【摘要】 采用视速度-偏振井间波场分离法分离得到纵波和横波波场,使用跨孔地震走时层析成像级联方法计算井间纵波和横波速度结构以及泊松比空间分布.综合纵横波速度、泊松比和测井参数,分析两井间岩性和储层特性.数值模型试验表明该方法垂直分辨率达到主频波长的1/4,并能准确分辨倾斜断层和垂直断层.处理相同纵波资料结果表明本文方法分辨率远远高于以往的井间走时层析成像方法,比井间声波层析成像分辨率更高.使用该方法处理垦71区井间资料,得到同台同源纵波和横波速度结构和泊松比分布.泊松比的低/高变化与测井参数指示的砂/泥岩层基本吻合.根据泊松比分布,参考岩石地震物理学测试数据,可以区分井间介质中的泥岩层、砂岩层,以及砂岩层中的饱水和饱油区,确定储层的连通性,圈定井间的剩余油藏.更多还原

【Abstract】 The P and S wave fields were obtained by crosswell apparent velocity-polarization separation method. Precise first-arriving times of P ahd S waves and the cross-hole seismic tomography cascade algorithm were used to obtain accurate and high resolution P wave and S wave velocity structures and Poisson s ratio. Joint interpretation of borehole logs, Poisson s ratio and velocity images of P- and S-wave was carried out to clarify the lithologic and reservoir characters between the two investigated boreholes. The experimental results with simulated and real seismic data show that this method can achieve a resolution for the thin horizontal layers up to 1/4 of the dominant wave length which is higher than that of acoustic waveform tomography, and can accurately distinguish slanting and vertical faults. We apply this method to obtain P wave and S wave velocity structures and Poisson s ratio in Ken 71 block. The research result reveals that the Poisson s ratio distribution matches well with borehole logs, and the distribution of the low/ high Poisson s ratio layers in the image is consistent with the location of sand/mud layers predicted from the borehole logs. According to seismic test data of rock physics, we can distinguish the shale, sandstone, water-bearing sandstone, oil-bearing sandstone, and can achieve fine descriptions of geologic formations, structures and reservoirs.更多还原