Simulations of reflection seismic profile of borehole area of Chinese Continental Scientific Drilling
中国大陆科学钻探孔区反射地震剖面的数值模拟与分析

In the present analysis the seismic velocity structure in the borehole area of Chinese continental scientific drilling was analyzed. Numerical simulations of profiles after stacking crossing the borehole in NNW-SSE direction for a 3-D reflection seismic survey and the DH99 2-D reflection seismic survey were carried out based on the structure analysis. The results suggest that arrival times in the simulated profile coincide well with those in observed profile after stacking, and the simulation can well perform the time-depth transformation. It implies that the structure in the borehole area used in the present analysis is available. The component of P-wave dominates in the reflection seismic profile, the component of S-wave can be neglected. The medium of high velocity and high density exists in the Sulu area, the velocity does not vary with the depth increase shallower than 2000m. The depths with large wave amplitudes in the numerical simulated profile using the velocity and density determined from the well log coincide almost with strong reflectors in the recorded seismic profile after stacking. It implies that the reflection seismic survey is a available strategy investigating the structure in the Sulu ultra-high pressure metamorphosed terrace. The numerical simulation is also a useful technique for investigation the structure because it can recover much information from the reflection profile.