Determination of physical property lower limit of deep clastic effective reservoirs of Paleogene in Dongying depression

Key words:  effective reservoir  physical property lower limit  influence factor  Palaeogene  Dongying depression

Abstract:

Due to the lack of core, formation testing and testing physical properties data, it is difficult to determine the physical property lower limit of the deep clastic effective reservoir of Palaeogene in Dongying depression. By applying distribution function curve, testing, formation testing and irreducible water saturation method, the physical property lower limit of researched area was determined，and the influence factors were analyzed. The results show that the porosity lower limit and log depth are linear relationship, and the permeability lower limit and depth are exponential relationship. The reservoir property, crude oil property, temperature and pressure affect physical property lower limit of effective reservoir. Secondary pores increases the porosity lower limit of effective reservoir. The lower the density and viscosity of crude oil，the smaller the physical property lower limit of effective reservoir. The physical property lower limit of effective reservoir reduces with temperature rising or deep overpressure. The physical property lower limit of the effective reservoir is mainly controlled by temperature-pres-sure system.