【作者】 于芳；

【导师】 范维玉；

【作者基本信息】 中国石油大学 ， 化学工程与技术， 2008， 博士

【摘要】 化学复合驱技术是一项重要的三次采油技术,是采用碱、表面活性剂和高分子聚合物之间的有机复合从而大幅度提高驱油效率。石油磺酸盐是一种以石油馏分油为原料合成的阴离子型表面活性剂,用作驱油剂具有界面活性强,与原油配伍性好,水溶性好的优点,一直受到广泛重视。石油磺酸盐由于原料油成分复杂,分子结构和组成极为复杂,结构和性能差异大。三次采油中所应用的表面活性剂应满足低界面张力、低吸附量才能达到提高采收率的目的,故开发具有高界面活性,低吸附损失的石油磺酸盐具有重要的实际意义。本论文采用单管降膜式反应器合成NPS-1石油磺酸盐,对产物的化学结构、组成进行分析表征,考察其表面张力、油水界面活性、在固体介质上的吸附性质等胶体界面化学性质及其影响因素,并进行岩心驱替实验。同时,本论文将NPS-1石油磺酸盐萃取分离为不同平均相对分子量的组分,考察各组分的组成结构及其界面化学性质,探讨石油磺酸盐的化学结构对界面化学性质及应用性能的影响机理,从而为研制高效、低成本的石油磺酸盐产品提供理论指导。研究结果表明:选取绥中36-1减二线、减三线馏分油为原料油,以气相SO₃为磺化剂,采用膜式磺化工艺在优化工艺条件下合成的NPS-1石油磺酸盐产物收率及表面活性均较高,平均相对分子量适中,且具有较宽的平均相对分子量分布,适合用作三次采油驱油剂。将NPS-1石油磺酸盐分离为不同平均相对分子量的四组分,各组分的分子结构、界面化学性质及驱油性能显著不同。各组分复配所表现出的界面张力协同效应不同,协同效应与复配组分的分子结构、复配比例及油相等都有关系。NPS-1石油磺酸盐组分-煤油体系的油水界面张力值与ζ电位值之间存在一定的对照性。石油磺酸盐油水体系界面张力曲线的转折点为浓度0.0025g/mL处,即临界胶束浓度处,NaCl、NaOH和Na₂CO₃均可降低石油磺酸盐油水体系的界面张力;不同的醇对石油磺酸盐油水体系界面张力的影响不同;石油磺酸盐与其它表面活性剂间的协同作用具有选择性。NPS-1石油磺酸盐水溶液-煤油体系ζ电位绝对值随石油磺酸盐浓度的增大而先增大再减小,NaCl和Na₂SO₄可降低体系的ζ电位绝对值。NPS-1石油磺酸盐在孤岛地层砂上的静态吸附量在临界胶束浓度处达到最大值;其静态吸附量随着溶液pH值的升高而逐渐降低;不同种类电解质对其吸附损失的影响不同;HPAM在低浓度下能够增大石油磺酸盐的静态吸附量。针对胜利油田15-403井原油及胜利油田回注地层水,筛选得到最佳驱油剂配方为0.0010g/mLNPS-1+ 0.0040g/mL尼纳尔。按该配方配制的溶液使水驱采收率由38.1%提高至65.9%,具有较好的应用前景。更多还原

【Abstract】 Complex Chemical flooding is an important enhanced oil recovery （EOR） technology. Alkaline, surfactant and polymer are combined effectively in this method, thus oil-displacement efficiency is increased greatly. Petroleum sulfonate is a kind of anionic surfactant synthesized by raw material of oleum distillates. As oil displacement agent it possesses high interfacial activity, compatibility with reservoir fluids and good water solubility. Thus much attention has been paid to it. The composition of raw material is complex, thus the composition and structure of petroleum sulfonate is complex. Furthermore, the composition and property among petroleum sulfonate products is different. The surfactants for EOR which possess low interfacial tension（IFT） and low adsorptive loss can increase oil-displacement efficiency, thus researching petroleum sulfonate with high interfacial activity and low adsorptive loss are of great significance.In this paper, a kind of petroleum sulfonate （NPS-1） was synthesized in single-tube film sulfonation reactor. The chemical structure and composition of products is characterized. The colloid and interface chemistry properties were studied such as surface tension, oil-water interfacial activity and adsorption property on solid medium. The oil-displacement efficiency was also investigated in core-flooding experiments. Furthermore, NPS-1 is separated into fractions with different average relative molecular mass by means of solvent extraction. The molecular structure and interfacial chemistry property of fractions are investigated. And the effect mechanism of the structure of petroleum sulfonate on the interface chemistry properties and the applied performance is studied, which providing the theoretical guidance for synthesizing petroleum sulfonate with high efficiency and low cost.The results show that NPS-1 is synthesized in film sulfonation reactor by the raw material of Suizhong36-1 No.2 or No.3 vacuum cut gas oil and SO₃ sulfonation agent. The yield and surfacial activity of petroleum sulfonate synthesized under optimized sulfonation conditions is high. NPS-1 possesses appropriate average relative molecular mass and its average relative molecular mass distributes within broad range. Thus it is fit for enhanced oil recovery as oil-displacement surfactant.NPS-1 is separated into four fractions with different average relative molecular mass. The molecular structure, interface chemistry property and oil-displacement performance of the fractions are different significantly. Synergism of components is different, which is related to the molecular structure of components, mixture ratio and oil phase. The IFT between NPS-1 fractions solution and kerosene oil possesses correlation withζpotential.Turning point of the IFT curves of NPS-1 solution-oil phase system is at the concentration 0.0025g/mL, which is the critical micellar concentration （CMC）. The addition of NaCl, NaOH and Na2CO3 can decrease the IFT. Different alcohol have different effect on the IFT of petroleum sulfonate-oil phase system. The synergism between petroleum sulfonate and other surfactants exhibits selectivity.ζpotential absolute value of NPS-1 solution- kerosene oil system increases and then declines with the increase of NPS-1 concentration. NaCl and Na2SO4 can decreaseζpotential absolute value of the system.The static adsorption of NPS-1 on Gudao reservoir sand reaches maximum at the CMC. The static adsorption decline continueously with the increase of pH value. The effect of different electrolytes on the adsorption of NPS-1 is different. HPAM can increase the static adsorption of NPS-1 at low concentration.The optimum oil-displacement agent prescription is selected for crude oil of Well15-403 and reservoir water of Shengli Oil Field, which is 0.0010g/mLNPS-1+ 0.0040g/mLNinol. This oil-displacement agent solutions can increase the water-flooding oil recovery from 38.1% to 65.9%, thus it possesses good applying prospect.更多还原