海上稠油油藏早期注聚产液指数变化规律  

Liquid Productivity Index Behavior for Earlier Polymer Flood in Offshore Heterogeneous Heavy-Oil Reservoirs

作　　者：未志杰 WEI Zhi-jie(State Key Laboratory of Offshore Oil Exploitation,CNOOC Research Institute Co.LTD.,Beijing 100028,China)

机构地区：[1]海洋石油高效开发国家重点实验室,中海油研究总院有限责任公司,北京100028

出　　处：《科学技术与工程》2018年第23期212-218,共7页Science Technology and Engineering

基　　金：“十三五”国家科技重大专项课题(2016ZX05025-003)资助

摘　　要：针对海上稠油油田早期注聚过程中部分井产液能力存在明显下降的问题,通过构建基于Buckley-Leverett公式的非均质油藏聚合物驱产液指数计算模型,较系统研究不同的原油黏度、渗透率级差、注聚时机、注聚黏度等影响因素条件下的产液指数变化规律。结果发现:聚驱阶段的产液指数整体呈现"四段式"变化特征,依次为上升段、快速下降段、平稳段以及回升段,海上典型稠油油田的产液指数相比转注聚时最大下降幅度可达53.1%,波谷时机为累积注入0.25倍孔隙体积聚合物时。波谷时机随着原油黏度或低渗层相对厚度的增大而提前,随着级差的增大而推迟;最大下降幅度随着注聚黏度或级差的增大、注聚时机的推迟而增大。当级差为2或高低渗层孔隙度比为1.6时,无因次产液指数曲线可出现2次波谷。上述成果对海上稠油聚合物驱方案设计与调整具有重要的指导意义。To address the considerable liquid productivity index reduction of some producers during earlier polymer flood in offshore heterogeneous heavy-oil reservoirs,a sophisticated mathematical model to predicate liquid productivity index behavior is constructed based on the Buckley-Leverett function,thereby allowing to conduct research under different influence factor conditions,such as crude oil viscosity,permeability contrast,polymer injection timing,polymer viscosity etc.It is found that the liquid productivity index generally displays four-stage alteration features during polymer flooding.It first increases,then quickly declines,then goes stale,and finally rebounds.The liquid productivity index first increases,then quickly declines,then goes stale,and finally rebounds during polymer flooding process.The trough of liquid productivity index takes place when the injected volume of polymer solution reaches 0.25 pore volume,and the corresponding maximum relative reduction value can be 53.1%compared with polymer flood start-up for typical offshore heavy-oil reservoir.The trough timing is advanced with increasing oil viscosity or relative thickness of low-permeability zone,delayed with increasing permeability contrast.The maximum relative reduction value of liquid productivity index increases with larger polymer viscosity or permeability contrast as well as later polymer injection timing.There are two troughs for normalized liquid productivity index curves when permeability contrast is 2 or porosity ratio is 1.6.These conclusions can provide important guidance for polymer flood development plan design and adjustment in offshore heterogeneous heavy-oil reservoirs.

关 键 词：非均质性 稠油 聚合物驱 产液指数 注聚时机 

分 类 号：TE357[石油与天然气工程—油气田开发工程]