Wax Deposition in Pores and the Permeability Change for High-wax Crude in a Sandstone Reservoir

Abstract

Wax deposition in pay zone is an important factor that influences well productivity for high-wax crude oilfield. Taking Hongze oilfield as an example, rheological property of the crude and effective flow permeability at different temperature was measured. Flow pattern and process of wax deposition in porous medium was studied. Experiment results show that seepage flow of high-wax crude is significantly sensitive to temperature. It is non-Darcy flow and there exist threshold pressure gradient when temperature is lower than wax appearance temperature. According to experimental data, seepage flow and deposition patterns were proposed.