琼东南盆地深水区中央峡谷黄流组储层特征及主控因素

Characteristics and controlling factors about the reservoir of Huangliu Formation in the central canyon of Qiongdongnan Basin

在利用钻井和岩心资料基础上,结合铸体薄片、常规物性、压汞实验等分析测试手段,对琼东南盆地深水区中央峡谷黄流组储层特征及其影响因素进行了分析。研究表明,中央峡谷黄流组砂岩以岩屑石英砂岩为主,砂岩粒级较细且分选好,成熟度较高。原生粒间孔为主要孔隙类型,孔隙结构普遍为中孔细喉型。储层物性总体表现为中孔-特高孔、中渗-特高渗的特征。沉积微相和成岩作用是影响黄流组储层物性的主要因素,深水浊流沉积的水道砂岩是发育优质储层的前提,同时中央峡谷特殊的水深和温压条件是影响储层成岩作用的重要因素。海水深度大,而实际地层埋深浅,储层总体处于低温常压环境中,以致成岩作用程度普遍不强,但中央峡谷黄流组储层物性的内在差异仍主要受控于压实作用,中央峡谷自西向东,水深增加,实际地层埋深变浅,压实作用减弱,储层孔隙度和渗透率较好,总体上峡谷东部气层含气饱和度也较西部高。

Based on the use of drilling and core data,combined with the identification of casting thin sections,scanning electron microscopy,capilllary pressure experiment and so on,we analyze the reservoir characteristics and controlling factors of Huangliu Formation in the central canyon of Qiongdongnan Basin.The research shows that the finely granular lithic quartz-sandstone is dominated in the Huangliu Formation,and the sorting degree of sandstone is good,indicating the high maturity of rock composition and structure.Primary intergranular pore is the dominant reservoir space type,and the pore texture of sandstone is characterized by medium pore and fine throat at large.The reservoir propertity has the characterise of medium-ultrahigh porosity and medium-ultrahigh permeability.Sedimentary facies and diagenesis are the main factors on reservoir property.The channel sandstone of deepwater turbidity current deposits is the precondition of the development of high-quality reservoir,and the special water depth and temperature-pressure condition are the important factors that affect the diagenesis of reservoir.Because of deep seawater and shallowly buried stratum,the reservoir of Huangliu Formation is in the environment of low temperature and normal pressure in general,so that the diagenesis is generally not strong.But the differences of reservoir porosity and permeability is mainly controlled by compaction.From the west to the east in the central canyon,the depth of seawater increases gradually and the buried depth of stratum gets shallower,the compaction in the west is stronger than the east of central canyon,so the porosity and permeability of reservoir in the east is relatively high,as also as the gas saturation.