Numerical and experimental investigation on the effect of retrograde vaporization on fines migration and drift in porous oil reservoir: roles of phase change heat transfer and saturation

Abstract

Retrograde vaporization effects on oil production are nearly unprecedented to reservoir engineering community, and its relation to formation damage should be explored. For this purpose, this paper elucidates the importance and role of this phenomenon and its phase change heat transfer (PCHT) on fines migration and subsequent, permeability damage in porous rocks bearing oil and gas. Initially, a fine particle energy conversion equation was successfully acquired by combining fine particle mass balance and general energy equations. Moreover, the computational fluid dynamic model (CFD) was adopted for performing numerical modeling. A 2D CFD model using FEA-Comsol 5.0 version was used to simulate the retrograde vaporization of reservoir fluids. Pore walls are designed as non-adiabatic, and therefore, a modified Dittus-Boelter mass transfer model is provided for a fine particle detachment under PCHT. Hence, from the simulation results it was observed that there is a high degree of heat release during reservoir fluid phase change that is from oil to gas for decreasing pressure and increasing saturation time. This heat transfer from the oil and gas influxes contributes in the expulsion and migration of in situ fines in porous media. Also, an increasing rate of enthalpy was achieved that produces a non-isentropic flow, which is required to mobilize the fines in porous medium, and a satisfactory phase transition simulation outputs were obtained and presented as well. Altogether, these factors play a significant role in the fine particle eviction from the pore chamber, thereby plugging in the pore throat and consequently, decreasing the well productivity during transient flow.