王集泌162区块非均质稠油油藏化学驱油体系评价OA

According to the geological characteristics of the common heavy oil reservoir in Wangji B162 block,in order to further enhance oil recovery,the chemical flooding system was studied,and a chemical oil recovery system evaluation was conducted based on factors such as polymer viscosity,viscosity tempera-ture,long-term thermal stability,and the influence of mineralization on viscosity.The results showed that:①The selected polymer aged for 180 days at reservoir temperature(56.5 ℃),with a viscosity retention rate of 88.1％;② When the optimal concentration of surfactant is 500-3 000 mg/L,the interfacial tension can reach an ultra-low order of 10-4 mN/m;when it's above 1 000 mg/L,the interfacial tension of the polymer/surfactant flooding system can reach the order of 10-3 mN/m;③The single core oil displacement experiment shows that the heterogeneous composite flooding system(polymer+surfactant+PPG)has an in-creased recovery rate of 10.63％,4.51％,and 3.74％compared to the single polymer,binary composite system(polymer+surfactant),and heterogeneous system(polymer+PPG)respectively;④The double tube parallel core experiment shows that when the injection amount is the same,scheme 3 using a heteroge-neous system for single injection into high permeability layers increases the recovery rate by 3.9％compared to scheme 2 using high and low permeability layers for simultaneous injection;The total slug volume is 0.6 PV,and the main slug adopts a multi-stage slug combination scheme 4,which increases the recovery rate by 3.6％compared to scheme 3 with a single main slug;1 000 mg/L·PV increases oil recovery by 9.01％,with better enhanced oil recovery and economic benefit compared with other schemes.