蒸汽驱对储层孔隙结构和矿物组成的影响

THE EFFECT OF STEAM FLOODINGON PORE STRUCTURE AND RESERVOIR MINERALS

以辽河高升油田莲花油层 ,通过室内模拟实验和矿场岩心分析了蒸汽驱对储层孔隙结构和矿物组成的影响。研究表明蒸汽驱导致储层孔隙度、孔隙直径增大 ,喉道半径、渗透率减小 ,增强了孔喉分布的非均质性 ,蒸汽对粘土矿物的微结构有强烈的破坏力。同时 ,室内实验表明蒸汽驱过程中 ,2 5 0℃时有蒙脱石、沸石等矿物产生 ,但由于稠油对蒙脱石等细小的微粒有较强的携带能力 ,最终导致储层中蒙脱石的含量降低。

This paper shows the effect of steam flooding on pore structure and reservoir minerals in Lian-hua reservoir of Liaohe Gaosheng oil field based on lab simulation and core analysis. The pore structure of reservoir media are studied to compare with heat simulation experiments. Steam flooding will lead to the increase of porosity and pore diameter, and the decrease of pore throat and permeability. Thus, the heterogeneity of pore structure becomes more serious .Steam has strong effect on the microstructure of the clay minerals .The experimental tests prove that new minerals, such as smectite and zeolite, will be formed at 250℃. However, the heavy oil can easily carry fine particles(<4μm) ,and finally the content of smectite in reservoir will decline .The main factors of formation damage during the steam flooding are particle migration and swell of smectite.