Abstract Wettability alteration (Δθ), changes in interfacial tension (ΔIFT) and fluid pH are investigated for Asmari formation carbonate and sandstone reservoirs of the large Ahwaz oil field (Iran) with a range of low salinity water-based fluids accompanied by a non-ionic surfactant (LSWF-surfactant) and the acidic (total acidic number = 0.58 mg KOH g−1) Asmari crude oil. On initial contact with the LSWF-surfactant the carefully prepared reservoir rock slices, soaked and aged in the crude oil all displayed oil-wet states. Metal-salt (potassium chloride, sodium sulfate, magnesium sulfate heptahydrate, calcium chloride dihydrate and lithium chloride) enriched aqueous solutions of various concentration (1000–4000 ppm) mixed with 400 ppm Triton™ X-100 (surfactant) were used in the Δθ, ΔIFT and pH tests. The test results for these variables suggest that the calcium chloride dihydrate (4000 ppm) solution with surfactant has the most beneficial impacts on both the carbonate and sandstone reservoir samples evaluated in terms of improving oil mobilization. Glass micro-model fluid-flow experiments to evaluate and compare oil recovered by secondary recovery (LSWF only injected) and by tertiary recovery (LSWF-surfactant injection) confirm the rock slice tests, with calcium chloride dihydrate achieving substantially higher ultimate oil recovery than the other LSWF solutions tested.

中文翻译：

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含非离子表面活性剂的离子溶液对润湿性、界面张力和微模型驱替实验研究的新见解

摘要 研究了大型 Ahwaz 油田（伊朗）的 Asmari 地层碳酸盐和砂岩储层的润湿性改变 (Δθ)、界面张力 (ΔIFT) 变化和流体 pH离子表面活性剂（LSWF-表面活性剂）和酸性（总酸值 = 0.58 mg KOH g-1）Asmari 原油。在与 LSWF 表面活性剂最初接触时，精心准备的储层岩石切片，在原油中浸泡和老化，都显示出油湿状态。在 Δθ 中使用了各种浓度 (1000–4000 ppm) 的金属盐（氯化钾、硫酸钠、七水硫酸镁、二水氯化钙和氯化锂）与 400 ppm Triton™ X-100（表面活性剂）混合的富集水溶液, ΔIFT 和 pH 测试。这些变量的测试结果表明，含表面活性剂的氯化钙二水合物 (4000 ppm) 溶液对碳酸盐岩和砂岩储层样品在改善石油流动性方面的评估效果最为显着。玻璃微模型流体流动实验评估和比较二次采收（仅注入 LSWF）和三次采收（LSWF 表面活性剂注入）回收的石油证实了岩石切片测试，二水氯化钙实现的最终石油采收率显着高于测试的其他 LSWF 解决方案。