学生将理论知识与实际工程问题相结合,实现科研能力与创新能力的相互促进。

氧化型低密度脂蛋白对2型糖尿病合并肺结核患者的风险评估价值

目的探讨氧化型低密度脂蛋白(oxLDL)对2型糖尿病(T2DM)合并肺结核(PTB)患者的风险评估潜力。方法前瞻性纳入2022年6月至2023年6月门诊就诊的单纯高脂血症组病例60例、PTB组病例100例、T2DM组病例100例和T2DM合并PTB组病例100例,其中PTB组、T2DM组和T2DM合并PTB组再二次分组为血脂正常亚组40例和高脂血症亚组60例,共计360例为病例组;健康人群60例为对照组;入组年龄段为35~70岁。各组均采集静脉血,检测血液中的HbA1C、INS、FSG、TC、TG、HDL、LDL、ApoA I和Apo B,并采用ELISA法检测oxLDL,比较各组间的水平差异。应用多元logistic回归分析oxLDL水平与PTB和T2DM合并PTB的关联。结果T2DM高脂血症亚组的BMI、血糖、血脂和胰岛素抵抗等情况与T2DM合并PTB高脂血症亚组对比差异均无统计学意义(P>0.05);T2DM高脂血症亚组oxLDL水平高于对照组2倍以上,其血脂正常亚组的oxLDL水平显著高于对照组(P<0.05);T2DM合并PTB高脂血症亚组和单纯高脂血症组的oxLDL水平均显著高于对照组2倍以上,但与PTB高脂血症亚组相比,差异均无统计学意义(P>0.05)。相关性分析显示,T2DM高脂血症亚组和T2DM合并PTB高脂血症亚组的TG和LDL均与oxLDL呈显著正线性相关(R=0.352,P<0.05),PTB高脂血症亚组人群的CHOL和LDL均与oxLDL呈显著正线性相关(R=0.441,P<0.05);多元logistic回归分析显示oxLDL高于对照组2倍以上水平均是PTB和T2DM合并PTB的独立危险因素(均P<0.05)。结论显著升高的oxLDL水平可能是T2DM和PTB共病的危险因素,建议对oxLDL高于对照组2倍以上水平作为一个有临床意义的病理水平去进一步评估。

H_(2)S/CO_(2)共存环境中X65钢点腐蚀形成机理及预测方法

碳钢管材广泛应用于油气生产系统,在含CO_(2)、H_(2)S、氯离子等多种腐蚀介质共存的多相流环境中,容易发生腐蚀穿孔泄漏,可能造成管道和设备的失效,进而带来安全隐患和经济损失。目前针对H_(2)S/CO_(2)共存环境下金属腐蚀的研究主要集中在较高H_(2)S分压下,多种形式FeS产物的生成规律、产物膜保护特性和点蚀形成机理,很少研究极微量H_(2)S诱发点腐蚀的可能性和发生条件。为此,以X65钢为例,利用大型H_(2)S多相流腐蚀环路实验系统完成了4组测试实验和2组验证实验,研究了40℃、恒定CO_(2)分压环境下,不同H_(2)S分压对低碳钢点腐蚀行为的影响规律,并提出了一种基于热力学理论的预测方法。研究结果表明:①当H_(2)S分压高于50 Pa时,X65钢的腐蚀速率低且表现为全面腐蚀;而当H_(2)S分压低于24 Pa时,随着H_(2)S分压的逐步降低,X65钢的点腐蚀加剧,H_(2)S为2.4 Pa时的点腐蚀速率超过11 mm/a。②当H_(2)S分压极低且马基诺型FeS的过饱和度低于1时,快速形成的FeS膜不能完整覆盖金属表面,暴露表面会在电偶腐蚀的作用下,被饱和CO_(2)溶液快速腐蚀,最终导致低碳钢发生局部点腐蚀。③建立不同H_(2)S分压下低碳钢表面马基诺型FeS过饱和度边界控制曲线,可以准确预测不同条件下碳钢的点腐蚀行为。结论认为,在相关行业标准规定的H_(2)S分压下限以内,H_(2)S/CO_(2)共存环境中极微量的H_(2)S仍然可能会诱发碳钢发生点腐蚀,该认识对于H_(2)S/CO_(2)共存环境下油气管道的局部点腐蚀预测和防腐防护研发具有重要理论和现实意义。