西湖凹陷高压形成机制及其对油气成藏的影响

Origin mechanism of high formation pressure and its influence on hydrocarbon accumulation in Xihu sag

西湖凹陷普遍存在高压,且主要分布在埋深较大的中深层系,该区高压形成的主要原因是欠压实和生烃作用,部分叠加有构造作用。通过相关地质因素间的关系分析,论证了高压对西湖凹陷烃类的生成、运移、储集和保存等方面的影响,建立了独特的"高压控藏、塔式聚集"的油气成藏模式,为该区油气勘探指明了方向。

High pressure is widespread and mainly occurs in the middle-deep formation in Xihu sag, East China Sea, where its major origins are under- compaction and hydrocarbon generation, with tec- tonic action partly added. By analyzing the rela-tionships among the relative geologic factors, the influences of high pressure on hydrocarbon genera- tion, migration, accumulation and preservation were discussed, and a peculiar hydrocarbon accu- mulation model with ＂high-pressure-controlled accumulation and tower-type accumulating＂ was es- tablished, indicating the direction of hydrocarbon exploration in Xihu sag.