Research On The Effects Of Amphiphiles On Colloid Structure Of Heavy Oil

Amphiphile molecules have both hydrophilicity and lipophilicity character, which makes it have high value in the field of reducing the viscosity of heavy oil. In this paper, we have used a combination of rheological methods, DSC, conductivity measurement and other methods, to research and explore the influence of amphiphile molecules to asphaltene aggregates of heavy oilthere are three kinds of heavy oil used in the experiment. Two kinds of heavy oil are from Caoqiao oilfield, and one is form Tarim oilfield. Add different kinds of amphiphile molecules into the heavy oil,and analyze it with rheological methods.It indicates that the DBSA can make the viscosity of heavy oil higher, while amine amphiphile and lauric acid can make the viscosity lower. Different kinds of oil has different components,asphaltene colloid structure, the content of acid fractions and alkalinous fractions can influence the effect of amphiphile molecules. With the mechanism of action explored further,It is believed that the asphaltene aggregate size increases with decreasing solvent aromaticity up to a solubility limit, beyond which the aggregate size decreases with heptane addition,within which the aggregate size increases with heptanes addition. DBSA and PTSA is a good asphaltene dispersant for heavy oils. When DBSA is added into the heavy oils, the asphaltene aggregates become larger, meaning that the structure of asphaltene aggregates becomes loose. The loose asphaltene aggregates can entrap much more liquid oils and leads to the increase of effective asphaltene aggregates content in the oil phase. The basic LAM interacts preferably with organic acids in the heavy oils and not with asphaltenes, while the organic acids are important stabilizers for asphaltene aggregates. When LAM is added into the heavy oils, the asphaltene aggregates become smaller, meaning that the structure of asphaltene aggregates becomes compact. The compact asphaltene aggregates will release some entrapped liquid oils into the oil phase, thus decreasing the viscosity of heavy oils. If add the low polymer directly into the heavy oil, the low polymer would curl in the oil phase, which makes it hard to effect with asphaltene aggregates. If dissolve the low polymer into methylbenzene before adding into the heavy oil, the low polymer would become stretch,and easier to effect with asphaltene aggregates, form salvation shell, low the ductility of asphaltene aggregates, stop the surrounding aromatic sheets from being aggregated with asphaltene aggregates. Thus, the asphaltene aggregates become smaller,and the viscosity of heavy oil becomes lower.