C井区葡I1~2层分类井聚驱注入调整方案研究

Study on Injection Adjustment Scheme of Polymer Flooding in PuI 1~2 Layer of C Well Area

前期聚驱方案设计采取了统一聚驱参数进行开采,未能考虑到井组间的注采差异。现该井区已进入含水下降的阶段,平面差异比较大,受油层发育和井间连通的影响,不同井组的注采差异明显。研究含水下降阶段各分类井组的个性化调整方法,根据划分不同的井组制定调整方案,以此来进一步提高采收率。现将整个目的层井组按照油层连通性等物性参数分为A、B、C 3类,统一使用900万相对分子质量聚合物设计6种不同段塞组合方案,通过预测开发效果来确定一个最优方案。以B类井组为例,预测结果表明合理的3类段塞聚合物注入质量浓度和用量分别为1 500、1 300、1 100 mg·L^(-1)和200、200、100 mg·L^(-1)·PV;优化方案聚驱阶段采出程度为15.13%,最终采收率为56.51%。与常规水驱相比,采收率提高了10.62%。

In the early stage of polymer flooding plan,the unified polymer flooding parameters were adopted,and the injection-production difference between well groups was not considered.The well area has entered the stage of water cut decline,the plane difference is relatively large,affected by reservoir development and inter-well connectivity,injection and production of different well groups have obvious difference.In this paper,the individual adjustment method of each kind of well group in the drawdown stage of water cut was mainly studied,according to dividing different well group,the adjustment plan was determined in order to further enhance recovery factor.The whole target formation was divided into A,B and C according to the physical parameters,and six different slug combinations were designed by using 9 million molecular weight polymer,an optimal scheme was determined by predicting the effect of development.Taking the B type well group as an example,the prediction results showed that the reasonable injection mass concentration and dosage of the three types of slug polymer were 1 500,1 300,1 100 mg·L^(-1)and 200,200,100 mg·L^(-1)·PV,respectively.The recovery degree of polymer flooding was 15.13%and the final recovery was56.51%.Compared with conventional water flooding,the recovery factor was increased by 10.62%.