谱分解在南黄海中部隆起中-古生界储层预测中的应用

Application of spectral decomposition to detect Mesozoic-Paleozoic reservoir on the central uplift of the South Yellow Sea Basin

大陆架科学钻探CSDP-02井的钻探,开启了南黄海中-古生界研究的新局面。本文利用过CSDP-02井的多道地震、测井和岩心资料,在对中部隆起中-古生界地层频谱分析的基础上,采用基于S变换的谱分解方法,对南黄海中部隆起中-古生界地层进行了谱分解,将地震数据由时间域转换到频率域,得到了不同频率的等频率剖面。结果表明,南黄海中部隆起存在3套可能的储集层,分别对应三叠系青龙组灰岩、二叠系龙潭组砂岩和石炭系灰岩,在等频率剖面上,均表现为明显的低频异常,频谱特征呈现低频高能、高频低能的特征,在高频剖面上,储层异常被浅层高频异常掩盖。通过与CSDP-02井的岩心和测井结果进行对比发现,3套储集层的频率衰减现象与岩心取样中的油浸层相关,这是我国首次在南黄海中-古生界发现油气显示,对指导南黄海中-古生界油气勘探具有重要意义。

The drilling of well CSDP-02 of the＂Continental Shelf Drilling Program＂creates a new situation for the exploration of Mesozoic-Paleozoic reservoir on the central uplift of the South Yellow Sea Basin.In this study,based on the spectrum analysis of Mesozoic-Paleozoic strata,as well as the multi-trace seismic,logging and core data of Well CSDP-02,S-transform is applied to multi-trace seismic data from Mesozoic-Paleozoic strata of the central uplift to get different instantaneous frequency volumes.The results show that,the three possible reservoirs of Qinglong Formation,Dalong-Longtan Formation and Chihsia Formation-Carboniferous all show low frequency anomalies with a Spectrum analysis showing low frequency low intensity or high frequency low intensity anomalies.At high frequency section,the reservoirs standout from surrounding geology and shallow layers are also bright at such high frequency,which will deteriorate the likelihood to identify the anomalies of target layer from iso-frequency sections.Compared with core description of Well CSDP-02,the low frequency anomalies are related with oil immersion layer observed from well sample,which has a great significance for the exploration of Mesozoic-Paleozoic layer of the South Yellow Sea Basin.