Two Environmentally Friendly Alkyl-o-Glucoside-Based Formulations for Hole Cleaning during Heavy and Extra-Heavy Oilfield Drilling

Abstract

The formulation of antiaccretion additives for cleaning the hole in long-range directional or tangential wells in heavy and extraheavy oil reservoirs is considered a technological challenge due to the unconsolidated characteristics of the formations (such as gravel, sand, pea, etc.) as well as the physicochemical properties of the heavy crude oil. In this work, we propose a hole cleaning formulation that can solubilize the asphaltenes present in Mexican heavy crude oil and that is also efficient in eliminating the accretion due to heavy oil fractions. Alkyl-o-glucoside (APG) whose alkyl group has 12 carbons was used as the biosurfactant. The addition of the cosurfactant ethylene glycol butyl ether (EGBE) to the aqueous solution of APG reduced its surface tension. The aqueous APG solutions were able to solubilize the asphaltenes inside the micelles. The addition of EGBE increased the stability of the aspahltenes/APG/water emulsion. The APG/EGBE/Limonene antiaccretion additive proposed in this work for the mobilization of the trapped nonaqueous phase liquid showed a higher cleaning efficiency factor (CEF) than conventional diluents. Higher cleaning efficiency was obtained when the test temperature was increased.