复杂地区可控震源高效采集技术

Technologies of Vibroseis High Efficient Acquisition in Complex Terrain Area

中国西部地区地表多以戈壁沙漠为主,非常适合可控震源施工,随着油气勘探和开发的不断深入,高密度、宽方位或全方位三维地震勘探技术被大量应用,随之带来巨大的成本压力。阐述了可控震源从传统的多台多次组合激发,逐步发展形成的拆分振次技术、交替扫描技术、滑动扫描技术、拆分台次技术、谐波压制技术。这些技术突破了可控震源传统的扫描方法,通过相互结合,联合应用,生产效率大大提高,单炮激发成本大幅降低,很好地解决了高密度地震勘探的成本问题,有效推动了西部复杂探区高密度、高覆盖、全方位三维地震勘探技术的推广应用。2005年以来,在对可控震源激发参数进行大量研究和试验基础上,逐步形成了可控震源经济、高效的激发技术和参数优化方法。在TH盆地致密砂岩油气藏勘探中,不仅中浅层信噪比明显提高,同相轴连续性明显增强,同时深层以及煤下和层间弱反射层的信噪比也有较大提高,进一步推动了西部盆地致密砂岩油气藏的勘探进程。

The surface landforms are mainly Gobi and desert in western China, which makes it suitable for vibroseis tasks. The basins in western China are rich in oil and gas. With the further development ofoilfield E ＆ P, the technique of high-density, wide-range and 3D seismic survey has been widely applied and brings heavy cost press. Therelbre, it is very necessary to find out vibroseis acquisition techniques with high efficiency and low cost. The paper elaborates the advancement of the techniques from conventional multiple vibroseis combination acquisition to split sweep, alternate sweep, slip sweep, split vibroseis array and harmonic attenuation. These techniques surpass the conventional sweep method of vibroseis. And the combination of these techniques greatly improved the production efficiency. Thus, the cost of per shot was greatly reduced. It also reduces the cost of high-density seismic exploration and promotes the application of high-density, multiple coverage, omnibearing 3 D seismic exploration technique. Since 2005, the Tuha Bureau of BGP has gradually developed the cheapest and highly efficient acquisition method and parameter optimization method of vibroseis based on a lot of researches and field tests of vibroseis acquisition parameters. During the exploration of tight sand reservoir in TH basin, the signal-to-noise ratio has improved and the continuity of event has strengthened obviously in middle-shallow layer. Meanwhile, the signal-to-noise ratio of deep layer. layer under the coal and weak reflection layer of interlayer has improved greatly. It promotes the exploration process of tight sand reservoir in western basins.