安棚油田部分井低砂比砂堵原因及对策
The Causes and Solutions of Sand Plug ging in Wells with Low Proppant Concentration in Anpeng Oilfield
-
摘要: 安棚油田压裂施工低砂比砂堵的原因是天然裂缝发育,滤失严重;裂缝起裂位置与最大主应力方向不一致,近井段摩阻大;岩石弹性模量高,人工裂缝窄。提出消除低砂比砂堵的措施是前置液中加入降滤失剂、延长低砂比注入段和降低管内摩阻,并通过施工实例证实了这些措施的良好效果。Abstract: The causes of sand plugging during fractur ing oper-ation with low proppant concentration in Anpeng oilfield are that nat ural fractures are highly developed leading to severe lost circulation;that the fracture beginning position has a different direction with that of the maximum main stress and near wellbore friction drag is large;and that the rocks have l arge elastic modulus.Several measures are pre-sented to solve this problem inc luding adding fluid loss ad-ditives to ahead fluid,elongating the injection in terval of fluid with low proppant concentration,and lowering friction drag in the casing.Field application of these measures was successful.