A Multilevel Iterative Method to Quantify Effects of Pore-Size Distribution on Phase Equilibrium of Multicomponent Fluids in Unconventional Plays

作者：Li Baoyan^*; Mezzatesta Alberto^*; Li Yinghui^*; Ma Yixin^*; Jamili Ahmad^*

来源：Petrophysics, 2016, 57(2): 120-138.

In order to quantify the influence of pore confinement on hydrocarbon phase behavior in the nonuniform pores of organic-rich shale reservoirs, we propose a new phase equilibrium model and a multilevel iterative method to solve the highly nonlinear system of equations governing the phase equilibrium of hydrocarbon systems subject to pore-confinement effects. Through this new method, we analyze the influence of pore-size distribution on the phase behavior of fluids in organic-rich shale reservoirs, including the Bakken and the Eagle Ford shale formations. The results show that the suppression of saturation pressures of confined hydrocarbons in shale-oil and shale gas condensate formations can be overestimated by 10% if an average pore size is used for the estimation. Based on the proposed phase-equilibrium model, we observe that pore confinement effects on the properties of the hydrocarbons encountered in shale-oil and shale-gas gas/condensate formations become significant only at low pressures and temperatures.

• 出版日期2016-4