摘要
低渗透油气藏对地层有效应力很敏感，用常规压汞技术测得的三维应力释放后的岩样孔喉分布实际是视孔喉分布，与地下状态会有很大出入。用焉耆盆地宝浪油田２０块低孔低渗天然柱状岩心，分成２０对平行样，分别采用有效应力下单向水平流动压汞技术和常规压汞技术测定它们的压汞曲线，进行２种实验技术的对比实验研究。与常规压汞技术测定结果相比，在有效应力作用下的单向水平流动压汞技术测得的岩样毛细管排驱压力、中值压力大幅度增加（分别增加７７．８９％和５８．１６％），孔喉的最大半径和中值半径大幅度降低（分别降低７５．４％和６１．１７％），喉道分选性变好，空气渗透率降低幅度大（７１．６２％），孔隙度降低幅度较小（１３．０８％）。单相水平流动压汞与常规压汞所得的低渗透油藏的孔喉分布特征参数差别大，但二者相关性良好，在对低渗透油藏岩样进行大量常规压汞测试的同时，进行少量的单向水平流动压汞与常规压汞对比实验，就可由大量常规压汞资料准确获得地层有效应力作用下低渗透油藏储集层的孔隙结构特征参数。图４表１参３（郭海莉摘）
Low permeability oil/gas reservoir is very sensitive to its effective rock stresses, pore throat size distribution obtained from core samples by conventional Hg injection technique is actual an apparent pore throat size distribution and differs largely to those under subsurface conditions. Low permeability cores from Baolang oil field, Yanqi basin are divided into 20 pairs to make parallel tests. The directional horizontal flow Hg injection under effective stress and conventional Hg injection techniques are used parallelly to obtain Hg injection curves respectively and their results are correlated to have a comparison. As compared with those results from conventional Hg injection tests, displacement capillary pressures, median pressures obtained by single direction horizontal flow Hg injection increase significantly (increased by 77.89% and 58.16% respectively), maximum pore throat radius and median radius decrease significantly (decreased by 75.4% and 61.17% respectively), sorting of pore throat size becomes more better, air permeability decreases significantly (71.62%), and the decrease of porosity is rather moderate (13.08%). The characteristic parameters of parallel tests differ significantly but can be correlated finely. It is, therefore, only relatively small number of core samples need to make single direction horizontal flow Hg injection tests, then the characteristic parameters of low permeability reservoir rocks can be obtained by correlating with those results obtained from convention Hg tests.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
1998年第6期61-62,66,共3页
Petroleum Exploration and Development
关键词
储集层
孔隙结构
水单流动压汞
常规压汞
Low permeability pools, Mercury injection test, Overburden pressure, Throat radius
