超低渗透油藏活性酸酸化增注技术研究

受储层物性及注入方式的影响,镇北、华庆油田部分井投注后达不到配注要求.依据对超低渗欠注区块储层物性及目前注水现状的分析,通过室内实验研究了酸液配方体系,并对施工工艺进行了优化.所研制的酸液体系可使岩心的渗透率提高30%;通过酸液驱替可以有效消除注水对岩心造成的伤害,渗透率得以恢复.15口井现场酸化增注试验措施有效率达到93.3%,平均注水压力下降2.9 MPa,平均单井日增注量15 m3,取得了较好的增注效果.

Active acidization technology of superlow-permeability reservoirs for increasing water injection

The water injection of some oil wells in Zhenbei oilfield and Huaqing oilfield is not enough due to reservoir property and water injection mode.According to the analysis of reservoir property and present water injection state,it is held that the acidization of the superlow-permeability reservoirs is needed.The acidizing liquid system was developed by laboratory experiments,and the acidizing technology is optimized.It was injected into core and can make the permeability of the core increased 30%.It can remove the damage of water injection to cores,and makes the permeability of the cores recovered.The field acidizing tests of 15 wells show that the effectiveness ratio of the acidizing construction is 93.3%,and that water injection pressure declines 2.9 MPa and single-well water injection increases by 15 m 3 / d on average.