摘要
鄂尔多斯盆地苏里格气田东部盒8储层微观孔隙结构复杂、渗流规律研究相对薄弱,利用常规方法难以对储层品质进行合理评价。为此,综合利用铸体薄片、扫描电镜、恒速压汞、核磁共振及真实砂岩微观水驱油模型对苏里格气田东部盒8储层微观孔隙结构与可动流体饱和度的影响因素进行研究。结果表明,研究区孔隙组合类型以残余粒间孔-晶间孔型、晶间孔-岩屑溶孔型和微裂缝-微孔型为主,其发育程度及储层物性依次变差,储层渗流能力、驱油效率、矿场采收率及可动流体饱和度依次降低,相应的驱替类型由网状-均匀驱替转变为指状驱替。核磁共振数据表明,研究区盒8储层可动流体饱和度平均为39.16%,以Ⅱ类、Ⅲ类及Ⅳ类储层为主。可动流体饱和度与孔隙度、渗透率、残余粒间孔面孔率、喉道半径平均值、有效孔隙体积和喉道体积呈正相关,而与孔喉半径比呈负相关。
The pore structure of He8 reservoir in eastern Sulige Gasfield of Ordos Basin is complex,and the study on seep-age laws is relatively weak.It is difficult to evaluate the reservoir quality by conventional methods.Therefore,techniques of casting thin sections,scanning electron microscope,rate-controlled mercury penetration,nuclear magnetic resonance and microscopic waterflooding model based on real sandstone were used to study microscopic pore structure and influencing fac-tors on movable fluid saturation.The results show that the types of reservoir space are mainly residual intergranular poreintercrystalline pore,intercrystalline pore-debris dissolved pore and microcracks-micropore,and their development degree successively decreases and their physical properties become worse in order.The reservoir seepage capacity,oil displace-ment efficiency,mine recovery and movable fluid saturation also decrease successively and the corresponding oil displace-ment pattern changes from homogeneous network-like flooding to finger-like flooding.Nuclear magnetic resonance data show that the average saturation of movable fluid in He8 reservoir is 39.16%,and the types of reservoir are mainly II,III and IV.The movable fluid saturation is positively related to porosity,permeability,residual intergranular pore face rate,av-erage throat radius,effective pore volume and throat volume,and it is negatively related to pore throat radius ratio.
作者
惠威
贾昱昕
程凡
刘斐雯
任大忠
HUI Wei;JIA Yuxin;CHENG Fan;LIU Feiwen;REN Dazhong(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an City,Shaanxi Province,710049,China;No.11 Oil Production Plant,Changqing Oilfield Company,PetroChina,Xi’an City,Shaanxi Province,710201,China;State Key Laboratory of Continental Dynamics,Northwest University,Xi’an City,Shaanxi Province,710069,China)
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2018年第5期10-16,共7页
Petroleum Geology and Recovery Efficiency
基金
国家青年科学基金项目"致密砂岩油藏成岩-烃类充注时序对微纳米孔隙结构的约束机制及石油充注孔喉下限研究"(41702146)
关键词
孔隙结构
可动流体
核磁共振
恒速压汞
苏里格气田
microscopic pore structure
moveable fluid
nuclear magnetic resonance
rate-controlled mercury penetration
Sulige Gasfield
