准噶尔盆地沙窝地高精度三维地震采集参数设计与论证

Evaluation and design of high precision 3-D seismic survey in Shawodi area, Junggar Basin

1. 中国石化江苏油田物探处,江苏淮阴 223125;2. 中国石油大学CNPC物探重点实验室,北京 102249;3. 中国石油大学地球资源与信息学院,山东东营 257061

Geophysical Company of Jiangsu Oilfield, SI-NOPEC, Huaiyin 223125, China

高精度地震勘探对地震采集参数和观测系统的要求较高,通过地震勘探设计与评价技术(SED)可以给出适合研究区地震地质条件的采集参数,以提高野外采集资料的品质。给出了SED技术的基本原理。在准噶尔盆地沙窝地探区利用SED技术进行了高精度三维地震采集参数的设计和论证。首先建立地震地质模型,模拟野外单炮记录;然后对覆盖次数、纵/横向分辨率、面元大小、最大/最小偏移距、最大非纵距、记录长度及采样间隔等进行了设计与论证;最后结合仪器因素优选了8线14炮细分面元观测系统。对观测系统的属性分析表明,该观测系统在保持主测线方向覆盖优势的同时,实现了较宽方位角的激发和接收,这对压制侧面和散射干扰十分有利;均匀分布的近、中、远炮检距对速度分析十分有利;而合理的覆盖次数和相对较少的炮数,降低了勘探成本。

Seismic Evaluation and Design (SED)is a new technology being used in field data acquisition in recent years. This technique bases itself on seismic survey modeling software, using geological information and geophysical parameters in surveying area to build seismic-geology model, simulate the field surveying, offers aid in making field plan according to correlative theory and technology. SED technique is fully used in Shawodi area to design and demonstrate the basic parameters, include fold times, vertical/horizontal resolution, CRS scale, max/min offset, max cross line distance, record length and sample interval et al. A bin-divisible lay out with 8 lines and 14 shots is selected through attribute analysis combined with instrument. This kind of lay out a-chieves the relatively wide azimuth relationship between shots and receivers while keeps predominance along the inline direction, that is helpful to decrease the lateral and dispersion waves, improve the coupling of static time correc-tioa As the result, the designed lay out saved cost with reasonable fold and shot number.