Abstract: With the compaction of shale as a two-dimensional function of depth-of-burial versus time, the formulae for computation of the velocity, volume and coefficient of compaction-fluid flow under. overstatic pressure drive are derived, based on data from sonic logging in shale and the differential equations of the relationship between the over-static pressure gradient of shale and its porosity, permeability and viscosity of the fluid as proposed by Smith, etal. Shale of normal and teverse rhythmic sedimentation and the character of fluid flow in the vertical shale sequence are studied in the light of the sedimentary conditions in the Huanghua depression, and parameters for expulsion of fluid by compaction and primary migration of hydrocarbons are Worked out. The author has proposed two curves reflecting the compaction of shales on the margin and in the center of the Qikou depression and examined the process of expulsion of compaction fluid and hydrocarbons from data of tra-nsformation of organic matter into petroleum.