关键词: 深层油气勘探, "两宽一高"地震采集, 宽频可控震源, 弱信号处理, 复杂构造成像, 五维解释技术

Abstract: China is rich in deep oil-gas resources, showing a great exploration potential. The exploration history of deep reservoirs as well as oil-gas exploration practice indicate that geophysical techniques play an extremely important role. Focusing on key challenges such as large burial depth, weak seismic reflection energy, low imaging accuracy and complex reservoirs in the deep target strata, scientific research and technical breakthroughs have been performed and made on seismic equipment, acquisition, processing and interpretation, as well as gravity-magnetic-electric-seismic joint exploration, thus forming a set of seismic technologies for deep oil-gas exploration. Extensive practices have shown that the large-tonnage broadband vibroseis is an important technique for improving deep seismic signal energy and signal-to-noise ratio, the "broadband, wide azimuth and high density" (BWH)seismic acquisition technology is an effective way to achieve the target for deep oil and gas exploration; weak signal processing, complex structure imaging, and 5D seismic interpretation technique are key processing and interpretation techniques to solve all problems in deep exploration. Moreover, the combination of multiple physical fields, such as gravity, magnetism, electricity and seismic exploration, is an efficient method to reduce the risk of deep exploration and development. These geophysical techniques have been successfully applied in some basins in China, such as Tarim Basin and Sichuan Basin, which have provided supports for making major breakthroughs such as the discovery of 1 billion-ton gas field in Fuman area of Tarim Basin, and a trillion cubic meter gas area in Penglai area of the north slope of central Sichuan Basin. Facing the current and future demands for geological research, discoveries in hydrocarbon exploration, safe and efficient drilling during deep exploration, it is recommended to continuously make breakthroughs in five aspects, i.e., basic theory, acquisition, processing, target identification, wellbore seismic and non-seismic techniques, actively expand the exploration fields of deep to ultra-deep oil and gas, and carry out research and on-site experiments of marine geophysical exploration technology based on ocean bottom node (OBN), thus providing technical support for deep sea exploration.

Key words: deep oil-gas exploration, BWH seismic acquisition, broadband vibroseis, week signal processing, complex structure imaging, 5D interpretation technique