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温度和氧压对沥青吸氧老化性能的影响 总被引:7,自引:1,他引:6
本文在0.12~0.30MPa(O_2)、25~80℃条件下,详细考察了温度和氧压对欢三联直馏沥青和欢喜蛉氧化沥青吸氧老化性能的影响,提出了包含氧压、温度、时间和吸氧量在内的完整吸氧动力学模型,并着重分析了温度和氧庄与总包速度常数或总包最大吸氧量间的关系,揭示了两种不同类型沥青吸氧老化的本质和区别。 相似文献
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围压对构造裂缝孔隙度的重要影响 总被引:2,自引:0,他引:2
构造裂缝对致密储层中油气运移、聚集起着重要作用,裂缝孔隙度也是油藏评价的重要参数.以往的研究、计算方法,忽视了围压对构造裂缝孔隙度的影响.文中提出用曲率法或主曲率法等计算构造裂缝孔隙度应考虑岩层所处围压(深度)的重要影响. 相似文献
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饱和度历史、围压和润湿性对饱和度指数的影响 总被引:1,自引:0,他引:1
阿尔奇公式中的饱和度指数n,是一个重要的岩石物理参数,其数值通常由实验室的岩心分析确定。经典测井理论认为,饱和度指数对于给定的岩石是不变的。对储集层砂岩和奥斯汀灰岩饱和度指数的测量结果表明,同一块岩样的饱和度指数的数值受多种因素的影响而变化。这些影响因素包括岩石的饱和度历史、对岩石所加的压力和温度的大小及岩石的润湿性等,其中尤以饱和度历史和润湿性的影响最为显著。 相似文献
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选取3组岩心,在对碳酸盐岩低渗透率气藏储层岩心建立不同含水饱和度的基础上进行不同围压条件下的电阻率实验测试,分析不同围压条件下岩心电阻率及饱和度指数n随不同围压变化的关系,探讨围压对岩心电阻率的影响机理。相同围压下,低孔隙度低渗透率碳酸盐岩孔隙度越大,饱和度指数n越小。低孔隙度低渗透率碳酸盐岩在低饱和度阶段电阻率随围压的增加而减小;中含水饱和度时,随着围压的增大电阻率先减小再略微增加;在高饱和度阶段,电阻率随围压增加略微增大。随着围压的增加,饱和度指数n减小,且随围压增大,饱和度指数变化幅度降低。该研究成果为室内碳酸盐岩岩电参数获取及实践中储量精确计算提供了依据。 相似文献
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致密砂岩启动压力测试中围压模式的优选 总被引:1,自引:0,他引:1
为了优选出一种适合室内测定启动压力梯度的围压控制方法,应用先进的ASF300TM 设备分别开展了恒定围压和恒定净围压2 种控制模式下的实验。每种控制模式分别以恒定注入压力和恒定注入流量的方式向实验岩心注入实验流体,最终将实验测试结果进行回归拟合计算,得到4 种不同的启动压力梯度值,并根据不同实验条件对实验结果进行详细分析,结合应力敏感实验和有效应力理论的结论,对上述4 种结果进行综合评价。经分析可知:在恒定围压模式下测得2 组启动压力,但数值都偏大;为降低实验误差,可将净围压控制在11 MPa 以上,在恒定净围压模式下,测试结果准确。因此,在恒定注入压力方式下,以恒定净围压模式开展实验是室内测试致密岩心启动压力梯度比较理想的方法。 相似文献
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在岩心流动试验过程中 ,注入介质对岩心渗透率的影响必然会引起注入压力出现一定幅度的起伏。为了维持岩心密封胶筒内外合理的压差 ,保证胶筒不窜流、不刺漏 ,通常采用手动方式对环压进行调整。文章以LP0 5C往复柱塞平流泵为对象 ,设计了测量转换电路、测频接口 ;以调整环压的传统经验为基础 ,编制了控制软件 ,最终采用计算机对流压及环压进行实时监控 ,实现岩心流动试验装置压力系统的自动控制 相似文献
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斜井破裂压力是压裂设计的一个重要参数,一般只能从已知射孔方位角来预测该参数。但现场采用的是非定向射孔,缺乏相应破裂压力的预测方法,而传统的破裂压力计算方法并没有获得非定向射孔井破裂压力的变化规律。为此,针对射孔斜井的主应力与射孔夹角未知的情况,利用应力分析及裂缝起裂机理,分析相位对斜井破裂压力的影响,并分析了多缝破裂压力的变化及破裂压力与裂缝延伸条数的关系。结果表明:当射孔方位角变化,各个射孔破裂压力交替地达到最大、最小值,在某个方位角,相应有多个破裂压力;其中最小破裂压力对应射孔处裂缝最先产生,通过优化射孔参数可降低裂缝起裂压力、优化裂缝延伸参数。这为优化压裂设计、降低施工风险及提高后期改造效果提供了依据。 相似文献
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֣��־������࣬�Ѿ��꣬IJ�������������� 《天然气工业》2017,37(1):119-123
??At present, the mechanical testing on the ductility of cement sheath is faced with multiple technical difficulties. In this paper, numerical simulation and laboratory evaluation were adopted to compare the mechanical properties of typical elastic, flexible, ductile and neat cement systems at home and abroad by different loading rates, value range of stress–strain curve, confining pressure and temperature.
It is shown that when the loading rate is lower, the stress–strain curve of set cement is not smooth, but distorted, and the stress cannot be responded in time; that when the loading rate is higher, the stress–strain curve of set cement is smooth, and the yield stage is remarkable,
