聚驱后油藏激活内源微生物的驱油工艺

Technology of Indigenous Microbial Activation for Enhancement of Oil Recovery in the Reservoir after Polymer Flooding of Daqing Oilfield

采用优选的激活剂与保护剂聚合物交替注入工艺在萨南南二区东部聚驱后典型油藏开展激活内源微生物驱油现场试验。应用效果表明，在激活剂由注入到采出的过程中产气增压效果明显，注入压力由注前的11．0MPa上升到13．5MPa，注后7个月压力又回升到12．5MPa以上，进一步验证激活剂的加入促使油藏内源微生物微氧和无氧代谢过程的交替进行，同时也监测到油藏内源微生物“原位”地下发酵过程中的代谢产物CH4和CO2气体组分和δ^13C（PDB）N位素的含量变化，试验区阶段累计增油4057t。这表明聚驱后油藏采用激活本源微生物驱油的工艺方法是可行的，为同类油藏进一步提高采收率提供了一条新途径。

Field tests of active indigenous microbial flooding were carried out in the typical reservoir after polymer flooding in the east of south II of Sa Nan. The optimized activator was injected alternately with protectant polymer. The results showed that the pressure increased from 11.0MPa to 1 3.5MPa during the injection of activator. After 7 month of injection, the pressure increased above 12.5MPa, which further verified the alternate processes of indigenous microbial micro-oxygen and anaerobic metabolism were promoted by activator. The change of content of CH4, CO2 and 6 13C（PDB） isotope were monitored during microbial in situ underground fermentation. The incremental oil was 4057t. Indigenous microbial activation for enhancement of oil recovery in the reservoir after polymer flooding is feasible, which provide a new way to further improve the recovery of similar reservoirs.