Improving shale inhibitive performance using methyl glucoside (MEG) in potassium chloride mud

Abstract

Oil-based mud has shown a commended performance over the years in mitigating borehole instability especially when penetrating through a reactive shale zone which is known to have swelling and dispersion problems. However, the strict environmental regulations worldwide have limited the use of oil-based mud. Therefore the methyl glucoside, known as MEG, a specially formulated water-based mud has been introduced where its performance is close to the oil-based mud. This project studied the effect of using MEG in potassium chloride (MEG/KCl) mud in controlling shale swelling and dispersion. Five different concentrations (0, 5, 15, 25, and 35% by weight) were used in the hot rolling dispersion test. Besides, the rheological properties and fluid loss control were also tested as per the American Petroleum Institute – Recommended Practice – 13B (2009). The results showed that MEG/KCl mud was capable of improving the shale inhibitive performance to mitigate the shale swelling and dispersion problems. The higher concentration of MEG used such as 25% and 35%, the less shale would swell or disperse. However, the effectiveness of MEG was corresponding with clay content present in the shale.