Abstract:

The offshore oil and gas exploration is gradually advancing deeper. Meanwhile, the South China Sea has great potential for deep-water oil and gas resources. Generally, for the deep water exploration, the project scale is large, the requirements of the project management are high, and the investigation is difficult. Due to the factors such as the changeable marine climate environment, the relatively complex geological environment, the professional survey vessels or survey equipment, and the high requirement of underwater positioning accuracy, the commissioned technical requirements, project capital cost and operation safety risk in the deep water survey area are significantly higher than those in the shallow area. In a deep-water work area in the South China Sea, the seabed picking up, well pass section, maximum negative amplitu de and seismic slice of the 3D seismic data are used to evaluate the bathymetry, seabed topography, shallow strata, faults, amplitude anomalies and other investigation contents of the work area, so as to carry out the disaster prediction and safety assessment of the shallow geological conditions to guide the emplacement, installation and production of the underwater engineering facilities system in the target oil and gas mining area. Based on the 3D seismic data, a relatively simple and practical method for geological hazard assessment in shallow layer of the deep water is explored. As a part of the desktop research stage in the whole life cycle of EPCI （Engineering, Procurement, Construction and Installation）, this method provides necessary support for the smooth development of the project plan.

Key words: shallow hazards, maximum negative amplitude, seismic slice, 3D seismic, deep-water work area, the South China Sea