Enhancement of Condensate Recovery of Fractured Well by Accumulated Condensate Vaporization at HPHT Reservoir Conditions

Abstract

On the example of a gas condensate reservoir of field in Western Siberia with HPHT conditions, high condensate content and low permeability, the problem of reducing well productivity during operation are considered. Restoring of the near wellbore area permeability methods, reduced due to the buildup of retrograde condensate are studied. The effectiveness of previously performed acid treatments and solvent injection has been considered in order to increase the productivity of such wells. The analysis of the ambiguity and variable success of such events is carried out. An unconventional, but promising method of the condensate saturation reducing in the near wellbore areaof wells with multi-stage fracturing is proposed. These wells operate Achimov deposits with HPHT. This method consists of creating special thermobaric conditions in the near wellbore area, which allow to vaporize the largest part of the hydrocarbon condensate accumulated around the borehole. A condensate-saturated gas is extracted from the well to the surface. A search was held for simple, available and inexpensive technologies aimed at increasing both pressure and temperature in the wellbore and near-wellbore region. Based on the results of calculations performed on digital wells models in OLGA software, the thermobaric conditions created at the bottom due to the thermobarochemical effects are determined. The measures effectiveness of the retrograde condensate evaporation in the near wellbore areaand restoration of well productivity have been evaluated.