SKIN FACTOR PREDICTION OF FORMATION DAMAGE DUE TO ASPHALT DEPOSITION

Asphalt deposition is one of the important causes for formation damage and production reduction.Asphalt deposition is affected by such factors as formation temperature and pressure,and their influences may be displayed through the solubility of asphalt in the crude.State equilibrium theory and Flory-Huggins theory of the asphalt solubility in the crudewere used to investigate the solubility of asphalt in the crude oil in different pressure and temperature conditions.The theory proposed by Kumar,which is on how the suspending fines block the formation pores was applied to calculate the formation damage skin factor because of asphalt deposition.By studying the case history of asphalt deposition in Suizhong 36-1 Oilfield,it can be concluded that this prediction method is feasible.