压扭性盆地石油地质特征

Petroleum Geological Characteristics of Compresso-Shear Basin

通过对世界上压扭性盆地的成盆机制、演化模式和油气地质特点分析,总结压扭性盆地具有6个方面的石油地质特征:①压扭作用期间盆地的沉积速率较高,一般形成较厚的粗碎屑沉积,它们常构成很好的油气储集层;②盆地的烃源岩往往来自于前压扭期形成的富含有机质的岩石,但在强烈的压扭作用期间,在冲断带的前缘深坳陷(前渊)中有可能发育深水-半深水相的烃源岩;③压扭(张扭)作用期间形成的雁行式褶皱(包括背斜和断鼻等)往往是很好的油气圈闭;④压扭作用易于成藏;⑤压扭作用可以促进有机质的成熟生烃作用;⑥压扭性盆地的周边冲断带是油气赋存的有利部位。

The basin-formed mechanism, evolution model and petroliferous geological features of compresso-shear basins in the world are analyzed, by which six aspects of the features are summarized as follows： 1） in the compresso-shear process, the sedimentary speed of basin is high, forming thicker coarse-grained clastic rocks which normally shape good petroleum reservoir; 2） the source rocks of basin tend to coming from the organic matter-enriched rocks formed in pre-compresso-shear stages, except that in intense compresso-shear process, deep water-semi deep water source rocks are possibly developed in frontal of deep depression （fore deep） of thrust belt; 3） the en echelon folds （including anticline and fauh-nose structure） are generally as good oil traps; 4） the compresso-shear process is helpful to hydrocarbon accumulation; 5） it may promote the maturity and hydrocarbon-generating process of organic matter, and 6） the thrust belts in the surrounding areas of compresso-shear basin are favorable domains for petroleum concentration.