Effects of Shear Fracture on In-depth Profile Modification of Weak Gels

Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the indepth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs, and the weak gels in these two cases became small gel particles after water flooding. The differences were： the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor （FRR） caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack, which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack, while in the quartz sand pack, the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water, the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.

A Laminar Flow Model for Mucous Gel Transport in a Cough Machine Simulating Trachea: Effect of Surfactant as a Sol Phase Layer

In this paper, a planar three layer quasisteady laminar flow model is proposed in a cough machine which simulates mucous gel transport in model trachea due to mild forced expiration. The flow is governed by the time dependent pressure gradient generated in trachea due to mild forced expiration. Mucous gel is represented by a viscoelastic Voigt element whereas sol phase fluid and air are considered as Newtonian fluids. For fixed airflow rate, it is shown that when the viscosity of mucous gel is small, mucous gel transport decreases as the elastic modulus increases. However, elastic modulus has negligible effect on large gel viscosity. It is also shown that for fixed airflow rate and fixed airway dimension, mucous gel transport increases with the thickness of sol phase fluid and this increase is further enhanced as the viscosity of sol phase fluid decreases. The effect of surfactant is studied by considering sol phase as surfactant layer which causes slip at the wall and interface of sol phase and mucous gel. It is found that in the presence of surfactant mucous gel transport is enhanced.

Adsorption behavior of gel-type weak acid resin (110-H) for Pb^(2+)

The adsorption properties of a novel gel-type weak acid resin (110-H) for Pb2+ were investigated using chemical methods and IR spectrometry.The optimal adsorption condition of 110-H for Pb2+ is at pH=6.49 in HAc-NaAc medium and the statically saturated adsorption capacity is 485 mg/g at 298 K.Pb2+ adsorbed on 110-H resin can be eluted with 0.025 mol/L HCl quantificationally.The adsorption rate constants determined under the temperatures of 288,298,308 and 318 K are 2.46×10-5,3.82×10-5,4.46×10-5 and 5.71×10-5 s-1,respectively.The apparent activation energy,Ea,is 18.1 kJ/mol and the thermodynamic parameters of adsorption,ΔH=20.9 kJ/mol,ΔS=161 J/(mol.K) and ΔG298 K =-48.0 kJ/mol,respectively.The adsorption behavior of 110-H resin for Pb2+ accords with the Langmuir isotherm.Infrared spectra show that the oxygen atoms of the functional group of resin coordinate with Pb2+ to form the coordination bands.

The Thermal and Mechanical Properties of Ultra-High Molecular Weight Polyethylene/Montmorillonite (UHMWPE/MMT) Nanocomposites Hybrid Gel Using Pressure-Induced Flow (PIF) Processing

Hybrid organic-inorganic polymer nanocomposites incorporating organically modified montmorillonite (MMT) and ultra-high molecular weight polyethylene (UHMWPE) were examined. UHMWPE/MMT hybrid nanocomposites were prepared using gel and pressure-induced flow(PIF) processing methods at a gel weight concentration of 8% UHMWPE with various organoclay contents (0, 0.4, 0.8, 1.2, and 1.6 parts per hundred parts). The interlayer properties of the nanocomposites were studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The thermal and mechanical interfacial properties of the nanocomposites were investigated through thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and the use of a universal test machine (UTM). TEM indicates that the nanocomposites are formed upon dispersion of MMT in the polymer matrix. From the DSC, TGA, and DMA results, we find that the thermal stability of the UHMWPE nanocomposites increases as the MMT content increases. The nanocomposites show higher tensile strengths than pure UHMWPE gel sheet. These findings indicate that the interfacial and mechanical properties are improved by the addition of MMT and PIF processing.

