南堡凹陷老爷庙油田新近系储层特征与油气成藏

Neogene reservoirs and hydrocarbon accumulation in the Laoyemiao Oil Field, Nanpu depression, Hebei

关键词:  新近系  储层  油气成藏  南堡凹陷

Key words:  Neogene  reservoir  hydrocarbon accumulation  Nanpu depression

摘要:

南堡凹陷老爷庙油田新近系馆陶组和明化镇组仍是目前勘探和开发的重点层段。新近系以河流相沉积为主,储层岩石类型以长石砂岩和岩屑长石砂岩为主;孔隙结构以中孔和大孔为主,分选较好;储层成岩作用相对较弱,碳酸盐析出是降低原生孔隙的重要因素,孔隙类型以粒间孔为主,馆陶组见少量粒间溶孔和粒内溶孔。储层成岩作用对油气聚集有利,储层沉积微相控制了油气的聚集和分布,河道和废弃河道砂体具有良好的储盖配置关系,是最有利的油气聚集相带;心滩砂体由于其封盖条件不如河道砂体优越,而含油气性相对较差。

Abstract:

The Neogene Guantao and Minghuazhen Formations have long been the key horizons in the exploration and development of the Laoyemiao Oil Field, Nanpu depression. The Neogene strata in this area mainly consist of the fluvial deposits. These well-sorted reservoir rocks are composed of arkose and lithic arkose, and contain mesopores and macropores. The diagenetic are relatively weak. The precipitation of carbonates is considered as an important factor in controlling the decrease of primary porosity.The porosity types consist dominantly of intergranular porosity.The intergranular solution openings and intragranular solution openings are rare in the Guantao Formation. The diagenesis of the reservoirs facilitates the hydrocarbon accumulation. The sedimentary microfacies of the reservoirs may exercise a major control on the hydrocarbon accumulation and distribution. Both the channels and abandoned channels have good reservoirseal associations, and are thus interpreted as most favourable facies belts for the hydrocarbon accumulation. As for the sealing conditions, the channel bar sandstones are not favourable as the channel sandstones and thus have relatively poor oil potential.