宽方位地震勘探技术新进展

本文从地震采集、处理和解释三个方面总结了宽方位地震勘探目前所取得的进展，分析了目前存在的问题，并对发展方向作了预测，得出以下认识：1宽方位地震采集的核心理念是如何经济可行地获取宽方位数据体，陆上多采用可控震源高效激发实现，螺旋采集技术结合震源同步激发技术可进一步提高海上采集效率，降低勘探成本； 2炮检距向量片（OVT）技术是面向宽方位地震资料处理的一项新技术，考虑了宽方位观测带来的方位各向异性问题，有利于提高地震成像精度，同时在处理过程中可以保留炮检距和方位角信息，有望在复杂构造地震成像和储层描述中发挥更大作用； 3在HTI介质中地震波能量衰减方位各向异性程度较其他属性要明显，且对裂缝尺度和流体类型敏感，今后业界将应更加关注综合利用地震波能量衰减、频率、相位方位各向异性提高裂缝预测精度； 4宽方位地震观测在高陡构造和复杂断块成像、岩性和裂缝型储层预测等方面具有明显优势并已得到实践检验，但对于诸如复杂山地等地表起伏剧烈、速度纵横向变化大、静校正问题严重的地区，在相关处理技术未完善的情况下，应慎用宽方位地震观测。

Recent advances in wide-azimuth seismic exploration

In this paper, some recent advances in terms of wide-azimuth acquisition, processing and interpretation are summarized. The current existing problems are discussed and the development direction of wide-azimuth seismic is also predicted. The conclusions are summarized as follows. Firstly, the core idea of wide-azimuth seismic acquisition is how to acquire a wide-azimuth dataset with economically feasible methods, for instance high-productivity vibroseis acquisition on land. For marine seismic, coil shooting combined with simultaneous shooting is an effective way to further improve the acquisition productivity and thus reduce the cost. Secondly, offset vector tile (OVT) processing, which is convenient for azimuthal anisotropy analysis, is a new technique for wide-azimuth seismic processing and beneficial for improving the imaging accuracy. Meanwhile, OVT processing can preserve the offset and azimuth information on imaging gathers and thus is expected to play a greater role in seismic imaging and reservoir characterization. Thirdly, azimuthal variation in attenuation is more remarkable than other seismic attributes when seismic wave propagating in HTI media, and is more sensitive to fracture sizes and fluid content. The seismic industry will pay more attention to azimuthal variations in attenuation, frequency and phase to improve fracture characterization. Finally, wide-azimuth seismic has obvious advantages in many aspects such as high-dip structure and complex fault block imaging, lithology and fracture characterizations which have been approved by field test. However, wide-azimuth seismic should be carried out cautiously before corresponding processing techniques are well developed in complex mountainous areas with rugged topography, great changes of vertical and lateral velocities and severe static problems.