Use Multiple Wave Data To Improve The Imaging Accuracy Method Research

With the development of offshore oil and gas exploration, seismic acquisition technology in the past has been difficult to meet the current needs of the people,OBS as a new seismic acquisition technology has attracted wide attention. In conventional seismic acquisition technology or in OBS seismic acquisition technology, in marine seismic exploration, multiple waves is always one of the hotspots. After the study found multiple waves also carry a large underground information, especially the complex structure, and has a more broad than the first wave illumination. In the OBS(marine seismic exploration instrument),because it is placed in the seafloor, and each OBS interval is usually more than 200 meters, by using the conventional first wave of migration, the poor effect of shallow layer. However, we use multiple imaging, not only can obtain wide lighting, and can be helpful for imaging shallow area, obtained better effect of seafloor. Especially in OBS data missing, due to the multiple waves travel a longer time, little affected by the seafloor anomaly body. Therefore, it is possible to get than primary wave more reliable continuous imaging results. So we in hydrate exploration or seabed stability research, using the characteristics of multiple wave imaging can complete geophysical survey task for us to better.On the use of multiple research methods to improve the accuracy of imaging data, the paper mainly from the OBS component data of the wave field separation, ray tracing building velocity modeling, reverse time migration in the three aspects to achieve. First introduced the principle of OBS and the identification of exploration of multiple wave and attenuation, and then introduces the reverse time migration principle and Realization of RTM migration, finally using ray tracing building velocity model and implementation of reverse time migration. In the course of the study first studied the theoretical model in primary and multiple wave reverse time migration results, and then carries on the contrast analysis to the data measured in primary and multiple wave imaging results, OBS location and wavelet delay of multiple wave imaging precision influence is discussed in the end. Through the study of the theoretical model and measured data, we found that the multiple wave data can indeed improve the seafloor imaging, is conducive to our hydrate exploration and reverse time migration can in large dip angle imaging have more advantages than one-way wave. Reverse time migration method can adapt to the special observation system of OBS, it does not need to ensure that the shot points and receiver points at the same level, imaging is more flexible.