摘要
根据文献报道的华北、大庆、胜坨等油田的资料,论述了长期注水引起的储层特性变化:黏土分散、运移;岩石润湿性向亲水转化;相渗曲线发生相应变化;孔喉半径增大;地层渗透率增大;地层温度改变(降低);地层原油黏度升高;剩余油分布变零散。定性分析了储层物性变化引起的聚合物驱参数变化:注入地层的聚合物溶液黏度降低;不可及孔隙体积减小;聚合物吸附滞留量减小;残余阻力系数减小。针对某油藏的聚合物驱选取水驱前、水驱后两组参数(平均渗透率,地层温度,地层原油黏度,聚合物溶液黏度,聚合物吸附量,残余阻力系数,不可及孔隙体积),采用CMG软件预测聚合物驱的效果,聚合物注入总量0.25 PV,年注入量0.025 PV,结果表明含水为零时(水驱前)聚驱的预测增产油量,由水驱前参数计算的值低于由水驱后参数计算的值,由水驱前参数计算的见聚时间,晚于由水驱后参数计算的见聚时间。由此得出结论,在聚合物驱参数实验筛选和计算机模拟中应考虑注水引起的储层物性变化。
The changes in physical characteristics of reservoirs caused by long term water flooding were discussed in terms of the field data of Huabei,Daqing,Shengtuo,and other oil fields published elsewhere and presented as follows：clay minerals dispersion and transportation;rock wettability alteration towardz hydrophilicity;changes in relative permeabilities curves;pore throat radius enlargement;raise of reservoir permeability;variation（reduction） of reservoir temperature;raise of in-place oil viscosity;and disruption of continuous distribution of residual oil.These changes in reservoir characteristics caused in turn some changes in physical parameters for a polymer flood operation,the laters were qualitatively analysized and covered：reduction of polymer solution viscosity within the reservoir;reduction of inaccessible pore volume;reduction in polymer adsorption/retention;and reduction in residual resistance factor.The results of an unnamed polymer flood project with polymer solution volume to be injected 0.25 PV totally and 0.025 PV per year were predicted by using a CMG software and the parameters for polymer flood conducted before or after water flood such as average reservoir permeability,reservoir temperature,viscosity of oil in-place,polymer soultion viscosity,polymer adsorption,residual resistance factor,and inaccessible pore volume and it was ascertained that for a polymer flood project started at zero watercut,or before water flood,the enhancement in oil recovery predicted by using the parameters for polymer flood before water flood was smaller than that after water flood and the beginning of polymer production was later in the former case than that in the later case.It was concluded that the changes in physical characteristics of the reservoir should be taken into consideration in parameters sieving experiments and in computer simulation for a polymer flood project.
出处
《油田化学》
CAS
CSCD
北大核心
2009年第3期334-337,共4页
Oilfield Chemistry
基金
国家863项目"渤海油田聚合物驱提高采收率技术研究"(项目编号2007AA090701)
关键词
储层物性
时变性
水驱油藏
聚合物驱
参数筛选
计算机模拟
数值模拟
physical characteristics of reservoir
time variation
water flooding reservoirs
polymer flood
parameters selection
computer simulation
digital simulation
