保护储层修井液实验研究及应用

延长油田属于低渗透油田,修井过程中工作液侵入是造成油田储层伤害的主要因素之一.为了降低外来工作液对储层的伤害,缩短修井产量恢复时间,研制了有利于保护储层的修井液.通过微波法对黄原胶XG改性得到的XG-GM作为增粘剂.对该增粘剂性能进行评价,并对降滤失剂、粘土防膨剂、表面活性剂、缓蚀剂等进行优选并组合复配.确定的修井液：清水＋0.4％XG ＋2％RS ＋0.3％AY ＋0.3％MOA-E ＋0.2％S-HSJ ＋JZ-2.实验表明,该修井液具有良好的增粘流变性,API滤失量控制在10.5 mL,岩屑回收率为95.3％,低界面张力.动态伤害模拟实验表明,该修井液体系对岩心的恢复率为84.6％～92.4％.在延长油田应用结果表明,该修井液体系能有效地保护油气层,提高单井产量,应用前景良好.

Research and application on reservoir protection workover fluid

Yanchang Oilfield belongs to low permeability reservoirs,working liquid in the process of repairing operation is the main factors of reservoir damage.In order to prevent the working liquid damaging reservoir,short the period of yield recovery,reservoir protection workover fluid has been studied through optimizing and combination.Modified by the microwave method for xanthan gum XG get XG-GM as adhesives.To evaluate its properties XG-GM the adhesives,temporary and plugging agent in clay expansion agent and surfactants,laboratory optimization and compound,this formulas of perforating fluid is clean water ＋ 0.4％ XG ＋ 2％ RS ＋ 0.3 ％ AY ＋ 0.3 ％ MOA-E ＋ 0.2％ S-HSJ ＋ JZ-2 （density is adjustable） the solid free system passed the test.Experiment showed working fluid low API filtration,viscous rheology is controlled in 10.5 mL,cuttings rolling recovery was 95.3％,can stain resistance and good demulsibility and biodegradable.Dynamic damaging and simulative experiments of core show system the perforating fluid system for the core recovery rate is 84.6％ ～ 92.4％.In oilfield Northern Shaanxi application results show system the system can effectively protect reservoir and enhance the output recovery effect,it is good prospects.