摘要
为了明晰渤海海域C油田馆三上段与馆三下段油层电阻率差异明显的问题,选取岩心样品,基于孔隙度测定、渗透率测定、压汞分析、核磁共振分析和薄片观察,系统分析了孔隙结构对油层电阻率的影响机理。结果表明:(1)低阻油层孔隙度、渗透率及其相关性显著低于正常电阻率油层;(2)相比于正常电阻率油层,低阻油层孔径中值更低;(3)低阻油层孔隙结构表现为2种类型,第1类以微孔隙为主,对水分子具有较强的吸附性,第2类微孔隙和大孔隙均存在,且微孔隙更为发育,孔隙非均质性强、连通性差,束缚水饱和度高。相比之下,第1类储集空间电阻率更低,表明微孔隙对电阻率的降低作用更为显著;(4)低阻油层主要发育片状喉道,接触类型为线接触,随着电阻率的增大,喉道类型逐渐转变为原生孔,接触类型逐渐转变为点接触。
In order to clarify resistivity difference between upper and lower N1gⅢformations in Bohai Sea,the influence mechanism of pore structure on reservoir resistivity is studied by the porosity and permeability measurement,mercury intrusion analysis,nuclear magnetic resonance(NMR)analysis and thin section observation of the core samples from C oilfield.The results show that:(1)Porosity,permeability and their correlation of low resistivity reservoirs are significantly lower than those of normal resistivity reservoirs.(2)Compared with normal resistivity reservoir,the low resistivity reservoirs have smaller median pore diameter.(3)The pore structure of the low resistivity reservoirs can be divided into two types.The first type is dominated by micropores,which have strong adsorption to water molecules.The second type has both micropores and macropores,and the micropores are more developed.The reservoir with the second type of pore structure has strong heterogeneity,poor connectivity and high irreducible water saturation.In contrast,the resistivity of the first type of reservoir space is lower,indicating that micropores have a more significant effect on the reduction of resistivity.(4)The low resistivity reservoir mainly develops flake throat,and the type of contact is line contact.With the increase of resistivity,the type of throat changes to primary pores gradually,while the contact type gradually changes to point contact.
作者
王飞腾
侯东梅
李彦来
权勃
刘博伟
WANG Feiteng;HOU Dongmei;LI Yanlai;QUAN Bo;LIU Bowei(Bohai Oilfield Research Institute,Tianjin Branch of CNOOC Ltd.,Tianjin 300459,China)
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2022年第6期32-37,共6页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
“十三五”国家科技重大专项“渤海油田高效开发示范工程”(2016zx05058)。
关键词
孔隙结构
低阻油层
孔渗关系
孔径分布
孔喉特征
pore structure
low resistivity reservoir
porosity-permeability relationship
pore size distribution
pore throat characteristics
