发动机温度过高故障的预防与排除

介绍了发动机温度过高导致的故障现象，并就其危害做了阐述，对水冷发动机温度过高的故障诊断分五步进行了详细论述，最后对发动机水冷系的保养提出建议。     

支撑剂单颗粒沉降速率与线性胶压裂液黏弹性关系

通过线性胶压裂液中的单颗粒支撑剂静态沉降实验,研究黏弹性对支撑剂沉降速率的影响,并尝试用线性胶压裂液内部结构的表征解释所得结论。结果表明,支撑剂单颗粒沉降速率都随着黏弹性模量的增大而减小。对于羟丙基瓜尔胶HPG和纤维素FAG-500线性胶,以黏性为主,耐高温聚合物XST239线性胶黏性和弹性相当,此3种液体悬砂能力是黏性和弹性综合作用的结果,所以与复模量G*拟合相关系数最高,拟合结果分别为lgu=-1.6928lg G*+0.2468、lgu=-0.9214 lg G*-0.1824、lgu=-0.8307 lg G*-0.2132。低浓度速溶黄原胶XCD溶液以弹性为主,支撑剂沉降速率由弹性模量决定,lgu=-2.0426 lg G'-0.1286,场发射冷冻扫描电镜FE-SEM表征分析表明,XCD液体内部为蜂窝结构,XST239液体内部是非常密集的片层结构,HPG和FAG-500液体内部为疏松的片层结构。     

Discussion on rheology in petroleum and nature gas teservoir stimulation

Petroleum and nature gas not only are important resources,but also are important strategic materials of our country.All methods the enhancing the producing degree of petroleum and natural gas reservoir,increasing single well production and extending the stimulation period of validity are important stratagem for petroleum and natural gas exploitation.Fracturing and acidizing are the main methods for stimulation as well as one of representative examples of rheology theory application in engineering.Based on analysis of low permeability reservoir characteristics,the fracturing and acidizing stimulation principles and main controlling factors were discussed.And the mechanical characteristics,chemical reaction and rheological behavior in the stimulation process were reviewed.Furthermore research trends afterwards including the material and fluid rheology in oil and natural gas production process,the deep rock fracture initiation and extension rheology,and the fracturing and acidizing application rheology were also proposed in this paper.     

Study of rheological characterization off enugreek gum with modified maxwellmodel

1 INTRODUCTIONFenugreek,i.e.trigonella foenum-graecum,is an an-nual herbaceous plant of leguminosae,which arewidely planted in China.Fenugreek seed consists oftesta,endosperm and plumula cotyledon.Fenugreekgum is taken from endosperm,which contains morethan 60% galactomannans with the ratio of galac-tose to mannose 1:1.2.It is soluble in water,aque-ous acid and alkali,respectively,and insoluble in or-ganic solvents.It is a natural polysaccharide whichis composed of a linear backbone of 1-4 β linkedD-mannose units with 1-6 αlinked D-galactoseunits attached as side chains.Its molecular formulais (C_6H_(10)O_5)_n.H_2O.Its structure can be showed asFig.1.Its molecular weight is about 2.5 x 10~5to l.3 x 10~5 that is determined by measuring theviscosity.In practice,due to possessing the advan-tages of low friction resistance,low damage to the     

页岩水力裂缝形态的大尺度物模实验——本研究认识对页岩现场体积压裂具普遍参考价值

近年来,美国页岩气开发技术日趋成熟,特别是水平井钻井技术和大规模体积压裂技术,更使开卷有益国成为世界第一天然气生产国,也带来了全球性的页岩气革命。     

粘弹性清洁压裂液的作用机理和现场应用

常规水基压裂液破胶后具有较高的残渣量,对支撑裂缝伤害较大,在一定程度上影响了油气田的产量.研究开发出了新型的VES清洁压裂液体系,它是由VES粘弹性表面活性剂和水或盐水组成.该压裂液集粘弹性、抗剪切性、自动破胶性于一体.通过分析VES清洁压裂液的粘弹性形成机理、抗剪切机理、携砂机理、破胶机理、滤失机理、伤害机理,表明粘弹性清洁压裂液具有独特的分子结构和独特的流变性能,它具有配制简便,使用添加剂种类少,不存在残渣,对储层伤害小等特点.现场实验表明,清洁压裂液具有破胶性能,施工摩阻低,携砂能力强,可有效地控制缝高.与使用水基压裂液的邻井相比,粘弹性清洁压裂液压裂施工后增产效果明显.     

粘弹性胶束压裂液的形成与流变性质

由C16、C18烷基三甲基季铵盐和助剂配制了压裂用表面活性剂VES 60。考察了VES 60/水及其他体系形成胶束凝胶的能力。得到了一种蠕虫状胶束和一种片状胶束的环境扫描电镜照片。测定了体积分数(下同)为5%的CTAC与NaSal、NaSal+KNO3水溶液形成的胶束凝胶的粘度(70℃)随剪切速率的变化,讨论了两种盐之间的协同作用。在不同温度(10～40℃)和10s-1下,4%VES 60水溶液形成胶束的动力学包括三个阶段:链分散,低粘度;链缔合,粘度快速增大;链动态平衡,粘度基本稳定。在170s-1下4%VES 60的胶束溶液的粘度随温度升高而下降,在50～80℃区间下降幅度很小,粘度约在60mPa·s上下,在80℃以上急剧降低。20℃时4%VES 60胶束溶液的流变性符合H B模型,k′=8.664Pa·sn′,n′=0.2678,τy=5.4Pa。随表面活性剂体积分数增大(2.0%～5.0%),30℃时VES 60胶束溶液的粘弹性参数G′,G″和η 增大,tanδ减小,即弹性增强而粘性相对减弱。图5表2参6。     

乳化压裂液在低渗强水敏地层中的应用研究

阿塞拜疆Kursenge和Karabagli油田属于中温、低压、低孔、低渗油藏,需要采用必要的增产措施以获得较高的单井产量,提高油藏整体动用程度。由于储层属低压、强水敏,不利于水力压裂增产作业,经过伤害因素分析和研究,研制出了低伤害乳化压裂液。该压裂液有助于保护储层,降低伤害,达到改造储层、提高产量的目的。现场应用表明,乳化压裂液施工成功率达100%,压裂后增产有效率达83%,效果明显的达50%以上。     

压裂液对储层的损害及其保护技术

压裂液对储层损害分析及其保护技术是油气藏保护的重要内容之一。依据近几年压裂液的研究成果,介绍了压裂液损害储层的类型,分析了压裂液滤液、残渣、滤饼及浓缩对地层的损害机理和保护措施。介绍了研究压裂液对储层损害的6种方法,即:①支撑裂缝导流能力;②岩心损害的测定;③残渣含量;④助排性能测定;⑤乳化及破乳性能;⑥粘土稳定试验。最后指出了低损害水基压裂液发展的方向。     

香豆胶锆压裂液在超深井中的应用研究

针对吐哈油田超深井油气藏和压裂施工的特点，分析了超深井压裂液选择的依据，筛选了适合该油、气藏特征的香豆胶锆压裂液体系，介绍了室内性能测试结果和现场应用情况。室内实验和现场应用表明，该压裂液体系具有良好的综合性能，可以满足超深井压裂施工需要。