摘要
针对W油田C_(6)低渗透油藏水驱前后储层特征变化规律不明确的问题,通过X衍射、扫描电镜、铸体薄片、压汞实验、相渗实验以及真实砂岩微观渗流实验等方法,研究了油藏注水前后储层岩性、物性及渗流特征的变化规律,并分析了储层特征变化的机理及影响原因。研究结果表明:水驱后,黏土矿物总量整体呈减少趋势,方解石含量增加,在黏土矿物中,伊利石含量减小,绿泥石含量稍有增加;岩样长期水驱前后,物性好的岩样孔喉中值半径变大,渗透率增大,非均质性变弱;物性较差的岩样孔喉中值半径变小,渗透率降低,非均质性变强;水驱后的相渗曲线整体向左偏移,岩石的亲水性减弱,残余油饱和度增大,见水时间更早,含水上升更快;注入水长期冲刷对储层造成一定伤害,水驱油的驱替效果变差。研究成果为低渗透油藏的描述、开发效果评价及开发方案调整提供了依据。
In response to the problem that the change law of reservoir characteristics before and after water flooding in the C_(6) low-permeability reservoir in W Oilfield is unclear,the X-ray diffraction,scanning electron microscope,casting sheet,mercury injection experiment,phase permeability experiment and real sandstone microscopic seepage experiment were applied to study the change law of reservoir lithology,physical properties and seepage characteristics before and after water injection,and to analyze the mechanism and influence reasons of reservoir characteristics change.The research result shows:After water flooding,the total amount of clay minerals shows a decreasing trend as a whole,and the content of calcite increases.Among the clay minerals,the content of illite decreases and the content of chlorite increases slightly;Before and after long-term water flooding of rock samples,the median radius of pore throats of rock samples with good physical properties becomes larger,the permeability increases,and the heterogeneity becomes weak,while the median radius of pore throats of rock samples with poor physical properties becomes smaller,the permeability decreases,and the heterogeneity becomes stronger.The phase-permeability curve after flooding shifts to the left as a whole,the hydrophilicity of the rock weakens,the residual oil saturation increases,the water breakthrough time is earlier,and the water cut rises faster.The long-term scouring of injected water will cause certain damage to the reservoir,and the displacement effect of water-flooding oil will become worse.The research results provide a basis for the description,development effect evaluation and development plan adjustment of low permeability reservoirs.
作者
邵晓岩
杨学武
孟令为
岳文成
莫磊
蔡涛
刘安
Shao Xiaoyan;Yang Xuewu;Meng Lingwei;Yue Wencheng;Mo Lei;Cai Tao;Liu An(PetroChina Changqing Oilfield Company,Yinchuan,Ningxia 750006,China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2022年第5期107-112,共6页
Special Oil & Gas Reservoirs
基金
国家自然科学基金“致密油循环水力压裂裂缝形成及渗流力作用机理研究”(51974253)。
关键词
低渗透油藏
水驱
矿物组成
物性
渗流特征
low permeability reservoir
water flooding
mineral composition
physical properties
seepage characteristics
