地震拓频处理技术在乌尔逊断陷北部储层预测中的应用

Application of seismic frequency expanding processing technology in the reservoir prediction of North Wuerxun Rift

常规地震分辨率已无法满足复杂地质研究需求,提高地震资料分辨率和信噪比是进行油气小尺度勘探、储层预测和精细开发的关键。HFE地震高频拓展技术通过选择合适的最大切除倾角和子波压缩程度参数把低频子波压缩成高频子波,能提高地震资料分辨能力,保持地震资料的信噪比、相对振幅关系和时频特性,使薄层地震响应更加突出。应用HFE拓频技术对海拉尔盆地乌尔逊断陷北部地区地震资料进行研究,结果表明:铜钵庙组大一段、南二段1砂组、南一段3砂组地震频率拓宽了40 Hz;28口探评井中14口钻遇砂岩储层,14口储层不发育,地震预测砂体符合率100%;识别出有利岩性体9个,已钻7口井均钻遇预测储层,在6个砂体中获工业油流;预测出铜钵庙构造带在东部物源控制下沿铜钵庙断裂发育一系列扇三角洲前缘砂体,预测结果与钻井结果吻合。研究成果为海拉尔盆地乌尔逊断陷北部地区隐蔽性油气藏勘探开发提供了可靠的技术支持。

The conventional seismic resolution cannot meet the requirements of complex geological research, so improving the seismic data resolution and signal-to-noise ratio is the key to small-scale petroleum exploration, reservoir prediction and fine development. With the help of selecting the appropriate maximal cut tip and wavelet compressed degree for the seismic high-frequency expanding(HFE) technique, the low-frequency wavelet is compressed into the high-frequency one, which can improve the resolution of the seismic data and maintain the signal-to-noise ratio, relative amplitude relationship and time-frequency characteristics of the seismic data, and make the seismic response of thin-layer more obvious. The HFE technique is applied to study seismic data in North Wuerxun Rift of Hailar Basin. The results show that the seismic frequency in K_(1)d_(1), Sand Group 1 of K_(1)n_(2) and Sand Group 3 in K_(1)n_(1) of Tongbomiao Formation are expanded by 40 Hz;14 of 28 exploration evaluating wells encounter the sandstone reservoirs, the reservoirs in 14 wells are not well-developed, the sandbody coincidence ratio of the seismic prediction reached 100%;9 favorable lithological sandbodies are recognized, 7 drilled wells encounter the reservoirs, and commercial oil flow is discovered in 6 sandbodies;a series of well-developed fan-delta-front sandbodies are predicted in Tongbomiao Tectonic Belt controlled by eastern provenance, the predicted result is consistent with the drilling results. The study achievements provide reliable technical support for the exploration and development of subtle hydrocarbon reservoirs in North Wuerxun Rift of Hailar Basin.