强非均质性油藏空气泡沫调驱先导试验——以胡状集油田胡12断块为例

Pilot test of air foam drive of serious heterogeneous reservoirs——taking Hu12 fault block in Huzhuangji Oilfield as an example

强非均质性油藏注水开发后形成优势渗流通道,综合含水率高达98%以上。为提高该类油藏的采收率,在胡状集油田胡12断块开展了空气泡沫调驱先导试验。室内实验结果表明,空气泡沫体系不但能够与原油发生低温氧化反应,而且能够封堵优势渗流通道,提高最终采收率。现场实施空气泡沫调驱后,注入井注入压力提高了78%,5个月油井未见气体产出,水线推进速度大大减缓,试验井组的综合含水率下降了3.4%,产油量增加了38.5%。实践证实,在严重非均质性油藏特高含水开发期,空气泡沫调驱是封堵优势渗流通道、恢复地层能量、降低含水率和提高采收率的有效手段。

Water flooding development in serious heterogeneous reservoirs will result in preferential seepage channels and injected water short-cycle to cause 98% of composite water cut. In order to enhance oil recovery of this type of reservoirs ,a pilot test of the air foam drive was carried out in Hu12 fault block of Huzhuangji Oilfield in Zhongyuan Oilfield. The laboratory experiment shows that the air foam system not only can cause low-temperature oxidation with crude oil,but also can plug the preferential seepage channels to increase the ultimate oil recovery. After the air foam drive is applied in the field,78% of water injection pressure of the injector increased,and no injected gas break through during more than 5 months testing period. Promotion speed of waterfront reduced greatly ,3.4% of the composite water cut dropped,and oil production rate rose by 38.5% in tested well group. This study indicated that the air foam drive is one of the new and efficient methods for plugging the preferential seepage channels,restoring the formation pressure,and reducing the water cut and enhancing the oil recovery in the extra-high water cut development period of a serious heterogeneous reservoir.