Investigation of local thermal nonequilibrium effects on oil in situ combustion simulation

In the models developed for oil in situ combustion so far, local thermal equilibrium (LTE) was assumed between reservoir rock and fluids without being validated. As presence of a combustion zone makes the validation of this assumption questionable, in this study a new two-energy equations model is developed describing the temperature fields of rock and fluids separately. Investigating the effect of local thermal nonequilibrium between rock and fluids indicates that LTE will fail if the grain's diameter size order exceeds a millimeter. In this case, using LTE will lead to overestimating the heat and mass transfer rates.     

Mn~(2+)和La~(3+)对提高六铝酸盐热稳定性燃烧活性的作用

催化燃烧是提高效率,降低热NO_x污染的有效方法,要求活性组分及其载体具有良好的抗烧结性。这可通过在Al_2O_3中引入碱土金属离子组成层状结构的六铝酸盐来实现。以La~(3+)取代部分碱土离子(如Ba~(2+)等),能更容易获取纯净的六铝酸盐,而以Mn~(2+)取代部分Al~(3+),既可提高甲烷完全燃烧的活性,又增进了催化剂的高温热稳定性,再结合制备方法的改进,氧化铝载体及其活性组分的高温性能会得到显著改善。     

可膨胀管技术及其管材性能

由于可膨胀管技术应用范围广,近几年在国外得到了极大的发展.可膨胀管技术利用液压或机械方式使管材直径增大,从而保持较大的井径.作为可膨胀管的材料必须具有足够高的变形能力,且膨胀后的力学性能基本能达到普通套管的水平.提出可膨胀管的管材需具有较低屈强比、较高的形变强化指数等性能,且其变形能力可通过改善组织及合理的热处理工艺加以提高,可选用常规套管材料、特种材料及管线钢等.     

Combustion and thermal behaviour of ballistically modified eva and estane based RDX-AP propellants

Abstract

This paper reports the findings of the combustion and thermal studies on RDXAP based propellants with ethylene vinyl acetate (EVA) and polyurethane-ester-MDI (Estane) binder systems plasticised with triacetin (TA) and glycidyl azide pre-polymer (GAP). Effect of incorporation of selected ballistic modifiers namely iron oxide, copper chromite, basic lead salicylate+cuprous oxide+carbon black combination and sodium borohydride (adsorbed on aluminium oxide) was also studied during this work. Incorporation of GAP as plasticizer in place of TA led to improvement in F by 36–52 J/g. Closed vessel evaluation results were in close agreement with the theoretically predicted performance. Burn rate enhancement by ballistic modifiers was observed in both acoustic burn rate experiments as well as closed vessel test. A major finding was the realization of pressure index value of the order of 0˙65–0˙68 with copper chromite in the high pressure regions (14–200 MPa) which is not reported earlier. DTA and DSC studies indicate that RDX decomposition is the major process during propellant degradation and ballistic modifiers catalyse condensed-phase/near-surface reactions involving GAP.     

成核剂对聚丙烯结晶形态及力学性能的影响

分别以HPN-68 L,NA-21,苯甲酸钠(NA),A1为成核剂,采用熔融混合法对聚丙烯(PP)进行改性。利用偏光显微镜,差示扫描量热仪(DSC)和万能材料试验机考察了成核剂的种类和用量对PP的结晶形态、热性能和力学性能的影响。结果表明,分别添加几种成核剂后PP的结晶温度明显提高,晶体尺寸减小,弯曲强度和弯曲模量明显增大,拉伸模量略有提高,但拉伸强度未发生明显变化,断裂伸长率降低;成核剂A 1与HPN-68 L对PP力学性能的影响相当,但添加前者PP的结晶温度略低于添加后者的。     

柴油机排放碳颗粒物燃烧催化剂性能的研究

在固定床反应装置上考察了碳颗粒物燃烧催化剂的活性。以Ｃｕ－Ｖ－Ｏ催化剂为基础，添加第三金属组分后，得到活性较高的Ｃｕ－Ｖ－Ｍｎ－Ｏ催化剂。通过ＩＲ、ＢＥＴ、ＤＴＡ和ＸＲＤ等手段，研究了溶液ｐＨ值和焙烧温度对Ｃｕ－Ｖ－Ｍｎ－Ｏ催化剂性能的影响。结果表明，溶液中酸的存在对催化剂活性不利，ＣＵ３Ｖ２Ｏ８是催化剂的主要活性晶相。     

