廊固凹陷WX0井区沙四段储层特征研究

通过岩心观察、薄片鉴定、物性、压汞数据分析等技术手段,对廊固凹陷WX0井区沙四段储层特征进行研究,结果表明,WX0井区沙四段储层岩石类型主要为细粉长石砂岩,属于低孔特低渗储层,孔喉结构类型属于粗-中喉型,储层主要发育原生粒间孔隙,粒间(内)溶孔和裂缝较少。研究区储层经历了压实、溶蚀、胶结、交代等四种成岩作用,处于早成岩B期、晚成岩A期、晚成岩B期三个阶段。沉积作用和成岩作用是控制储层物性的主要因素,沉积作用控制有利的沉积相带,水下分流河道和河口砂坝是有利的油气聚集区,压实和胶结作用使储层物性变差,溶蚀作用产生次生孔隙,使储层孔渗变好。

Reservoir characteristics of the 4~(th) member of Shahejie formation in WX0 well block,Langgu depression

The reservoir characteristics of the 4~(th) member of Shahejie formation in WXO well block of Langgu depression were studied through cores observation, rock thin section identification, physical properties analysis and the mercury injection, the results indicate the reservoir characteristics of the 4~(th) member 4 of Shahejie formation in WXO well block are mainly of fine-silt feldspar sandstone, the reservoir belongs to low porosity, ultra-low permeability reservoir, and the pore throat structure is of wide-fine throat type. The main reservoir spaces are original intergranular pores, inter-granular dissolution pores, intragranular dissolution pores and the fracture is less. The diageneses contain compaction, cementation, dissolution and metasomasis. The diagenetic experienced early diagenetic B stage and late diagenetic A and B stage. Sedimentation and diagenesis have an important influence on physical properties of reservoir. The sedimentation determines the favorable the sedimentary facies, and the subsea distributary channel and mouth bar were favorable facies belt for hydrocarbon accumulation. The compaction and cementation make the properties of reservoir poor, the dissolution leads to secondary pores, which increases the porosity and permeability of the reservoirs.