二连哈南油田油井复合解堵酸化液研究及应用

Study and application of compound acidizing fluid for plugging removal in Hanan Oilfield, Erlian

哈南油田属低渗透复杂断块油田,储层物性差,油层总厚度虽然大,但储层多而且单层薄。由于粘土运移及蜡和胶质沥青质垢的生成,近年来油井产量逐年下降。因此决定在解除地层有机伤害和无机伤害的同时提高地层基质渗透率,采用有机解堵剂和深度基质酸化相结合的方法,提高油井产量。在室内对酸液、添加剂进行了优选,确定采用有机酸和盐酸为前置酸,有机酸、盐酸和氢氟酸为主体酸,有机酸和盐酸为后置酸;选择由分散剂、有机溶剂和破乳剂等组成的FAX-1油垢清洗剂,能将垢(除无机质外)完全、快速地溶解并不产生乳状液;采用廊坊分院压裂酸化中心的FAH缓蚀剂;开发了高性能的FAD综合添加剂。前置酸、后置酸和主体酸的性能评价结果表明,在80℃下静置48 h后,无异常变化;动态腐蚀速率为6.23 g/m2·h(80℃);表面张力为25.96 mN/m;20 min内完全破乳。先后进行了3口井的酸化,酸化后表皮系数降低,产油量明显提高。

Hanan oilfield has low permeable complex fault reservoirs, with multiple but relative thin oil bearing layers, and the physical properties of the reservoirs are poor. Oil production in recent years decreases due to clay migration and the formation of wax and gel asphalt scales. By using organic plugging removal agent, and adopting deep matrix acidizing, the organic damage and inorganic damage can be removed and matrix permeability improved at the same time. Based on the laboratory optimization, it is determined that the organic acid and hy- drochloric acid can be used as flushing acid, and organic acid, hydrochloric acid and hydrofluoric acid as the host acid, while organic acid and hydrochloric acid as tail acid. The scale cleaner FAX-1 composed of dispersing a-gent, organic solvent and gel-breaking agent can completely and quickly solve the scale without emulsion, and high performance retardant and other additives are also used. Evaluation results show that it is stable and qualified, and its use in 3 wells are successful, as the skin factor drops down and oil production improves remarkably.