The Causes and Solutions of Sand Plug ging in Wells with Low Proppant Concentration in Anpeng Oilfield

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.