高盐油藏无机凝胶与泡沫复合调驱研究

Compatibility of Inorganic Gel and Surfactant in High⁃Salt Reservoir

吐哈雁木西油藏具有岩石胶结度较低、储层非均质性强和注入水矿化度高等特点,长期注水开发已经形成了优势通道,现有技术难以满足深部液流转向。以目标油藏储层地质特征和流体特性等为模拟对象,开展了无机凝胶与表面活性剂适应性研究。结果表明,非离子表面活性剂(DWS)溶液具有良好抗盐性。无机凝胶(硅酸钙或硅酸镁)对DWS溶液影响不大,表明实施交替注入调驱的驱油效果不会受到太大影响。当表面活性剂与原油发生乳化作用时,"贾敏效应"可以产生附加渗流阻力和液流转向效果,因而采收率呈现较大幅度升高。在三种无机凝胶与表面活性剂和氮气组合方式中,"无机凝胶+表面活性剂溶液+气"交替注入方式注入压力较高,液流转向和扩大波及体积效果较好,因而采收率增幅较大。

Yanmuxi reservoir in Tuha shows low rock cementation,strong reservoir heterogeneity and high salinity of injected water.Long term water injection development has formed an advantage channel,and the existing technology is difficult to meet the technical requirements of deep liquid flow diversion.The compatibility of inorganic gel and surfactant was studied based on the reservoir geological and fluid characteristics of the target reservoir.The results showed that nonionic surfactant(DWS)solution had good salt resistance property.Inorganic gel(calcium silicate or magnesium silicate)has little effect on DWS solution,indicating that the displacement effect during alternate injection process and profile control will not be affected too much.When surfactant emulsifies with crude oil,"Jiamin effect"can produce additional seepage resistance and liquid flow diversion effect,so the recovery rate increases greatly.In the three combinations of inorganic gels,surfactants and nitrogen,the"inorganic gel+surfactant solution+gas"alternate injection mode exhibits higher injection pressure,and superior liquid flow diverting and expanding the volume effect.