表面活性剂驱油性能评价及其在低渗透油田的应用

Evaluation and Application of a New Surfactant Oil-Displacing Agent in Low Permeability Oilfield

陈刚 宋莹盼 唐德尧 赵景瑞

CHEN Gang SONG Ying-Pan TANG De-Yao ZHAO Jing-Rui

结合低渗透油田储层和化学驱油技术特点，考察了双子型表面活性剂驱油剂YC-2 表界面活性、乳化能力及驱油效果。实验结果表明，该驱油剂在浓度为3000mg/L时的表面张力可以达到30mN/m左右，与原油间的界面张力可以达到10-3mN/m超低数量级，并且对NaCl和CaCl2 体现出较强的抗盐能力；表面活性剂YC-2 溶液/原油乳液体系析水快，有利于产出液的破乳。驱油实验结果表明，浓度为3000mg/L的表面活性剂YC-2 溶液在气测渗透率为0.3541× 10-3μm2岩心水驱（采收率50%）基础上可进一步提高采收率15% 以上；该表面活性剂适用于低渗透油层驱油，随着岩心渗透率的提高，表面活性剂驱油效率降低。该驱油剂产品已在延长油田青化砭、瓦窑堡、青平川等采油厂应用，取得了显著的驱油效果。

Based on the chemical-displacing technology in low-permeability oilfield，the surface/interfacial activity ，emulsifing ability and displacing efficiency of a gemini surfactant oil-displacing agent YC- 2 were investigated. The results showed that when the concentration of YC-2 was of 3000mg/L，the surface tension of YC- 2 solution was around 30mN/m，and the interface tension between YC-2 solution and the crude oil could reached the ultra-low order magnitude（~10-3 mN/m）. The YC-2 solution had strong salt resistance to NaCl and CaCl2. Moreover ，the YC-2 solution/crude oil emulsion exudated water quickly ，which was favorable for the disemulsion of the produced fluid. The oil displacement experiment showed that oil-displacing agent YC- 2 solution with the concentration of 3000mg/L could enhance the oil displacement efficiency of the core of Kg 0.3541× 10-3μm2 over 15% based on the water flooding（50%）. With the increase of the permeabililty of the core ，the displacing efficiency of the YC- 2 solution reduced ， indicating that the YC- 2 was suitable for the low permeability reservoir. The surfactant YC- 2 had been applied in Qinghuabian ，Wayaobao，Qingpinchuan oilfield factory of Yanchang Oilfield，and remarkable displacement efficiency had been obtained.