摘要：
渤海海域LD油田为典型的厚层油藏,采用大套多层合采的开发方式,为了提高油田采收率,该油田开展了早期聚合物驱矿场试验,厚油层开发受重力影响以及在聚合物驱等因素的共同作用下,在中、高含水期油藏剩余油分布较为复杂.为进一步研究聚合物驱后油藏剩余油分布状况,开展了室内岩心驱替实验.结合油藏属性,根据相似原则设计物理模拟参数,研究了不同韵律地层对早期聚合物驱剩余油分布规律以及生产动态的影响.研究结果表明:均质韵律条件下受到重力分异作用,油层为底部水淹,而早期聚合物驱能在一定程度上减缓重力分异作用,剩余油主要富集在生产井附近储层顶部;正韵律条件下受到重力分异和储层非均质性的共同影响,底部高渗透层水淹,剩余油主要分布在顶部低渗透层中,早期聚合物驱能有效动用中、低渗透层中的剩余油,而剩余油主要分布在靠近采油井的低渗透层;反韵律条件下,水驱波及程度较均匀,剩余油主要富集在局部未波及区域,早期聚合物驱能进一步扩大波及程度;复合韵律条件下,水驱和注聚合物驱与均质韵律驱替状况类似,剩余油主要分布在靠近生产井的低渗透层.%Bohai LD Oilfield is developed by commingling production in thick layers.Due to the field test at early polymer injection and the effect of gravity on developing the thick reservoirs,the remaining oil in the period of middle and high water cut is relatively complicated.In order to further study the remaining oil distribution of oil reservoir after the polymer flooding,laboratory core displacement experiment was carried out.Combined with the reservoir properties,physical simulation parameters were designed according to the similarity principle,and the effect of different stratum rhythm on remaining oil distribution in the early polymer injection and the production performance was researched.The research results indicate that due to gravitational differentiation,the oil reservoir is flooded at the bottom under the condition of homogeneous rhythm,and early polymer injection can slow the gravitational differentiation to a certain extent,so the remaining oil is mainly concentrated at the top of the reservoir near the production well;under the condition of positive rhythm,influenced by the gravitational differentiation and the reservoir heterogeneity,the high permeability layer is flooded at the bottom and the remaining oil is concentrated in the lower permeability layer at the top;early polymer injection can effectively drive the remaining oil in the medium and low permeability layer,and the remaining oil is concentrated in the low permeability layernear the production well;under the condition of reverse rhythm,the swept degree of water flooding is relatively uniform,and the remaining oil is mainly concentrated in the locally non-swept region,and the early polymer iniection can further extend the swept degree;under the condition of composite rhythm,the displacement situation of water drive and the polymer drive are similar to that of the homogenous rhythn,and the remaining oil is concentrated in the low permeability layer near the production well.
