大庆萨中二类油层对三元驱油体系的吸附特性

Adsorption properties of ASP flooding system for the central Saertu sub reservoir in Daqing

通过大庆萨中二类油层三元复合驱矿场试验,分析一、二类油层岩心的矿物组成和孔隙结构特征,绘制一、二类油层砂的吸附等温线,考察化学剂在天然岩心上动态滞留量,比较一、二类油层的吸附差异;通过单一矿物对三元组分的吸附实验,分析二类油层高吸附的原因.结果表明:二类油层的黏土矿物质量分数显著高于一类油层的,且绿泥石质量分数较高;二类油层的渗透率约为一类油层的1/3,喉道半径较小.三元驱油体系中3种化学剂在黏土矿物上的吸附量明显大于骨架矿物的,三元组分的吸附损失主要由黏土矿物引起,其中绿泥石对化学剂的吸附作用较强.3种化学剂在油砂上的吸附等温线为Langmuir型,NaOH和表面活性剂的饱和吸附量较高,HPAM的饱和吸附量较低;表面活性剂的饱和吸附量受岩心性质影响较大.3种化学剂在二类油层岩心的动态滞留量均高于一类油层岩心的,NaOH和表面活性剂的动态滞留量低于静态吸附量,HPAM的动态滞留量大于静态吸附量.该研究结果为复合驱油体系配方优化及矿场试验方案设计提供依据.

This paper,based on the test of ASP Flooding System for the central Saertu second reservoir Daqing,analyzed the mineral composition and pore structure character of the first and second reservoir,drew a picture of adsorption isotherm of the first and second oil sand,investigated the dynamic retention of the chemistry in natural core,discussed and compared adsorption differences between the first reservoir and the second one,and revealed the reason why the second reservoir showing the higher adsorption by experimenting the adsorption of ternary component on single mineral.So it was concluded that the clay minerals content of the second reservoir are significantly higher than the first one,especially the chlorite;the permeability of the second reservoir is one third of the first and throat radius of the second reservoir are also smaller;clay mineral adsorption of the three chemicals in ASP system is obviously greater than the matrix mineral adsorption;the adsorption loss of the three chemicals is mainly caused by the clay minerals,of which chlorite has a stronger adsorption capacity;the adsorption isotherms of the three chemicals on the oil sand corresponds well with the Langmuir type that the saturated adsorption of NaOH and the surfactants are higher than the HPAM,the core properties has great influence on the saturated adsorption of the surfactants;the dynamic retention of the three chemicals in the second core are higher than the first,the dynamic retention of NaOH and the surfactant is lower than static absorbance,and the HPAM is exactly on the contrary trend.The study of adsorption properties and laws of Class II Reservoirs provide the theoretical bases for prescription optimization of combination flooding systems and conceptual design of field tests.