低渗透油藏内烯烃磺酸盐微乳液体系配方优选 及性能评价*

Formula Optimization and Performance Evaluation of Internal Olefin Sulfonate Microemulsion System Used in Low Permeability Reservoir

赵柏杨 夏连晶

ZHAO Baiyang，XIA Lianjing

为获得驱油性能良好的高分子内烯烃磺酸盐（IOS）体系，通过正交实验法确定了C24-28IOS/t-戊醇/Na2CO3/NaCl微乳液最优配方，通过微观驱油实验分析了IOS微乳液的驱油机理，通过低渗透岩心驱油实验研究了微乳液的驱油效果，评价了微乳液的性能并在大庆榆树林油田进行了现场应用。结果表明，配方为0.3% C24-28IOS、 0.6% t-戊醇、1.25% NaCl、1.25% Na2CO3的内烯烃磺酸盐微乳液接近达到中相状态。微乳液能与油形成低界面张力，降低残余油饱和度，提高采收率；微乳液具有乳化增黏作用，在驱替过程中能起到控制流度的作用从而扩大波及体积；同时由于微乳液的弹性，其变形的微观力对提高驱油效率起着重要作用。室内岩心驱油实验结果表明，IOS微乳液增油降水效果明显，与水驱相比，微乳液驱驱油效率提高9.16个百分点、含水率降低8.2个百分点。低渗透油藏高含水开发后期注入IOS微乳液能起到明显的增油效果。图27表3参19

In order to obtain a internal olefin sulfonate（IOS）microemulsion system with good oil displacement performance，the optimum formula of C24-28IOS/t-pentol/Na2CO3/NaCl microemulsion was determined by orthogonal test，then the displacement mechanism of the IOS microemulsion system to five kinds of remaining oil was studied through microscopic oil displacement test， and the oil displacement effect of the system was analyzed by oil displacement experiment of low permeability core. The performance of microemulsion system was evaluated，and it was applied in Daqing oilfield. The results showed that the IOS microemulsion with 0.3% C24-28IOS，0.6% t-amyl alcohol，1.25% NaCl and 1.25% Na2CO3 was close to the mesophase state. Microemulsion could form low interfacial tension with oil，reduce residual oil saturation and improve oil recovery. Microemulsion had the function of emulsification and viscosity increasing，which could control the fluidity and expand the swept volume in the process of displacement. Meanwhile，due to the elasticity of microemulsion，its deformation micro force played an important role in improving oil displacement efficiency. The results of core flooding experiment showed that IOS microemulsion had obvious effect of increasing oil and decreasing water cut. Compared with water flooding，microemulsion had 9.16% higher displacementefficiency and 8.2% lower water cut. The injection of IOS microemulsion in the later stage of high water cut development in lowpermeability reservoir could obviously increase oil production.

10.19346/j.cnki.1000-4092.2020.01.018