准噶尔盆地玛湖凹陷二叠系风城组岩性对岩石力学特性的影响

以准噶尔盆地玛湖凹陷下二叠统风城组储层岩石为研究对象,基于室内力学试验研究了风城组储层不同岩性岩石的力学行为,从而揭示风城组储层不同岩性岩石的力学特性。在此基础上,讨论了矿物组成对风城组储层岩石强度参数的影响。玛湖凹陷风城组储层岩石具有较强的非均质性,造成不同岩性岩石力学特性存在较明显的差异,其中云质类岩石的力学强度和弹性模量较大而泊松比较小;岩石破坏形式较单一,其中单轴条件下,岩样脆性较强,表现为拉张破坏特征,而高围压条件下,岩样脆性减弱、延性增强,主要表现为单剪切破坏特征;岩石的抗压强度、抗张强度、断裂韧性值随着硅质矿物含量的增加呈减小的趋势,而随着钙质矿物含量的增加呈增大的趋势。     

成核剂对抗冲共聚聚丙烯性能的影响

研究了成核剂HPN-A,HPN-B对抗冲共聚聚丙烯2500H力学性能、热性能以及收缩率的影响。结果表明:成核剂HPN-B对2500H的性能影响较大,其添加量为0.08%(质量分数)时,试样的弯曲模量和拉伸强度分别提高22%和5.4%;成核剂HPN-B在提高试样刚性的同时,使试样的简支梁缺口冲击强度也略有提高。在热加工性能方面,成核剂HPN-B提高了试样的结晶温度和负荷变形温度,使试样的横向收缩率和纵向收缩率分别缩小6.15%和8.20%。     

考虑岩样尺度效应时钻井液对岩石力学性质影响的试验评价

在考虑试验岩样尺度效应的基础上,进行的模拟地层条件下钻井液对岩石力学性质影响的试验研究结果表明:经钻井液处理后的Φ25mm×25mm岩样的抗张强度高于未经钻井液处理的Φ50mm×50mm岩样,且处理后的岩样抗张强度均高于未处理的岩样。对于钻井液处理前后同尺寸的岩样,由于试验岩样中泥质软颗粒含量高低不同,在孔隙度小于2.5%时,孔隙度越小,处理前后的抗张强度相差越大,且处理前的岩样抗张强度比处理后的岩样大4MPa左右;在孔隙度大于2.5%时,钻井液处理前后的岩石抗张强度趋于一致。在模拟地层条件下,钻井液处理后的岩样抗压强度和弹性模量显著下降,泊松比增大。岩石矿物中的泥质黏土矿物遇到钻井滤液后产生软化效应,致使岩样呈现:经钻井液处理时间越长,其抗压强度和弹性模量下降越多的趋势。     

Effect of different BPS concentration on the thermal decomposition and thermal stability properties of GAP curing

ABSTRACT

In order to study the optimal ratio of the degree of bis-propargyl-succinate (BPS) cures Glycidyl azide polymer (GAP), the thermal kinetics of BPS cured system was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG), the thermal stability and mechanical properties were studied. GAP was cured by the reaction of the azide group with BPS through a 1,3-dipolar cycloaddition reaction to form a 1,2,3-triazole network. It was found that the DSC curves of the BPS cured system show an obvious exothermic peak at around 230–260°C for each sample at different heating rates. TG-DTG curves of the BPS/GAP system exhibit two major stages of mass loss for different samples at different heating rates. When the mass ratio of BPS and GAP is 0.4:1, the thermal stability and mechanical properties were optimal. Meanwhile, the activation energy and frequency factor are calculated by Kissinger and Flynn–Wall–Ozawa methods by non-isothermal thermoanalytical data, the kinetic parameters proved that 0.4 BPS sample shows high thermal stability and the parameters are significant for further research of curing system.     

