Abstract:

There are various types of fracture-cavity deeply buried reservoir with strong heterogeneity in the Ordovician in Tazhong area. The model is designed in accordance with real condition in Tazhong area. The complex fracture-cavity reservoir has been found to be equal to a geological model composed of staggered micro-network and cavity which can depict the inner fracture-cavity reservoir structure and parameters variation accurately. It applied the staggered-grid high-order finite difference method of wave equation forward modeling technology to simulate seismic wave field, and used the conventional processing methods and wave equation prestack depth migration to get the migration profiles. The interpretation could be evaluated and verified by the migration result. The amplitude, phase and frequency information are used to analysis the seismic wave field characteristics. It studies that the reservoir location and structure variety effect on the seismic wave field. Then it combines the well-to-seismic relation and the seismic simulation response characteristics to establish the recognition mode. It identifies that the seismic response of layered igneous rock, volcanic neck and intrusive igneous rock exist in this area. It illustrates the fracture-cavity reservoir seismic structure in the top surface and the inner of the carbonate layer.

Key words: Tazhong area, Ordovician, fracture-cavity reservoir, igneous rock, forward modeling, seismic wave field recognition mode