Criteria for Distinguishing Floc Sedimentation and Gel-Like Network Sedimentation of Cohesive Fine-Grained Sediment in a Turbulent Flow

The study on the criteria used to distinguish floc sedimentation and gel-like network sedimentation of cohesive fine-grained sediment in a turbulent flow has rarely been carried out. In this preliminary study, we derive three criteria to distinguish these two different sedimentation phases by considering the comparison of the time that a characteristic floc takes to settle through mean distance between characteristic flocs and the time that it takes to move through the same distance under the influence of a turbulent flow. These criteria incorporate physical and chemical factors that have been verified to have some influences on the sediment flocculation in some published literatures, and a simple analysis result is found to be consistent with our qualitative understandings of flocculation phenomenon of cohesive fine-grained sediment.

聚乙烯相对分子质量及其分布快速评价方法研究

以国内外采用不同工艺和催化剂生产的17种聚乙烯的测试结果为基础,通过理论推导与模型拟合相结合,建立了以熔体流动速率快速计算相对分子质量及其分布的方法,并由此计算出数均分子量。经验证,该方法准确性较好,可弥补凝胶渗透色谱法的不足,有利于装置生产过程中准确控制产品质量和提高新产品开发效率。

环保型弱凝胶护壁护心钻井液研究与应用

海域浅层气地质调查和盐湖环境科学钻探在松散砂岩钻探取样工程中,存在孔壁易坍塌、成孔率低等技术难题,为此开展了松散砂岩地层环保型弱凝胶护壁护心钻井液技术研究。通过弱凝胶结构研究及成胶剂、交联剂及抗盐降滤失剂等材料优选,研发了一套环保型弱凝胶护壁护心钻井液,评价了钻井液的流变性、滤失性、抑制性、护心性能、环保性能等性能,并在山西某盐湖环境科学钻探工程进行现场应用。室内测试及现场应用结果表明:研制的弱凝胶护壁护心钻井液具有良好的流变性、降滤失性、抑制性(岩屑回收率96.3%)、护壁护心性能及环保性能(BOD5/COD比值24.6%,EC50值47950 mg/L),能有效解决松散砂岩类地层孔壁坍塌、岩屑不易携带等问题,在松散地层钻探工程中具有广阔的应用前景。

无固相弱凝胶射孔液在渤海油田大位移井完井中的应用

为了减少渤海油田完井作业过程中完井液的漏失,缩短返排时间,保障渤海油田大斜度、大位移井作业安全,降低压力亏空地层射孔作业卡枪的风险,此文分析了封堵机理及其特点,研发了无固相弱凝胶射孔液体系,并通过室内实验评价其剪切稀释、触变、封堵、抗温、抑制和返排等性能。实验表明,该体系既可通过形成弱凝胶封堵射孔产生的射孔孔眼,阻止完井液漏失,减少对地层的污染;同时也可提高压力亏空地层的地层承压能力,能有效悬浮地层出砂,防止射孔枪卡钻,还具有易返排的特性。该体系在渤海油田大斜度、大位移井的成功应用,有效满足了大斜度、大位移井射孔作业的需求。应用表明,该体系能大幅减少亏空地层作业过程中完井液的漏失量,缩短油井的返排时间,储层保护效果明显,具有很强的推广意义。

Determination of Trace Non Rare Earth Elements in High Purity Rare Earth Oxides by ICP－AES with Microcolumn Preconcentration in a Flow Injection System

A new method for the determination of trace non-rare earth elements in high purity rare earth oxides by ICP-AES with preconcentration on an active carbon-silica gel microcolumn in a flow injection system is described in this paper. Experimental parameters such as pH, flow rate,reagent concentration,length of reaction coil,eluent acidity,etc. were optimized. In the buffer solution of NH3. H2O/NH4Cl at pH 4. 6,Al,Cr,Cu,Fe, Pb, V and Zn can be preconcentrated and then eluted with 4. 5 mol/L nitric acid utilizing stop-flow technique. The enrichment factors were in range of 8. 1￣12. 6 with detection limits of μg/m level ,and the RSD with metals at μg/g level were 2. 3￣5. 0% (n= 7). The method proposed can reduce the matrix interference effectively , and has been applied to the determination of non-rare earth metals atμg/g level in high purity Eu2O3 with satisfactory results.