波纹管成型及膨胀过程力学性能分析

为了确保膨胀波纹管能满足其在膨胀后具有尽可能大的抗外挤强度和抗内压强度等性能要求,重点对YS1、YS2和YS3这3种材料的波纹管成型及膨胀过程力学性能变化进行了分析,模拟分析了波纹管膨胀压力,并在地面对波纹管进行了膨胀试验。试验及模拟结果表明,对241.3 mm井眼用的2种管材的波纹管,液压膨胀模拟到16 MPa,具有较好的膨胀圆度;对3种常见管材、241.3 mm井眼用的波纹管,抗内压强度为23.55～30.10 MPa,满足抗内压要求。光管的抗外挤强度为5.20～8.57 MPa,在井下岩层中的抗外挤强度为15.45～20.49 MPa,满足抗外挤要求。     

Molecular investigations on the interactions of graphene,crude oil fractions and mineral aggregates at low,medium and high temperatures

Performance of the nanoparticle-modified asphalt binder is greatly influenced by adhesion properties between asphalt binder and nanoparticle. In this work, the adhesion properties of crude oil fractions (e.g., Saturate, Asphaltene, Resin and Aromatic components of asphalt binder), graphene and mineral aggregates (silicon dioxide) at various temperatures are investigated through molecular dynamic simulation and REAXFF force field. The results from SARA-graphene interface demonstrations that aromatic and asphaltene have 30% higher adhesion properties than saturate and resin. Also, while using graphene is valuable for the adhesion properties of the binder, it has no significant advantage over binder in binder-aggregate interactions.     

大斜度井投捞系统动力学模型及力学特性

大斜度井井斜角大、井身结构复杂,其投捞操作的可靠性受一系列理论难题的影响,目前缺乏大斜度井投捞系统动力学理论研究成果,无法进行投捞系统力学特性分析和基于基础理论的投捞工艺改进研究。通过提出钢丝-油管接触分析、油管压差阻力计算等系列方法,以此建立了综合考虑井口辅助装置、钢丝、投捞器相互作用的大斜度井钢丝投捞系统动力学模型,基于有限差分法、高斯消去法结合迭代法实现了模型的求解,利用现场实测结果验证了模型的有效性。根据投捞系统的动力学模型,开展了大斜度井投捞系统力学特性研究,揭示了投捞工具串下入、投送、上提、打捞等过程载荷变化规律,以及下冲过程中井斜、井深、井眼轨迹、冲程、投捞器几何参数等因素对下冲速度的影响机理。     

成岩相对低渗透储层砂岩岩石力学性质的控制——以鄂尔多斯盆地东部上古生界天然气储层为例

砂岩岩石力学性质对储层压裂设计具有重要影响,通过岩相学观察以及岩石力学试验,研究了鄂尔多斯盆地东部上古生界低渗透储层砂岩成岩相类型、岩石力学参数以及可压裂性,分析了影响岩石力学性质的岩相学因素。研究区上古生界低渗透储层砂岩可分出6种成岩相：蚀变杂基充填强压实致密成岩相、石英加大硅质胶结粒间孔成岩相、碳酸盐胶结交代致密成岩相、钙质溶蚀孔成岩相、杂基溶蚀孔成岩相和岩屑溶蚀孔成岩相。不同成岩相砂岩的抗压强度、弹性模量和泊松比均有所差异,脆性矿物含量、硅质胶结物含量以及压实重结晶程度越高的成岩相,则其抗压强度越大,反之则越小;孔隙度越大的成岩相,弹性模量越小;石英等脆性矿物含量越高、压实程度越弱、孔隙度越高的成岩相,则其泊松比越小,反之则越大。脆性系数较大的石英加大硅质胶结成岩相、钙质胶结溶蚀孔成岩相和杂基溶蚀孔成岩相可压裂性好,其他几类成岩相砂岩可压裂性相对较差。     

燕山稀土顺丁橡胶微观结构及力学性能

本文介绍了燕山石化橡胶厂所生产稀土顺丁橡胶的微观结构及力学性能,并与国外同类品牌胶种进行了对比。结果表明:产品的顺式含量高,力学性能稳定,优于镍系和其他国外品牌的稀土顺丁橡胶。