微观非均质调驱剂油藏适应性及液流转向效果

Adaptability and Liquid Flow Diversion Effect of Microheterogeneous Regulator

针对渤海水驱稠油油田改善平面及微观非均质性特点,实现油层内部液流转向技术需求,以渤海LD5-2油藏地质特征和流体性质为模拟对象,研究了微观非均质调驱剂(聚合物微球、冻胶分散体)的水化膨胀性、渗流特性和液流转向效果。结果表明,聚合物微球材质透光性较差,外观形态呈现球型;冻胶分散体材质透光性较好,外观为不规则片状。聚合物微球初始粒径中值为8.7数9.2μm,微球颗粒在注入水中吸水膨胀,浸泡7 d后微球粒径基本稳定,最大膨胀倍数2.5数3.0。聚合物微球和冻胶分散体颗粒都具有较强的注入能力和较弱的液流转向能力,仅适用于中低渗透层内部微观液流转向。与聚合物微球相比,冻胶分散体的吸水缓膨能力、在多孔介质运移过程中的滞留和液流转向能力较差。对于平均渗透率高和非均质性强的油藏,需将宏观和微观液流转向措施即强凝胶与颗粒类相结合以扩大波及体积和提高采收率。

Aiming at improving the plane and micro heterogeneity characteristics of water drive heavy oil field in Bohai,and in order to realize the technical requirement of liquid flow diversion in reservoir,the geological characteristics and fluid properties of LD5-2 reservoir in Bohai were taken as simulation object.The hydration expansion,seepage characteristic and fluid flow diversion effect of microheterogeneous regulators including polymer microsphere and gel dispersion were studied.The results showed that the polymer microsphere had poor light transmittance and the appearance was spherical.While the gel dispersion had good light transmittance and the appearance was irregular slice.The initial median particle diameter of polymer microsphere was 8.7—9.2μm.The microsphere swelled in injection water.The particle size was basically stable after immersing 7 days and the maximum expansion ratio was 2.5—3.0.Polymer microsphere and gel dispersion had strong injection ability and weak liquid flow diversion ability,which were suitable for micro-liquid flow diversion in low and medium permeability layers.Compared with polymer microsphere,the abilities of water absorption,retention in porous media during migration and liquid flow diversion of gel dispersion were poor.The reservoir with high average permeability and high heterogeneity should be combined with macro and micro fluid diversion measures.That was to say,the combination of strong gel and particles could increase the expand sweep volume and enhance oil recovery greatly.