indicating that higher loading rate can reflect the yield strain behavior of set cement more truly; that the recommended Young's modulus range of set cement should be changed based on the actual downhole conditions; that temperature has more effect on yield stress and ultimate strain, but less effect on elastic modulus; that confining pressure has more effect on ultimate stress and ultimate strain, but less effect on elastic modulus; and that when the confining pressure is lower and temperature is higher, the yield stage of set cement is more remarkable. It is concluded that these mechanical behaviors of cement system in different conditions provide a technical support for understanding the mechanical essence of downhole cement sheath and exploring the mechanical integrity of cement sheath and even that of the whole wellbore. 相似文献
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Mohammad Jafari Aliasghar Akbari Nasrekani Mostafa Nakhaei Abbas Babazadeh 《Petroleum Science and Technology》2017,35(2):141-147
In this research, a polyphosphoric acid (PPA) additive was used to modify a performance graded binder (PG 58-22). Experimental program included use of three PPA contents (0.5%, 1%, and 1.5%) by weight of bitumen and use of antistripping limestone aggregates. High-temperature rheological properties of asphalt binders were evaluated through the frequency sweep test. Complex modulus test was also used to evaluate rutting characteristics of asphalt mixtures. Results showed that PPA significantly improved rutting resistance of both unmodified asphalt binder and unmodified asphalt mixture, especially for the asphalt binder. 相似文献
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Xiang Liu Zhengwei Zhang Xiaolong Yang Zhuangzhuang Liu 《Petroleum Science and Technology》2018,36(16):1258-1264
To evaluate sensitivity of moisture damage resistance with chemical composition of asphalt, the adhesion energy, debonding energy as well as compatibility ratio of 69 asphalt-aggregate combinations were calculated with thermodynamical models. Pearson correlation analysis and regression analysis were carried out to correlate the relationships between asphalt chemical composition (saturates, aromatics, resins, asphaltenes, and wax) and moisture stability of asphalt mixture. The results showed that more resins and less asphaltenes in asphalt could lead to better moisture stability of asphalt mixture under dry and wet conditions, which can be effectively predicted by multiple regression models with different asphalt chemical components. 相似文献
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沥青路面低温开裂问题的探讨 总被引:1,自引:0,他引:1
沥青路面的低温开裂已成为各国道路界普遍关注的核心问题。分析了国内外低温开裂研究的进展,并从温缩裂缝的形式、影响因素、温度在沥青路面中的分布规律、评价指标方面进行了综合阐述。 相似文献