针对渤海A油田注水井堵塞的解堵增注液研究

Research of Blocking Removal and Augmented Injection Fluid for Water Injection Wells in Bohai A Oil-field

针对渤海A油田注水井堵塞(水质超标、腐蚀堵塞和油垢堵塞)特点,结合储层酸敏特性,提出了"抗酸敏"复合解堵增注思路;在研制安全性好、溶垢性强的有机解堵剂和优选抗酸敏无机解堵剂的基础上,确定了渤海A油田注水井解堵增注液配方;系统评价了解堵增注液防膨性、铁离子稳定性、腐蚀性、配伍性,解堵增注液不仅具有较好的稳定黏土和铁离子稳定能力,而且具有较小的腐蚀性和较好的配伍性;为了更真实地模拟现场堵塞,提出了"高浓度模拟水混合"的岩心堵塞模拟方法;从溶垢性和解堵性能评价结果可知,解堵增注液对有机垢、无机垢、铁腐蚀产物和综合堵塞均具有较好的解堵效果,解堵后渗透率恢复值均大于100%,明显提高了基质的渗透率,解堵效果明显优于现场单一的氟硼酸解堵液。

Aiming at the characteristics of injection well blocking(water quality overweight,blocking by corrosion and oil scale)in Bohai A Oilfield and combined with the characteristics of reservoir acid sensitivity,and the idea of'acid sensitivity prevention'compound broken down augmented injection was put forward.On the basis of developing good safety,strong scale dissolving organic plugging removal agent and optimizing anti-sensitive inorganic plugging removal agent,the formula for blocking removal and augmented fluid used in water-injected wells was determined in Bohai A Oilfield.The expansion ability,iron ion stability,corrosion resistance,compatibility were systematically evaluated,blocking removal augmented injection fluid not only had good clay and iron ion stabilities,and also had a less corrosion and good compatibility.To more realistic simulate the field blockings,a method of'high concentration of mixed simulation water' for core plugging simulation was put forward.It is indicated from reconciliation plugging performance evaluation result that broken down augmented injection fluid has better blocking removal effect on organic scale,inorganic scale and iron corrosion products and comprehensive blocking,after broken down the permeability recovery value is higher than 100%, it significantly improves the matrix permeability,the effect is obviously better than that of fluorine boric acid solution.