Experimental investigation of the oil based Aphron drilling fluid for determining the most stable fluid formulation

Abstract

Colloidal gas Aphrons, as a type of low weighted drilling fluid, have been recently used and their positive effect on formation damage has been proven. The stability of Aphron fluids is an important issue that can affect fluid loss. The purpose of this study is to provide the most stable oil-based Aphron drilling fluids. In this study, the continuous phase of the created fluids are made using oil based fluids and bubbles covered with Dodecyl benzene sulfonate and dispersed in the continuous phase which was viscositfied with the vegetable oil based polyurethane polymer. The stability of Aphron fluid is analyzed taking the drained liquid volume, Aphron half-life, and gas void fraction into account. It is observed that the oil based Aphron fluid including 13.4 kg/m3 concentration of the surfactant and 15 kg/m3 polymer was the most stable fluid, in which the sizes of bubbles have minimum variation with time.