费尔干纳盆地明格布拉克油田属于超深层油气藏,油气层普遍存在超压异常,压力系数可达2.0以上,地层发育盐岩、膏盐层,低孔隙储层中裂缝发育,油田的这些特征与流体封存箱的形成和存在有很大关系。通过研究认为,不均衡压实及构造挤压环境是新近系地层形成超压的宏观成因机制,而发育岩盐层且累积厚度达到了200 m以上是现今油田保存超压的重要条件;古近系及新近系下部地层中存在两个超压流体封存箱,上部封存箱的地层压力系数略大于下部封存箱,上、下超压封存箱内流体性质存在较大的差异,是两个相对独立的成藏系统。上部封存箱又被2个岩盐封隔层分隔为3个次一级的、呈阶梯式的超压箱。封存箱内的超压、微裂缝以及岩盐层是钻探过程中发生井涌、井漏及卡钻等钻井事故的主要原因;除已发现的下部封存箱和上Ⅲ次级封存箱油气藏外,上Ⅱ次级封存箱的底部具有一定的勘探潜力;超深层的高密度原油与超压流体封存箱的存在有关,封存箱内的超高压使油气藏储层裂缝处于开启状态,有利于形成高产油气流,但同时也易于早期见水。

Mingbulak oil field in Fergana Basin is an over deep oil and gas reservoir,which is characteristic with the prevalence of abnormal overpressure,pressure coefficient up to 2.0,and with the development of rock salt,gypsum salt bed,low porosity reservoir with abundant fracture.These characteristics have close relation-ship with the formation and existence of overpressure fluid compartments.By researching these properties,it is found that sediment undercompaction due to rapid subsidence and tectonic compression are main formation mechanisms of overpressure in Upper Tertiary formation,and the development of rock salt layers and its accu-mulated thickness over 200 m are important conditions for oil formations.Two overpressure fluid compartments can be identified in Tertiary formations;the pressure coefficient of the upper compartment is bigger than the low-er one.The fluid properties of both compartments are clearly different,and they are two relatively independent accumulation systems;The u