延长油田典型致密油储层渗吸-驱替采油机理定量分析  

Quantitative analysis of the mechanism of imbibition and displacement recovery of typical tight oil reservoirs in Yanchang Oilfield

作　　者：申哲娜 王香增 康宵瑜 王成俊 金志 SHEN Zhena;WANG Xiangzeng;KANG Xiaoyu;WANG Chengjun;JIN Zhi(Research Institute of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi’an City,Shaanxi Province,710075,China)

机构地区：[1]陕西延长石油(集团)有限责任公司研究院,陕西西安710075

出　　处：《油气地质与采收率》2018年第5期99-103,共5页Petroleum Geology and Recovery Efficiency

基　　金：国土资源部矿场资源节约与综合利用项目"特低渗透油藏高效开发提高采收率示范工程"(ycsy2012ky-G03)

摘　　要：渗吸法驱油是致密油储层重要的采油方式之一,目前主要针对裂缝系统与基质系统之间的渗吸机理进行了较为深入的研究,但对于渗吸和驱替作用对渗流阶段采出程度的影响和贡献却未形成统一的认识。为此,基于延长油田水磨沟区长8致密油储层的孔隙结构分布特征以及裂缝系统和基质系统驱替压力特征分析,利用核磁共振技术定量表征驱替法和渗吸法对采出程度和可动流体分布的影响。实验结果表明:研究区致密油储层渗流能力的主控因素为喉道半径;裂缝性岩心样品基质系统的采出程度主要受控于渗吸作用,裂缝系统的采出程度主要受控于驱替作用;核磁共振定量分析驱替法和渗吸法的采收率分别为32.30%~39.32%和9.60%~19.49%;致密油储层岩心样品的微观孔隙结构复杂,且渗吸-驱替过程中流体流动方向受微观孔喉润湿性影响,因此渗吸法与驱替法的可动流体分布没有严格的孔隙尺寸界限。Imbibition is one of the important oil recovery mode for the tight oil reservoir.Imbibition mechanism between the fracture and the matrix was studied thoroughly,but there is no agreement on the influence and contribution of imbibition and displacement on the recovery degree in the seepage stage.Therefore,based on the pore structure distribution character-istics and the pressure characteristics of the fracture system and matrix system of Chang8 tight oil reservoir in Shuimogou area of Yanchang Oilfield,NMR technology was used to quantitatively characterize the influence of displacement method and imbibition method on the recovery degree and the distribution of movable fluid.The experimental results show that the main controlling factor on the seepage ability of the tight oil reservoir in the study area is the throat radius;the recovery de-gree of the matrix system in the fractured core samples is mainly controlled by the imbibition,and the recovery degree of the fracture system is mainly controlled by the displacement.The recovery of the displacement and imbibition methods based on NMR quantitative analysis was 32.30%-39.32%and 9.60%-19.49%respectively.The microscopic pore struc-ture of the core samples in the tight oil reservoir is complex,and the flow direction of the fluid during the process of imbibi-tion and displacement is affected by the wettability of the microscopic pore throat,so the distribution of the movable fluid obtained by the imbibition and displacement method has no strict pore size boundaries.

关 键 词：致密油储层 渗吸-驱替 定量分析 核磁共振 可动流体分布 延长油田 

分 类 号：TE312[石油与天然气工程—油气田开发工程]