分层解释性反演技术在薄互层砂体预测中的应用

Application of interpretatively layered inversion technique in the prediction of thin interbedded sand

大庆油田有限责任公司勘探开发研究院,黑龙江大庆 163712

Exploration and Development Research Institute of Daqing Oilfield Company Limited, Daqing 163712, China

介绍了一种在薄互层条件下,用地震解释层位控制,以测井曲线为出发点进行外推内插,形成初始波阻抗模型,并通过对初始模型的不断更新,使模型的合成记录最佳逼近实际地震记录的方法。该方法把地震和测井有机地联合起来,突破了传统意义上地震资料分辨率的限制,大大提高了薄层的识别能力。反演结果能较好地反映主力油层葡I2和葡I3的横向变化。将该技术应用于肇州油田州603区块和州62-平61水平井的设计和轨迹调整中。州62-平61井共钻进水平段614m,葡I2层水平钻进了280m,向下调整钻遇葡I3层,水平钻进334m。该水平井砂岩钻遇率达74.4%,初期平均产油30t/d以上。利用该技术在徐21井区作单井评价,也取得了较好的效果。

This paper presents a method for the construction of wave impedance model in which the wave impedance model is constructed initially by extrapolation and interpolation of logging curves under the constraints of interpreted horizons, and then is updated until the synthetic seismograms of the model optimally approaches to real seismograms. By combining seismic data and logging data organically, this method breaks the resolving power limit of seismic data, resulting in great improvement in the ability of identification of thin layers. The method has been used in the design and adjustment of horizontal well Zhou 62-Ping 61 in block 603 in Zhaozhou oilfield. The inversion result clearly depicts the lateral variations of major oil layers Pu I2 and Pu I3. Well Zhou 62-Ping 61 made a horizontal footage of 614m, Pu I2 horizontally 280m, and then drilled downward encountering Pu I3 and made another horizontal footage of 224m. The hit rate of sand in the horizontal well is 74. 4%, produced aver-agely more than 30 tons oil per day. Satisfactory results have been also achieved by using the method in the evaluation of borefield of well Xu 21.