Most shallow reservoirs in Bohai sea are unconsolidatedformation with heavy oil, and they are developed mainly by using a sand exclusion management.
渤海浅层油藏大多为胶结疏松的稠油油藏，这类油藏的开发目前主要采取防砂管理方式。
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The caliper problem occurred during the drilling in the Nanpu oilfield, due to shallow depth in the reservoir, unconsolidatedformation and lower gel strength.
Methods of tunnel excavation in unconsolidated formations and the collapse zone treatment are intro-duced according to the formation properties fo exit section of Yangzong No.