Oil and gas secondary migration can be divided into two stages according to type of drive: drive by self-weight stress gradient and stacked stress gradient of tectonic and seif-weight stresses.

• 油气二次运移可分为两个阶段，即沉积物的自重应力梯度驱动阶段和构造应力与自重应力的叠加应力梯度驱动阶段。