高精度三维地震资料采集技术——以官渡地区山地地震勘探为例

High-precision 3D seismic data acquisition-Case study of seismic exploration in mountainous area at Guandu region

（1.中国石油化工股份有限公司华东分公司第六物探大队,江苏南京210009； 2.西北大学地质学系,陕西西安710069； 3.中国石油化工股份有限公司江汉油田分公司勘探开发研究院，湖北潜江433100）

The Sixth Geophysical Prospecting Crew, East China Bureau of Petroleum, SINOPEC, Nanjing 210009, China

川东南官渡地区地表地质条件复杂，悬崖峭壁林立，沟壑纵横，为典型的山地地形。野外地震资料采集难，如激发接收条件横向变化大，静校正问题突出，干扰严重等。为此，开展了高精度三维地震资料采集技术研究。首先进行了面向地质目标的精细设计，包括对采集参数的综合分析和论证、观测系统设计等，确定了适合该区高精度勘探的采集参数，所采用的宽方位斜交观测系统使反射面元和方位角分布更加均匀，因此可以消除由地面障碍物和地下阴影造成的影响，以及获取地下裂缝信息；通过高密度表层结构调查，以及对多种信息的综合分析，建立了合理的表层结构模型，提供了精确的静校正数据；对于接收点和激发点的布设，采用了大比例尺地形图和高精度卫星图片结合的方法，对于不能布设炮点的地区则采用变观的方法解决丢炮问题。在官渡地区，应用高精度三维地震资料采集技术获得了信噪比高、高频成分和层间信息丰富、构造形态清晰的高精度三维地震剖面。

Guandu region in southeastern Sichuan is the typical mountainous area. Because of the complexity in surface geological condition, field data acquisition has many difficulties, such as big lateral changes of shooting and receiving, statics problem and serious interference. Aiming at these problems, high-precision 3D seismic acquisition techniques are studied. First, some proper acquisition parameters to high-precision 3D seismic exploration are carfefully designed, including the analysis and demonstration on parameters and geometry design. The wide-azimuth oblique crossing geometry is applied to make the distribution of reflecting bin and azimuth more reasonable. Therefore, more information of fractures is obtained in eliminating the influence from surface obstacles and subsurface shadow. After comprehensive information analysis and high-density surface structure investigation, the superficial structural model is established to provide accurate statics data. Source and receiver points were designed by applying a large scale topographic map combined with high precision satellite remote sensing data. The changeable geometry was adopted to avoid losing shot where the shot couldn’t be arranged. In Guandu area, seismic profiles with high signal-to-noise ratio, abundant intrabed and high frequency information, and clear structure are obtained by high-precision 3D seismic acquisition technique.