碳酸盐岩油藏聚合物凝胶调堵体系的性能评价及应用

针对碳酸盐岩油藏经过长期注水开发后波及效率降低、水窜严重、提高采收率效果差的难题,提出利用流道调整配合注水开发的方法,研发耐温耐盐聚合物凝胶调堵体系,考察其在高温高盐油藏条件下的应用性能。根据油藏条件及剩余油情况分析耐温耐盐聚合物整体调堵可行性。结果表明:体系耐温可达140℃,耐盐2.36×10^(5) mg/L,岩心封堵率为95.21%;采用“两头封堵”(即注水井与采油井同步作业)措施后,含水率由100%下降至50%;施工前、后相同生产时间累积增油800 t,平均日增油5.5 t。

聚醚脂肪酸类油基钻井液提切剂的研制与应用

针对油基钻井液切力低,易导致沉砂卡钻等严重问题的现状,合成了一种聚醚脂肪酸类油基钻井液用提切剂LQZ。利用红外光谱、热重曲线、凝胶强度和界面扩张流变参数等测试方法,分析了提切剂的结构、热稳定性、凝胶性能和作用机理,同时探究了基础油、油水比、密度和温度对其提切效果的影响。结果表明,该提切剂分子中含有羟基、酰胺基、酯基、醚键,能形成网架结构,提高悬浮能力,且具有快速弱凝胶特点;300℃无明显热分解;加量小于0.85%时有利于乳液稳定性;该提切剂对白油基、柴油基和合成基钻井液体系普遍适用,且白油基中效果最好;当钻井液油水比为8∶2、密度为2.1 g/cm^(3)、190℃时提切效率最佳,动切力、φ6及φ3读数和静切力增长约1倍;与国外同类产品相比,LQZ具有提切不增塑性黏度的优势。LQZ在现场页岩油气井应用时,动切力、φ6及φ3读数和静切力基本增加100%,塑性黏度无明显增长。LQZ能够提高油基钻井液悬浮能力,不显著增加塑性黏度,具有很好的推广应用前景。

顺北油气田用抗高温弱凝胶防气侵钻井液体系

顺北油气田奥陶系一间房组和鹰山组的碳酸盐岩储层微裂缝发育且气层活跃,钻井液受气侵严重,主要存在油气上窜速度快,频次高,程度严重,漏涌同存等气侵特点。分析总结了顺北油气田现用防气侵方法和存在的问题,提出使用弱凝胶钻井液体系防气侵的对策。为提高该体系的抗高温性及防气侵效果,研制出高温稳定剂MG-HT、抗高温流型调节剂JHVIS、抗高温降滤失剂JHFLO和耐温封堵剂JHSEAL,并优选了其他配套处理剂,形成一套抗温效果好、堵气和承压能力强的抗高温弱凝胶防气侵钻井液体系。该体系抗温可达180℃,密度可达1.8 g/cm^(3),具有较好的流变性、降滤失性和抗污染性;此外,体系的φ6和φ3读数均大于5,低剪切速率黏度大于15 000 mPa·s,正向承压能力大于5 MPa,反向承压能力高于1MPa,具有良好的防气侵效果。为顺北油气田碳酸盐岩裂缝性储层的安全、快速勘探和开发提供了技术支持。

