摘要
模拟井眼条件研究了不同剪切速梯、温度、压差条件下钻井液对油层的损害程度。结果表明 ,钻井液中的固相粒子在级配合理的情况下 ,对高渗透率的岩心损害深度浅 ,反排易于解除损害 ;而对低渗透率的岩心 ,细微粒子和液相进入油层深部后不易用反排方式解除 ,损害较严重 ;速梯增加以及温度升高也会加大损害程度 ;随压差的增大 ,岩心渗透率恢复值没有一定的规律。用动失水法评价钻井液对油层的损害半径 ,更接近于井下实际情况。
The damage degree of drilling fluids to reservoirs is studied under the conditions such as different shearing velocity gradients, temperatures and pressure differences existing in a formation The study result shows that the solid particles in drilling fluids caused a shallow damages to the cores of high permeability properly graded and the damage is eliminated easily by flowback and the damage to the cores of low permeability is eliminated hardly because fine particals and liquid enter the deep reservoir along the cores, which means the damage is serious The degree of damage raises with the increase of velocity gradient and temperature The restoration rate of cores is irregular when pressure difference is increased The method of dynamic filtration is used to evaluate the damage radius of drilling fluids to the reservoirs, which is approaching to the actual situation in hole
出处
《江汉石油学院学报》
CSCD
北大核心
2000年第3期97-98,共2页
Journal of Jianghan Petroleum Institute
关键词
防止地层损害
钻井液
井眼状况
渗透率
油层
formation damage prevention
drilling fluid
wellbore condition
permeability
laboratory testing
