Colloidal gas aphron drilling fluid properties generated by natural surfactants: Experimental investigation

Abstract

Colloidal gas aphron (CGA) fluids are special types of fluids containing micro-bubbles with sizes between 10 and 100 microns which are created by mixing an aphronizer surfactant in a polymeric solution at high speed. Recently, CGA fluids have been successfully employed as drilling fluid in petroleum upstream. CGA based drilling fluid properties like stability and aphron size distribution highly depends on the characteristics of an aphronizer surfactant. As a result, selection of an appropriate surface active agent plays a vital role for generating micro-bubbles with the favorable properties. The main objective of the present paper is to evaluate the potential of new natural surfactants as aphronizer in CGA-based drilling fluids. In this regard, two new natural surfactants which derived from roots of Seidlitzia Rosmarinus and leaves of Henna plant are employed for preparing aphron-based fluids. Physico-chemical properties of the aphronized fluids prepared from these surfactants were investigated by various standard experiments including bubble size measurements, rheological characterizations and stability tests. Moreover, the effects of polymer and surfactant concentrations were studied systematically. Based on the experimental results obtained from this work, the two aforementioned natural surfactants are appropriate for generating CGA based drilling fluid while they have no environmental impacts, and have very low cost in comparison with commercial and industrial surfactants.