碳酸盐岩油藏乳状液暂堵及暂堵后酸化实验研究

针对国外某油田高温高盐碳酸盐岩油藏油层厚度大、非均质性严重、酸化后易出现含水率上升的问题,开展了乳状液暂堵酸化技术研究。研制了烷基多烯多胺油溶表面活性剂NEWJ-18,可使柴油和高矿化度水在油水比1∶9~4∶6的范围内形成稳定的油包水乳状液。该乳状液遇酸易破乳,且具有油水比越低,乳状液黏度越高的特点。物理模拟实验表明,以油水比4∶6制备的乳状液具有选择性封堵高渗透层的能力,可使后续酸液转向低渗透层,从而改善低渗透层的酸化效果。

Research on Emulsion Temporary Plugging and Acidification Experiment in Carbonate Reservoir

The research on the integrated technique of emulsion temporary plugging and acidification is carried out in the paper. This new technology applies to high-temperature and high-salt carbonate reservoirs with large thickness, serious anisotropy and high water-cut after acidification in an overseas oilfield. The alkyl polyene polyamine oil soluble surfactant NEWJ-18 is studied in this research, which can make diesel and concentrated water into steady oil-in-water emulsion when the oil-water ratio is between 1:9 and 4:6. The emulsion can be easily broken when encountering with acids. Furthermore, the emulsion has a feature that the lower the oil-water ratio is, the higher the viscosity will be. TheSphysicalSsimulation experiments show that emulsion prepared in the oil-water ratio 4:6 has a capacity of selectively plugging in high permeability layer. This leads following acids steering to low permeability layer and so that it can improve the acidizing effect in this layer.