柴达木盆地英西地区E^(2)_(3)储层孔隙特征及宏观微观渗流特征  

Pore Characteristics and Macro and Micro Oil-Water Seepage characteristics of E^(2)_(3) Reservoir in Yingxi Area of Qaidam Basin

作　　者：郑永仙 陈晓冬 王果 王妍芝 任晓娟[2] 罗向荣[2] 李晓骁 ZHENG Yongxian;CHEN Xiaodong;WANG Guo;WANG Yanzhi;REN Xiaojuan;LUO Xiangrong;LI Xiaoxiao(Research Institute of Exploration & Development,PetroChina Qinghai Oilfield Company,Dunhuang,Gansu 736202,China;College of Petroleum Engineering,Xi’ an Shiyou University,Xi’ an,Shaanxi 710065,China;College of Petroleum Engineering,China University of Petroleum (Beijing),Beijing 102249,China)

机构地区：[1]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202 [2]西安石油大学石油工程学院,陕西西安710065 [3]中国石油大学(北京)石油工程学院,北京102249

出　　处：《西安石油大学学报（自然科学版）》2021年第4期75-82,共8页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：中国石油天然气股份有限公司重大科技专项“柴达木盆地建设千万吨油气田综合配套技术研究”(2011E-03);陕西省自然科学基础研究计划项目(2021JQ-599)。

摘　　要：为探究不同孔隙结构类型对碳酸盐岩储层油水两相渗流特征的影响,以柴达木盆地英西地区E^(2)_(3)储层为例,通过对储层孔隙结构组合方式的分类,结合核磁共振T2谱,开展了单相和油水两相启动压力梯度实验以及宏观微观油水两相渗流实验。结果表明:研究区储层可以分为裂缝型、溶孔型和基质孔隙型,裂缝和溶孔发育程度越高,大尺寸孔喉数量越多,样品物性越好。3类岩心油水两相渗流差异明显,裂缝和溶孔是主要的渗流空间,大尺寸孔喉连通性好,驱油效率高;基质孔隙型岩心的渗流能力与裂缝型和溶孔型岩心的渗流能力相差10~103倍,且大尺寸孔喉连通性差,驱油效率低。溶孔型和裂缝型的单相和油水两相启动压力梯度较低,变化幅度不大;而基质孔隙型的单相启动压力梯度最高,且油水两相启动压力上升明显,验证了基质孔隙型水驱油效果差、渗流能力弱的特点。In order to explore the influence of pore structure on the characteristics of oil-water two-phase seepage in carbonate reservoirs,taking the E^(2)_(3) reservoir in Yingxi area of Qaidam Basin as an example,the threshold pressure gradient experiments of single phase and oil-water two-phase and the macro/micro oil-water two-phase seepage experiments were carried out by classifying the pore structure of the reservoir and combining with T2 spectrum of NMR.The results show that the reservoirs in the study area can be divided into fracture type,dissolved pore type and matrix pore type.The higher the development degree of fracture and dissolved pore and the more the number of large-size pore throats,the better the physical properties of core samples.There are obvious differences in oil-water two-phase seepage among the three types of cores.In the fracture type and dissolved pore type reservoirs,fractures and dissolved pores are the main seepage space,there is good connectivity among large-size pore throats,and corresponding cores have high oil displacement efficiency.The percolation capacity of matrix pore type cores is 1/10~1/103 of that of fracture type and dissolved pore type cores,and the connectivity among large-size pore throats is poor,and the oil displacement efficiency of corresponding cores is low.The single-phase and oil-water two-phase threshold pressure gradient of dissolved pore type and fracture-type cores is low,and its variation range is small;The single-phase threshold pressure gradient of matrix pore type cores is the highest,and the oil-water two-phase threshold pressure gradient rises significantly,which verifies that the matrix pore type cores have poor oil displacement effect and weak seepage capacity.

关 键 词：孔隙结构 渗流特征 碳酸盐岩储层 启动压力梯度 柴达木盆地 

分 类 号：TE312[石油与天然气工程—油气田开发工程]