渤海湾盆地济阳坳陷冶里—亮甲山组层状储层成因及其影响因素

THE GENESIS AND INFLUENTIAL FACTORS OF LAYERED RESERVOIR OF YELI-LIANGJIASHAN FORMATION IN THE JIYANG DEPRESSION OF THE BOHAI BAY BASIN

渤海湾盆地济阳坳陷下古生界奥陶系冶里—亮甲山组主要为一套厚层白云岩,其中发育大量的溶蚀孔洞,在裂缝沟通的情况下能够成为良好的油气储集层。利用渗透—回流模式,探讨了冶里—亮甲山组白云岩的成因机制,认为在白云岩化作用的基础上,早奥陶世末期的怀远运动导致研究区发生区域性隆升,形成风化壳型溶蚀孔洞,但这些孔洞是无效的储集空间;经过后期断裂作用的改造,地层中产生大量的裂缝将其沟通,才能使白云岩成为有效储层;断层的发育又沟通了大气降水和湖水,对储层进行二次溶蚀改造。因此,该区断裂作用决定了储层的形成和发育规模。

It was discovered that abundant isolated vug occurred in the Yeli--Liangjiashan Formation of Ordovician in the Jiyang Depression of the Bohai Bay Basin, which would turn into effective reservoir once connected by fractures. The article applied the seepage reflux mechanism developed by K. S. Deffeyes in1965 to interpret the genesis of the dolomite of the Yeli--Liangjiashan Formation, and raised that regional weathering crust was formed by Huanyuan tectonic movement, which resulted in regional uplifting in the end of Early Ordovician, and that a great quantity of weathering crust vugs were developed on the basis of dolomitisation. After these isolated vugs in the formation connected by the large mounts of fractures, which were generated by later fracturing reformation, the effective dolomite reservoir was formed. At the same time, the later faults linked up the atmospheric water and the lake water and reconstructed the reservoir by secondary corrosion. So the conclusion was that the development and its scale of this kind reservoir were controlled by later fracturing.