论文详情
针对塔河油田外围地区深层碳酸盐岩缝洞型储层埋深大、油气响应模式复杂、强地震反射界面屏蔽、储层预测与油气识别难度大的问题,在测井资料解释的基础上,构建了适用于研究区深层缝洞型碳酸盐岩储层岩石物理模型。结合测井、岩石物理、地震资料,基于典型非均质数值模型,利用非均质介质弹性波数值模拟,分析了单一界面、薄层、不同宽度缝洞体、厚溶洞体等4种模型的AVO特征以及强阻抗差界面波对AVO的影响。结果表明:缝洞体AVO特征与薄层或单一界面变化趋势相同,振幅大小不同;压制强振幅干扰后,高含气储层AVO特征呈现正高截距(P)、负高梯度(G)特征,含油储层次之。井旁实际地震道集与油气生产情况综合分析表明:在研究区以高过成熟油和凝析油气为主的油气类型条件下,P×G属性与单井初期产量具有较好的对应性。研究结果为该地区深层奥陶系碳酸盐岩储层流体识别提供了参考依据。
Deep fracture-cavity carbonate (DFCC) reservoirs in the peripheral area of the Tahe Oilfield are characterized by large burial depth,complex oil-gas response,and strong shielding of the seismic reflection interface.This leads to difficult reservoir prediction and oil-gas identification.A petrophysical model of the DFCC reservoir in the study area was constructed based on well logging data interpretation.By exploiting a heterogeneous numerical model,the amplitude-versus-offset (AVO) characteristics and the influence of interface waves originating from strong impedance differences on the AVO were analyzed.In particular,four cases were investigated:single interface,thin layer,slit cavity with different widths,and thick cave.The results showed that the AVO characteristics of DFCC bodies are the same as those of thin layers or single interfaces,while the amplitudes are different.After suppressing the strong amplitude interference,the AVO characteristics of high gas-bearing reservoirs presented a large positive intercept and a large negative gradient,whereas oil-bearing reservoirs did not present these characteristics.A comprehensive analysis of actual seismic traces and oil-gas production beside the wells showed that the study area is dominated by over-mature oil and condensate oil-gas.Moreover,the P×G attribute shows good agreement with the initial production of a single well.The research results provide a reference for fluid identification in Ordovician carbonate reservoirs in the study area.
国家科技重大专项专题“碳酸盐岩‘断溶体’地球物理识别及预测技术研究”(2016ZX05014-001-006)资助。