论文详情
要：塔河奥陶系碳酸盐岩油藏储集空间以溶洞储集体为主。溶洞储集体地震反射特征受溶洞规模、溶洞充填物类型及充填程度的共同影响,仅依据地震反射特征难以准确刻画溶洞规模。从地震、地质及钻井资料出发,建立了不同规模、不同充填物的溶洞模型,利用非均匀介质波动方程正演模拟技术,对比分析了不同规模、不同充填物的溶洞模型对地震反射振幅及频率响应的影响,提出了基于高频衰减梯度属性的溶洞储集体规模识别技术。以塔河油田岩溶古河道溶洞储集体为例,利用高频衰减梯度属性识别岩溶古河道规模,结果表明,高频衰减梯度不受溶洞储集体充填物的物性差异的影响,直观反映了溶洞发育的规模。基于高频衰减梯度属性的岩溶古河道溶洞储集体规模识别结果与已钻井结果高度吻合,证明了该方法的有效性。
Reservoir space of the Ordovician carbonates in the Tahe oilfield in China is dominated by erosive reservoirs.The seismic reflection characteristics of the karst cave reservoirs combine effects of scale,filling type,and filling degree,making it difficult to accurately depict their scale based on seismic reflection characteristics.Using seismic,geology,and drilling data,karst cave reservoir models with different scales and different fillings were constructed.Following that,numerical simulation using wave equations for an inhomogeneous medium were adopted,to further compare and analyze the effects of scale and filling of karst caves on seismic reflection,and frequency response characteristics.A scale identification technique for karst cave reservoirs based on the high-frequency attenuation gradient is proposed.The proposed technique was applied to field data from the Tahe oilfield,for the scale characterization of karst paleochannels.The results showed that the high-frequency attenuation gradient was unaffected by different fillings of the karst paleochannels,which can directly reflect the scale of karst caves.The predicted scales of karst paleochannels,based on the high-frequency attenuation gradient,showed good agreement with drilling data,confirming the effectiveness of the proposed technique.
国家科技重大专项(2016ZX05014-001,2016ZX05053-001)共同资助。