Recent advances in wide-azimuth seismic exploration
Liu Yimou1,2, Yin Xingyao1, Zhang Sanyuan3, Wu Guochen1, Tao Xiayan4
1. School of Geosciences, China University of Petroleum (East China), Qingdao, Shandong 266580, China; 2. Exploration and Development Department, Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China; 3. Exploration Department of Jianghan Oilfield Branch of SINOPEC Group, Qianjiang, Hubei 433100, China; 4. School of Resources and Environment, Southwest Petroleum University, Chengdu, Sichuan 610500, China
Abstract：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.
