砂砾岩致密油藏超临界二氧化碳吞吐适应性分析

为研究砂砾岩致密油藏超临界CO_2吞吐效果,基于M油田砂砾岩致密油藏岩储层条件室内模拟超临界CO_2吞吐饱和油岩心、含束缚水饱和油岩心。通过吞吐前后岩心中采出油量、采出油组分变化、吞吐前后油相渗透率变化得出:束缚水存在增加了超临界CO_2吞吐采出流体量但降低了原油的采收率,同时减弱了CO_2对原油的萃取能力,使得采出油组分变轻,CO_2萃取原油组分区间为C_(12)～C_(21);CO_2与地层水作用产生沉淀现象是导致吞吐后岩心油相渗透率下降的主要原因,CO_2与水作用强度大于与原油作用强度。

Study on Adaptability of supercritical CO2 huff and puff in tight glutenite reservoir

To study the effect of supercritical CO2 huff and puff in tight sandy conglomerate reservoirs.Based on the reservoir conditions of tight sandy conglomerate reservoir in M oilfield, the saturated oil cores with supercritical CO2 huff and puff and the saturated oil cores with irreducible water are simulated indoors.Through the changes of oil production volume, oil components and oil phase permeability before and after huff and puff, it can be concluded that the existence of bound water increases the fluid volume produced by supercritical CO2 huff and puff, but reduces the oil recovery, and weakens the extraction ability of CO2 to crude oil, making the oil components produced lighter, and the interval of CO2 extracted crude oil components is C12-C21; the interaction between CO2 and formation water produces precipitation.It seems that the main reason for the decrease of oil phase permeability of core after huff and puff is that the interaction strength between CO2 and water is greater than that with crude oil.