海上高含水大液量水平井凝胶堵水数值模拟

复杂条件下的水平井化学堵水不可控因素多,施工条件苛刻,堵水成功率低。针对这些问题,文中采用物理实验及数值模拟,开展岩心尺度纳米酚醛凝胶堵水效果研究,建立了考虑交联反应、吸附理论的凝胶堵水机理模型,通过实验数据拟合,获取了Langmuir等温吸附系数、岩石最大吸附量和残余阻力系数等关键参数。以文昌19-1油田典型大液量(大于1000 m^(3))、高含水率(大于90%)水平井——A8H1井为例,通过近井地带网格加密建立单井堵水数值模型,开展水平井凝胶堵水效果影响因素研究。结果表明:堵剂用量受实际油藏岩石的吸附水平限制,A8H1井最优堵剂用量为250 m^(3);油井含水率越低,生产压差和地层渗透率级差越小,水平井凝胶堵水效果越好。研究成果可为类似复杂水平井凝胶堵水选井及工艺方案设计提供参考。

耐温耐盐聚合物弱凝胶体系制备及性能评价

针对长期水驱后造成非均质性越发严重的高温高矿化度老油田,以华北油田为研究对象,以丙烯酰胺和丙烯酸为主要反应单体,并引入了耐温耐盐单体NVP、疏水功能单体,通过共聚反应合成了具有疏水功能聚合物,并与酚醛树脂交联剂发生交联反应制备了耐温耐盐弱凝胶体系,研究了弱凝胶的耐温耐盐、注入性、封堵性能及液流转向能力。研究结果表明,当聚合物质量浓度为2000 mg/L、聚交比为1∶1.5、助剂过硫酸胺质量浓度为2000 mg/L,在油藏温度为120℃、注入水矿化度为40 300.86 mg/L的条件下,所形成的弱凝胶具有良好的耐温耐盐性能,成胶强度大于1000 mPa·s,且90 d后的黏度平均保留率达80%以上,且90 d后弱凝胶的微观网络骨架明显、稳定性良好。岩心流动实验结果表明,弱凝胶体系的注入性良好,在不同渗透率级差下,弱凝胶封堵后,液流转向效果明显,低渗层分流率增幅最高达48.33%,吸水剖面改善能力良好。通过对不同渗透率的填砂管进行封堵,填砂管各测压点依次起压,弱凝胶运移能力良好且封堵率均达85%以上。

导声垫在自体动静脉内瘘狭窄超声检查中的应用研究

目的 探讨导声垫在自体动静脉内瘘狭窄超声检查中的应用价值。方法 对31例自体动静脉内瘘静脉通路狭窄患者行上肢血管超声检查,在分别使用耦合剂、应用导声垫情况下采集数据,对比使用不同透声媒质时静脉内径测量的可重复性,以及评估狭窄处内径与肱动脉流量的相关性。结果 31例均为腕部桡动脉-头静脉端侧吻合,4例狭窄处位于瘘口头静脉端,27例狭窄处位于头静脉前臂段;使用耦合剂测量狭窄处内径(1.41±0.45)mm,使用导声垫测量狭窄处内径(1.89±0.53)mm,差异具有统计学意义(t=-3.806,P<0.001)。耦合剂组观察者间ICC为0.887(95%CI:0.761~0.946,P<0.001),导声垫组观察者间ICC为0.974(95%CI:0.948~0.988,P<0.001)。多普勒超声测量上臂中段肱动脉流量为(381.29±159.77)ml/min,使用耦合剂和使用导声垫测量狭窄处内径与肱动脉流量均呈显著相关(r=0.765、0.817,均P<0.001)。结论 自体动静脉内瘘静脉通路狭窄患者行上肢血管超声检查时,使用导声垫可减少静脉受压形变,且测量静脉内径的可重复性高于使用耦合剂,其测值与肱动脉流量相关性更好。

