关键词: 渤海湾盆地, 含油气层系, 分布规律, 控制因素

Abstract: Multiple oil and gas bearing layer of a big time span occur in Bohai Bay Basin, and the major assemblage is different from one part to another, so it is of great importance for exploration practice to acquire a deep understanding of the distribution of oil and gas series. On the basis of comprehensive study of tectonic evolution and sequence stratigraphy, this paper analyses the regional distribution regularity and controlling factors of oil and gas bearing series in the basin, and gets four conclusions. (a)The primary controlling factor accounting for the forming of multiple oil and gas series is the tectonic evolution which determines the overall vertical oil and gas distribution features. Sags with similar tectonic evolution history have the same major oil and gas bearing formation assemblage that generally contribute about 70%~80% of proven reserves of the whole sag. (b) The uplifts surrounding the basin are major sediment source areas. The spatial matching relations of a sag and the uplifts has significant influence on the composition of sequences and the development of source rock-reservoir-cap rocks, thus controlling the vertical oil and gas distribution. (c) An evident strike-slip displacement may enhance the sealing ability of faults and enable oil and gas to accumulate in lower horizons. (d) For sags of high reserve abundance, they have large time span of oil and gas series; for those of low reserve abundance, the major reservoirs are near the mature source rock body.

Key words: Bohai Bay Basin, oil and gas bearing series, distribution regularity, controlling factors