关于聚合物驱分注时机的探讨

PROBE INTO THE TIME OF POLYMER FLOODING SEPARATELY

根据南二、三区东部聚合物驱开发工程中的分层注入实践,应用数值模拟手段,注入井分注时机、层段注入强度对开发效果的影响进行探讨。在地质模型建立过程中,共分9个模拟层。在注聚初期,主力油层内部聚合物驱的调剖作用表现较为明显,但进入含水回升阶段后出现剖面反转现象。注入井在含水稳定阶段、含水回升阶段实施分层注入可提高区块整体开发效果,不同阶段分注均比全过程笼统注入提高采收率1.5%-1.7%。由于在含水下降阶段和含水稳定阶段实施分注,一定程度上控制了主力油层的注入强度,动用程度难以进一步提高,采收率提高值略低于含水回升阶段分注。随着低渗透层段注入强度逐步增大,在不同阶段实施分注,模拟区采出程度均得到提高,提高值在0.37-1.7个百分点之间,但随着高渗透层段注入强度下降,采出程度呈下降趋势。

Under general injection,polymer solution dartle quickly in high permeability layer and injection status are bad in low permeable layer,which affects the polymer flooding of whole exploitation.Based on separate injection practice of polymer-driving exploitation project in the east of Nan 2 and 3 areas,numerical simulation is applied to discuss the exploitation effect of injection time and injection intension in the paper.In the process of geologic model establishment,in order to research the unit status employed,3 simulation layers in the pu22 unit are split in rhythm,in the end they are divided into 9 emulations layers totally.In the early time of injection polymer,the polymer solution changed the mobility ratio of oil and water,resulted in each layer sopping scale change,the effect of adjusting the section was obvious in the main layer,but in the phase aquifer rallied appeared section reversal development.The well injection adopts injection in a position to improve exploitation effort of the whole areas during containing water stabilization moment and containing water back moment.Injection separately at different moment increases recovery rate by 1.5%-1.7%.Due to adopting divided injection during containing water dropping moment and containing water stabilization moment,it control intensity of injection mainly layer in a certain extent.Employing level hardly gain more advance,the increasing number of recovery ratio slightly low than divided infusion during containing water back moment.With injection intensity of low permeability increasing,in different layer we inject polymer separately,exploitation degree is enhanced in stimulant area.The increase is between 0.37%～1.7%.But in the high permeability layer,exploitation degree is declined along with injection intensity increasing.So during separate injection polymer,the injection intensity should not be too low to affect exploitation for mostly oil-bearing formation.