Lübo Cheng

Dynamic Interfacial Tension Between Crude Oil and Novel Surfactant Flooding Systems Without Alkali

Abstract The surface tensions of tetradecylmethylnaphthalene sulfonate (TMNS) surfactant aqueous solution and the dynamic interfacial tension (DIT) between crude oil, from Shandong Shengli oil field of China, and the surfactant solution without alkaline, was measured. Results indicate that the TMNS surfactant had great capability and efficiency of lowering the solution surface tension. The critical micelle concentration (cmc) is 0.001 mass% and the surface tension at this concentration is 28.19 mN.m−1. It was also found that the TMNS surfactant is greatly effective in reducing the interfacial tensions and can lower the tension of crude oil-water interface to ultra-low at very low concentration, 0.002 mass%, without alkali and other additives. Both chromatogram separation of flooding and breakage of stratum are avoided effectively. The lower salinity is favorable for the flooding systems, lowering the DIT. The synthesized TMNS surfactant flooding systems without alkali and sodium chloride, decreasing the cost of oil recovery and avoiding the stratum being destroyed, would have a great prospect for enhanced oil recovery (EOR).

Synthesis and Surface Active Properties of Novel Nonionic Aryl Oleic Diethanolamide Surfactants

Abstract A series of novel aryl oleic diethanolamide (AOD) surfactants with different hydrophobic groups were synthesized. An aromatic ring introduced to a long alkyl chain had a significant effect on reducing water surface tension. The critical micelle concentration (CMC) and the surface tension (γ cmc ) at the CMC were investigated. The CMC was 4.56 × 10−8 mol/L to 5.83 × 10−6 mol/L for AOD1:1 (molar ratio of aryl oleic acid: diethanolamide = 1:1) and corresponding γ cmc was 36.4 mN/m to 39.3 mN/m. The CMC of AOD1:2 (molar ratio of aryl oleic acid: diethanolamide = 1:2) were in 1.21 × 10−7–9.98 × 10−6 mol/L and γ cmc were in 31.6–34.4 mN/m.

Synthesis and Interfacial Behavior of Decyl Methylnaphthalene Sulfonate

Abstract High purity decyl methylnaphthalene sulfonate (DMNS) surfactant was synthesized. The purity of product was determined by HPLC, and the structure was confirmed by IR, UV, and ESI-MS. The surface and oil-water interfacial activities of DMNS surfactant were studied. The effects of concentrations of the surfactant, alkali, and inorganic salt on the dynamic interfacial behavior of crude oil/Shengli Oil Field/surfactant oil flooding systems were studied, and comparitive studies of systems with strong and buffered alkali were also carried out. Results showed that DMNS surfactant possessed great capability and efficiency for lowering solution surface tension and oil-water interfacial tension. The critical micelle concentration (cmc) was 0.02% and the surface tension at this concentration was 31.61 mN.m−1. At proper concentrations of the surfactant, alkali, and inorganic salt, the dynamic interfacial tension between the crude oil of the Shengli Oil Field and the surfactant oil flooding system reached a minimum value of 10−5–10−6 mN.m−1 in a very short time (3–20 min) and maintained an ultra-low value (< 10−2 mN.m−1) for a long period of time (15–87 min). The crude oil/surfactant systems presented satisfactory interfacial behavior. DMNS has great potential to be used in enhanced oil recovery (EOR) with low cost and high efficiency.

Dynamic Interfacial Tension Between Crude Oil and Octylmethylnaphthalene Sulfonate Solution

The surface tension of surfactant aqueous solutions and dynamic interfacial tensions (DIT) between Shengli Oilfield crude oil and solution of octyl methylnaphthalene sulfonate surfactants (OMNS) have been measured. The effects of various parameters such as surfactant concentration, salinity and sodium carbonate concentration on the interfacial behavior of crude oil-water were investigated. It was found that the prepared surfactants can reduce the interfacial tension to ultra-low only at certain surfactant concentration, salinity and alkaline concentration ranges. It was also found that there exist optimum values with respect to all of surfactant concentration, salinity and alkaline concentration. The DIT can low to 10−6 mN.m−1 under the optimum conditions. Moreover, the DIT behavior of OMNS flooding without alkaline has also been investigated. It was found that the DIT also reaches ultra-low value under the optimum sodium chloride concentration without alkaline. The results show that the OMNS is more effective on lowering surface tension of aqueous solutions and dynamic interfacial tensions (DIT) between crude oil and water. OMNS possesses a great potential to be used in EOR with low costs and high efficiency.

A Study on Friedel-Crafts Alkylation in Ambient Temperature Ionic Liquids

Abstract Alkylation of naphthalene, α-methylnaphthalene, and β-methylnaphthalene with different alkylating agents, such as olefins, bromoalkane, and fatty alcohol, in novel environmentally friendly ambient temperature ionic liquid, ethyl-containing amine chloroaluminate (anhydrous aluminum chloride mole fraction, X = 0.67–0.75), has been investigated. On the basis of optimal reaction conditions, high conversion of alkylating agent and excellent selectivity for monoalkylated product were obtained. The products and unreacted reactants were easily isolated by extraction with cyclohexane.