原油乳状液微观组构剖析

 乳化作用对化学驱提高采收率影响很大，但因实验手段限制，对乳状液类型、粒径大小等组构特征如何影响采收率的问题尚未解决。本研究利用激光共聚焦逐层扫描三维重建技术研究乳状液组构，在对乳状液无损的条件下，分析化学驱矿场试验采出液中所产生的乳状液类型、粒径大小和黏度等特性，定性分析乳状液界面膜物质组成。依据采出乳状液的跟踪检测结果，以乳状液中原油物性和油水比为条件，以平均粒径和黏度为指标，使用反演法在实验室内模拟矿场试验采出乳状液。激光共聚焦扫描分析表明，与现场采出乳状液微观组构特征类似的乳状液能够通过反演法由室内实验准确制备；W/O乳状液的液膜主要由饱和烃和沥青质构成，非烃和芳烃以不连续的形式填充于乳状液液滴中。

Microcosmic Composition of Crude Oil Emulsion

The emulsification influences the result of oil recovery to a great extent in the process of chemical flooding. However, the mechanisms of how the oil recovery is influenced by the type, size and composition characteristics of the emulsion remain a problem to be studied. Laser Confocal Scanning Microscope（LCSM）with its high amplification and high resolution is used in this paper for that purpose. The microstructure in depth of the sample can be observed accurately. Three - dimensional image can be rebuilt by serial layer scanning. Therefore, the type, size and other characteristics of the emulsion can be analyzed without damaging the crude oil emulsion. According to the tracking test results, including the oil composition, the oil-water ratio, average particle size and the viscosity of the produced emulsion from pilot fields, the simulated emulsion can be made under the laboratory conditions by inversion method and identified by LCSM. Results show that emulsion can be prepared precisely in laboratory by inversion method with similar microcosmic compositions of the crude oil emulsion from pilot fields. Liquid membrane of the W/O emulsion is shown to be mainly composed of saturated hydrocarbon and asphaltene, while the liquid drop is filled with nonhydrocarbon and aromatic hydrocarbon in discontinuous shape.