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在油气勘探中,煤层的存在会对之上或之下的储层产生影响,给储层精确描述带来困难.永进油田西山窑组主力油层下方存在多套煤层,严重影响了储层的精细刻画.从正演模拟可以看出:1)煤层的强反射压制了储层同相轴,使储层呈弱反射特征;2)对合成地震记录做广义S变换(GST),煤层形成的GST谱能量团“亮点”叠置在目的层上,将储层的有效信息掩盖.分析实际资料还可以看出,该区存在目的层埋藏深(6000 m左右)、单层薄(最大8 m),主频低(约25 Hz)等难点.基于此,先利用匹配追踪技术进行煤层剥离,其中最佳匹配控制参数通过井旁道去煤层试验获取,对于本区相位选择范围为-2~0,尺度因子取0.95为好;再利用GST较高的时频分辨率特性,对有效信息集中在18~36 Hz频谱成分的目的层,在时频域进行分频重构.实际资料处理后,剖面及谱的能量团“亮点”能很好地对应储层,砂体反演的纵向厚度及横向分布范围与井点吻合度提高,GST分频重构则进一步凸显了本区储层特征.研究对深化永进油田及西部类似区块的储层认识,有积极的参考作用.
In oil and gas exploration, the existence of coal seam will affect the upper and lower reservoirs, which makes it difficult to accurately describe the reservoir.Several coal seams exist below the main oil layer of Xishanyao Formation in Yongjin Oilfield, which seriously affects the reservoir performance It can be seen from the forward modeling that: 1) the strong reflection of the coal seam suppresses the reservoir facies and makes the reservoir weakly reflective; 2) the generalized S-transform (GST) of synthetic seismograms and the formation of GST The spectral energy cluster “highlights ” is superimposed on the target layer to obscure the effective information of the reservoir.It can also be seen from the analysis of the actual data that the buried depth (about 6,000 m) m) and low frequency (about 25 Hz), etc. Based on this, the coal seam stripping is first carried out by using the matching pursuit technique, and the best matching control parameter is obtained through coal seam test in the by-pass path. ~ 0, scale factor of 0.95 is better; then use the higher GST time-frequency resolution characteristics of the effective information is concentrated in the 18 ~ 36 Hz spectral components of the target layer in the time-frequency domain frequency reconstruction. After the profile and spectral energy group “bright spot ” can well correspond to the reservoir, the longitudinal inversion of the sand body And lateral distribution of the goodness of fit well point increase, GST divide further highlights the reconstruction of the reservoir characteristics in this area. Yongjin field study and reservoir west of deepening the understanding of similar blocks, have a positive reference.