【作者】 段友智；

【导师】 李阳；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2010， 博士

【摘要】 通过电喷雾质谱及高效液相色谱测定含有单及多极性基团混合阴离子表面活性剂平均相对分子质量,结合1H-NMR谱及元素分析表征混合阴离子表面活性剂的组成及分子结构。组成及分子结构表征表明,非极性基团为多芳环分子结构的分子中通常含有双或多极性基团,烷烃基支链的数量较多,支链的分子链较短,界面活性相对较低;但在水相中溶解性能好,通常对分子结构为单极性基团的成分具有增溶作用;而平均相对分子质量较大的活性组分,烷烃基侧链的平均甲基数多,在油水界面上疏水基覆盖率增加,碳氢链的排列紧密,耐温性能好,是作为热采驱油剂使用时降低油水界面张力的主要成分,但在水相中的溶解性能差,单独使用无法获得超低油水界面张力。混合驱油体系正是通过结构差异的互补,改善亲水亲油失衡,增加大分子结构表面活性剂在油水界面的分配等协同作用,从而使整个体系获得超低油水界面张力。这种协同作用对各组分的组成平衡变化较为敏感,矿场应用时由于存在矿物质对各组分的不平衡吸附以及各组分在多孔隙结构中的渗流性能差异等,均会对组成平衡造成破坏,从而使协同作用减弱甚至消失。在驱油体系中加入分子量低、水溶解性好的非离子表面活性剂,可通过对大分子组分的增溶作用减少其向固体表面的分配,通过竞争吸附作用降低在矿物质表面的吸附损耗,以及对高价阳离子具有分散及螯合作用从而减少沉降损失,通过上述作用实现驱油体系在流动过程中的保持组分平衡及组分间的协同效应,从而提高洗油效率。此外,稠油油藏的非均质性及驱油体系与稠油间极其不利的流度比,驱油体系对低渗透率层及高残余油饱和度层位的波及效率低,是造成驱油体系驱油效率较低的外在因素。本文研制的温度选择性膨胀树脂调堵体系,该体系基液为低粘度的液体,可实现在中、深部地层的调堵;低温下化学性质稳定,注入蒸汽后高温引发调堵体系稠化,并形成以固化树脂为连续相,气体为分散相的膨胀树脂,并通过氢键与矿物质表面形成较强的键合力,对大孔道地层具有很高的封堵效率,并可利用注入蒸汽后的温度场分布,实现对高渗层及大孔道层位的封堵。双管岩心模拟蒸汽驱替实验表明,驱油体系与调堵体系的复合技术可使低渗透率及高残余油饱和度岩心的采收率提高23.4%,具有很好的应用前景。更多还原

【Abstract】 The mean molecular weight of mixture anionic surfactant is determined by using combination method of high pressure liquid chromatography (HPLC) and electrospray ionization mass spectra (ESI-MS), then the composition and molecular structure can be characterized by combining analysis of 1H-NMR spectrum and element. According to above results,there are di or poly-polar group exist in the molecule structure of the surfactant, especially for those which have more aromatic ring; The interfacial activity of the composition that has the more branched chain of alkyl group and the shorter molecular chain of branched chain is lower. However, it has outstanding dissolubility in water, therefore, it have excellent solubilization effect to the composition with mono-polar group; The active composition of macromolecule structure have more average number of methyl group, which will increase the coverage rate of hydrophobic group on oil aqueous interface, line hydrocarbon chain along closely, as well as the temperature tolerance is better than other composition, so which are the main composition on reducing interfacial tension as additive agents for thermal recovery; However, the main defect of these composition is low dissolubility in water, so the ultra-low interfacial tension can not be obtained when it used lonely. Therefore, the synergetic effect is very important to mixture flooding system, and the ultra-low interfacial tension can be obtained by means of complementation of molecule structure, improvement of the hydrophilic-lipophilic balance and increase the allocation of macromolecule on oil aqueous interface. However, the synergetic effect is sensitive to the composition balance, which will diminish or disappear for imbalance adsorption loss on rock and the difference of fluid flow ability through porous medium. Fortunately, the adsorption and precipitation loss of the mixture flooding system can decrease by means of adding small-molecule non-cloud point non-ionic surfactant, which have favorable water solubility and the chelation ability with multivalent cations, competitive adsorption with other composition, as a result, the adsorption site on surface of reservoir sand dramatically decrease, so the composition balance of flooding system can keep well, then enhanced oil recovery.Furthermore, the significant factor for low oil displacement efficiency in the formation of low permeability and high residual oil saturation is low sweep efficiency, which determined by seriously heterogeneity of heavy oil reservoir and the unfavorable mobility ratio between oil displacement system and heavy oil. The base solution of the new system used for profile control and blocking off is liquid with low viscosity liquid, so the aim of plugging off in mid-depth formation can be achieved; Latent curing agent used in the system is a kind of chemiacal agent which has steady chemical nature at reservoir temperature, however, it would be decomposed at higher temperature after steam injection, therefore, the condensation polymerization and densification of the system would be promoted, as a result, the temperature selectively blocking off can be achieved. At the same time, it strongly bonded with the surface of rock by hydrogen bond. At last, the swelling resin formed, in which hardened plastic is continual phase and gas is dispersion phase, so the efficiency of formation sealing to high capacity channel is higher.As is shown according to simulated experiment of steam flooding with multi-barrel, the recovery ratio has been enhanced 23.4% for the low permeability and high residual oil saturation formation with combination system of oil displacement and profile control.更多还原