Numerical Simulation of Jamin Damage in Drilling Process

Jamin damage is the phenomenon of reservoir permeability reduction caused by Jamin effect. The Jamin effect is a resistance effect. Bubbles in oil or oil droplets in water remain spherical due to interfacial tension, thus locking the oil displacement channel. The pore structure of reservoir rock has strong irregularity and is controlled by many factors, which makes the pore structure model based on classical geometry far from the real pore. Therefore, based on the classification theory and Darcy’s law, this paper establishes the space–time model of Jamin damage, and quantitatively describes the pore structure of reservoir to study the Jamin effect of two-phase flow in pore throat structure. The finite difference method is used to solve the model, and the model prediction results are consistent with the available field data. This paper reveals the change law of skin factor caused by Jamin effect in borehole scale, which is of great significance to guide the formulation of reservoir protection measures.