富县采油厂水平井前置酸加砂压裂酸液配方试验

Formula Test of Acid Liquor for Sand Fracturing with Pre-acid in Horizontal Wells of Fuxian Oil Production Plant

为了解决富县采油厂油层水平井常规加砂压裂过程中给储层和支撑裂缝带来的损害导致压裂效果有限甚至压裂无效的问题,达到提高储层改造效果的目的,针对富县采油厂储层孔喉半径小、排驱压力高、孔渗性差、填隙物含量高等特点,通过室内实验配制出适合富县采油厂主力层位长6和长8油层的前置酸酸液体系。酸液体系为:12%盐酸+3%氢氟酸+0.5%缓蚀剂+0.5%破乳助排剂+0.5%黏土稳定剂+0.1%柠檬酸。室内实验和现场应用表明:该前置酸酸液能够有效降低压裂过程对储层和支撑裂缝的伤害90%以上,对低产低效储层改造具有重要指导意义。

In order to solve the damage caused to the reservoir and supporting fractures during the process of conventional sand fracturing of the horizontal wells in Fuxian oil production plant,which will result in limited or even ineffective fracturing,and to improve reservoir reconstruction effect,laboratory experiments have prepared a pre-acid system suitable for 6 and 8 oil layers of the main layers of the Fuxian oil production plant which aims for the characteristics of Fuxian oil production plant such as small pore throat radius,high displacement pressure,poor porosity and permeability,and high interstitial fillings content and so on.The acid solution system is:12%hydrochloric acid+3%hydrofluoric acid+0.5%corrosion inhibitor+0.5%demulsification aid+0.5%clay stabilizer+0.1%citric acid.Laboratory experiments and field applications show that the pre-acid solution can effectively reduce the damage to the reservoir and supporting fractures by more than 90%during the fracturing process,and has important guiding significance for the reconstruction of low-production and low-efficiency reservoirs.