摘要
由于塔中北坡中奥陶统致密碳酸盐岩与上奥陶统碎屑岩存在较大的波阻抗差异,以致在地震剖面上形成"两谷夹一峰"的连续强反射界面T74,它屏蔽了下伏地层尤其是一间房组内幕缝洞型储层的地震响应,难以识别及预测一间房组内幕缝洞型储层。为此,依据塔中北坡实际地层结构,并考虑了一间房组的储层发育特征建立了储层模型,采用非均质介质波动方程并基于交错网格有限差分格式进行数值模拟;在此基础上应用多子波分解的波形分解技术,开展去除强反射界面影响的技术研究。结果表明:在T74之下的一间房组中、下部缝洞型储层表现为"一谷一峰"地震响应特征;单一分量地震数据体不能反映一间房组中、下部缝洞型储层的地震响应特征,第2~第5分量叠加地震数据体有效地去除了T74的影响,使掩盖在T74之下的一间房组中、下部缝洞型储层的"一谷一峰"地震响应被突显,且与井震标定结果吻合较好。
A big impedance difference between middle Ordovician and upper Ordovician in northern slop of Centre Tarim Basin produces extremely strong reflection, which imposed huge interference to seismic records from Yi-Jianfang Formation. However, in the middle and bottom of Yi-Jianfang Formation, there are lots of fractured reservoirs that we are very concerned about. To solve this problem, we first construct a geophysical model based on geological and seismic data, and apply forward modeling with the algorithm of inhomogeneous medium wave equation. On this basis, we use multi-wavelet decomposition to remove strong interference in synthetic data. The results indicate that middle and bottom reservoirs of Yi-Jianfang Formation show up as “one trough following one peak” response set in seismic data. Multi-wavelet technique can help to decompose the waveform. With this method, we effectively removed this strong interference in synthetic data. A single component seismic data cannot reflect reservoir characteristics in Yi-Jianfang Formation, so we process component stack in interested areas. Finally we characterize fractured cavity reservoirs on seismic data without interference. Predicted results have high coincidence with logging data interpretation results. © 2017, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2017年第2期326-332,共7页
Oil Geophysical Prospecting
基金
国家重大科技专项(2016ZX05014001)
中石化重大科技专项(ZDP17001)联合资助
