文昌A凹陷珠海组低渗储层主控因素分析

Analysis on Main Controlling Factors of Low Permeability Reservoir in Zhuhai Formation in Wenchang A Sag

摘要:

文昌A凹陷珠海组属于低—特低渗储层，由于低渗储层砂岩致密、孔隙结构复杂，制约了油气田的产能及采收率的提高。通过应用测井资料、扫描电镜、粒度、压汞等分析化验资料，对文昌A凹陷珠海组低渗储层主控因素进行了综合研究。研究结果表明:储层孔隙以原生剩余粒间孔为主，次生溶孔次之，压实作用损失孔隙15.7%～23.6%，胶结作用损失孔隙4.2%～14.9%，成岩压实和胶结作用是储层低渗特征的主控因素。沉积作用控制着储层的厚度、砂岩粒度和泥质含量，决定着储层原生孔隙大小，是控制储层低渗成因的基本因素。而溶蚀作用不是广泛发育，是低渗储层形成的一个重要原因。

Abstract:

The reservoir of Zhuhai formation is the lowextra low permeability in Wenchang A sag. Due to low permeability reservoir, its sand rocks are dense with complex pore structures, which have restricted the improvement of the capacity and recovery of oil and gas fields. Through analysis on logs, scanning electron microscope, grain size and mercury penetration, main controlling factors of the lowextra low permeability reservoir of Zhuhai formation have been synthetically studied in Wenchang A Sag. It is showed that the pores of reservoir are mainly original residual intergranular pores，and secondarily are secondary dissolved pores. The compaction reduced about 15.7%～23.6% of porosity, while the cementation reduced about 4.2%～14.9% porosity. The compaction and cementation of the diagenesis are the main controlling factors. The deposition controls the thickness, sand grain size and shale content of the reservoir, and decides the sizes of primary pores. It is the basic controlling factor of low permeability of the reservoir. It is also an important factor for forming low permeability reservoir, and the denudation is not widely developed.