靖安油田长4+5油藏储集空间及成岩作用演化

Reservoir space and diagenesis evolution in the Chang 4+5 reservoir of Jing'an oilfield

利用铸体薄片、扫描电镜、阴极发光、X衍射分析等多种手段,研究了靖安油田长4+5油藏岩石学特征、储集特征、喉道特征、成岩作用及其演化特征。结果表明:研究区储层砂岩成分成熟度偏低,结构成熟度中等,储集空间以粒间孔、长石溶孔为主,储层喉道较细,分选较差,排驱压力、中值压力较高,退汞效率较低。储层孔隙中常见自生石英、长石加大、绿泥石等黏土充填。研究区孔喉组合主要表现为小孔-细喉型。研究区储层岩石成岩作用主要有压实作用、胶结作用、交代作用以及溶蚀作用,经历了复杂的成岩演化过程,对储层物性具有重要的影响。

The Chang 4+5 reservoir of the Jing'an oilfield is studied for petrology,reservoir space,pore throat,diagenesis and evolution characteristics by using casting thin section,scanning electron microscope,cathodoluminescence and X-ray diffraction analysis.The results show that the sandstone reservoir in the study area is characterized by low compositional maturity,medium textural maturity,intergranular pores and feldspathic dissolved pores,fine pore throat,poor sorting,high displacement pressure and median pressure,and low mercury withdrawal efficiency.Clay filling is often seen in reservoir pores such as authigenic quartz,augmented feldspar,and chlorite,etc.Pore-throat combination pattern in the study area is featured by tiny pore-fine throat.The diagenesis of reservoir rock involves compaction,cementation,metasomatism and denudation.Complex diagenetic evolution process had exerted significant influence on petrophysical properties.