东营凹陷民丰地区裂解气藏超压释放机理

Overpressure relief mechanisms of cracked gas reservoir in Minfeng area of Dongying Depression

民丰地区裂解气藏形成于超压环境,但后期泄压过程使现今气藏基本处于静水压力状况,对气藏超压释放机理进行深入研究有助于油气运聚及分布的研究。研究认为,研究区超压释放机理主要包括饱和天然气藏深埋、轻烃扩散作用、热流值降低、地质体较致密时的沉积深埋、渗析作用。其中,饱和天然气藏的深埋和轻烃扩散是导致研究区裂解气藏超压释放的关键因素。

The cracked gas reservoir in Minfeng area was formed in an overpressure environment,but current reservoir is almost at hydrostatic pressure after pressure relief in later period.In-depth study of overpressure relief mechanism is helpful to the study of hydrocarbon migration and accumulation.The mechanisms of overpressure relief revealed through investigation mainly include deep burial of saturated gas reservoir,diffusion of light hydrocarbon,reduction of heat flux,deep sedimentary burial and dialysis effect of competent formation,of which deep burial of saturated gas reservoir and diffusion of light hydrocarbon are key factors resulting in overpressure relief in the study area.