厚层油藏高含水期基于剩余油的分层精细注水  

Study on layered fine injection method based on remaining oil in high water-cut stage of thick-layered reservoir

作　　者：张静 蔡晖 刘斌 范晶 郑彬 ZHANG Jing;CAI Hui;LIU Bin;FAN Jing;ZHENG Bin(Tianjin Branch of CNOOC lid.,Tianjin 300459,China)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《复杂油气藏》2021年第1期51-56,共6页Complex Hydrocarbon Reservoirs

基　　金：国家科技重大专项“渤海油田加密调整及提高采收率油藏工程技术示范”(2016ZX05058001);中海石油(中国)有限公司科研项目“海上砂岩油田剩余油地质成因及精准挖潜研究”(YXKY-2019-KFSC-01)。

摘　　要：海上厚层油藏长期注聚后进入高含水期,由于非均质性影响,层间动用程度差异较大,厚度法等传统分层注水方法无法考虑到层间剩余油分布、井距及横向厚度变化带来的剩余储量差异影响。以渤海L油田为研究对象,基于吸水剖面资料,引入无因次吸水强度表征参数,考虑早期注聚,以非活塞式水驱油理论为基础,定量计算了各小层平均剩余油饱和度,建立了基于各小层剩余油分布、不同井距、横向厚度变化情况下分层精细配注新方法。该方法考虑了纵向水淹、井距及横向厚度变化带来的剩余储量差异影响,依据井组不同方向注水井控制剩余储量进行注水量调整,减少剩余储量小且动用程度较高层的无效水循环,增加剩余储量大且动用程度较低层的驱替强度。应用于渤海L油田,井组含水从实施前的92%下降至80%,单井日增油26 m^(3)/d,累增油1.1×10^(4)m^(3)。After long-term polymer injection,the offshore thick-layered reservoir has entered into a high water-cut stage.Due to the influence of heterogeneity,the degree of production varies greatly between layers.The thickness method and other traditional layered water injection methods can not take into account the remaining oil distribution,well spacing and lateral thickness change.Taking the Bohai L Oilfield as the research object,based on the water absorption profile data,introducing dimensionless water absorption strength characterization parameters,considering early polymer injection,and based on the non-piston water drive theory,the average remaining oil saturation of each layer was quantitatively calculated.A new layered fine injection method based on the remaining oil distribution in each small layer,different well spacing,and lateral thickness changes was established.This method takes into account the impact of the difference in remaining reserves caused by longitudinal water flooding,well spacing and lateral thickness changes.According to the injection wells in different directions of the well group,the remaining reserves are controlled to adjust the water injection volume,so as to reduce the invalid water circulation with small residual reserves and high degree of production,and increase the displacement intensity of the layer with large residual reserves and low degree of production.When applied to Bohai L Oilfield,the water cut of the well group decreased by 12.0%compared with before implementation,the daily oil increase of a single well was 26 m^(3)/d,and the cumulative oil increase was 1.1×10^(4) m^(3).

关 键 词：厚层油藏 高含水期 吸水剖面 平均剩余油饱和度 井距 分层配注 

分 类 号：TE341[石油与天然气工程—油气田开发工程]