电针夹脊穴联合祛风骨痛凝胶膏治疗2型糖尿病足气虚血瘀证临床研究

目的:观察电针夹脊穴联合祛风骨痛凝胶膏治疗2型糖尿病足气虚血瘀证患者的临床效果。方法:选择2型糖尿病足气虚血瘀证患者80例,以随机数字表法分为对照组(n=40)、治疗组(n=40)。治疗组采用电针夹脊穴联合祛风骨痛凝胶膏治疗;对照组应用电针夹脊穴治疗。比较两组患者临床症状积分、血液流变学指标、微循环血流情况。结果:治疗组的总有效率92.50%高于对照组的总有效率87.50%,差异有统计学意义(P<0.05)。治疗4周后,两组患者皮肤温度、疼痛程度、麻木程度、皮肤色泽、间歇性跛行距离的积分均较治疗前降低,且治疗组低于对照组,差异有统计学意义(均P<0.05)。治疗组血液流变学指标低于对照组,两组足背温度、温控血流、阻断后反应性充血、经皮氧分压均高于治疗前,且治疗组高于对照组,差异有统计学意义(均P<0.05)。结论:电针夹脊穴联合祛风骨痛凝胶膏能有效改善2型糖尿病足气虚血瘀证患者的临床症状,降低血液黏度,改善微循环血流状态,临床应用安全、作用持久。

颗粒性质对凝胶流变性的影响

颗粒性质能够显著改善凝胶性能,为分析颗粒性质对凝胶流变性的影响,以瓜尔胶基水凝胶和玻璃微珠、氧化铝粉、炭粉等颗粒为原料,利用激光粒度仪、扫描电子显微镜、真密度分析仪和旋转流变仪等开展了研究。通过考察颗粒粒径、形状、密度和浓度等参数,揭示了颗粒的加入对凝胶表观黏度和屈服应力等性能的影响。结果表明,凝胶中加入颗粒会显著增加其黏度;凝胶的黏度随颗粒粒径的增大而增加,随颗粒界面粗糙度的增加而增加,随颗粒真实密度的增加而减小;凝胶的屈服应力与其黏度的变化规律相似。研究结果可为凝胶流变性的调控提供参考。

基于双流体喷嘴的磁性琼脂糖微球的制备及其蛋白吸附性能探究

针对现有磁性琼脂糖微球(MAM)制备技术工艺流程长、重复性差、难以实现规模化及连续化生产等问题,提出了一种基于双流体喷嘴雾化技术的新型磁性琼脂糖微球制备方法;探究了不同雾化条件下,液滴尺寸变化的规律;在优化后的喷雾条件下,成功制备出球形度高、粒径小、磁响应迅速的磁性琼脂糖微球;将筛分后的微球制备成DEAE阴离子交换剂(DEAE-MAM),并以牛血清白蛋白(BSA)为模型蛋白,探究了不同粒径下的DEAE-MAM的蛋白吸附性能。结果表明,在保证水相性质一致的前提下,喷雾条件通过改变气液比影响液滴尺寸,进而影响微球粒径;粒径最小的DEAE-MAM(d_(32)=36μm)离子交换容量最大(192.5μmol/ml),饱和吸附量最高(150.0 mg/ml)。

抗高温高黏弹性凝胶调剖体系研究与应用

柳160-1断块属于复杂断块油藏,随着长期注水开发,已形成优势渗流通道,驱替效率低,无效注水循环严重,多轮次调剖效果逐渐变差;纵向上多层合采合注,层间矛盾突出,剖面动用程度低。为了有效封堵优势渗流通道,深部液流转向,提高油藏波及面积,针对油藏开发及储层发育特点,有针对性地开展抗高温高黏弹性凝胶调剖体系封堵实验研究。室内实验结果表明,该体系具有较好的耐温抗盐性能和封堵性能。矿场试验表明,通过实施深部调剖,油藏各系开发指标显著提升,对高渗透层封堵效果好,可有效改善吸水剖面,动用程度提高2.3个百分点,多向见效比例提升1.3%,放大生产压差8.5MPa,提高波及系数0.06个百分点,单井初期日增油9.4t,综合含水率下降2.5个百分点,阶段累计增油2756t。该类深部调剖技术的成功应用对同类型油藏稳油控水具有重要意义。