碳酸盐岩潜山不同级别构造裂缝分布规律数值模拟——以渤海湾盆地富台油田为例

为明确碳酸盐岩潜山不同级别构造裂缝的分布规律，观察并统计了渤海湾盆地富台油田奥陶系碳酸盐岩储层岩心裂缝特征，以裂缝开度和流体在裂缝中流态为依据将富台潜山裂缝划分为3个级别，并应用数值模拟方法计算出各层位不同级别构造裂缝分布情况。研究结果表明，富台潜山奥陶系储层构造裂缝可以划分为大裂缝（开度大于1.0mm）、中裂缝（开度为0.5~1.0mm）、小裂缝（开度小于0.5mm）。不同级别裂缝分布主要受到构造部位、断层和岩性控制，数值模拟结果显示大裂缝主要在八陡组、上马家沟组和下马家沟组的背斜核部及断层附近发育，中裂缝主要在背斜翼部及冶里组—亮甲山组发育，小裂缝在研究区发育较少，零星分布于八陡组和上马家沟组。

Numerical Simulation for the Distribution of Different Levels of Tectonic Fractures in Carbonate Buried Hills:Taking Futai Oilfield in Bohai Bay Basin as an Example

In order to analyze the distribution of different levels of tectonic fractures in carbonate buried hills,based on core observation and statistics of carbonate reservoirs of Ordovician in Futai Oilfield in Bohai Bay Basin,tectonic fractures are divided into three levels according to aperture and fluid phase behavior in fractures.The distribution of different levels tectonic fractures in each formation is numerically simulated subsequently.The results indicate as follows,tectonic fractures in carbonate reservoirs of Ordovician in Futai buried hill can be divided into large aperture fracture (aperture>1.0mm),medium aperture fracture (aperture:0.5-1.0mm) and small aperture fracture (aperture<0.5mm).Distribution of different levels of tectonic fractures is affected by tectonic position,faults and lithological characters.The numerical simulation results show that large aperture fractures mainly distribute in anticline core and near faults in O₂bd,O₂smand O₂xm.Medium aperture fractures mainly distribute in anticline flank and O1y.Small aperture fractures scatter in O₂bd and O₂sm.